Antibiotic resistance of lactic acid bacteria isolated from dry-fermented sausages Maria Jo˜ao Fraqueza PII: DOI: Reference:
S0168-1605(15)00238-X doi: 10.1016/j.ijfoodmicro.2015.04.035 FOOD 6900
To appear in:
International Journal of Food Microbiology
Please cite this article as: Fraqueza, Maria Jo˜ao, Antibiotic resistance of lactic acid bacteria isolated from dry-fermented sausages, International Journal of Food Microbiology (2015), doi: 10.1016/j.ijfoodmicro.2015.04.035
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ACCEPTED MANUSCRIPT Antibiotic resistance of lactic acid bacteria isolated from dry-fermented sausages Maria João Fraqueza
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CIISA, Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade
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Técnica, Pólo Universitário do Alto da Ajuda, 1300-477 Lisbon, Portugal.
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* Name of corresponding author: Maria João dos Ramos Fraqueza Address: Faculty of Veterinary Medicine. University of Lisbon. CIISA. Av. da
FAX: 351 21 3652889
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Telephone: 351 21 3652884
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Universidade Técnica, Pólo Universitário, Alto da Ajuda,1300-477 Lisbon. Portugal.
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Email: [email protected]
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ACCEPTED MANUSCRIPT Abstract Dry-fermented sausages are meat products highly valued by many consumers.
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Manufacturing process involves fermentation driven by natural microbiota or
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intentionally added starter cultures and further drying. The most relevant fermentative
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microbiota is lactic acid bacteria (LAB) such as Lactobacillus, Pediococcus and Enterococcus, producing mainly lactate and contributing to product preservation. The great diversity of LAB in dry-fermented sausages is linked to manufacturing practices.
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Indigenous starters development is considered to be a very promising field, because it
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allows for high sanitary and sensorial quality of sausage production. LAB have a long history of safe use in fermented food, however, since they are present in human gastrointestinal tract, and are also intentionally added to the diet, concerns
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have been raised about the antimicrobial resistance in these beneficial bacteria. In fact, the food chain has been recognized as one of the key routes of antimicrobial resistance
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transmission from animal to human bacterial populations. The World Health Organization 2014 report on global surveillance of antimicrobial resistance reveals that
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this issue is no longer a future prediction, since evidences establish a link between the antimicrobial drugs use in food-producing animals and the emergence of resistance among common pathogens. This poses a risk to the treatment of nosocomial and community-acquired infections. This review describes the possible sources and transmission routes of antibiotic resistant LAB of dry-fermented sausages, presenting LAB antibiotic resistance profile and related genetic determinants. Whenever LAB are used as starters in dry-fermented sausages processing, safety concerns regarding antimicrobial resistance should be addressed since antibiotic resistant genes could be mobilized and transferred to other bacteria. Key words: Lactic acid bacteria, antibiotic resistance, dry-fermented products, safety.
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ACCEPTED MANUSCRIPT Highlights
Lactic acid bacteria have a long history of safe use in dry-fermented sausage
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Antibiotic resistant lactic acid bacteria have been isolated from dry-fermented
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production and consumption.
sausages.
Interventions at processing level are difficult to prevent the presence of
Care must be taken regarding antibiotic-resistance expressed by strains intended
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to be use as starters.
Acquired resistance on strains mediated by mobile genes may put at risk the
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public health.
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antibiotic resistant strains.
Risk management strategies for food chain are crucial to avoid antibiotic
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Introduction
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resistant lactic acid bacteria.
There is a great diversity of dry-fermented sausage as a result of manufacturing with different raw meat types and origins, formulations, condiments, additives, meat grinding size, casing diameter, smoking and drying periods (Toldrá et al., 2007). Meat sausages preservation is achieved by fermentation with a pH decrease due to lactate production by natural microbiota or added starter cultures. The main fermentative microbiota is lactic acid bacteria (LAB) including Lactobacillus, Pediococcus, Enterococcus, Leuconostoc, Lactococcus and Weissella (Fontana et al., 2012). LAB constitutes a diverse group widely distributed throughout nature, being also 3
ACCEPTED MANUSCRIPT an important component of indigenous microbiota in healthy humans and animals. LAB diversity in dry-fermented sausages’ is linked to manufacturing practices, and it
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has been reported that indigenous starters development is very promising approach
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since it enables sausages’ production with high sanitary and sensory characteristics
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(Talon et al., 2007). However, some issues concerning consumers´ safety have been expressed around this late use of LAB.
LAB have a long history of safe use in fermented food production and consumption that
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support their GRAS (generally recognized as safe) and QPS (qualified presumption of
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safety) status provided by FDA (US Food and Drug administration) and EFSA (European Food safety Authority), respectively. However the detection pf antibiotic resistant (AR) strains among LAB has resulted in their recognition as reservoir of AR
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genes horizontally transmissible to pathogens through the food chain, this being a matter of concern (Devirgiliis et al., 2013; Marshall et al., 2009).
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In fact, the food chain has been recognized as one of the key routes of antimicrobial resistance transmission from animal to human bacterial populations. The World Health
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Organization 2014 report on global surveillance of antimicrobial resistance reveals that this issue is no longer a future prediction since evidences establish a link between antimicrobials drugs use in food-producing animals and the emergence of resistance among common pathogens. This poses a risk to the treatment of nosocomial and community-acquired infections. This review describes the diversity and role of LAB in fermented sausages, stressing safety requirements for LAB regarding the antibiotic resistance issue. The possible sources and transmission routes of antibiotic resistant LAB in dry-fermented meat sausages are discussed and common LAB antibiotic resistance profile of isolates from fermented sausages and related genetic determinants are presented. Finally, some
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ACCEPTED MANUSCRIPT remarks are pointed out considering safety concerns for LAB selected to be used as
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starters in dry-fermented sausages.
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Antibiotic resistance issue: facts and trends
Since the discovery of Penicillin in 1928 and the introduction of the first antimicrobial sulfonamides (1930) (Davies and Davies, 2010), antibiotics have been used, playing a
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decisive role in human health and life expectancy. However, concerns have been raised
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about pathogenic bacteria and their antibiotic resistances. In fact, infections caused by these resistant microorganims are more difficult to treat and have higher costs, due to more intensive and time consuming care needed. According to the recent report of
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WHO (2014), antibiotic resistance within a wide range of infectious agents is a growing public health threat of broad concern to society and multiple sectors, since many of the
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available treatment options for common infections may become ineffective. The resistance to antibiotics is an eventual characteristic in bacterial biomes and can be
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seen as an adaptation result that easily occurs under the effect of an environmental change (Rodríguez-Rojas et al., 2013). Antimicrobial resistance is the bacterial ability to survive and grow in the presence of a chemical molecule that would normally kill them or limit their growth. From the presence of particular resistant genes the bacteria will be able to avoid antimicrobials by major mechanisms described: direct inactivation of the active molecule; loss of bacterial susceptibility to the antimicrobial by modification of the target of action; and reduction of the drug concentration that reaches the target molecule without modification of the compound itself (efflux pump). The antibiotic defence mechanisms of intrinsic resistance are, in most of cases, related to the presence of low affinity targets, absence of targets, innate production of enzymes that
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ACCEPTED MANUSCRIPT inactivate the drug, inaccessibility of the drug into the bacterial cell by decreased drug uptake or extrusion by efflux of drug (Kumar et al., 2005).
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The resistance to a specific antimicrobial drug should be considered ‘intrinsic" or
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‘natural’ when it is inherent to a bacterial species, being present in all its strains. On the
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other hand, resistance is named “acquired”, if a susceptible species’ strain becomes resistant to a specific antimicrobial drug. This can be due either to added genes (genes acquired by the bacteria via gain of exogenous DNA, gene exchange between bacteria)
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or to the mutation of indigenous genes (Ammor et al, 2007; van Reenen and Dicks,
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2011).
Antibiotic resistance genes can be spread from one bacterium to another (Horizontal transfer of genetic material) through several mechanisms. The transfers of DNA by
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transduction (via bacteriophages) or by transformation (when DNA is released from a bacterium and taken up by another) are not believed to be relevant mechanisms of
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antibiotic resistance transfer (Ammor et al., 2007). By contrast, conjugation, i.e., the direct cell-to-cell contact, can potentially achieve horizontal gene transfer, as it has been
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shown to be a genetic information transfer mechanism with a broad host range (Courvalin, 1994).
Intrinsic resistance is estimated to present a minimal potential for horizontal spread (between different bacterial species), as was demonstrated for example with the chromosomal vancomycin resistance determinant of the Lactobacillus rhamnosus strain GG (Tynkkynen et al., 1998). Similar to intrinsic resistance, acquired resistance usually possesses a low risk of horizontal dissemination, when the resistance is a result of a chromosomal mutation. By contrast, acquired resistance is considered to have a higher potential for antibiotic resistance horizontal dissemination, when the resistance genes
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ACCEPTED MANUSCRIPT are present on mobile genetic elements (plasmids and transposons) (Devirgiliis et al., 2013, van Reenen and Dicks, 2011).
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The genetic origin of antibiotic resistance is a controversial topic; usually the antibiotic
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resistance in bacteria from the food chain is attributed to the contact with the
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antimicrobial agent in concern, and consequent development of resistance against the antibiotic (Levy and Marshall, 2004). However, recent studies have demonstrated that antibiotic resistance genes were around long before the human use of antibiotics
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(Bhullar et al., 2012, D’Costa et al., 2011). More than the use of antibiotics, the major
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problem for antibiotic resistance developing links to its misuse. The large scale antibiotic application in human and veterinary medicine, agriculture and aquaculture is pointed out as one of the main causes of the increasing rate of resistant
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bacteria.
Over the last years, human antibiotic use has grown substantially (increasing 36%
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between 2000 and 2010), mainly in developing countries (Boeckel et al., 2014). The largest absolute increases in use were observed for cephalosporins, broad-spectrum
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penicillins and fluoroquinolones. The frequent use of antibiotics in veterinary medicine, to treat or prevent diseases raised concerns about the potential for emerging new antibiotic resistant strains. Bacterial populations isolated from the intestine of animals exposed to antibiotics were found to be five times more likely to be resistant to any given antibiotic than other resistant microbial populations (Sarmah et al., 2006). In fact, the last European Surveillance of Veterinary Antimicrobial Consumption (ESVAC, 2013) report, regarding the overall sales in 2011 for 25 countries, states that the largest proportions, expressed as mg/PCU, were accounted for tetracyclines (37%), penicillins (23%), sulfonamides (11%) and polymyxins (7%).
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ACCEPTED MANUSCRIPT The excessive use of antimicrobial agents in animal husbandry contributes for the selection of resistant bacteria in the food chain (Teale, 2002). The overuse and the
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misuses of antibiotics promote the selection and dissemination of antibiotic resistant
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bacteria and resistance genes, as well as the emergence of new resistant bacteria through
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genetic mutations and gene movements.
The several human activities had a predominant role in the promotion and growth of antibiotic resistance genes environmental reservoirs. In fact, the increased antibiotic
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pollution promoted by human activities had a role in selecting antibiotic resistant
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mutants and favouring the acquisition of antibiotic resistance determinants by genetransfer elements that can be spread among the environmental microbiota (Martinez, 2009). Antibiotic abuse can enrich the population of resistant microorganisms and
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reduce the number of susceptible ones. Bacteria containing resistance genes in mobile genetic elements are a threat to public
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health, since they can act as reservoirs, allowing for resistance genes dissemination especially in dense microbial community environments (Haug et al., 2011; Marty et al.,
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2012; Salyers et al., 2004,). Consequently, foods colonized by bacteria that harbour such transferable antibiotic resistance genes are a major concern. Antibioresistance of foodborne bacteria has aroused great interest because they may act as reservoirs for antibiotic resistance genes (Talon and Leroy, 2011).
Common lactic acid bacteria in fermented meat sausages: their role and diversity
LAB include a diverse group of Gram-positive non-spore forming cocci, coccobacilli or rods, with common morphological, metabolic and physiological characteristics (Batt
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ACCEPTED MANUSCRIPT 2000). They are facultative anaerobic with variable oxygen tolerance in different species.
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LAB growth depends on the presence of fermentable carbohydrates. They are classified
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as homofermentative or heterofermentative based on end products of glucose
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metabolism. While homofermentative LAB convert glucose mainly to lactic acid using the glycolysis (Embden–Meyerhof–Parnas or Embden–Meyerhof) pathway, the heterofermentative LAB use the phosphoketolase (6-phosphogluconate) pathway and
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convert glucose to lactic acid, carbon dioxide and ethanol or acetic acid. LAB are a
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diverse group of organisms with diverse metabolic capacity. This diversity makes them easily adaptable to a wide range of conditions, allowing them to thrive in acid foods’ fermentations. This heterogeneous group of bacteria comprises about 20 genera within
include
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the phylum Firmicutes, class Bacilli, and order Lactobacillales. The different families Aerococcaceae,
Carnobacteriacea,
Enterococcaceae,
Lactobacillaceae,
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Leuconostocaceae, and Streptococcaceae (Ludwig et al., 2009). From a practical point of view, the genera Aerococcus, Carnobacterium, Enterococcus, Lactobacillus,
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Lactococcus, Leuconostoc, Oenococcus, Pediococcus, Streptococcus, Tetragenococcus, Vagococcus and Weissella have been considered as the principal LAB (Axelsson, 2004; Wright and Axelsson, 2012; Vandamme et al., 2014). LAB are widely found in nature, adapted to different carbohydrate rich environmental niches, as well as to terrestrial and marine animals. In food products, LAB are found in dairy products (yoghurt and cheese), in fermented vegetables (olives, sauerkraut), in meat and fermented meats products and in sourdough bread (Coeuret et al. 2003, De Vuyst et al., 2014, Hurtado et al., 2012, Medina et al., 2011, Panagou et al., 2013, Reis et al., 2012,). LAB play a recognized role in fermented foods preservation and safety, thus promoting final products microbial stability. The preservation ability of LAB is
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ACCEPTED MANUSCRIPT based on competition for nutrients and the production of antimicrobial active metabolites such as organic acids (mainly lactic acid and acetic acid), hydrogen
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peroxide and peptidic compounds (bacteriocins) (Reis et al., 2012).
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Bacterial communities coexist in fermented meat products, allowing for microbial
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diversity. Many factors influence the final microbiota of fermented meat sausages. The presence of ecological determinants influences the establishment of a specific microbial consortium that will determine the rate of colonization. The selective influence of
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intrinsic (concentration and availability of nutrients, pH, redox potential, buffering
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capacity, aw, meat structure) and extrinsic (temperature, relative humidity and oxygen availability) factors may determine differences in microbial ecosystem raw meat substrate. This initial microbiota will be influenced by technological particularities used
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in sausage processing and will adapt to this special niche. The addition of ingredients such as sodium chloride, nitrate/nitrite, sugars, wine, condiments (garlic, pepper), as
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well as the particular aw (0.85–0.92), temperature (12–18°C to 24–30°C), oxygen gradient during ripening and smoking application will select a microbiota able to
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develop in fermented meat sausages. Among the different genera belonging to the LAB group, those that are frequently found in fermented sausages are Lactobacillus, Enterococcus, Pediococcus and Leuconostoc (Table 1). Several LAB species well-adapted to the dry-fermented sausages environment (Table 1), were isolated from different fermented sausages produced worldwide and further identified (Adiguzel and Atasever, 2009; Danilović et al., 2011; Federici et al., 2014; Panagou et al., 2013; Wanangkarn et al., 2014,). Meat origin, sausage composition, sugar absence, ripening temperature, smoking or contamination by environmental microbiota during home- or small-scale production units can explain the broad species
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ACCEPTED MANUSCRIPT diversity (Marty et al., 2012; Wanangkarn et al., 2014). The predominant species in dry-fermented sausages are Lactobacillus sakei, Lactobacillus curvatus, Lactobacillus
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plantarum, Leuconostoc mesenteroideus, Pediococcus spp., Enterococcus spp., which
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growth is modulated and adapted to the existing stringent conditions of processing
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(Federici et al., 2014; Wanangkarn et al., 2014). Some Lactobacillus species will dominate because they can develop continuously throughout the fermentation process, since they have a greater acid tolerance and capability to adapt to redox changes than
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other bacterial species. Of note the genome of L. sakei 23K, isolated from a French
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sausage, showed the existence of particularities in its genetic repertoire, absent from other lactobacilli, such as a versatile redox metabolism giving resilience against changing redox and oxygen levels, or energy production pathways not normally
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associated with a lactic acid bacterium (Chaillou et al., 2005). This suggests biological functions that could have a role in species adaptation to meat products. Genes
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potentially responsible for biofilm formation and cellular aggregation that may assist the microorganism to colonize meat surfaces were also identified (Chaillou et al., 2005;
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Muscariello et al., 2013). L. sakei and L. plantarum are surprisingly well equipped to cope with changing oxygen conditions (Guilbaud et al., 2012; Serrano et al., 2007) present in dry-fermented meat sausage’s processing. The genetic diversity is not only found at specific but also at intra-specific level, with well adapted strains to the processing units’ environmental conditions, constituting the so-called “house microbiota” that naturally colonizes meat sausages during processing, being responsible for the spontaneous fermentation of meat with production of lactic acid and other metabolites involved in the development of the sensory characteristics of sausages (flavor, colour, texture), the enhance of safety, stability and the shelf life of the fermented sausages (Fadda et al., 2003; van Kranenburg et al., 2002). The use of small
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ACCEPTED MANUSCRIPT portions of fermented meat (backslopping) for sausage manufacture purposes became the origin of the starters composed of selected strains intentionally added to meat
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sausage to better controlling the fermentation process. The idea of starter cultures
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application in fermented sausages was developed with Jensen and Paddock in 1940 (US
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Patent 2,225,783), becoming increasingly frequent in order to confer protection and standardization of the dry-fermented sausages process (Toldrá et al., 2007). LAB´s protective effects are also attributed to bacteriocins which are ribosomally
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synthesized peptides with antimicrobial activity against food pathogens (Reis et al.,
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2012). For instance, L. curvatus CRL705, a strain isolated from an Argentinean artisanal fermented sausage showed the ability to produce the two-component lactocin 705 bacteriocin and “AL705,” a bacteriocin with antilisterial activity (Hebert et al.,
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2012).
While the protective role of LAB in dry-fermented sausages is demonstrated, the claim
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of LAB strains probiotic effect in dry-fermented dry sausages needs further studies. Full assessment of fermented sausages´ probiotic effects in human health is not possible yet.
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Probiotic LAB in meat products have been marketed since 1998 by German and Japanese producers (Arihara, 2006). However, their usefulness is controversial due to the preliminary nature of most of the scientific results reported so far (de Vuyst et al., 2008).
Safety requirements of LAB isolated from dry-fermented sausages
The early records of fermented meat products are very old. Indeed, sausages have been already cited by Homer in the Odyssey written in the 8th Century Before Christ (Zeuthen, 2007). The know-how of fermented sausages' processing was spread from
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ACCEPTED MANUSCRIPT Greece, Rome and Chine all over the European (particularly Southern Europe), American and Asian continents (Toldrá el al., 2007).
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Since dry-fermented sausages are highly valued and constitute a frequently consumed
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food item, it might be said that LAB are ingested in high levels along with traditional
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dry-fermented sausages consumption. Reported cases of disease related with the most frequent LAB species isolated from these products are, as far as we know, rare. Lactobacillus infections occur at a very low rate in the generally healthy population -
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estimated 1/10 million people over a period of more than a century (Bernardeau et al.,
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2006).
Traditional dry-fermented sausages, and their LAB microbiota, fit in the concept of “history of safe use”, defined in EFSA´s safety assessment guidance (EFSA, 2005), due
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to all evidences of safe production and consumption by genetically diverse human population over the years. So, there is reasonable certainty that no harm will result from
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dry-fermented sausages consumption. According to Bourdichon et al. (2012), to include a microbial specie in a safety list, its presence should be documented, regarding not
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only the occurrence of a specific microorganism in a fermented food product, but also by providing evidences whether the presence of the microorganism is beneficial, fortuitous or undesired. LAB have the GRAS (generally regarded as safe) status provided by the US Food and Drug Administration (FDA) (Chamba and Jamet, 2008). In addition, the European Food Safety Authority (EFSA) has adopted a generic approach to the safety assessment of the microorganisms used in food/feed resulting in the application of the concept 'Qualified Presumption of Safety' (QPS) to a selected group of microorganisms including LAB (EFSA, 2005). Thus, as LAB are inherent components of traditional fermented sausages, the QPS concept is applicable to the defined strains of this microbial group
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ACCEPTED MANUSCRIPT intended to be deliberately added as starters to the raw meat for sausages manufacturing purposes.
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The safety assessment of the strains used as starter or protective cultures for dry-
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fermented sausages' production should discard the presence of antibiotic resistance
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genes in the selected strains to avoid their transmission to commensal or pathogenic bacteria (EFSA, 2012, 2013). Likewise, strains should not produce other virulence factors such as biogenic amines (EFSA, 2011).
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Different factors or circumstances could change the “reasonable certainty of no harm”
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and since LAB are present in human gastrointestinal tract, and are also intentionally added to the food use in the diet, concerns arouse about the antimicrobial resistance of these beneficial bacteria. Bacteria used as starter cultures or protective cultures for dry-
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fermented sausages’ production could possibly contain antibiotic resistance genes, which might be transferred to commensal or pathogenic bacteria and this fact it is not
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accepted by EFSA. Antimicrobial resistance was introduced as a possible safety concern for the assessment and inclusion of bacterial species in the QPS list (EFSA, 2012).
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QPS approach has proved to be a useful tool to harmonize and prioritize safety assessment linked to the taxonomy, familiarity, pathogenicity and end use of the microorganisms (EFSA, 2005, EFSA, 2013). Virulent factors, biogenic amines production (EFSA, 2011) and antibiotic resistance determinants of human and veterinary clinical significance are requirements for QPS qualification, being imperative their absence. EFSA (2013) has stated that a total of 35 Lactobacillus species can be considered to have QPS-status, being present in this group the most frequent species identified also in dry-fermented sausages such as L. sakei, L. curvatus, L. plantarum, L. fermentum, L. brevis, L. rhamnosus and L. alimentarius. In addition to Lactobacillus species, also
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ACCEPTED MANUSCRIPT other LAB species have been granted QPS-status. They include four Leuconostocs, (Ln. citreum, Ln. lactis, Ln. mesenteroides and Ln. pseudomesenteroides), three Pediococci
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(P. acidilactici, P. dextrinicus and P. pentosaceus), Lc. lactis and Streptococcus
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thermophilus. Enterococcus faecium was not recommended for the QPS list in spite of
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the recent scientific knowledge allowing a differentiation of pathogenic from nonpathogenic strains.
The safety of bacteria used as starters or probiotics must be assured. The use of
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Enterococcus as human probiotics remains controversial, in light of the capability of
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most species to turn into opportunistic pathogens (Devirgiliis et al., 2011, Franz et al., 2011).
Enterococcus faecium assessment for QPS has been performed by EFSA (EFSA, 2013),
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that concluded that although a differentiation between the clade A containing strains associated to clinical infections from the clade B composed by commensal strains is
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possible (de Been et al. 2013; Galloway-Peña et al., 2012; Palmer et al., 2012), this knowledge is too recent for a recommendation, considering the past evolution of the
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epidemiology of Enterococcus infections in humans. This scientific information was used by the FEEDAP panel that excluded Enterococcus faecium strains belonging to the hospital-associated clade from the use in animal nutrition because of the hazard they present to vulnerable subpopulations. Strains intended for animal nutrition use shall be susceptible to ampicillin (MIC ≤ 2 mg/L) and must not harbour the genetic virulent elements IS16, hylEfm, and esp (EFSA, 2012). The presence of one or more virulence determinants does not make a strain necessarily pathogenic, although our understanding so far is that mobile genetic elements drive evolution of strains to specialization and adaptation of specific genetic lineages with the hospital niche, with acquisition of genes that increase the cells fitness. Such includes genes for antibiotic resistances, surface
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ACCEPTED MANUSCRIPT structure genes, metabolism genes, recognized virulence factor genes, as well as many currently still undefined virulence-associated genes (Franz et al., 2011). A complete
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picture of all the genes and biological processes that determine pathogenicity it is still
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not elucidated, so case to case study of selected Enterococcus strains should be
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performed.
Sources and possible transmission routes of antibiotic resistant LAB to dry-
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fermented sausages
The food chain can be considered the main route of transmission of antibiotic resistant bacteria between food animals and humans. However, the environment and its impact
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on food animals and human life should be also considered, since the release of antibiotics together with antibiotic resistance bacteria can impact the environmental
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microbiota as well (Martinez, 2009). The possible transmission routes of antibiotic resistant bacteria from food animals to humans and to environment results of the
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application of antibiotic in food animals, as therapeutic, prophylactic, and subtherapeutic uses. This determines a selective pressure on bacteria with the outcoming of the resistant bacteria and their further spread; antibiotic resistance arises as a result of natural selection. Forslund et al. (2013) provided evidences that support an association between antibiotic use in food animals and increased antibiotic-resistant bacteria in humans. However, it is important to note that the resistant bacteria spread from humans itself to other humans and to environment. It is crucial to integrate aspects from human medicine, animal health and environmental considerations (Berkner et al., 2014). Nowadays, the pollution of antibiotic resistance is considered to be done not only by antibiotics and consequent resistant bacteria but also by their resistant genetic
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ACCEPTED MANUSCRIPT determinants persistent on environment (Martinez, 2009). Why is resistance inevitable and where does it come from? The answers to these questions are still limited by our
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current knowledge about this particular issue.
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The dry-fermented sausage microbiome, as was referred in this review, depends on
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several factors; raw meat microbial contamination as well as other secondary and auxiliary ingredients used on sausage formulation will be the start point of antibiotic resistant LAB presence (Figure 1). These resistant bacteria are already present in meat
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coming from a slaughter house (Tommey et al., 2010) and their load will be influenced
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by the delay in cold application. Environmental bacteria are inevitably found in unprocessed meat, even when slaughtering occurs under proper hygienic conditions (Devirgiliis et al., 2011). According to Comunian et al. (2010), the highest number of
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Lactobacillus resistant strains was observed on Salame Piacentino produced in areas where more intensive animal husbandry practices have been applied.
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Natural casings used in meat stuffing will be other potential source of antibiotic resistant LAB. In fact, the usual preparation and preservation of this matrix it is not
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sufficient to eliminate all microorganisms and particularly many species of Lactobacilli and Lactococcus (L. reuteri, L. plantarum, L. brevis and Lc. garvieae) that are present in animal intestinal tract (Devirgiliis et al., 2011; Leser et al., 2002; Pyörälä et al., 2014). It is usual to have loads of 3-4 log cfu.g-1 of LAB in natural casings (Trigo and Fraqueza, 1998). There is also a high probability of Lactobacilli adhesion to casings (Barriga and Piette, 1996). Even with acid addition or other chemical (phosphates) treatments, microorganisms can persist in casings (Bakker et al., 1999). Spices and herbs are natural products and may therefore be burdened with a large number of Gram negative and positive microorganisms (Schweiggert et al., 2007). Among Gram positive microorganism, Enterococci, Staphylococcus and Bacillaceae are
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ACCEPTED MANUSCRIPT reported (Banerjee and Sarkar, 2003, Martín et al., 2009). As many other agricultural commodities, spices are exposed to a wide range of environmental microbial
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contamination during collection, processing, and in the retail markets, namely dust,
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waste water, and animal and even human excreta (Banerjee and Sarkar, 2003). The
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prevention of microbial contamination in dried herbs and spices lies on the application of good hygiene practices during growing, harvesting and processing from farm to fork, and effective decontamination (Sagoo et al., 2009). Spices commonly used for dry-
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fermented sausages production include ground black pepper, paprika, garlic, mace,
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pimento, nutmeg, clove, sage, coriander, oregano and rosemary (Chi and Wu, 2007). They are added as flavorings and coloring agents. However, they are also a source of many other substances, such as sugars, nitrates, and metallic ions (Aguirrezábal et al.,
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1998), and some of them have antioxidant and antibacterial properties. Nutrients and metallic elements present in spices may stimulate LAB growth and/or biochemical
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activity. It has been shown that L. curvatus growth was not stimulated by most of the spices (paprika, nutmeg, rosemary, and mace) although pepper and garlic, as sources of
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trace elements and/or additional carbohydrates may stimulate lactic acid or biomass production. However, bacteria differ in their resistance to a given spice or herb and respective concentration (Verluyten et al., 2004). When 0.70% garlic was added to meat emulsion simulating a fermented sausage matrix, a bactericidal action was observed towards L. curvatus LTH 1174. Nevertheless, this effect depend on garlic concentration, since with 0.35% a regrowth of LAB population was noticed, and L. curvatus LTH 1174 reached a maximum cell concentration of 2.00 g of CDM (cell dry mass). liter−1 after 80 h of growth, higher than values noticed for reference (Verluyten et al., 2004). During production, man may be involved in all operative steps of dry-fermented sausages. The use of good hygiene practices during manufacturing of dry-fermented
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ACCEPTED MANUSCRIPT sausages is essential to avoid the transmission of potential antibiotic resistant LAB present in the gut microbiota of processing handlers (Tuohy et al., 2009). In this regard,
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handler’s health status assessment and proper training will be important to communicate
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and efficiently implement preventive measures (Fraqueza and Barreto, 2014; Henriques
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et al., 2014).
The persistence of LAB in industrial plant´s environment is stated by several authors (Talon et al., 2007). LAB will persist after all the biocide stress settled by the hygiene
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program application, which aims to eliminate faecal contaminants, but will select the
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resistant ones. What it is still not known is the possible impact of practices selecting the antibiotic resistant LAB strains present in plant’s environment. The microbiome of dry-fermented sausages is complex and will be stretched by
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smoking and drying steps. It can be admitted that smoke´s phenolic and alcoholic compounds transmitted to the fermented sausage might influence LAB development
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but, according to Janssens et al. (2013), following fermentation, the bacterial communities were not perturbed by the smoking treatment. In particular, L. sakei
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remained dominant throughout the ripening stage and prevailed in the end-products. However, uncertainty remains about the modulation effect of these hurdles on antibiotic resistant strains of L. sakei or other predominant species. Antibiotic resistant LAB may be present in dry-fermented sausage’s process by, for example, contamination of raw materials and ingredients, faecal contamination of the process, recontamination by improper handling, or lack of a microbial destructive treatment step (which is the case in a traditional dry-fermented sausage process). Also, antibiotic resistant bacteria elimination is not a guaranty of resistant determinants exclusion. But, the risk of antibiotic resistance transmission via food chain could be the same as for foodborne pathogens? So far, as a preventive measure related to food
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ACCEPTED MANUSCRIPT processes, it was stated that, the risk of antibiotic resistance bacteria transmission could be considerably reduced with proper food handling, good hygiene practices and good
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manufacturing practices (Singer et al., 2003). The accomplishment of standard
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operating procedures such as the selection and control of ingredient’s suppliers is
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important, but in a preventive food safety system this is not enough. Precise knowledge and understanding of how manufacturing conditions (low and high temperatures, water activity (aw), oxygen, carbon source availability, acidity, chemicals or other
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microorganisms presence) may affect antibiotic resistant LAB strains is needed. In fact,
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bacterial metabolism situation is highly relevant for antibiotic susceptibility (Martinez and Rojo, 2011). Membrane permeability is the first step in the crosstalk between bacteria and their surrounding environment, in order to optimize cellular metabolism as
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a function of environmental conditions. Because of this, the expression of porins and modifications in the lipid composition of bacterial membranes are tightly regulated in
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response to extracellular inputs. Since antibiotics co-opt bacterial transporters for their entry into bacterial cells, changes in the transporters’ composition due to adjustment of
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bacterial metabolism to an environmental shift might challenge the antibiotic susceptibility (Martinez and Rojo, 2011). Dry-fermented sausages provide an environment in which close contact among bacteria could facilitate horizontal genetic transfer. The potential of LAB to serve as hosts for antibiotic-resistance genes, with the risk of gene transfer (Devirgiliis et al., 2013; Gevers et al., 2003; Nawaz et al., 2011) to many other LAB or pathogenic bacteria present in dry-fermented sausage should be considered, to assure the principle of precaution.
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ACCEPTED MANUSCRIPT Antibiotic resistance profile of LAB isolated from dry-fermented sausages and
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detection of particular genes causing resistance
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Knowledge concerning the safety of indigenous or non starter LAB from dry-fermented
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sausages is relevant for the selection and application of a starter or protective culture and for the quality improvement of fermented meat products production. Antimicrobial resistance assessment should be performed in Lactobacilli and other LAB naturally
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involved in sausages fermentation used as starters, because they may act as reservoirs
technological
interest
should
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for antibiotic-resistance genes. Safety assessment requirements for LAB strains of include
the
characterization
of
the
antibiotic
resistance/susceptibility profile. In addition, the potential transmission of the antibiotic
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resistance(s) of medical interest detected should be also determined. The antibiotic susceptibility of LAB isolated from dry-fermented sausages is usually performed
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according to the Clinical and Laboratory Standards Institute guidelines (CLSI, 2013). However, the assessment of the suitability for QPS status of strains intended to use as
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starters should follow the EFSA guidance documents (EFSA, 2012, 2013) to identify the potential resistance to antimicrobials of human and veterinary use. LAB possesses a broad spectrum of natural (intrinsic) and acquired antibiotic resistances and some of the antibiotic resistance determinants identified in LAB are presented in Table 2. The vancomycin-resistant phenotype of some Lactobacillus is perhaps the best characterized intrinsic resistance in LAB. Several Lactobacillus, Leuconostoc and Pediococcus species are intrinsically resistant to vancomycin due to the replacement of the terminal D-alanine residue by D-lactate or D-serine in the muramylpentapeptide (Table 2), preventing vancomycin binding (Delcour et al., 1999).
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ACCEPTED MANUSCRIPT This resistance is chromosomally encoded and not inducible or transferable (Gueimonde et al., 2013).
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LAB resistance to aminoglycosides (neomycin, kanamycin, streptomycin) is also
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considered intrinsic being attributed to the absence of cytochrome-mediated electron
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transport, which mediates drug uptake (Charteris et al., 2001, Danielsen and Wind, 2003).
According to Hummel et al. (2007), Lactobacilli are also naturally resistant to
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quinolones (ciprofloxacin, norfloxacin, nalidixic acid) by a currently unknown
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resistance mechanism (Table 2).
Enterococcus appears to be intrinsically resistant to semysintethic penicillins (oxacillin), cephalosporins of all classes, monobactams and polymixins. The resistance
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is due to the inhibition of penicillin-binding proteins by β-lactam antibiotics. The resistance to streptogramin A/B combination (quinupristin/dalfopristin) is mediated by
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the expression of an ABC porter designated lsa (Table 2; Werner, 2012). The resistance to fluoroquinolones by Enterococcus faecalis is associated with expression of
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chromosomal qnr homologues (Arsene and Leclerq, 2007). Lactobacilli have a high natural resistance to other antibiotics such as bacitracin, cefoxitin, metronidazole, nitrofurantoin and sulphadiazine (Bernardeau et al., 2008; Danielsen and Wind, 2003; Tynkkynen et al., 1998; Zhou et al. 2005). Nucleic acid synthesis inhibitors resistance, as observed for trimethoprim, seems to be intrinsic, although further characterizations are required on this topic (Ammor et al., 2008). The intrinsic antibiotic resistance presented by Lactobacilli against frequently used antibiotics used in human treatments, such as quinolones, glycopeptides and aminoglycosides, could be desirable since their beneficial use help them to maintain gastrointestinal tract balance in antibiotic-induced diarrhea cases (Charteris et al. 2001).
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ACCEPTED MANUSCRIPT However, this must be carefully addressed since resistant genotypes also arise from scratch by mutation. The dynamics of how the resistome evolves and changes are
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presently not well understood (Berkner et al., 2014). The presence of intrinsic antibiotic
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resistance genes is not a major safety concern itself, as long as the genes are not
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mobilized and transferred to other bacteria.
Apart from the large spectrum of intrinsic resistances presented by LAB, this bacterial group has the potential to acquire resistance to all antimicrobial drugs available. Many
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studies described the presence of antimicrobial resistance in LAB, their mechanisms of
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resistance acquisition and determinants evolved (Table 2). Resistances could be the result of point mutations of housekeeping genes selected under antibiotic pressure and spread by clonal dissemination (vertically) but can be caused by acquired determinants
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(ex. tet, erm, van, bla) spread horizontally when located on mobile elements such as plasmids or transposons (Table 2) (Ammor et al., 2007; Danielsen et al., 2002;
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Deghorain et al., 2007; Gevers et al., 2003, Hummel et al., 2007; Werner, 2012). LAB have been found to be susceptible to cell wall synthesis inhibitors, like penicillins
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and ampicillin (Danielsen and Wind, 2003). For instance, penicillin resistance in E. faecalis is linked to the expression of β-lactamases while for E. faecium this resistance is mediated by a point mutation in the houseeking php5gene (Table 2; Werner, 2012). Lactobacilli are usually susceptible to antibiotics that inhibit protein synthesis such as chloramphenicol, erythromycin, quinupristin/dalfopristin, lincomycin, clindamycin and tetracyclines (Aymerich et al., 2006; Comunian et al., 2010; Federici et al., 2014; Hummel et al., 2007; Landeta et al., 2013). Antibiotic resistance characterization of Lactobacilli isolated from dry-fermented sausages is getting more attention and the most assessed antibiotics were tetracycline and erythromycin, followed by chloramphenicol, streptomycin, ampicillin, vancomycin,
23
ACCEPTED MANUSCRIPT and clindamycin (Table 3). Indeed, antibiotic multi-resistant Lactobacilli have been isolated from dry-fermented sausages as reported by Aymerich et al. (2006). L. sakei, L.
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curvatus and Leuconostoc mesenteroides isolates from chorizo, fuet and salchichon
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were resistant to vancomycin (100%), 98% to gentamicin and 43% to ampicillin. All
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isolates were susceptible to erythromycin and only two L. sakei isolates showed resistance to linezolid. Tetracycline resistant isolates were only detected at low percentages (12% of average) (Table 3).
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L. sakei, Pediococcus pentosaceus, L. plantarum, L. paraplantarum, and Lactococcus
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isolates from a typical fermented Italian sausage presented a high resistance frequency to streptomycin and gentamycin, with 88.46% and 69.23% respectively (Federici et al., 2014). However, Lactobacilli were particularly sensitive to clindamycin (84.62%) and
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erythromycin (76.92%). While 13% of L. sakei presented resistance to tetracycline, the others Lactobacilli were 80-100% resistant. Of note, most of the L. sakei isolated in
antibiotic
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traditional dry-fermented sausages from South Portugal were susceptible to several tested,
namely
cloranfenicol,
quinupristin–dalfopristin,
lincomycin,
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erythromycin, rifampicim, showing 19% resistance to tetracycline, 56% to gentamicin and 59% to penicillin. All L. sakei were resistant to vancomycin. The L. plantarum strains, also isolated in the same products, presented the same intrinsic resistance to vancomycin and a higher frequency of resistance to tetracycline (25%), lincomycin (50%) and penicillin (81%) (Fraqueza et al., data not published). Gevers and coauthors (2000, 2003) reported the highest levels of resistance to tetracycline (55%) on Lactobacilli strains isolated from dry-fermented sausages (Table 3). In general, the predominant species isolated from dry-fermented sausages, such as L. sakei had a resistance rate to tetracycline of 12-70%, while L. plantarum presented frequencies of 75-80% (Aymerich et al., 2006; Federici et al., 2014; Gevers et al., 2000;
24
ACCEPTED MANUSCRIPT Landeta et al. 2013; Zonenschain et al., 2009). Most of the studies conducted with Lactobacilli isolates from dry-fermented sausages had a particular interest on
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tetracycline or erythromycin resistance assessing the presence of genes tet (including
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tet(M), tet(O), tet(S), tet(W), tet(K), tet(L)) and erm (including ermA, ermB and ermC).
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So far, the most common resistance genes detected in LAB isolates from dry-fermented sausages, were tet(M), tet(W), and tet(S) for tetracycline and erm(B) and erm(C) for erythromycin resistance (Table 3) (Gevers et al., 2003, Zonenschain et al., 2009). For L.
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sakei, L. alimentarius and L. plantarum strains isolated from fermented sausages with
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resistance to tetracycline was demonstrated to harbor a tetM gene localized in a plasmid (Gevers et al., 2003). The tetM gene can also be linked to a family of transposons known for its ability to perform conjugative transposition with direct transfer between
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D
different bacteria. Lactobacillus spp. can act as reservoir of acquired antibiotic resistance genes that can be disseminated to other bacteria and exchanged by bacteria
al., 2009).
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from many different ecosystems and also between humans and animals (Devirgiliis et
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Scarce information about resistance to chloramphenicol in LAB from dry-fermented sausage is available (Aymerich et al., 2006). Nevertheless, Hummel et al. (2007) reported that the cat gene, encoding for chloramphenicol acetyltransferase, was not expressed in Lactobacilli from dry-fermented sausages. By contrast, this gene was detected in L. reuteri (Lin et al., 1996), L. acidophilus and L. delbrueckii subsp. bulgaricus (Hummel et al., 2007), L. johnsonii (Mayrhofer et al., 2010) and L. plantarum (Ahn et al., 1992) isolated from different foods. E. faecium and E. faecalis are common species in sausage fermentations (Table 3) and show a wide profile of antibiotic resistance (gentamycin, tetracyclin, clindamycin, vancomycin, cloranfenicol, ciprofloxacin, penicillin and nitrofurantoine). In particular,
25
ACCEPTED MANUSCRIPT the genes genes erm(B), aac(69)-Ie-aph(299), tet(M) and van(A) have been detected in some E. faecalis strains (Ribeiro et al., 2009), while the tetM gene was present in all E.
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faecium strains (Landeta et al., 2013).
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Since this species may play a role in fermentation and contribute to the uniqueness of some dry-fermented sausages, their presence poses some concern regarding their potential pathogenicity and the risk of gene resistance transmission via the food chain,
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particularly if strain selection to be used as starters is considered.
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Genotyping methods to assess resistant isolates include different PCR –based methods, southern hybridization, plasmid profiling and microarray (Ammor et al., 2008; Aquilanti et al., 2007). The situation is clearer when there is an agreement of
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phenotypic and genotypic resistance patterns. However, a phenotypically resistant bacterium strain may be genotypically “susceptible”. This is usually due to the fact that
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appropriate genes are not included in the test patterns, or that there are unknown resistance genes. In contrast, a susceptible phenotype may also carry silent genes, which
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are observed with genotyping. The silence of antibiotic resistance may be caused by down-regulation in a promoter region or by other mechanisms. Despite of their “silence”, they still could be a potential concern, since they could be transferred to other species in which they would be activated. It is clear that further work must be performed in order to well characterize the resistance phenotype and genotype of LAB strains intended to be used as starters in dryfermented sausages.
Final Remarks
26
ACCEPTED MANUSCRIPT LAB have a long history of safe use in dry-fermented sausage production and consumption. However, antibiotic resistant LAB have been isolated from this fermented
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product.
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There are increasing evidences supporting the crucial role of foodborne LAB as
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reservoir of AR genes horizontally transmissible to pathogens through the food chain. Only resistance acquired by mutation or horizontal gene transfer poses a risk for public health.
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L. sakei and L. plantarum are the predominant species in dry-fermented sausages
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microbiota. Accordingly, special care should be taken regarding the antibiotic resistance profile of the strains prior their use as starters in dry-fermented sausages manufacturing. LAB antibiotic resistance expression without detection of known genes highlight the
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D
need to develop methods well adapted to the variation in the nucleotide sequence of the resistance gene in question, or the assessment of other genes that may confer resistance
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to the same antibiotic. Furthermore, differences in resistance phenotypes may be due to non-functional and / or silent genes.
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It is important to assess the real risk of harbouring a high load of LAB with AR genes in dry-fermented sausages and in the human gut. This will allow the adoption of specific management strategies throughout the food chain to diminish or avoid the presence of antibiotic resistant LAB in dry-fermented sausages. Since it is a multifactorial problem, it should be faced integrating environmental aspects and the use of antibiotic in food animals and in humans.
Acknowledgements The author wish to thank the Centro de Investigação Interdisciplinar em Sanidade Animal (CIISA) for logistic support and the financial support from the Fundação para a Ciência e a Tecnologia (FCT) project “Portuguese traditional meat products: strategies 27
ACCEPTED MANUSCRIPT to improve safety and quality” (PTDC/AGR-ALI/119075/2010). We gratefully thank
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Fernando Bernardo by all moments of helpful discussion during manuscript preparation.
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References
Adiguzel, G.C., Atasever, M., 2009. Phenotypic and genotypic characterization of lactic acid bacteria isolated from Turkish dry fermented sausage. Romanian
NU
Biotechnological Letters 14 (1), 4130-4138.
MA
Aguirrezábal, M., Mateo, J., Domínguez, C., Zumalacárregui, J. M., 1998. Spanish paprika and garlic as sources of compounds of technological interest for the production of dry fermented sausages. Science des Aliments 18, 409-414.
TE
D
Ahn, C., Collins-Thompson, D., Duncan, C., Stiles, M.E., 1992. Mobilization and location of the genetic determinant of chloram-phenicol resistance from
CE P
Lactobacillus plantarum caTC2R. Plasmid 27, 169–176. Albano, H., van Reenen, C. A., Todorov , S. D., Cruz, D., Fraga, L., Hogg, T., Dicks, L.
AC
M.T., Teixeira, P., 2009. Phenotypic and genetic heterogeneity of lactic acid bacteria isolated from ‘‘Alheira”, a traditional fermented sausage produced in Portugal. Meat Science 82, 389–398. Ammor, M. S., Mayo, B., 2007. Selection criteria for lactic acid bacteria to be used as functional starter cultures in dry sausage production: An update. Meat Science 76, 138-146. Ammor, M.S., Flórez, A.B., Van Hoek, A.H.A.M., de los Reyes-Gavilán, C.G., Aarts, H.J.M., Margolles, A., 2008. Molecular characterization of intrinsic and acquired antibiotic resistance in lactic acid bacteria and bifidobacteria. Journal of Molecular Microbiology and Biotechnology 14, 6–15.
28
ACCEPTED MANUSCRIPT Aquilanti, L., Garofalo, C., Osimani, A., Silvestri, G., Vignaroli, C., Clementi, F., 2007. Isolation and molecular characterization of antibiotic-resistant lactic acid bacteria
T
from poultry and swine meat products. Journal of Food Protection 70, 557–565.
IP
Arihara, K., 2006. Strategies for designing novel functional meat products. Meat
SC R
Science 74, 219–229.
Arsene, S., Leclerq, R., 2007. Role of a qnr-like gene in the intrinsic resistanec of Enterococcus faecalis to fluoroquinolones. Antimicrobial Agents Chemotherapy
NU
51, 3254-3258.
MA
Axelsson, L., 2004. Lactic Acid Bacteria: Classification and Physiology. In: Salminen, S., von Wright, A. and Ouwehand, A. (Eds.) Lactic Acid Bacteria. Microbiological and Functional Aspects. New York: Marcel Dekker Inc. pp. 1-66.
TE
D
Aymerich T., Martín, B. , Garriga, M., Hugas, M., 2003. Microbial Quality and Direct PCR Identification of Lactic Acid Bacteria and Nonpathogenic Staphylococci
CE P
from Artisanal Low-Acid Sausages. Applied and Environmental Microbiology 69, 8, 4583–4594.
AC
Aymerich T., Martin, B.; Garriga, M., Vidal-Carou, M.C., Bover-Cid, S., Hugas, M., 2006. Safety properties and molecular strain typing of lactic acid bacteria from slightly fermented sausages. Journal of Applied Microbiology 100, 1, 40–49. Bakker, W.A.M., Houben, J.H., Koolmees, P.A., Bindrich, U., Sprehe, L., 1999. Effect of initial mild curing, with additives, of hog and sheep sausage casings on their microbial quality and mechanical properties after storage at difference temperatures. Meat Science 51, 163-174. Banerjee, M., Sarkar, P. K., 2003. Microbiological quality of some retail spices in India. Food Research International 36, 469-474.
29
ACCEPTED MANUSCRIPT Barriga, M. I., Piette, J. P. G., 1996. Reduction of adhesion of a Lactobacillus sp. to collagen sausage casing by proteins. Food Research International 29 (34), 249-
T
251.
IP
Batt, C.A., 2000. Lactococcus: Introduction. In: Robinson, R.K., Batt, C.A. and Patel,
SC R
P.D. (Eds). Encyclopedia of Food Microbiology. London, U.K.: Academic Press. pp. 1164-1166.
Berkner, S., Konradi, S., Schönfeld, J., 2014. Antibiotic resistance and the environment-
NU
there and back again. EMBO reports 15 (7), 740-744.
MA
Bernardeau, M., Gueguen, M., Vernoux, J.P., 2006. Beneficial lactobacilli in food and feed: long-term use, biodiversity and proposals for specific and realistic safety assessments. FEMS Microbiology Reviews 30 (4), 487–513.
TE
D
Bernardeau, M., Vernoux, J.P., Henri-Dubernet, S., Guégen, M., 2008. Safety assessment of dairy microorganisms: The Lactobacillus genus. International
CE P
Journal of Food Microbiology 126, 278-285. Bhullar, K., Waglechner, N., Pawlowski, A., Koteva, K., Bank, E.D., Johnston, M.D., Wright, G.D., 2012. Antibiotic Resistance Is Prevalent in an
AC
Barton, H.A.,
Isolated Cave Microbiome, PLoS ONE 7(4), e34953. Boeckel, T. P. Van, Gandra, S., Ashok, A., Caudron, Q., Grenfell, B. T., Levin, S. A. Laxminarayan, R., 2014. Global antibiotic consumption 2000 to 2010: an analysis of national pharmaceutical sales data. The Lancet Infectious diseases 14, 742-750. Bourdichon, F., Casaregola, S., Farrokh, C., Frisvad, J. C., Gerds, M. L., Hammes , W. P., Harnett , J., Huys, G., Laulund, S., Ouwehand, A., Powell, I. B., Prajapati, J. B., Seto, Y., Schure, E. T., Van Boven, A., Vankerckhoven, V., Zgoda, A., Tuijtelaars, S., Hansen, E. B., 2012. Food fermentations: Microorganisms with
30
ACCEPTED MANUSCRIPT technological beneficial use. International Journal of Food Microbiology 154, 8797.
T
Cauwerts, K., Decostere, A., De Graef, E.M., Haesebrouck, F., Pasmans, F., 2007. High
IP
prevalence of tetracycline resistance in Enterococcus isolates from broilers
SC R
carrying the erm(B) gene. Avian Pathology 36, 395-399.
Chaillou, S., Champomier-Verge`s, M.-C., Cornet, M., Crutz-Le Coq, A.-M., Dudez, A.-M., Martin, V., Beaufils, S., Darbon-Ronge`re, E.,
Bossy, R., Loux, V.,
NU
Zagorec, M., 2005. The complete genome sequence of the meat-borne lactic acid
MA
bacterium Lactobacillus sakei 23K. Nature Biotechnology 23 (12), 1527-1533. Chamba, J. F., Jamet, E., 2008. Contribution to the safety assessment of technological microflora found in fermented dairy products. International Journal of Food
TE
D
Microbiology 126, 263-266.
Charteris, W. P., Kelley, P. M., Morelli, L., Collins, J. K., 2001. Gradient diffusion
CE P
antibiotic susceptibility testing of potentially probiotic lactobacilli. Journal of Food Protection 64, 2007-2014.
AC
Chi, S.-P., Wu, Y.-C., 2007. Spices and seasonings, In: Toldrá, F. (Ed.). Handbook of Fermented Meat and Poultry, 1st Edition. Blackwell Publishing. USA. pp. 87-100. Chopra, I., Roberts. M., 2001. Tetracycline antibiotics: mode of action, applications, molecular biology, and epidemiology of bacterial resistance. Microbiology and Molecular Biology Reviews 65, 232-260. CLSI, 2013. Clinical and Laboratory Standards Institute (CLSI). Performance standards for Antimicrobial susceptibility testing. Clinical and Laboratory Standard Institute, CLSI document M100-S23- Twenty third Informational supplement. CLSI, Wayne, Pennsylvania.
31
ACCEPTED MANUSCRIPT Coeuret, V., Dubernet, S., Bernardeau, M., Gueguen, M., Vernoux, J. P., 2003. Isolation, characterisation and identification of lactobacilli focusing mainly on
T
cheeses and other dairy products. Lait 83, 269-306.
IP
Comunian, R., Daga, E., Dupré, I., Paba, A., Devirgiliis, C., Piccioni, V., Perozzi, G.,
SC R
Zonenschain, D., Rebecchi, A., Morelli, L., Lorentiis, A.D., Giraffa, G., 2010. Susceptibility to tetracycline and erythromycin of Lactobacillus paracasei strains isolated from traditional Italian fermented foods. International Journal of Food
NU
Microbiology 138, 151-156.
MA
Courvalin, P., 1994. Transfer of antibiotic resistance genes between gram-positive and gram-negative bacteria. Antimicrobial agents and chemotherapy 38 (7), 14471451.
TE
D
Cox, G., Whright, G. D., 2013. Intrinsic antibiotic resistance: Mechanisms, origins, challenges and solutions. International Journal of Medical Microbiology 303, 287-
CE P
292.
Danielsen , M., 2002. Characterization of the tetracycline resistance plasmid pMD5057
AC
from Lactobacillus plantarum 5057 reveals a composite structure. Plasmid 48, 98103.
Danielsen, M., Wind, A. A., 2003. Susceptibility of Lactobacillus ssp. to antimicrobial agents. International Journal of Food Microbiology 82,1-11. Danilović, B., Joković, N., Petrović, L., Veljović, K., Tolinački, M., Savić, D., 2011. The characterisation of lactic acid bacteria during the fermentation of an artisan Serbian sausage (Petrovská Klobása). Meat Science 88, 668–674. Davies J., Davies, D., 2010. Origins and Evolution of Antibiotic Resistance Microbiology and Molecular Biology Reviews 74(3),417-433.
32
ACCEPTED MANUSCRIPT D'Costa, V.M., King, C.E., Kalan, L., Morar, M., Sung, W.W., Schwarz, C., Froese, D., Zazula, G., Calmels, F., Debruyne, R., Golding, G.B., Poinar, H.N., Wright, G.D.,
T
2011. Antibiotic resistance is ancient. Nature 31, 477, 457-461.
IP
de Been, M., van Schaik, W., Cheng, L., Corander, J., Willems, R.J., 2013. Recent
SC R
recombination events in the core genome are associated with adaptive evolution in Enterococcus faecium. Genome Biololy Evolution 5(8), 1524–1535 De Vuyst, L., Falony, G., Leroy, F., 2008. Probiotics in fermented sausages. Meat
NU
Science 80, 75–78.
MA
De Vuyst, L., Van Kerrebroeck, S., Harth, H., Huys, G., Daniel, H.-M., Weckx S., 2014. Microbial ecology of sourdough fermentations: Diverse or uniform? Food Microbiology 37, 11-29.
TE
D
Deghorain, M., Goffin, P., Fontaine, L., Mainardi, J.-L., Daniel, R., Errington, J., Hallet, B., Hols, P., 2007. Selectivity for D-Lactate Incorporation into the
CE P
Peptidoglycan Precursors of Lactobacillus plantarum: Role of Aad a VanX-Like D-Alanyl-D-Alanine Dipeptidase. Journal of Bacteriology 189, 4332–4337.
AC
Delcour, J., Ferain, T., Deghorain, M., Palumbo, E., Hols, P., 1999. The biosynthesis and functionality of the cell-wall of lactic acid bacteria. Antonie Van Leeuwenhoek 76, 159–184. Devirgiliis, C., Barile, S., Perozzi, G., 2011. Antibiotic resistance determinants in the interplay between food and gut microbiota. Genes and Nutrition 6, 275–284. Devirgiliis, C., Zinno P., Perozzi G. 2013. Update on antibiotic resistance in foodborne Lactobacillus and Lactococcus species. Frontiers in Microbiology 4, 301. Dina, J., Malbruny, B., Leclercq, R., 2003. Nonsense Mutations in the lsa-Like Gene in Enterococcus faecalis Isolates Susceptible to Lincosamides and Streptogramins A. Antimicrobial Agents and Chemotherapy 47, 2307–2309.
33
ACCEPTED MANUSCRIPT EFSA, 2005. QPS. Qualified Presumption of Safety of Micro-organisms in Food and Feed. EFSA Scientific Colloquium Summary Report. European Food Safety
T
Authority – October 2005. Parma, Italy. ISBN 92-9199-012-4. pp. 143.
IP
EFSA, 2011. EFSA Panel on Biological Hazards (BIOHAZ); Scientific Opinion on
SC R
Scientific Opinion on risk based control of biogenic amine formation in fermented foods. EFSA Journal 2011, 9(10):2393. pp. 93.
EFSA, 2012. EFSA Panel on Additives and Products or Substances used in Animal
NU
Feed (FEEDAP). Guidance on the assessment of bacterial susceptibility to
MA
antimicrobials of human and veterinary importance. EFSA Journal 2012 10(6):2740. pp.10.
EFSA, 2013. EFSA BIOHAZ Panel (EFSA Panel on Biological Hazards), 2013.
TE
D
Scientific Opinion on the maintenance of the list of QPS biological agents intentionally added to food and feed (2013 update). EFSA Journal 2013
CE P
11(11):3449, pp.108.
Elisha, B.G., Courvalin, P., 1995. Analysis of genes encoding D-alanine:D-alanine
AC
ligase-related enzymes in Leuconostoc mesenteroides and Lactobacillus spp. Gene 152, 79-83. ESVAC, 2013. European Medicines Agency, European Surveillance of Veterinary. Antimicrobial Consumption Sales of veterinary antimicrobial agents in 25 EU/EEA countries in 2011' (EMA/236501/2013). Canary Wharf London, UK. 97p. Fadda, S., López, C., Vignolo, G., 2010. Role of lactic acid bacteria during meat conditioning and fermentation: peptides generated as sensorial and hygienic biomarkers. Meat Science 86(1), 66-79.
34
ACCEPTED MANUSCRIPT Federici, S., Ciarrocchi, F., Campana, R., Ciandrini, E., Blasi, G., Baffone, W., 2014. Identification and functional traits of lactic acid bacteria isolated from Ciauscolo
T
salami produced in Central Italy. Meat Science 98, 575–584.
IP
Finley, R.L., Collignon, P., Larsson, D.G.J., McEwen, S. A., Li, X.-Z., Gaze, W.H.,
SC R
Reid-Smith, R., Timinouni, M., Graham, D.W., Topp, E., 2013. The Scourge of Antibiotic Resistance: The Important Role of the Environment. Clinical Infectious Diseases 57(5), 704–710.
NU
Fontana, C., Fadda, S., Cocconcelli, P. S., Vignolo, G., 2012. Lactic acid bacteria in meat fermentations. In: Lahtinen, S., Ouwehand, A.C., Salminen, S., Von Wright,
MA
A. (Eds). Lactic acid bacteria-microbiological and functional aspects. 4th Edition. CRCPress. Taylor & Francis Group, UK. pp. 247-264.
TE
D
Forslund, K., Sunagawa, S., Kultima, J.R., Mende, D. R., Arumugam, M., Typas, A., Bork, P., 2013. Country-specific antibiotic use practices impact the human gut
CE P
resistome. Genome Research 23: 1163-1169. Franz, C.M.A.P., Huch, M., Abriouel, H. , Holzapfel. W., Gálvez, A., 2011. Enterococci
AC
as probiotics and their implications in food safety. International Journal of Food Microbiology 151, 125–140. Fraqueza, M.J., Barreto, A.S., 2014. HACCP: Hazard Analysis and Critical Control Points, In: Toldra, F., Hui, Y. H., Astiasaran, I., Sebranek, J., Talon, R., (Eds.). Handbook of Fermented Meat and Poultry, 2nd Edition. Wiley-Blackwell. ISBN: 978-1-118-52269-1, 469p. Galloway-Penã, J., Roh, J.H., Latorre,M., Qin, X., Murray, B.E., 2012. Genomic and SNP analyses demonstrate a distant separation of the hospital and communityassociated clades of Enterococcus faecium. PLoS One 7:e30187.
35
ACCEPTED MANUSCRIPT Gevers, D., Buys, G., Devlieghere, F., Uyttendaele, M., Debevere, O., Swings, E., 2000. Isolation and identification of tetracycline resistant Lactic Acid Bacteria from Pre-
T
packed sliced meat products. Systematic Applied Microbiology 23, 279-284.
IP
Gevers, D., Huys, G., Swings, J., 2003. In vitro conjugal transfer of tetracycline
SC R
resistance from Lactobacillus isolates to other Gram-positive bacteria. FEMS Microbiology Letters 225, 25-130.
Gfeller, K.Y., Roth, M., Meile, L.,Teuber, M., 2003. Sequence and genetic organization
NU
of the 19.3-kb erythromycin- and dalfopristin-resistance plasmid pLME300 from
MA
Lactobacillus fermentum ROT1. Plasmid 50, 190–201. Gueimonde, M., Sánchez, B., Reyes-Gavilán, C.G., Margolles, A., 2013. Antibiotic resistance in probiotic bactéria. Frontiers in Microbiology 4, 202, pp.6. 2011.
TE
D
Guilbaud, M., Zagorec, M., Chaillou, S., Champomier-Vergès, M.C.,
Intraspecies diversity of Lactobacillus sakei response to oxidative stress and
CE P
variability of strain performance in mixed strains challenges. Food Microbiology 29 (2), 197-204.
AC
Haug, M.C., Tanner, S.A., Lacroix, C., Stevens, M.J., Meile, L., 2011. Monitoring horizontal antibiotic resistance gene transferin a colonic fermentation model. FEMS Microbiology Ecology 78, 210-219. Hebert, E. M., Saavedra, L. Taranto, M. P., Mozzi, F., Magni, C., Nader, M. E. F., Font de Valdez, G., Sesma, F. Vignolo, G., Raya, R. R., 2012. Genome Sequence of the Bacteriocin-Producing Lactobacillus curvatus Strain CRL705. Journal of Bacteriology 194 (2), 538-539. Henriques, A.R., Telo da Gama, L., Fraqueza, M.J., 2014. Assessing Listeria monocytogenes presence in Portuguese ready-to-eat meat processing industries based on hygienic and safety audit. Food Research International 63, 81–88.
36
ACCEPTED MANUSCRIPT Holzapfel, W.H., Haberer, P., Geisen, R., Bjorkroth, J., Schillinger, U., 2001. Taxonomy and important features of probiotic microorganisms in food and
T
nutrition. The American Journal of Clinical Nutrition 73, 365S-73S.
IP
Hummel, A. S., Hertel, C., Holzapfel, W. H., Franz, C. M. A. P., 2007. Antibiotic
SC R
Resistances of Starter and Probiotic Strains of Lactic Acid Bacteria. Applied Environmental Microbiology 73(3), 730-739.
Hurtado, A., Reguant, C., Bordons, A., Rozès, N., 2012. Lactic acid bacteria from
NU
fermented table olives. Food Microbiology 31, 1-8.
coagulase-negative
MA
Janssens, M., Myter, N., De Vuyst, L., Leroy, F., 2013. Community dynamics of staphylococci
during
spontaneous
artisan-type
meat
fermentations differ between smoking and moulding treatments. International
TE
D
Journal of Food Microbiology 166 (1), 168–175. Klare, I., Konstabel, C., Werner, G., Huys, G., Vankerckhoven V., Kahlmeter, G.,
CE P
Hildebrandt, B., Muller-Bertling, S., Witte, W., Goossens, H., 2007. Antimicrobial susceptibilities of Lactobacillus, Pediococcus and Lactococcus
AC
human isolates and cultures intended for probiotic or nutritional use. Journal Antimicrobial Chemotheraphy 59, 900-912. Kozacinski, L., Drosinos, E., Caklovica, F., Cocolin, L., Gasparik-Reichardt, J., Slavica Veskovi, S., 2008. Investigation of Microbial Association of Traditionally Fermented Sausages. Microflora in Traditionally Fermented Sausages, Food Technology Biotechnology 46, 1, 93–106. Kumar, A., Schweizer, H. P., 2005. Bacterial resistance to antibiotics: Active efflux and reduced uptake. Advanced Drug Delivery Reviews 57, 1486-1513.
37
ACCEPTED MANUSCRIPT Landeta, G., Curiel, J.A., Carrascosa, A.V., Muñoz, R., de las Rivas, B., 2013. Technological and safety properties of lactic acid bacteria isolated from Spanish
T
dry-cured sausages. Meat Science 95, 272–280.
antibiotics
by
target
modification.
Antimicrobial
Agents
SC R
streptogramin
IP
Leclercq, R., Courvalin, P., 1991. Bacterial resistance to macrolide, lincosamide, and
Chemotheraphy 35(7), 1267–1272.
Leser, T. D., Amenuvor, J. Z., Jensen, T. K., Lindecrona, R. H., Boye, M., Moller, K.,
NU
2002. Culture-Independent Analysis of Gut Bacteria: the Pig Gastrointestinal
MA
Tract Microbiota Revisited. Applied Environmental Microbiology 68, 673-690. Levy, S.B., Marshall, B., 2004. Antibacterial resistance worldwide: causes, challenges and responses. Nature Medicine 10, S122 - S129.
TE
D
Lin, C. F., Fung, Z. F., Wu, C. L., Chung, T. C., 1996. Molecular characterization of a plasmid-borne (pTC82) chloramphenicol resistance determinant (cat-TC) from
CE P
Lactobacillus reuteri G4. Plasmid 36, 2, 116–124. Ludwig, W., Schleifer, K.H., and Whitman, W.B., 2009. Order II. Lactobacillales ord.
AC
nov." In: De Vos, P., Garrity, G.M., Jones, D., Krieg, N.R., Ludwig, W., Rainey, F.A., Schleifer, K.H., Whitman, W.B. (Eds). Bergey's Manual of Systematic Bacteriology, Second edition, vol. 3 (The Firmicutes), Springer, Dordrecht, Heidelberg, London, New York. p. 464. Marshall, B.M., Ochieng, D.J., Levy, S.B., 2009. Commensals: underappreciated reservoir of antibiotic resistance. Microbe 4, 231–238. Martín, B., Corominas, L., Garriga, M., Aymerich, T., 2009. Identification and tracing of Enterococcus spp. by RAPD-PCR in traditional fermented sausages and meat environment. Journal of Applied Microbiology 106(1), 66-77.
38
ACCEPTED MANUSCRIPT Martinez, J. L., 2009. Environmental pollution by antibiotics and by antibiotic resistance determinants. Environmental Pollution, 157, 2893-2902.
T
Martinez, J.L., Rojo, F., 2011. Metabolic regulation of antibiotic resistance. FEMS
IP
microbiology Review 35, 5, 768–789.
SC R
Marty, E., Buchs, J., Eugster-Meier, E., Lacroix, C., Meile, L., 2012. Identification of Staphylococci and dominant Lactic Acid Bacteria in spontaneously fermented Swiss meat products using PCR-RFLP. Food Microbiology 29, 157-166.
NU
Mayrhofer, S., Mair, C., Kneifel, W., Domig, K. J., 2011. Susceptibility of
MA
Bifidobacteria of animal origin to selected antimicrobial agents. Chemotherapy Research and Practice 2011, 989520, pp. 6. Medina, R.B., Oliszewski, R., Abeijón Mukdsi, M.C., Van Nieuwenhove, C.P.,
TE
D
González, S.N., 2011. Sheep and goat’s dairy products from South America: Microbiota and its metabolic activity. Small Ruminant Research 101, 84-91.
CE P
Muscariello, L., Marino, C., Capri, U., Vastano, V., Marasco, R., Sacco, M., 2013. CcpA and three newly identified proteins are involved in biofilm development in
AC
Lactobacillus plantarum. Journal of Basic Microbiology, 53(1):62-71. doi: 10.1002/jobm.201100456. Epub 2012 May 15. Nawaz, M., Wang, J., Zhou, A., Ma, C., Wu, X., Moore, J.E., Millar, B.C., Xu, J., 2011. Characterization and transfer of antibiotic resistance in lactic acid bacteria from fermented food products. Current Microbiology 62, 1081–1089. Oki, K., Rai, A. K., Sumie Sato, S., Watanabe, K., Tamang, J. P., 2011. Lactic acid bacteria isolated from ethnic preserved meat products of the Western Himalayas. Food Microbiology 28, 1308-1315. Palmer, K.L., Godfrey, P., Griggs, A., Kos, V.N., Zucker, J., Cerqueira, G., Gevers, D., Walker, S., Wortman, J., Feldgarden, M., Haas, B., Birren, B., Gilmore, M. S.,
39
ACCEPTED MANUSCRIPT 2012. Comparative genomics of Enterococci: variation in Enterococcus faecalis, clade structure in E. faecium, and defining characteristics of E. gallinarum and E.
T
casseliflavus. MBio. 3:e00318–00311.
IP
Panagou, E.Z., Nychas, G.-J.E., Sofos, J.N., 2013. Types of traditional Greek foods and
SC R
their safety. Food Control 29, 32–41.
Paramithiotis, S., Kagkli, D.-M.; Blana, V. A., Nychas, G.-J. E., Drosinos, E. H., 2008. Identification and characterization of Enterococcus spp. in Greek spontaneous
NU
sausage fermentation. Journal of Food Protection 6, 1244-1247.
MA
Patarata, L., 2002. Caracterização e avaliação da aptidão tecnológica de bactérias do ácido láctico e Micrococcaceae em produtos de salsicharia. Efeito da sua utilização em culturas de arranque e de formulação acidificante no fabrico de
TE
D
linguiça tradicional transmontana. PhD thesis, UTAD, Vila Real, 262 p. Pyörälä, S., Baptiste , K. E., Catry, B., van Duijkeren , E., Greko, C., Moreno, M. A.,
CE P
Pomba, M. C. M. F., Rantala, M., Ružauskas, M., Sanders, P. , E. Threlfall, J., Torren-Edo, J., Törneke, K., 2014. Macrolides and lincosamides in cattle and
AC
pigs: Use and development of antimicrobial resistance. The Veterinary Journal 200, 230-239. Reis, J.A., Paula, A.T., Casarotti, S.N., Penna, A.L.B., 2012. Lactic acid bacteria antimicrobial compounds: Characteristics and applications. Food Engineering Reviews 4, 124-140. Ribeiro, T., Oliveira, M., Fraqueza, M. J., Laukova, A., Elias, M., Tenreiro, R. Barreto, A. S., Semedo-Lemsaddek, T., 2009. Antibiotic resistance and virulence factors among enterococci isolated from chouriço, a traditional Portuguese dry fermented sausage. Journal of Food Protection 74, 465-469.
40
ACCEPTED MANUSCRIPT Rodríguez-Rojas, A., Rodríguez-Beltrán J., Couce, A., Blázquez, J., 2013. Antibiotics and antibiotic resistance: A bitter fight against evolution. International Journal of
T
Medical Microbiology 303, 293-297.
IP
Rojo-Bezares, B., Sáenz, Y., Poeta, P., Zarazaga, M., Ruiz-Larrea, F., Torres, C., 2006.
SC R
Assessment of antibiotic susceptibility within lactic acid bactéria strains isolated from wine. International Journal of Food Microbiology 111, 234–240 Sagoo, S.K., Little, C.L., Greenwood, M., Mithani, V., Grant, K.A., McLauchlin, J., de
NU
Pinna, E., Threlfall, E.J., 2009. Assessment of the microbiological safety of dried
MA
spices and herbs from production and retail premises in the United Kingdom. Food Microbiology 26 (1), 39-43.
Salyers, A.A., Gupta, A., Wang, Y., 2004. Human intestinal bacteria as reservoirs for
TE
D
antibiotic resistance genes. Trends Microbiology 12, 412-416. Sarmah, A.K., Meyer, M. T., Boxall, A.B.A., 2006. A global perspective on the use,
CE P
sales, exposure pathways, occurrence, fate and effects of veterinary antibiotics (VAs) in the environment. Chemosphere 65, 725–759.
AC
Schweiggert, U., Carle, R., Schieber, A., 2007. Conventional and alternative processes for spice production a review. Trends in Food Science & Technology 18, 260268.
Serrano, L.M., Molenaar, D., Wels, M., Teusink, B., Bron, P.A., de Vos, W.M., Smid, E.J., 2007. Thioredoxin reductase is a key factor in the oxidative stress response of Lactobacillus plantarum WCFS1. Microbial Cell Factory 28, 6:29. Shen, J., Wang, Y., Schwarz, S., 2013. Presence and dissemination of the multiresistance gene cfr in Gram-positive and Gram-negative bacteria. The Journal of Antimicrobial Chemotherapy 68, 1697-1706.
41
ACCEPTED MANUSCRIPT Singer, R.S., Finch, R., Wegener, H.C., Bywater, R., Walters, J., Lipsitch, M., 2003. Antibiotic resistance—the interplay between antibiotic use in animals and human
T
beings. The Lancet Infectious Diseases 3, 47-51.
IP
Talon, R., Leroy, S., 2011. Diversity and safety hazards of bacteria involved in meat
SC R
fermentations. Meat Science 89, 303–309.
Talon, R., Leroy, S., Lebert, I., 2007. Microbial ecosystems of traditional fermented meat products: The importance of indigenous starters. Meat Science 77, 55–62.
NU
Tannock, G.W., 2004. A special fondness for lactobacilli. Applied Environmental
MA
Microbiology 70, 3189-3194.
Teale, C.J., 2002. Antimicrobial resistance and the food chain. Journal Applied Microbiology 92 Suppl, 85S-9S.
TE
D
Toldrá, F., Nip, W.-K., Hiu, Y.H., 2007. Dry-fermented sausages: an overview. In: Toldra F. (Ed.). Handbook of Fermented Meat and Poultry, 1st Edition. Blackwell
CE P
Publishing, USA. pp321-325. Toomey, N., Bolton, D., Fanning, S., 2010. Characterization and transferability of
AC
antibiotic resistance genes from lactic acid bacteria isolated from Irish pork and beef abattoirs. Research in Microbiology 161, 127-135. Trigo, M.J., Fraqueza, M.J., 1998. Effect of gamma radiation on microbial population of natural casings. Radiation Physics and Chemistry 52(1-6), 125-128. Tuohy, K.M., Gougoulias, C., Shen, Q., 2009 . Studying the human gut microbiota in the trans-omics era-focus on metagenomics and metabonomics. Current Pharmaceutical Design 15 (13), 1415-1427. Tynkkynen, S., Singh, K.V. and Varmanen, P., 1998. Vancomycin resistance factor of Lactobacillus rhamnosus GG in relation to enterococcal vancomycin resistance (van) genes. International Journal Food Microbiology 41, 195-204.
42
ACCEPTED MANUSCRIPT Urso, R., Comi, G., Cocolin, L., 2006. Ecology of lactic acid bacteria in Italian fermented sausages: isolation, identification and molecular characterization.
T
Systematic and Applied Microbiology 29, 8, 671-680.
IP
van Kranenburg, R.,Kleerebezem,M., van Hylckama Vlieg, J., Ursing, B. M.,
SC R
Boekhorst, J., Smit, B. A., Ayad, E.H.E., Smit, G., Siezen, R.J., 2002. Flavour formation from amino acids by lactic acid bacteria: predictions from genome sequence analysis. International Dairy Journal 12, 111–121.
NU
van Reenen, C. A., Dicks, L. M. T., 2011. Horizontal gene transfer amongst probiotic
MA
lactic acid bacteria and other intestinal microbiota: what are the possibilities? A review. Archives of Microbiology 193(3), 157-168. Vandamme, P., Bruyne1, K., Pot, B., 2014. Lactic acid bacteria : biodiversity and
TE
D
taxonomy Phylogenetics and systematics. In: Holzapfel, W. H., Wood, B.J.B. (Eds.). Lactic Acid Bacteria Biodiversity and Taxonomy. John Wiley & Sons, Ltd,
CE P
UK. pp.31-39.
Verluyten, J., Leroy, F., de Vuyst, L., 2004. Effects of Different Spices Used in
AC
Production of Fermented Sausages on Growth of and Curvacin A Production by Lactobacillus curvatus LTH 1174. Applied and Environmental Microbiology 70 (8), 4807-4813. Wanangkarn A., Liu, D.-C., Swetwiwathana, A., Jindaprasert, A., Phraephaisarn, C., Chumnqoen, W., Tan, F.-J., 2014. Lactic acid bacterial population dynamics during fermentation and storage of Thai fermented sausage according to restriction fragment length polymorphism analysis. International Journal of Food Microbiology 186, 61-67. Werner, G., 2012. Current Trends of Emergence and Spread of Vancomycin-Resistant Enterococci. In: Pana, M. (Edt.) Antibiotic Resistant Bacteria - A Continuous
43
ACCEPTED MANUSCRIPT Challenge in the New Millennium. 306-357p. InTech, Available from: http://www.intechopen.com/books/antibiotic-resistant-bacteria-acontinuous-
T
challenge-in-the-new-millennium/current-trends-of-emergence-and-spread-of-
IP
vancomycinresistant-enterococci
SC R
WHO, 2014. Antimicrobial resistance: global report on surveillance. World Health Organization. Geneva, Switzerland. 232p. ISBN 978 92 4 156474 8. Wright, A. Von, Axelsson, L., 2012. In: Lahtinen, S.; Ouwehand, A.C., Salminen, S.,
NU
Wright, A. Von. (Eds). Lactic Acid Bacteria, Microbiological and Functional
MA
Aspects. 4th Edition. Edited by CRC Press Taylor & Francis Group, US. pp 2-14. Wright, G.D., 2007. The antibiotic resistome: the nexus of chemical and genetic diversity. Nature Reviews Microbiology 5 (3), 175-186.
TE
D
Zeuthen, P., 2007. A historical perspective of meat fermentation. In : Toldra F. (Ed.), Handbook of Fermented Meat and Poultry. 1st Edition. Blackwell Publishing,
CE P
USA. pp. 3-8.
Zhou, J.S., Pillidge, C.J., Gopal, P.K., Gill. H.S.,
2005. Antibiotic susceptibility
AC
profiles of new probiotic Lactobacillus and Bifidobacterium strains. International Journal of Food Microbiology 98, 211 – 217. Zonenschain, D., Rebecchi, A., Morelli, L., 2009. Erythromycin- and tetracyclineresistant lactobacilli in Italian fermented dry sausages. Journal of Applied Microbiology 107, 1559-1568.
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Men
Drying
Time
CR
Health status
TE D
cold
Bacteriostatic effect
Contact material
CE P
Maintenance status
Dryfermented sausage Temperature/time
Smoke nature
Hygiene status
AC
Ingredients
Temperature/Humidity
MA N
Training
US
Initial fecal contamination
Initial contamination
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Raw meat material
T
ACCEPTED MANUSCRIPT
Smoking
Figure 1. Sources and factors involved on selection and spread of antibiotic resistant LAB in dry-fermented sausages.
45
ACCEPTED MANUSCRIPT
Name product
Composition
Main process Conditions
Major known function
LAB Level
pork
short-ripened fermented sausage 30days 20-25°C, cold smoked 2 days
Microorganisms inhibition by acidification
Northeastern region of Thailand
Thai fermented sausage
Beef , bovine liver spleen , roasted rice powder garlic , salt , spices and seasonings
fermented sausage 3 days at room temperature
Acidification pH 4.1
Spain
Dry fermented sausage
pork
Fermented sausage
Swiss
Dry Fermented sausages not named
Western Himalayas/ India and Nepal
Jamma or Geema /Kargyong
wildlife meat (deer, wild boar, chamois) or meat from cattle, sheep and pork ethnic chevron (goat) meat
nd
US
Ciauscolo salami
MA N
Italy
CR
(log cfu/g)
Identification Method
IP
Region/ Country
T
Table 1: Overview of Lactic acid bacteria (LAB) species diversity of dry- fermented meat sausages from different geographical origins.
Species identification by 16S rRNA gene sequencing
Reported LAB species diversity
References
L. sakei/ P. pentosaceus/ L. plantarum/ L. paraplantarum/ E. faecalis/ L. paracasei /L. lactis /L. johnsonii /L. brevis/Lactococcus spp./Carnobacterium spp/ W. helénica/Leuconostoc mesenteroides L. sakei/L. plantarum/ L. mesenteroides L. brevis /P. pentosaceus /Lc. lactis / L. fermentum
Federici et al., 2014
Species identification by 16S rRNA gene sequencing
Acidification, Nitrate reduction activity,Lipolyti c activity
nd
Species identification by 16S rRNA gene sequencing
L. sakei /L. plantarum /L. paracasei/ L.coryniformi/E. faecium
Landeta et al., 2013
Fermentation and ripening conducted at 9-17 ºC, 15 days, cold smoking on last stage
Microorganisms inhibition by acidification (pH 4.6–6.6),
4.6–9.1
L. sakei /L. curvatus / E. faecalis/E. faecium /Pediococcus pentosaceus and others Streptococcus
Marty et al., 2012
Boiling, 15 min. Smoking, 15-20 days uncontrolled temperature and humidity
Acidification (pH 5.5), flavor
7.8-7.5
16S rRNA, genebased PCR – restriction fragment length polymorphism (RFLP) 16S rRNA and phenylalanyltRNA synthase (pheS) genes sequencing
E. durans/E. faecalis/E. faecium/E. hirae, Leuconostoc citreum, Leuc. mesenteroides, P. pentosaceus, and Weissella cibaria
Oki et al., 2011
AC
CE P
TE D
nd
Wanangkarn et al., 2012, 2014
46
ACCEPTED MANUSCRIPT
Composition
Main process Conditions
Major known function
LAB Level (log cfu/g)
Smoking, max. 8 days at temperatures below 37 ºCand with uncontrolled humidity
Aroma and taste, extension of shelf life
Italy
Piacentino salami
Pork meat
Aroma and taste
South-east Europe (Greece, Bosnia and Herzegovina, Croatia, Hungary, Italy and Serbia).
Sudzuk, Sremska, Friuli
pork and beef meat
Fermentation 8 days(RH= 40% to 90% at 15–25°C) Ripening (45 days) at RH =70–90% and 12–19°C. Ripening (28 days)
Italy
Fermented sausage
Spain
Fuet, Chorizo and Salchichon Chouriço
pork meat, lard, sodium chloride, nitrite and nitrate, and black pepper. pork meat
Trás-os-Montes, North Portugal
Pork meat and fat; salt, wine, garlic, bay, eventually paprika
species- and genus-specific primers and 16S rRNA gene sequencing Species identification by 16S rRNA gene sequencing
3-5
phenotypic identification API 50 CHL
Acidification pH=5.62-5.65
8–9
species-specific PCR and DGGE analysis followed by16S rRNA gene sequencing species-specific PCR and 16S rRNA gene sequencing Phenotypic and species specific PCR
MA N
3-9
CE P
Acidification (pH 4.7 to 5.7), aroma and taste
AC
Ripening (2845 days).
nd
CR
pork and poultry
US
Alheira
TE D
North Portugal
Identification Method
Reported LAB species diversity
References
T
Name product
IP
Region/ Country
Cold Ripening
Acidification (pH 5.3 to 6.2), aroma and taste
6.86- 8.99
Cold smoked, 1 to 4 weeks drying at a low temperature
Acidification (pH=5.5), aroma and taste
8
L. plantarum/L. paraplantarum/ L. brevis/ L. rhamnosus/ L. sakei/ L. zeae/ L. paracasei/ Leuconostoc mesenteroides, P. pentosaceus, P. acidilactici, Weissella cibaria/W. viridescens and E.faecium/ E. faecalis L. sakei/ L. curvatus/ L. plantarum/L.brevis/L.rhamnosus, L. paracasei and L. reuteri
Albano et al., 2009
L.sakei/L.curvatus/L.plantarum/L. pentosus/L.rhamnosus/L. brevis/L. paracasei/L. alimentarius/L. fermentum/L. bavaricus; Lac. lactis; P. pentosaceus/P. acidilactici; Leuc. mesenteroides; E. faecium L.sakei/ L.plantarum/ L. curvatus /L. casei/ L. brevis/L.paraplantarum/ Lactococcus garvieae/L. lactis/ Leuconostoc carnosum/ L.mesenteroides Weisella helénica/W. paramesenteroides L. sakei/L.plantarum/L. curvatus Leuconostoc mesenteroides E. faecium
Kozacinski et al., 2008
L. sakei/ L. plantarum
Patarata, 2002
Zonenschain et al., 2009
Urso et al., 2006
Aymerich et al., 2003, 2006
47
ACCEPTED MANUSCRIPT
Gene(s)
Localization
Ampicilin Penicillin
L. plantarum, L. casei, L. salivarius, L. leishmannii, L. acidophilus Lactobacilli
Point mutations
Chromosome
blaZ
E. faecalis
Reference
Not transferable
Reduced penicillin binding to the expressed protein
Danielsen and Wind, 2003
Transposon
transferable
Antibiotic hydrolysis by β lactamases
blaZ
Transposon
transferable
Aquilanti et al., 2007 Werner, 2012
E. faecium
pbp5 gene mutated
chromosome Transposon
Not transferable Transferable
Werner, 2012
Lactobacilli, (L. plantarum) and Leuconostoc mesenteroides E. faecium and E. faecalis
ddl vanX-like gene aad
Chromosome
Not transferable
vanA, vanB, vanD and vanM vanC, vanE, vanL and vanG cat
Transposons Plasmids Chromosome
Transferable
Plasmid
Transferable
Plasmid, Transposons Chromosome
Transferable
Plasmid, transposon
Transferable
Reduced penicillin binding to the expressed protein D-alanine ligase-related enzymes, d- Ddl (alanine:d-alanine) ligase vancomycine D-Ala-D-Lac mediated resistance; D-Ala-D-Ser mediated resistance chloramphenicol acetylation by acetyltransferases ribosomal protection proteins tet(O)/(M)(S) or efflux pump proteins tet(K)/(L) rRNA methylases (Ribosomal methylation
Cloranfenicol
L. acidophilus, L. plantarum
Tetracycline
Lactobacilli E. faecium and E. faecalis
tetM, tetO, tetS tetK, tetL
Lactobacilli Lactococcus
ermB,
MLSR phenotype Erytromycin
MA N
TE D CE P
AC
Vancomycin
Resistance mechanisms
CR
Species
US
Antibiotics
IP
T
Table 2: LAB antibiotic resistance determinants identified.
Risk of transmission
Not transferable
Not transferable
Elisha and Courvalin, 1995, Deghorain et al., 2007 Werner, 2012
Hummel et al., 2007 Ahn et al., 1992 Gevers et al., 2003, Ammor et al., 2008 Werner, 2012 Leclercq and Courvalin, 1991 48
ACCEPTED MANUSCRIPT
lnu(A)
Chromosome
Not transferable
Lincosamide transferase
Transferable
Antibiotic acetylation Transferases
Cauwerts et al., 2007 Gfeller et al., 2003
Quinupristin– dalfopristin Streptogramin
Lactobacilli Lb. fermentum
vat (E)
Plasmid
Enterococcus
lsa
Chromosome
Not transferable
Chromosome
Not transferable
ABC transporter rRNA methylases Enzymatic modification
Dina et al., 2003, Werner, 2012 Klare et al., 2007 Rojo-Bezares et al., 2006
Streptomycin Spectinomycin
Lactobacill, L. plantarum Pediococcus
ant(6) , mutations in genes encoding ribosomal proteins
StreptomycinStreptothricinKanamycin
E. faecium and E. faecalis
aadE-sat4-aphA
Transposon
Transferable
Enzymatic modification
Werner, 2012
GentamicinKanamycin
Lactobacilli, L. plantarun, L.casei, L.delbrueki E. faecium and E. faecalis Lactobacilli
aac(6)-aph(2), ant(6), aph(3)-IIIa
Chromosome
Not transferable
Enzymatic modification
Rojo-Bezares et al., 2006
aac(6')-Ii, aph(2”)-Ie, and ant(6)-Ia Gene mutations on A subunits of TopoisomeraseIV
Transposon
Transferable
Enzymatic modification
Werner, 2012
Chromosome
Not transferable
Hummel et al., 2007
gyrA, gyrB and parE genes qnr gene
Chromosome
Not transferable
Topoisomerases II and IV targets unknown resistance mechanism Topoisomerases II and IV targets
E. faecium
Chromosome
Not transferable
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Lactobacilli
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Lincosamide
E.faecalis
Werner, 2012 Shen et al., 2013
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plasmids Chromosome
Fluoroquinolones
Transferable Not transferable
by methylases) Modification of nucleotide A2058
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E. faecalis
ermA, ermC erm(T) Cfr msrA-C
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E. faecium and
Arsene et al., 2007
MLS phenotype- macrolides, lincosamides and streptogramins.
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Table 3: LAB antibiotic resistance profile isolates from dry fermented meat sausages and their genetic determinants. Origin
Main antibiotic resistance (%)
Resistance profile
Method (MIC or disc diffusion)
Antibioticresistant genes (PCR)
Antibiotic-resistant genes detected (%)
Reference
L. sakei (N=15)
Ciauscolo salami
L. sakei, (100% S resistant N=15; 93% CN resistant N=14; 33% Amp resistant N=5; 13% Tet resistant N=2); 7% Ery resistant N=1)
S-CN-AmpTet- Ery
tet(M), tet(W), tet(K), tet(L), tet(S), erm(A), erm(B), van(A), van(B),
ND
Federici et al., 2014
P. pentosaceus (100% S resistant N=9; 100% CN resistant N=9; 100% Tet resistant N=9); 100% Amp resistant N=9; 98% C resistant N=8; 33% Ery resistant N=3, 11% CD resistant N=1)
S-CN-AmpTet- C-EryCD
ampicillin (64–0.032 mg/ml), chloramphenicol (256– 0.125 mg/ml), clindamycin (32–0.032 mg/ml), erythromycin (32–0.016 mg/ml), gentamycin (2048–1 mg/ml), streptomycin sulfate (4096–2 mg/ml), tetracycline (128–0.064 mg/ml) vancomycin (256–0.125 mg/ml)
L. plantarum (N=5) L. plantarum (80% Tet resistant N=4; 60% S resistant N=3; 40% Ery resistant N=2; 40% C resistant N=2)
Lactococcus (N=1) L. sakei (N=20)
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L. plantarum (N=4)
Dry fermented sausage
CR
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L. paraplantarum (100% Tet resistant N=2; 100% S resistant N=2; 50% Ery resistant N=1; 50% CD resistant N=1; C resistant N=1; 50% CN resistant N=1)
Tet- S- EryAmp-CD-CCN
E. faecalis (100% CD resistant N=2; 100% Ery resistant N=2; 50% C resistant N=1; 50% CN resistant N=1)
CD- Ery- CCN
Lactococcus (100% Amp-C-CN-S-TetVan resistant N=1) L. sakei, (100% Van resistant N=20; 30% Rif resistant N=6; 20% Ai resistant N=4; 15% Tet resistant N=3) L. plantarum (100% Van resistant N=4; 100% Rif resistant N=4; 75% Tet
Amp-C-CNS-Tet-Van Van-Rif -AiTet
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E. faecalis (N=2)
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Tet- S-Ery-C
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L. paraplantarum (N=2)
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P. pentosaceus (N=9)
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Species name and number
Van-Rif - Tet
P. pentosaceus tetM (n=4, 44%) ermB (n=1, 11%)
ND
MIC breackpoints from FEEDAP Panel (EFSA, 2005)
L. paraplantarum erm(B) (n=1, 50%)
E. faecalis erm(B) (n=1, 50%)
ampicillin (10 μg), penicillin G (10 U), vancomycin (30 μg), amikacin (30 μg)1, gentamicin (10 μg),
tetM gene
Lactococcus tet(M) (n=1, 100%) L. sakei, tet(M) (N=2, 67%)
Landeta et al. 2013
L. plantarum, tet(M) (N=0, 0%)
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ACCEPTED MANUSCRIPT
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resistant, N=3)
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L.coryniformis (N=1)
E. faecium (N=19)
L. plantarum (N=12)
E. faecalis (N=20)
Dry fermented sausages Northern Italy: Salame Piacentino PDO
13% Tet resistance (N=4)
Dry fermented sausages North Italy: Piacentino salami (45days of ripening)
L. sakei, (70% Tet resistant N=17; 29% Ery resistant N=7)
Portuguese “chouriço” dry fermented sausage
E. faecalis 65% Ery resistant (N=13), 65% Gen resistant (13 of 20), 60% Tet resistant (N=12), , and 45% Van resistant (9 of 20)
Tet-Rif-CipP-Nit
Tet Tet-Ery
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7% Ery resistance (N=2)
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L. curvatus (N=16)
E. faecium (100% Tet resistant N=19; 100% Rif resistant N=19; 100% Cip resistant N=19, 68% P resistant N=13, 16% Nit resistant N=3)
Tet-Ery
L. curvatus, (62% Tet resistant N=10; 62% Ery resistant N=10)
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L. sakei (N=24)
tetracycline (30 μg), erythromycin (15 μg), clindamycin (2 μg)1, tobramycin (10 μg)1, rifampicin (5 μg) chloramphenicol (30 μg)2, penicillin G (10 U) 2, teicoplanin (30 μg) 2, nitrofurantoine (300 μg) 2, ciprofloxacin (5 μg) 2. Tetracycline MIC value of 32 μg/ml (n=1) Erythromycin MIC value of 64 μg/ml (n=3)
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2
30 isolates Lactobacillus paracasei
Method (MIC or disc diffusion)
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Resistance profile
Antibioticresistant genes (PCR)
Antibiotic-resistant genes detected (%)
Reference
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L. paracasei (N=2)
Main antibiotic resistance (%)
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Origin
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Species name and number
Eritromycine MIC value of ≥1024 μg/ml (n=2) Tetracycline MIC values of 8 µg/ml, and 32 µg/ml for L. plantarum , Erythromycin MIC values of 4 µg/ml
tet(M), tet(W), tet(L), tet(S), erm(A), erm(B),
tet(M), tet(W), tet(L), tet(S), erm(B), erm(C)
L. plantarum (92% Tet resistant N=11; 50% Ery resistant N=6)
Ery- CN-TetVan
vancomycin 30 mg; ampicillin 10 mg; penicillin G 10 U; gentamicin 10 mg; tetracycline 30 mg; and erythromycin 15 mg (disk diffusion method)
erm(B), (pbp5), aac(69)-Ie-aph(299), tet(M), van(A) and van(B)
E. faecium, tet(M) (N=19, 100%) tet (M) (N=4; 100%) erm(B) (N=2; 100%)
L. sakei, tet(M) (N=11, 65%), tet(W) (N=1, 6%) erm(B) (N=5, 71%) L. curvatus, tet(M) (N=7, 70%), tet(W) (N=4, 40%), erm(B) (N=10, 100%) L. plantarum; tet(M) (N=5, 45%, tet(W) (N=4, 36%), tet(S) (N=1, 9%); erm(B) (N=3, 50%); erm(C) (N=2, 33%) erm(B) (n=9, 45%), tet(M) (n=8, 40%), aac(69)Ie-aph(299) (n=8, 40%), and van(A) (n=8, 40%), pbp5 (n=0, 0%)
Comunian et al., 2010
Zonenschain et al., 2009
Ribeiro et al., 2009
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Origin
Main antibiotic resistance (%)
Resistance profile
Method (MIC or disc diffusion)
Antibioticresistant genes (PCR)
Antibiotic-resistant genes detected (%)
Reference
L. sakei (N=185); L. curvatus (N=53); Leuconostoc mesenteroides (N=12)
Dry fermented sausages Spain: chorizo, fuet and salchichon
43.6% ampicillin 1.2% chloramphenicol (30 µg) 98.4% gentamicin (10 µg) 0% erythromycin (15 µg) 0.8% linezolid (30 µg) 29.2% penicillin G 4.4% quinupristin/dalfopristin (15µg) 12% tetracycline (30 µg) 100% vancomycin (30 µg) (disk diffusion method)
Van-CNAmp-P-Tet-C
nd
nd
Aymerich et al., 2006
LAB (N=100)
Dry fermented sausages
55% Tet resistant LAB
Strains were considered resistant if inhibition halos diameters were: ≤19 mm for ampicillin (10 µg), penicillin G (10 U) and linezolid, ≤18 mm for tetracycline, ≤15 mm for quinupristin/ dalfopristin, ≤14 mm for vancomycin, ≤13 mm for chloramphenicol and erythromycin and ≤12 mm for gentamicin. ampicillin (25 pg), erythromycin (10 pg), rifampicin (30 pg) and tetracycline (30 pg)
L. sakei 100%Tet resistant (N=10), L. plantarum 100%Tet resistant (N=8), L. alimentarius 100%Tet resistant (N=3), L. curvatus 100%Tet resistant (N=3)
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CR
US
MA N TE D
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Tet
Gevers et al., 2000
tet(M),tet(O), tet(S), tet(K), and tet(L)
100% tet (M) L. sakei (n=10), L. plantarum (n=8), L. alimentarius (n=3), L. curvatus (n=3)
Gevers et al., 2003
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L. sakei (N=10), L. plantarum (N=8), L. alimentarius (N=3), L. curvatus (N=3)
42.8% resistant towards 3–4 antibiotics
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Species name and number
Legend: 1or 2 respective antibiotic tested on the specie Amp: ampicillin; CD: clindamycin; C: chloramphenicol; CN: gentamycin; S: streptomycin sulfate; Ery: erythromycin; Tet: tetracycline; Van: vancomycin; Rif: rifampicin; Cip: ciprofloxacin; ND- not detected, nd- not determined.
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S0168-1605(15)00238-X doi: 10.1016/j.ijfoodmicro.2015.04.035 FOOD 6900
To appear in:
International Journal of Food Microbiology
Please cite this article as: Fraqueza, Maria Jo˜ao, Antibiotic resistance of lactic acid bacteria isolated from dry-fermented sausages, International Journal of Food Microbiology (2015), doi: 10.1016/j.ijfoodmicro.2015.04.035
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ACCEPTED MANUSCRIPT Antibiotic resistance of lactic acid bacteria isolated from dry-fermented sausages Maria João Fraqueza
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CIISA, Faculty of Veterinary Medicine, University of Lisbon, Avenida da Universidade
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Técnica, Pólo Universitário do Alto da Ajuda, 1300-477 Lisbon, Portugal.
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* Name of corresponding author: Maria João dos Ramos Fraqueza Address: Faculty of Veterinary Medicine. University of Lisbon. CIISA. Av. da
FAX: 351 21 3652889
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Telephone: 351 21 3652884
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Universidade Técnica, Pólo Universitário, Alto da Ajuda,1300-477 Lisbon. Portugal.
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Email: [email protected]
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ACCEPTED MANUSCRIPT Abstract Dry-fermented sausages are meat products highly valued by many consumers.
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Manufacturing process involves fermentation driven by natural microbiota or
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intentionally added starter cultures and further drying. The most relevant fermentative
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microbiota is lactic acid bacteria (LAB) such as Lactobacillus, Pediococcus and Enterococcus, producing mainly lactate and contributing to product preservation. The great diversity of LAB in dry-fermented sausages is linked to manufacturing practices.
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Indigenous starters development is considered to be a very promising field, because it
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allows for high sanitary and sensorial quality of sausage production. LAB have a long history of safe use in fermented food, however, since they are present in human gastrointestinal tract, and are also intentionally added to the diet, concerns
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have been raised about the antimicrobial resistance in these beneficial bacteria. In fact, the food chain has been recognized as one of the key routes of antimicrobial resistance
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transmission from animal to human bacterial populations. The World Health Organization 2014 report on global surveillance of antimicrobial resistance reveals that
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this issue is no longer a future prediction, since evidences establish a link between the antimicrobial drugs use in food-producing animals and the emergence of resistance among common pathogens. This poses a risk to the treatment of nosocomial and community-acquired infections. This review describes the possible sources and transmission routes of antibiotic resistant LAB of dry-fermented sausages, presenting LAB antibiotic resistance profile and related genetic determinants. Whenever LAB are used as starters in dry-fermented sausages processing, safety concerns regarding antimicrobial resistance should be addressed since antibiotic resistant genes could be mobilized and transferred to other bacteria. Key words: Lactic acid bacteria, antibiotic resistance, dry-fermented products, safety.
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ACCEPTED MANUSCRIPT Highlights
Lactic acid bacteria have a long history of safe use in dry-fermented sausage
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Antibiotic resistant lactic acid bacteria have been isolated from dry-fermented
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production and consumption.
sausages.
Interventions at processing level are difficult to prevent the presence of
Care must be taken regarding antibiotic-resistance expressed by strains intended
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to be use as starters.
Acquired resistance on strains mediated by mobile genes may put at risk the
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public health.
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antibiotic resistant strains.
Risk management strategies for food chain are crucial to avoid antibiotic
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Introduction
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resistant lactic acid bacteria.
There is a great diversity of dry-fermented sausage as a result of manufacturing with different raw meat types and origins, formulations, condiments, additives, meat grinding size, casing diameter, smoking and drying periods (Toldrá et al., 2007). Meat sausages preservation is achieved by fermentation with a pH decrease due to lactate production by natural microbiota or added starter cultures. The main fermentative microbiota is lactic acid bacteria (LAB) including Lactobacillus, Pediococcus, Enterococcus, Leuconostoc, Lactococcus and Weissella (Fontana et al., 2012). LAB constitutes a diverse group widely distributed throughout nature, being also 3
ACCEPTED MANUSCRIPT an important component of indigenous microbiota in healthy humans and animals. LAB diversity in dry-fermented sausages’ is linked to manufacturing practices, and it
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has been reported that indigenous starters development is very promising approach
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since it enables sausages’ production with high sanitary and sensory characteristics
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(Talon et al., 2007). However, some issues concerning consumers´ safety have been expressed around this late use of LAB.
LAB have a long history of safe use in fermented food production and consumption that
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support their GRAS (generally recognized as safe) and QPS (qualified presumption of
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safety) status provided by FDA (US Food and Drug administration) and EFSA (European Food safety Authority), respectively. However the detection pf antibiotic resistant (AR) strains among LAB has resulted in their recognition as reservoir of AR
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genes horizontally transmissible to pathogens through the food chain, this being a matter of concern (Devirgiliis et al., 2013; Marshall et al., 2009).
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In fact, the food chain has been recognized as one of the key routes of antimicrobial resistance transmission from animal to human bacterial populations. The World Health
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Organization 2014 report on global surveillance of antimicrobial resistance reveals that this issue is no longer a future prediction since evidences establish a link between antimicrobials drugs use in food-producing animals and the emergence of resistance among common pathogens. This poses a risk to the treatment of nosocomial and community-acquired infections. This review describes the diversity and role of LAB in fermented sausages, stressing safety requirements for LAB regarding the antibiotic resistance issue. The possible sources and transmission routes of antibiotic resistant LAB in dry-fermented meat sausages are discussed and common LAB antibiotic resistance profile of isolates from fermented sausages and related genetic determinants are presented. Finally, some
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ACCEPTED MANUSCRIPT remarks are pointed out considering safety concerns for LAB selected to be used as
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starters in dry-fermented sausages.
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Antibiotic resistance issue: facts and trends
Since the discovery of Penicillin in 1928 and the introduction of the first antimicrobial sulfonamides (1930) (Davies and Davies, 2010), antibiotics have been used, playing a
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decisive role in human health and life expectancy. However, concerns have been raised
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about pathogenic bacteria and their antibiotic resistances. In fact, infections caused by these resistant microorganims are more difficult to treat and have higher costs, due to more intensive and time consuming care needed. According to the recent report of
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WHO (2014), antibiotic resistance within a wide range of infectious agents is a growing public health threat of broad concern to society and multiple sectors, since many of the
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available treatment options for common infections may become ineffective. The resistance to antibiotics is an eventual characteristic in bacterial biomes and can be
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seen as an adaptation result that easily occurs under the effect of an environmental change (Rodríguez-Rojas et al., 2013). Antimicrobial resistance is the bacterial ability to survive and grow in the presence of a chemical molecule that would normally kill them or limit their growth. From the presence of particular resistant genes the bacteria will be able to avoid antimicrobials by major mechanisms described: direct inactivation of the active molecule; loss of bacterial susceptibility to the antimicrobial by modification of the target of action; and reduction of the drug concentration that reaches the target molecule without modification of the compound itself (efflux pump). The antibiotic defence mechanisms of intrinsic resistance are, in most of cases, related to the presence of low affinity targets, absence of targets, innate production of enzymes that
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ACCEPTED MANUSCRIPT inactivate the drug, inaccessibility of the drug into the bacterial cell by decreased drug uptake or extrusion by efflux of drug (Kumar et al., 2005).
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The resistance to a specific antimicrobial drug should be considered ‘intrinsic" or
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‘natural’ when it is inherent to a bacterial species, being present in all its strains. On the
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other hand, resistance is named “acquired”, if a susceptible species’ strain becomes resistant to a specific antimicrobial drug. This can be due either to added genes (genes acquired by the bacteria via gain of exogenous DNA, gene exchange between bacteria)
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or to the mutation of indigenous genes (Ammor et al, 2007; van Reenen and Dicks,
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2011).
Antibiotic resistance genes can be spread from one bacterium to another (Horizontal transfer of genetic material) through several mechanisms. The transfers of DNA by
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transduction (via bacteriophages) or by transformation (when DNA is released from a bacterium and taken up by another) are not believed to be relevant mechanisms of
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antibiotic resistance transfer (Ammor et al., 2007). By contrast, conjugation, i.e., the direct cell-to-cell contact, can potentially achieve horizontal gene transfer, as it has been
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shown to be a genetic information transfer mechanism with a broad host range (Courvalin, 1994).
Intrinsic resistance is estimated to present a minimal potential for horizontal spread (between different bacterial species), as was demonstrated for example with the chromosomal vancomycin resistance determinant of the Lactobacillus rhamnosus strain GG (Tynkkynen et al., 1998). Similar to intrinsic resistance, acquired resistance usually possesses a low risk of horizontal dissemination, when the resistance is a result of a chromosomal mutation. By contrast, acquired resistance is considered to have a higher potential for antibiotic resistance horizontal dissemination, when the resistance genes
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ACCEPTED MANUSCRIPT are present on mobile genetic elements (plasmids and transposons) (Devirgiliis et al., 2013, van Reenen and Dicks, 2011).
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The genetic origin of antibiotic resistance is a controversial topic; usually the antibiotic
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resistance in bacteria from the food chain is attributed to the contact with the
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antimicrobial agent in concern, and consequent development of resistance against the antibiotic (Levy and Marshall, 2004). However, recent studies have demonstrated that antibiotic resistance genes were around long before the human use of antibiotics
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(Bhullar et al., 2012, D’Costa et al., 2011). More than the use of antibiotics, the major
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problem for antibiotic resistance developing links to its misuse. The large scale antibiotic application in human and veterinary medicine, agriculture and aquaculture is pointed out as one of the main causes of the increasing rate of resistant
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bacteria.
Over the last years, human antibiotic use has grown substantially (increasing 36%
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between 2000 and 2010), mainly in developing countries (Boeckel et al., 2014). The largest absolute increases in use were observed for cephalosporins, broad-spectrum
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penicillins and fluoroquinolones. The frequent use of antibiotics in veterinary medicine, to treat or prevent diseases raised concerns about the potential for emerging new antibiotic resistant strains. Bacterial populations isolated from the intestine of animals exposed to antibiotics were found to be five times more likely to be resistant to any given antibiotic than other resistant microbial populations (Sarmah et al., 2006). In fact, the last European Surveillance of Veterinary Antimicrobial Consumption (ESVAC, 2013) report, regarding the overall sales in 2011 for 25 countries, states that the largest proportions, expressed as mg/PCU, were accounted for tetracyclines (37%), penicillins (23%), sulfonamides (11%) and polymyxins (7%).
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ACCEPTED MANUSCRIPT The excessive use of antimicrobial agents in animal husbandry contributes for the selection of resistant bacteria in the food chain (Teale, 2002). The overuse and the
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misuses of antibiotics promote the selection and dissemination of antibiotic resistant
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bacteria and resistance genes, as well as the emergence of new resistant bacteria through
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genetic mutations and gene movements.
The several human activities had a predominant role in the promotion and growth of antibiotic resistance genes environmental reservoirs. In fact, the increased antibiotic
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pollution promoted by human activities had a role in selecting antibiotic resistant
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mutants and favouring the acquisition of antibiotic resistance determinants by genetransfer elements that can be spread among the environmental microbiota (Martinez, 2009). Antibiotic abuse can enrich the population of resistant microorganisms and
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reduce the number of susceptible ones. Bacteria containing resistance genes in mobile genetic elements are a threat to public
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health, since they can act as reservoirs, allowing for resistance genes dissemination especially in dense microbial community environments (Haug et al., 2011; Marty et al.,
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2012; Salyers et al., 2004,). Consequently, foods colonized by bacteria that harbour such transferable antibiotic resistance genes are a major concern. Antibioresistance of foodborne bacteria has aroused great interest because they may act as reservoirs for antibiotic resistance genes (Talon and Leroy, 2011).
Common lactic acid bacteria in fermented meat sausages: their role and diversity
LAB include a diverse group of Gram-positive non-spore forming cocci, coccobacilli or rods, with common morphological, metabolic and physiological characteristics (Batt
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ACCEPTED MANUSCRIPT 2000). They are facultative anaerobic with variable oxygen tolerance in different species.
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LAB growth depends on the presence of fermentable carbohydrates. They are classified
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as homofermentative or heterofermentative based on end products of glucose
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metabolism. While homofermentative LAB convert glucose mainly to lactic acid using the glycolysis (Embden–Meyerhof–Parnas or Embden–Meyerhof) pathway, the heterofermentative LAB use the phosphoketolase (6-phosphogluconate) pathway and
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convert glucose to lactic acid, carbon dioxide and ethanol or acetic acid. LAB are a
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diverse group of organisms with diverse metabolic capacity. This diversity makes them easily adaptable to a wide range of conditions, allowing them to thrive in acid foods’ fermentations. This heterogeneous group of bacteria comprises about 20 genera within
include
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the phylum Firmicutes, class Bacilli, and order Lactobacillales. The different families Aerococcaceae,
Carnobacteriacea,
Enterococcaceae,
Lactobacillaceae,
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Leuconostocaceae, and Streptococcaceae (Ludwig et al., 2009). From a practical point of view, the genera Aerococcus, Carnobacterium, Enterococcus, Lactobacillus,
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Lactococcus, Leuconostoc, Oenococcus, Pediococcus, Streptococcus, Tetragenococcus, Vagococcus and Weissella have been considered as the principal LAB (Axelsson, 2004; Wright and Axelsson, 2012; Vandamme et al., 2014). LAB are widely found in nature, adapted to different carbohydrate rich environmental niches, as well as to terrestrial and marine animals. In food products, LAB are found in dairy products (yoghurt and cheese), in fermented vegetables (olives, sauerkraut), in meat and fermented meats products and in sourdough bread (Coeuret et al. 2003, De Vuyst et al., 2014, Hurtado et al., 2012, Medina et al., 2011, Panagou et al., 2013, Reis et al., 2012,). LAB play a recognized role in fermented foods preservation and safety, thus promoting final products microbial stability. The preservation ability of LAB is
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ACCEPTED MANUSCRIPT based on competition for nutrients and the production of antimicrobial active metabolites such as organic acids (mainly lactic acid and acetic acid), hydrogen
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peroxide and peptidic compounds (bacteriocins) (Reis et al., 2012).
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Bacterial communities coexist in fermented meat products, allowing for microbial
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diversity. Many factors influence the final microbiota of fermented meat sausages. The presence of ecological determinants influences the establishment of a specific microbial consortium that will determine the rate of colonization. The selective influence of
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intrinsic (concentration and availability of nutrients, pH, redox potential, buffering
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capacity, aw, meat structure) and extrinsic (temperature, relative humidity and oxygen availability) factors may determine differences in microbial ecosystem raw meat substrate. This initial microbiota will be influenced by technological particularities used
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in sausage processing and will adapt to this special niche. The addition of ingredients such as sodium chloride, nitrate/nitrite, sugars, wine, condiments (garlic, pepper), as
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well as the particular aw (0.85–0.92), temperature (12–18°C to 24–30°C), oxygen gradient during ripening and smoking application will select a microbiota able to
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develop in fermented meat sausages. Among the different genera belonging to the LAB group, those that are frequently found in fermented sausages are Lactobacillus, Enterococcus, Pediococcus and Leuconostoc (Table 1). Several LAB species well-adapted to the dry-fermented sausages environment (Table 1), were isolated from different fermented sausages produced worldwide and further identified (Adiguzel and Atasever, 2009; Danilović et al., 2011; Federici et al., 2014; Panagou et al., 2013; Wanangkarn et al., 2014,). Meat origin, sausage composition, sugar absence, ripening temperature, smoking or contamination by environmental microbiota during home- or small-scale production units can explain the broad species
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ACCEPTED MANUSCRIPT diversity (Marty et al., 2012; Wanangkarn et al., 2014). The predominant species in dry-fermented sausages are Lactobacillus sakei, Lactobacillus curvatus, Lactobacillus
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plantarum, Leuconostoc mesenteroideus, Pediococcus spp., Enterococcus spp., which
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growth is modulated and adapted to the existing stringent conditions of processing
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(Federici et al., 2014; Wanangkarn et al., 2014). Some Lactobacillus species will dominate because they can develop continuously throughout the fermentation process, since they have a greater acid tolerance and capability to adapt to redox changes than
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other bacterial species. Of note the genome of L. sakei 23K, isolated from a French
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sausage, showed the existence of particularities in its genetic repertoire, absent from other lactobacilli, such as a versatile redox metabolism giving resilience against changing redox and oxygen levels, or energy production pathways not normally
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associated with a lactic acid bacterium (Chaillou et al., 2005). This suggests biological functions that could have a role in species adaptation to meat products. Genes
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potentially responsible for biofilm formation and cellular aggregation that may assist the microorganism to colonize meat surfaces were also identified (Chaillou et al., 2005;
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Muscariello et al., 2013). L. sakei and L. plantarum are surprisingly well equipped to cope with changing oxygen conditions (Guilbaud et al., 2012; Serrano et al., 2007) present in dry-fermented meat sausage’s processing. The genetic diversity is not only found at specific but also at intra-specific level, with well adapted strains to the processing units’ environmental conditions, constituting the so-called “house microbiota” that naturally colonizes meat sausages during processing, being responsible for the spontaneous fermentation of meat with production of lactic acid and other metabolites involved in the development of the sensory characteristics of sausages (flavor, colour, texture), the enhance of safety, stability and the shelf life of the fermented sausages (Fadda et al., 2003; van Kranenburg et al., 2002). The use of small
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ACCEPTED MANUSCRIPT portions of fermented meat (backslopping) for sausage manufacture purposes became the origin of the starters composed of selected strains intentionally added to meat
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sausage to better controlling the fermentation process. The idea of starter cultures
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application in fermented sausages was developed with Jensen and Paddock in 1940 (US
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Patent 2,225,783), becoming increasingly frequent in order to confer protection and standardization of the dry-fermented sausages process (Toldrá et al., 2007). LAB´s protective effects are also attributed to bacteriocins which are ribosomally
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synthesized peptides with antimicrobial activity against food pathogens (Reis et al.,
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2012). For instance, L. curvatus CRL705, a strain isolated from an Argentinean artisanal fermented sausage showed the ability to produce the two-component lactocin 705 bacteriocin and “AL705,” a bacteriocin with antilisterial activity (Hebert et al.,
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2012).
While the protective role of LAB in dry-fermented sausages is demonstrated, the claim
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of LAB strains probiotic effect in dry-fermented dry sausages needs further studies. Full assessment of fermented sausages´ probiotic effects in human health is not possible yet.
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Probiotic LAB in meat products have been marketed since 1998 by German and Japanese producers (Arihara, 2006). However, their usefulness is controversial due to the preliminary nature of most of the scientific results reported so far (de Vuyst et al., 2008).
Safety requirements of LAB isolated from dry-fermented sausages
The early records of fermented meat products are very old. Indeed, sausages have been already cited by Homer in the Odyssey written in the 8th Century Before Christ (Zeuthen, 2007). The know-how of fermented sausages' processing was spread from
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ACCEPTED MANUSCRIPT Greece, Rome and Chine all over the European (particularly Southern Europe), American and Asian continents (Toldrá el al., 2007).
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Since dry-fermented sausages are highly valued and constitute a frequently consumed
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food item, it might be said that LAB are ingested in high levels along with traditional
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dry-fermented sausages consumption. Reported cases of disease related with the most frequent LAB species isolated from these products are, as far as we know, rare. Lactobacillus infections occur at a very low rate in the generally healthy population -
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estimated 1/10 million people over a period of more than a century (Bernardeau et al.,
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2006).
Traditional dry-fermented sausages, and their LAB microbiota, fit in the concept of “history of safe use”, defined in EFSA´s safety assessment guidance (EFSA, 2005), due
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to all evidences of safe production and consumption by genetically diverse human population over the years. So, there is reasonable certainty that no harm will result from
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dry-fermented sausages consumption. According to Bourdichon et al. (2012), to include a microbial specie in a safety list, its presence should be documented, regarding not
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only the occurrence of a specific microorganism in a fermented food product, but also by providing evidences whether the presence of the microorganism is beneficial, fortuitous or undesired. LAB have the GRAS (generally regarded as safe) status provided by the US Food and Drug Administration (FDA) (Chamba and Jamet, 2008). In addition, the European Food Safety Authority (EFSA) has adopted a generic approach to the safety assessment of the microorganisms used in food/feed resulting in the application of the concept 'Qualified Presumption of Safety' (QPS) to a selected group of microorganisms including LAB (EFSA, 2005). Thus, as LAB are inherent components of traditional fermented sausages, the QPS concept is applicable to the defined strains of this microbial group
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ACCEPTED MANUSCRIPT intended to be deliberately added as starters to the raw meat for sausages manufacturing purposes.
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The safety assessment of the strains used as starter or protective cultures for dry-
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fermented sausages' production should discard the presence of antibiotic resistance
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genes in the selected strains to avoid their transmission to commensal or pathogenic bacteria (EFSA, 2012, 2013). Likewise, strains should not produce other virulence factors such as biogenic amines (EFSA, 2011).
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Different factors or circumstances could change the “reasonable certainty of no harm”
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and since LAB are present in human gastrointestinal tract, and are also intentionally added to the food use in the diet, concerns arouse about the antimicrobial resistance of these beneficial bacteria. Bacteria used as starter cultures or protective cultures for dry-
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fermented sausages’ production could possibly contain antibiotic resistance genes, which might be transferred to commensal or pathogenic bacteria and this fact it is not
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accepted by EFSA. Antimicrobial resistance was introduced as a possible safety concern for the assessment and inclusion of bacterial species in the QPS list (EFSA, 2012).
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QPS approach has proved to be a useful tool to harmonize and prioritize safety assessment linked to the taxonomy, familiarity, pathogenicity and end use of the microorganisms (EFSA, 2005, EFSA, 2013). Virulent factors, biogenic amines production (EFSA, 2011) and antibiotic resistance determinants of human and veterinary clinical significance are requirements for QPS qualification, being imperative their absence. EFSA (2013) has stated that a total of 35 Lactobacillus species can be considered to have QPS-status, being present in this group the most frequent species identified also in dry-fermented sausages such as L. sakei, L. curvatus, L. plantarum, L. fermentum, L. brevis, L. rhamnosus and L. alimentarius. In addition to Lactobacillus species, also
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ACCEPTED MANUSCRIPT other LAB species have been granted QPS-status. They include four Leuconostocs, (Ln. citreum, Ln. lactis, Ln. mesenteroides and Ln. pseudomesenteroides), three Pediococci
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(P. acidilactici, P. dextrinicus and P. pentosaceus), Lc. lactis and Streptococcus
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thermophilus. Enterococcus faecium was not recommended for the QPS list in spite of
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the recent scientific knowledge allowing a differentiation of pathogenic from nonpathogenic strains.
The safety of bacteria used as starters or probiotics must be assured. The use of
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Enterococcus as human probiotics remains controversial, in light of the capability of
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most species to turn into opportunistic pathogens (Devirgiliis et al., 2011, Franz et al., 2011).
Enterococcus faecium assessment for QPS has been performed by EFSA (EFSA, 2013),
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that concluded that although a differentiation between the clade A containing strains associated to clinical infections from the clade B composed by commensal strains is
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possible (de Been et al. 2013; Galloway-Peña et al., 2012; Palmer et al., 2012), this knowledge is too recent for a recommendation, considering the past evolution of the
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epidemiology of Enterococcus infections in humans. This scientific information was used by the FEEDAP panel that excluded Enterococcus faecium strains belonging to the hospital-associated clade from the use in animal nutrition because of the hazard they present to vulnerable subpopulations. Strains intended for animal nutrition use shall be susceptible to ampicillin (MIC ≤ 2 mg/L) and must not harbour the genetic virulent elements IS16, hylEfm, and esp (EFSA, 2012). The presence of one or more virulence determinants does not make a strain necessarily pathogenic, although our understanding so far is that mobile genetic elements drive evolution of strains to specialization and adaptation of specific genetic lineages with the hospital niche, with acquisition of genes that increase the cells fitness. Such includes genes for antibiotic resistances, surface
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ACCEPTED MANUSCRIPT structure genes, metabolism genes, recognized virulence factor genes, as well as many currently still undefined virulence-associated genes (Franz et al., 2011). A complete
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picture of all the genes and biological processes that determine pathogenicity it is still
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not elucidated, so case to case study of selected Enterococcus strains should be
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performed.
Sources and possible transmission routes of antibiotic resistant LAB to dry-
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fermented sausages
The food chain can be considered the main route of transmission of antibiotic resistant bacteria between food animals and humans. However, the environment and its impact
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on food animals and human life should be also considered, since the release of antibiotics together with antibiotic resistance bacteria can impact the environmental
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microbiota as well (Martinez, 2009). The possible transmission routes of antibiotic resistant bacteria from food animals to humans and to environment results of the
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application of antibiotic in food animals, as therapeutic, prophylactic, and subtherapeutic uses. This determines a selective pressure on bacteria with the outcoming of the resistant bacteria and their further spread; antibiotic resistance arises as a result of natural selection. Forslund et al. (2013) provided evidences that support an association between antibiotic use in food animals and increased antibiotic-resistant bacteria in humans. However, it is important to note that the resistant bacteria spread from humans itself to other humans and to environment. It is crucial to integrate aspects from human medicine, animal health and environmental considerations (Berkner et al., 2014). Nowadays, the pollution of antibiotic resistance is considered to be done not only by antibiotics and consequent resistant bacteria but also by their resistant genetic
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ACCEPTED MANUSCRIPT determinants persistent on environment (Martinez, 2009). Why is resistance inevitable and where does it come from? The answers to these questions are still limited by our
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current knowledge about this particular issue.
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The dry-fermented sausage microbiome, as was referred in this review, depends on
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several factors; raw meat microbial contamination as well as other secondary and auxiliary ingredients used on sausage formulation will be the start point of antibiotic resistant LAB presence (Figure 1). These resistant bacteria are already present in meat
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coming from a slaughter house (Tommey et al., 2010) and their load will be influenced
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by the delay in cold application. Environmental bacteria are inevitably found in unprocessed meat, even when slaughtering occurs under proper hygienic conditions (Devirgiliis et al., 2011). According to Comunian et al. (2010), the highest number of
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Lactobacillus resistant strains was observed on Salame Piacentino produced in areas where more intensive animal husbandry practices have been applied.
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Natural casings used in meat stuffing will be other potential source of antibiotic resistant LAB. In fact, the usual preparation and preservation of this matrix it is not
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sufficient to eliminate all microorganisms and particularly many species of Lactobacilli and Lactococcus (L. reuteri, L. plantarum, L. brevis and Lc. garvieae) that are present in animal intestinal tract (Devirgiliis et al., 2011; Leser et al., 2002; Pyörälä et al., 2014). It is usual to have loads of 3-4 log cfu.g-1 of LAB in natural casings (Trigo and Fraqueza, 1998). There is also a high probability of Lactobacilli adhesion to casings (Barriga and Piette, 1996). Even with acid addition or other chemical (phosphates) treatments, microorganisms can persist in casings (Bakker et al., 1999). Spices and herbs are natural products and may therefore be burdened with a large number of Gram negative and positive microorganisms (Schweiggert et al., 2007). Among Gram positive microorganism, Enterococci, Staphylococcus and Bacillaceae are
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ACCEPTED MANUSCRIPT reported (Banerjee and Sarkar, 2003, Martín et al., 2009). As many other agricultural commodities, spices are exposed to a wide range of environmental microbial
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contamination during collection, processing, and in the retail markets, namely dust,
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waste water, and animal and even human excreta (Banerjee and Sarkar, 2003). The
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prevention of microbial contamination in dried herbs and spices lies on the application of good hygiene practices during growing, harvesting and processing from farm to fork, and effective decontamination (Sagoo et al., 2009). Spices commonly used for dry-
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fermented sausages production include ground black pepper, paprika, garlic, mace,
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pimento, nutmeg, clove, sage, coriander, oregano and rosemary (Chi and Wu, 2007). They are added as flavorings and coloring agents. However, they are also a source of many other substances, such as sugars, nitrates, and metallic ions (Aguirrezábal et al.,
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1998), and some of them have antioxidant and antibacterial properties. Nutrients and metallic elements present in spices may stimulate LAB growth and/or biochemical
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activity. It has been shown that L. curvatus growth was not stimulated by most of the spices (paprika, nutmeg, rosemary, and mace) although pepper and garlic, as sources of
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trace elements and/or additional carbohydrates may stimulate lactic acid or biomass production. However, bacteria differ in their resistance to a given spice or herb and respective concentration (Verluyten et al., 2004). When 0.70% garlic was added to meat emulsion simulating a fermented sausage matrix, a bactericidal action was observed towards L. curvatus LTH 1174. Nevertheless, this effect depend on garlic concentration, since with 0.35% a regrowth of LAB population was noticed, and L. curvatus LTH 1174 reached a maximum cell concentration of 2.00 g of CDM (cell dry mass). liter−1 after 80 h of growth, higher than values noticed for reference (Verluyten et al., 2004). During production, man may be involved in all operative steps of dry-fermented sausages. The use of good hygiene practices during manufacturing of dry-fermented
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ACCEPTED MANUSCRIPT sausages is essential to avoid the transmission of potential antibiotic resistant LAB present in the gut microbiota of processing handlers (Tuohy et al., 2009). In this regard,
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handler’s health status assessment and proper training will be important to communicate
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and efficiently implement preventive measures (Fraqueza and Barreto, 2014; Henriques
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et al., 2014).
The persistence of LAB in industrial plant´s environment is stated by several authors (Talon et al., 2007). LAB will persist after all the biocide stress settled by the hygiene
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program application, which aims to eliminate faecal contaminants, but will select the
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resistant ones. What it is still not known is the possible impact of practices selecting the antibiotic resistant LAB strains present in plant’s environment. The microbiome of dry-fermented sausages is complex and will be stretched by
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smoking and drying steps. It can be admitted that smoke´s phenolic and alcoholic compounds transmitted to the fermented sausage might influence LAB development
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but, according to Janssens et al. (2013), following fermentation, the bacterial communities were not perturbed by the smoking treatment. In particular, L. sakei
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remained dominant throughout the ripening stage and prevailed in the end-products. However, uncertainty remains about the modulation effect of these hurdles on antibiotic resistant strains of L. sakei or other predominant species. Antibiotic resistant LAB may be present in dry-fermented sausage’s process by, for example, contamination of raw materials and ingredients, faecal contamination of the process, recontamination by improper handling, or lack of a microbial destructive treatment step (which is the case in a traditional dry-fermented sausage process). Also, antibiotic resistant bacteria elimination is not a guaranty of resistant determinants exclusion. But, the risk of antibiotic resistance transmission via food chain could be the same as for foodborne pathogens? So far, as a preventive measure related to food
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ACCEPTED MANUSCRIPT processes, it was stated that, the risk of antibiotic resistance bacteria transmission could be considerably reduced with proper food handling, good hygiene practices and good
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manufacturing practices (Singer et al., 2003). The accomplishment of standard
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operating procedures such as the selection and control of ingredient’s suppliers is
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important, but in a preventive food safety system this is not enough. Precise knowledge and understanding of how manufacturing conditions (low and high temperatures, water activity (aw), oxygen, carbon source availability, acidity, chemicals or other
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microorganisms presence) may affect antibiotic resistant LAB strains is needed. In fact,
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bacterial metabolism situation is highly relevant for antibiotic susceptibility (Martinez and Rojo, 2011). Membrane permeability is the first step in the crosstalk between bacteria and their surrounding environment, in order to optimize cellular metabolism as
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a function of environmental conditions. Because of this, the expression of porins and modifications in the lipid composition of bacterial membranes are tightly regulated in
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response to extracellular inputs. Since antibiotics co-opt bacterial transporters for their entry into bacterial cells, changes in the transporters’ composition due to adjustment of
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bacterial metabolism to an environmental shift might challenge the antibiotic susceptibility (Martinez and Rojo, 2011). Dry-fermented sausages provide an environment in which close contact among bacteria could facilitate horizontal genetic transfer. The potential of LAB to serve as hosts for antibiotic-resistance genes, with the risk of gene transfer (Devirgiliis et al., 2013; Gevers et al., 2003; Nawaz et al., 2011) to many other LAB or pathogenic bacteria present in dry-fermented sausage should be considered, to assure the principle of precaution.
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ACCEPTED MANUSCRIPT Antibiotic resistance profile of LAB isolated from dry-fermented sausages and
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detection of particular genes causing resistance
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Knowledge concerning the safety of indigenous or non starter LAB from dry-fermented
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sausages is relevant for the selection and application of a starter or protective culture and for the quality improvement of fermented meat products production. Antimicrobial resistance assessment should be performed in Lactobacilli and other LAB naturally
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involved in sausages fermentation used as starters, because they may act as reservoirs
technological
interest
should
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for antibiotic-resistance genes. Safety assessment requirements for LAB strains of include
the
characterization
of
the
antibiotic
resistance/susceptibility profile. In addition, the potential transmission of the antibiotic
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resistance(s) of medical interest detected should be also determined. The antibiotic susceptibility of LAB isolated from dry-fermented sausages is usually performed
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according to the Clinical and Laboratory Standards Institute guidelines (CLSI, 2013). However, the assessment of the suitability for QPS status of strains intended to use as
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starters should follow the EFSA guidance documents (EFSA, 2012, 2013) to identify the potential resistance to antimicrobials of human and veterinary use. LAB possesses a broad spectrum of natural (intrinsic) and acquired antibiotic resistances and some of the antibiotic resistance determinants identified in LAB are presented in Table 2. The vancomycin-resistant phenotype of some Lactobacillus is perhaps the best characterized intrinsic resistance in LAB. Several Lactobacillus, Leuconostoc and Pediococcus species are intrinsically resistant to vancomycin due to the replacement of the terminal D-alanine residue by D-lactate or D-serine in the muramylpentapeptide (Table 2), preventing vancomycin binding (Delcour et al., 1999).
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ACCEPTED MANUSCRIPT This resistance is chromosomally encoded and not inducible or transferable (Gueimonde et al., 2013).
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LAB resistance to aminoglycosides (neomycin, kanamycin, streptomycin) is also
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considered intrinsic being attributed to the absence of cytochrome-mediated electron
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transport, which mediates drug uptake (Charteris et al., 2001, Danielsen and Wind, 2003).
According to Hummel et al. (2007), Lactobacilli are also naturally resistant to
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quinolones (ciprofloxacin, norfloxacin, nalidixic acid) by a currently unknown
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resistance mechanism (Table 2).
Enterococcus appears to be intrinsically resistant to semysintethic penicillins (oxacillin), cephalosporins of all classes, monobactams and polymixins. The resistance
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is due to the inhibition of penicillin-binding proteins by β-lactam antibiotics. The resistance to streptogramin A/B combination (quinupristin/dalfopristin) is mediated by
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the expression of an ABC porter designated lsa (Table 2; Werner, 2012). The resistance to fluoroquinolones by Enterococcus faecalis is associated with expression of
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chromosomal qnr homologues (Arsene and Leclerq, 2007). Lactobacilli have a high natural resistance to other antibiotics such as bacitracin, cefoxitin, metronidazole, nitrofurantoin and sulphadiazine (Bernardeau et al., 2008; Danielsen and Wind, 2003; Tynkkynen et al., 1998; Zhou et al. 2005). Nucleic acid synthesis inhibitors resistance, as observed for trimethoprim, seems to be intrinsic, although further characterizations are required on this topic (Ammor et al., 2008). The intrinsic antibiotic resistance presented by Lactobacilli against frequently used antibiotics used in human treatments, such as quinolones, glycopeptides and aminoglycosides, could be desirable since their beneficial use help them to maintain gastrointestinal tract balance in antibiotic-induced diarrhea cases (Charteris et al. 2001).
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ACCEPTED MANUSCRIPT However, this must be carefully addressed since resistant genotypes also arise from scratch by mutation. The dynamics of how the resistome evolves and changes are
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presently not well understood (Berkner et al., 2014). The presence of intrinsic antibiotic
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resistance genes is not a major safety concern itself, as long as the genes are not
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mobilized and transferred to other bacteria.
Apart from the large spectrum of intrinsic resistances presented by LAB, this bacterial group has the potential to acquire resistance to all antimicrobial drugs available. Many
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studies described the presence of antimicrobial resistance in LAB, their mechanisms of
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resistance acquisition and determinants evolved (Table 2). Resistances could be the result of point mutations of housekeeping genes selected under antibiotic pressure and spread by clonal dissemination (vertically) but can be caused by acquired determinants
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(ex. tet, erm, van, bla) spread horizontally when located on mobile elements such as plasmids or transposons (Table 2) (Ammor et al., 2007; Danielsen et al., 2002;
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Deghorain et al., 2007; Gevers et al., 2003, Hummel et al., 2007; Werner, 2012). LAB have been found to be susceptible to cell wall synthesis inhibitors, like penicillins
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and ampicillin (Danielsen and Wind, 2003). For instance, penicillin resistance in E. faecalis is linked to the expression of β-lactamases while for E. faecium this resistance is mediated by a point mutation in the houseeking php5gene (Table 2; Werner, 2012). Lactobacilli are usually susceptible to antibiotics that inhibit protein synthesis such as chloramphenicol, erythromycin, quinupristin/dalfopristin, lincomycin, clindamycin and tetracyclines (Aymerich et al., 2006; Comunian et al., 2010; Federici et al., 2014; Hummel et al., 2007; Landeta et al., 2013). Antibiotic resistance characterization of Lactobacilli isolated from dry-fermented sausages is getting more attention and the most assessed antibiotics were tetracycline and erythromycin, followed by chloramphenicol, streptomycin, ampicillin, vancomycin,
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ACCEPTED MANUSCRIPT and clindamycin (Table 3). Indeed, antibiotic multi-resistant Lactobacilli have been isolated from dry-fermented sausages as reported by Aymerich et al. (2006). L. sakei, L.
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curvatus and Leuconostoc mesenteroides isolates from chorizo, fuet and salchichon
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were resistant to vancomycin (100%), 98% to gentamicin and 43% to ampicillin. All
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isolates were susceptible to erythromycin and only two L. sakei isolates showed resistance to linezolid. Tetracycline resistant isolates were only detected at low percentages (12% of average) (Table 3).
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L. sakei, Pediococcus pentosaceus, L. plantarum, L. paraplantarum, and Lactococcus
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isolates from a typical fermented Italian sausage presented a high resistance frequency to streptomycin and gentamycin, with 88.46% and 69.23% respectively (Federici et al., 2014). However, Lactobacilli were particularly sensitive to clindamycin (84.62%) and
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erythromycin (76.92%). While 13% of L. sakei presented resistance to tetracycline, the others Lactobacilli were 80-100% resistant. Of note, most of the L. sakei isolated in
antibiotic
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traditional dry-fermented sausages from South Portugal were susceptible to several tested,
namely
cloranfenicol,
quinupristin–dalfopristin,
lincomycin,
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erythromycin, rifampicim, showing 19% resistance to tetracycline, 56% to gentamicin and 59% to penicillin. All L. sakei were resistant to vancomycin. The L. plantarum strains, also isolated in the same products, presented the same intrinsic resistance to vancomycin and a higher frequency of resistance to tetracycline (25%), lincomycin (50%) and penicillin (81%) (Fraqueza et al., data not published). Gevers and coauthors (2000, 2003) reported the highest levels of resistance to tetracycline (55%) on Lactobacilli strains isolated from dry-fermented sausages (Table 3). In general, the predominant species isolated from dry-fermented sausages, such as L. sakei had a resistance rate to tetracycline of 12-70%, while L. plantarum presented frequencies of 75-80% (Aymerich et al., 2006; Federici et al., 2014; Gevers et al., 2000;
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ACCEPTED MANUSCRIPT Landeta et al. 2013; Zonenschain et al., 2009). Most of the studies conducted with Lactobacilli isolates from dry-fermented sausages had a particular interest on
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tetracycline or erythromycin resistance assessing the presence of genes tet (including
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tet(M), tet(O), tet(S), tet(W), tet(K), tet(L)) and erm (including ermA, ermB and ermC).
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So far, the most common resistance genes detected in LAB isolates from dry-fermented sausages, were tet(M), tet(W), and tet(S) for tetracycline and erm(B) and erm(C) for erythromycin resistance (Table 3) (Gevers et al., 2003, Zonenschain et al., 2009). For L.
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sakei, L. alimentarius and L. plantarum strains isolated from fermented sausages with
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resistance to tetracycline was demonstrated to harbor a tetM gene localized in a plasmid (Gevers et al., 2003). The tetM gene can also be linked to a family of transposons known for its ability to perform conjugative transposition with direct transfer between
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different bacteria. Lactobacillus spp. can act as reservoir of acquired antibiotic resistance genes that can be disseminated to other bacteria and exchanged by bacteria
al., 2009).
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from many different ecosystems and also between humans and animals (Devirgiliis et
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Scarce information about resistance to chloramphenicol in LAB from dry-fermented sausage is available (Aymerich et al., 2006). Nevertheless, Hummel et al. (2007) reported that the cat gene, encoding for chloramphenicol acetyltransferase, was not expressed in Lactobacilli from dry-fermented sausages. By contrast, this gene was detected in L. reuteri (Lin et al., 1996), L. acidophilus and L. delbrueckii subsp. bulgaricus (Hummel et al., 2007), L. johnsonii (Mayrhofer et al., 2010) and L. plantarum (Ahn et al., 1992) isolated from different foods. E. faecium and E. faecalis are common species in sausage fermentations (Table 3) and show a wide profile of antibiotic resistance (gentamycin, tetracyclin, clindamycin, vancomycin, cloranfenicol, ciprofloxacin, penicillin and nitrofurantoine). In particular,
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ACCEPTED MANUSCRIPT the genes genes erm(B), aac(69)-Ie-aph(299), tet(M) and van(A) have been detected in some E. faecalis strains (Ribeiro et al., 2009), while the tetM gene was present in all E.
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faecium strains (Landeta et al., 2013).
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Since this species may play a role in fermentation and contribute to the uniqueness of some dry-fermented sausages, their presence poses some concern regarding their potential pathogenicity and the risk of gene resistance transmission via the food chain,
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particularly if strain selection to be used as starters is considered.
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Genotyping methods to assess resistant isolates include different PCR –based methods, southern hybridization, plasmid profiling and microarray (Ammor et al., 2008; Aquilanti et al., 2007). The situation is clearer when there is an agreement of
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phenotypic and genotypic resistance patterns. However, a phenotypically resistant bacterium strain may be genotypically “susceptible”. This is usually due to the fact that
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appropriate genes are not included in the test patterns, or that there are unknown resistance genes. In contrast, a susceptible phenotype may also carry silent genes, which
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are observed with genotyping. The silence of antibiotic resistance may be caused by down-regulation in a promoter region or by other mechanisms. Despite of their “silence”, they still could be a potential concern, since they could be transferred to other species in which they would be activated. It is clear that further work must be performed in order to well characterize the resistance phenotype and genotype of LAB strains intended to be used as starters in dryfermented sausages.
Final Remarks
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ACCEPTED MANUSCRIPT LAB have a long history of safe use in dry-fermented sausage production and consumption. However, antibiotic resistant LAB have been isolated from this fermented
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product.
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There are increasing evidences supporting the crucial role of foodborne LAB as
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reservoir of AR genes horizontally transmissible to pathogens through the food chain. Only resistance acquired by mutation or horizontal gene transfer poses a risk for public health.
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L. sakei and L. plantarum are the predominant species in dry-fermented sausages
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microbiota. Accordingly, special care should be taken regarding the antibiotic resistance profile of the strains prior their use as starters in dry-fermented sausages manufacturing. LAB antibiotic resistance expression without detection of known genes highlight the
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need to develop methods well adapted to the variation in the nucleotide sequence of the resistance gene in question, or the assessment of other genes that may confer resistance
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to the same antibiotic. Furthermore, differences in resistance phenotypes may be due to non-functional and / or silent genes.
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It is important to assess the real risk of harbouring a high load of LAB with AR genes in dry-fermented sausages and in the human gut. This will allow the adoption of specific management strategies throughout the food chain to diminish or avoid the presence of antibiotic resistant LAB in dry-fermented sausages. Since it is a multifactorial problem, it should be faced integrating environmental aspects and the use of antibiotic in food animals and in humans.
Acknowledgements The author wish to thank the Centro de Investigação Interdisciplinar em Sanidade Animal (CIISA) for logistic support and the financial support from the Fundação para a Ciência e a Tecnologia (FCT) project “Portuguese traditional meat products: strategies 27
ACCEPTED MANUSCRIPT to improve safety and quality” (PTDC/AGR-ALI/119075/2010). We gratefully thank
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Fernando Bernardo by all moments of helpful discussion during manuscript preparation.
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References
Adiguzel, G.C., Atasever, M., 2009. Phenotypic and genotypic characterization of lactic acid bacteria isolated from Turkish dry fermented sausage. Romanian
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Biotechnological Letters 14 (1), 4130-4138.
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Aguirrezábal, M., Mateo, J., Domínguez, C., Zumalacárregui, J. M., 1998. Spanish paprika and garlic as sources of compounds of technological interest for the production of dry fermented sausages. Science des Aliments 18, 409-414.
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D
Ahn, C., Collins-Thompson, D., Duncan, C., Stiles, M.E., 1992. Mobilization and location of the genetic determinant of chloram-phenicol resistance from
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Lactobacillus plantarum caTC2R. Plasmid 27, 169–176. Albano, H., van Reenen, C. A., Todorov , S. D., Cruz, D., Fraga, L., Hogg, T., Dicks, L.
AC
M.T., Teixeira, P., 2009. Phenotypic and genetic heterogeneity of lactic acid bacteria isolated from ‘‘Alheira”, a traditional fermented sausage produced in Portugal. Meat Science 82, 389–398. Ammor, M. S., Mayo, B., 2007. Selection criteria for lactic acid bacteria to be used as functional starter cultures in dry sausage production: An update. Meat Science 76, 138-146. Ammor, M.S., Flórez, A.B., Van Hoek, A.H.A.M., de los Reyes-Gavilán, C.G., Aarts, H.J.M., Margolles, A., 2008. Molecular characterization of intrinsic and acquired antibiotic resistance in lactic acid bacteria and bifidobacteria. Journal of Molecular Microbiology and Biotechnology 14, 6–15.
28
ACCEPTED MANUSCRIPT Aquilanti, L., Garofalo, C., Osimani, A., Silvestri, G., Vignaroli, C., Clementi, F., 2007. Isolation and molecular characterization of antibiotic-resistant lactic acid bacteria
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from poultry and swine meat products. Journal of Food Protection 70, 557–565.
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Arihara, K., 2006. Strategies for designing novel functional meat products. Meat
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Science 74, 219–229.
Arsene, S., Leclerq, R., 2007. Role of a qnr-like gene in the intrinsic resistanec of Enterococcus faecalis to fluoroquinolones. Antimicrobial Agents Chemotherapy
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51, 3254-3258.
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Axelsson, L., 2004. Lactic Acid Bacteria: Classification and Physiology. In: Salminen, S., von Wright, A. and Ouwehand, A. (Eds.) Lactic Acid Bacteria. Microbiological and Functional Aspects. New York: Marcel Dekker Inc. pp. 1-66.
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Aymerich T., Martín, B. , Garriga, M., Hugas, M., 2003. Microbial Quality and Direct PCR Identification of Lactic Acid Bacteria and Nonpathogenic Staphylococci
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from Artisanal Low-Acid Sausages. Applied and Environmental Microbiology 69, 8, 4583–4594.
AC
Aymerich T., Martin, B.; Garriga, M., Vidal-Carou, M.C., Bover-Cid, S., Hugas, M., 2006. Safety properties and molecular strain typing of lactic acid bacteria from slightly fermented sausages. Journal of Applied Microbiology 100, 1, 40–49. Bakker, W.A.M., Houben, J.H., Koolmees, P.A., Bindrich, U., Sprehe, L., 1999. Effect of initial mild curing, with additives, of hog and sheep sausage casings on their microbial quality and mechanical properties after storage at difference temperatures. Meat Science 51, 163-174. Banerjee, M., Sarkar, P. K., 2003. Microbiological quality of some retail spices in India. Food Research International 36, 469-474.
29
ACCEPTED MANUSCRIPT Barriga, M. I., Piette, J. P. G., 1996. Reduction of adhesion of a Lactobacillus sp. to collagen sausage casing by proteins. Food Research International 29 (34), 249-
T
251.
IP
Batt, C.A., 2000. Lactococcus: Introduction. In: Robinson, R.K., Batt, C.A. and Patel,
SC R
P.D. (Eds). Encyclopedia of Food Microbiology. London, U.K.: Academic Press. pp. 1164-1166.
Berkner, S., Konradi, S., Schönfeld, J., 2014. Antibiotic resistance and the environment-
NU
there and back again. EMBO reports 15 (7), 740-744.
MA
Bernardeau, M., Gueguen, M., Vernoux, J.P., 2006. Beneficial lactobacilli in food and feed: long-term use, biodiversity and proposals for specific and realistic safety assessments. FEMS Microbiology Reviews 30 (4), 487–513.
TE
D
Bernardeau, M., Vernoux, J.P., Henri-Dubernet, S., Guégen, M., 2008. Safety assessment of dairy microorganisms: The Lactobacillus genus. International
CE P
Journal of Food Microbiology 126, 278-285. Bhullar, K., Waglechner, N., Pawlowski, A., Koteva, K., Bank, E.D., Johnston, M.D., Wright, G.D., 2012. Antibiotic Resistance Is Prevalent in an
AC
Barton, H.A.,
Isolated Cave Microbiome, PLoS ONE 7(4), e34953. Boeckel, T. P. Van, Gandra, S., Ashok, A., Caudron, Q., Grenfell, B. T., Levin, S. A. Laxminarayan, R., 2014. Global antibiotic consumption 2000 to 2010: an analysis of national pharmaceutical sales data. The Lancet Infectious diseases 14, 742-750. Bourdichon, F., Casaregola, S., Farrokh, C., Frisvad, J. C., Gerds, M. L., Hammes , W. P., Harnett , J., Huys, G., Laulund, S., Ouwehand, A., Powell, I. B., Prajapati, J. B., Seto, Y., Schure, E. T., Van Boven, A., Vankerckhoven, V., Zgoda, A., Tuijtelaars, S., Hansen, E. B., 2012. Food fermentations: Microorganisms with
30
ACCEPTED MANUSCRIPT technological beneficial use. International Journal of Food Microbiology 154, 8797.
T
Cauwerts, K., Decostere, A., De Graef, E.M., Haesebrouck, F., Pasmans, F., 2007. High
IP
prevalence of tetracycline resistance in Enterococcus isolates from broilers
SC R
carrying the erm(B) gene. Avian Pathology 36, 395-399.
Chaillou, S., Champomier-Verge`s, M.-C., Cornet, M., Crutz-Le Coq, A.-M., Dudez, A.-M., Martin, V., Beaufils, S., Darbon-Ronge`re, E.,
Bossy, R., Loux, V.,
NU
Zagorec, M., 2005. The complete genome sequence of the meat-borne lactic acid
MA
bacterium Lactobacillus sakei 23K. Nature Biotechnology 23 (12), 1527-1533. Chamba, J. F., Jamet, E., 2008. Contribution to the safety assessment of technological microflora found in fermented dairy products. International Journal of Food
TE
D
Microbiology 126, 263-266.
Charteris, W. P., Kelley, P. M., Morelli, L., Collins, J. K., 2001. Gradient diffusion
CE P
antibiotic susceptibility testing of potentially probiotic lactobacilli. Journal of Food Protection 64, 2007-2014.
AC
Chi, S.-P., Wu, Y.-C., 2007. Spices and seasonings, In: Toldrá, F. (Ed.). Handbook of Fermented Meat and Poultry, 1st Edition. Blackwell Publishing. USA. pp. 87-100. Chopra, I., Roberts. M., 2001. Tetracycline antibiotics: mode of action, applications, molecular biology, and epidemiology of bacterial resistance. Microbiology and Molecular Biology Reviews 65, 232-260. CLSI, 2013. Clinical and Laboratory Standards Institute (CLSI). Performance standards for Antimicrobial susceptibility testing. Clinical and Laboratory Standard Institute, CLSI document M100-S23- Twenty third Informational supplement. CLSI, Wayne, Pennsylvania.
31
ACCEPTED MANUSCRIPT Coeuret, V., Dubernet, S., Bernardeau, M., Gueguen, M., Vernoux, J. P., 2003. Isolation, characterisation and identification of lactobacilli focusing mainly on
T
cheeses and other dairy products. Lait 83, 269-306.
IP
Comunian, R., Daga, E., Dupré, I., Paba, A., Devirgiliis, C., Piccioni, V., Perozzi, G.,
SC R
Zonenschain, D., Rebecchi, A., Morelli, L., Lorentiis, A.D., Giraffa, G., 2010. Susceptibility to tetracycline and erythromycin of Lactobacillus paracasei strains isolated from traditional Italian fermented foods. International Journal of Food
NU
Microbiology 138, 151-156.
MA
Courvalin, P., 1994. Transfer of antibiotic resistance genes between gram-positive and gram-negative bacteria. Antimicrobial agents and chemotherapy 38 (7), 14471451.
TE
D
Cox, G., Whright, G. D., 2013. Intrinsic antibiotic resistance: Mechanisms, origins, challenges and solutions. International Journal of Medical Microbiology 303, 287-
CE P
292.
Danielsen , M., 2002. Characterization of the tetracycline resistance plasmid pMD5057
AC
from Lactobacillus plantarum 5057 reveals a composite structure. Plasmid 48, 98103.
Danielsen, M., Wind, A. A., 2003. Susceptibility of Lactobacillus ssp. to antimicrobial agents. International Journal of Food Microbiology 82,1-11. Danilović, B., Joković, N., Petrović, L., Veljović, K., Tolinački, M., Savić, D., 2011. The characterisation of lactic acid bacteria during the fermentation of an artisan Serbian sausage (Petrovská Klobása). Meat Science 88, 668–674. Davies J., Davies, D., 2010. Origins and Evolution of Antibiotic Resistance Microbiology and Molecular Biology Reviews 74(3),417-433.
32
ACCEPTED MANUSCRIPT D'Costa, V.M., King, C.E., Kalan, L., Morar, M., Sung, W.W., Schwarz, C., Froese, D., Zazula, G., Calmels, F., Debruyne, R., Golding, G.B., Poinar, H.N., Wright, G.D.,
T
2011. Antibiotic resistance is ancient. Nature 31, 477, 457-461.
IP
de Been, M., van Schaik, W., Cheng, L., Corander, J., Willems, R.J., 2013. Recent
SC R
recombination events in the core genome are associated with adaptive evolution in Enterococcus faecium. Genome Biololy Evolution 5(8), 1524–1535 De Vuyst, L., Falony, G., Leroy, F., 2008. Probiotics in fermented sausages. Meat
NU
Science 80, 75–78.
MA
De Vuyst, L., Van Kerrebroeck, S., Harth, H., Huys, G., Daniel, H.-M., Weckx S., 2014. Microbial ecology of sourdough fermentations: Diverse or uniform? Food Microbiology 37, 11-29.
TE
D
Deghorain, M., Goffin, P., Fontaine, L., Mainardi, J.-L., Daniel, R., Errington, J., Hallet, B., Hols, P., 2007. Selectivity for D-Lactate Incorporation into the
CE P
Peptidoglycan Precursors of Lactobacillus plantarum: Role of Aad a VanX-Like D-Alanyl-D-Alanine Dipeptidase. Journal of Bacteriology 189, 4332–4337.
AC
Delcour, J., Ferain, T., Deghorain, M., Palumbo, E., Hols, P., 1999. The biosynthesis and functionality of the cell-wall of lactic acid bacteria. Antonie Van Leeuwenhoek 76, 159–184. Devirgiliis, C., Barile, S., Perozzi, G., 2011. Antibiotic resistance determinants in the interplay between food and gut microbiota. Genes and Nutrition 6, 275–284. Devirgiliis, C., Zinno P., Perozzi G. 2013. Update on antibiotic resistance in foodborne Lactobacillus and Lactococcus species. Frontiers in Microbiology 4, 301. Dina, J., Malbruny, B., Leclercq, R., 2003. Nonsense Mutations in the lsa-Like Gene in Enterococcus faecalis Isolates Susceptible to Lincosamides and Streptogramins A. Antimicrobial Agents and Chemotherapy 47, 2307–2309.
33
ACCEPTED MANUSCRIPT EFSA, 2005. QPS. Qualified Presumption of Safety of Micro-organisms in Food and Feed. EFSA Scientific Colloquium Summary Report. European Food Safety
T
Authority – October 2005. Parma, Italy. ISBN 92-9199-012-4. pp. 143.
IP
EFSA, 2011. EFSA Panel on Biological Hazards (BIOHAZ); Scientific Opinion on
SC R
Scientific Opinion on risk based control of biogenic amine formation in fermented foods. EFSA Journal 2011, 9(10):2393. pp. 93.
EFSA, 2012. EFSA Panel on Additives and Products or Substances used in Animal
NU
Feed (FEEDAP). Guidance on the assessment of bacterial susceptibility to
MA
antimicrobials of human and veterinary importance. EFSA Journal 2012 10(6):2740. pp.10.
EFSA, 2013. EFSA BIOHAZ Panel (EFSA Panel on Biological Hazards), 2013.
TE
D
Scientific Opinion on the maintenance of the list of QPS biological agents intentionally added to food and feed (2013 update). EFSA Journal 2013
CE P
11(11):3449, pp.108.
Elisha, B.G., Courvalin, P., 1995. Analysis of genes encoding D-alanine:D-alanine
AC
ligase-related enzymes in Leuconostoc mesenteroides and Lactobacillus spp. Gene 152, 79-83. ESVAC, 2013. European Medicines Agency, European Surveillance of Veterinary. Antimicrobial Consumption Sales of veterinary antimicrobial agents in 25 EU/EEA countries in 2011' (EMA/236501/2013). Canary Wharf London, UK. 97p. Fadda, S., López, C., Vignolo, G., 2010. Role of lactic acid bacteria during meat conditioning and fermentation: peptides generated as sensorial and hygienic biomarkers. Meat Science 86(1), 66-79.
34
ACCEPTED MANUSCRIPT Federici, S., Ciarrocchi, F., Campana, R., Ciandrini, E., Blasi, G., Baffone, W., 2014. Identification and functional traits of lactic acid bacteria isolated from Ciauscolo
T
salami produced in Central Italy. Meat Science 98, 575–584.
IP
Finley, R.L., Collignon, P., Larsson, D.G.J., McEwen, S. A., Li, X.-Z., Gaze, W.H.,
SC R
Reid-Smith, R., Timinouni, M., Graham, D.W., Topp, E., 2013. The Scourge of Antibiotic Resistance: The Important Role of the Environment. Clinical Infectious Diseases 57(5), 704–710.
NU
Fontana, C., Fadda, S., Cocconcelli, P. S., Vignolo, G., 2012. Lactic acid bacteria in meat fermentations. In: Lahtinen, S., Ouwehand, A.C., Salminen, S., Von Wright,
MA
A. (Eds). Lactic acid bacteria-microbiological and functional aspects. 4th Edition. CRCPress. Taylor & Francis Group, UK. pp. 247-264.
TE
D
Forslund, K., Sunagawa, S., Kultima, J.R., Mende, D. R., Arumugam, M., Typas, A., Bork, P., 2013. Country-specific antibiotic use practices impact the human gut
CE P
resistome. Genome Research 23: 1163-1169. Franz, C.M.A.P., Huch, M., Abriouel, H. , Holzapfel. W., Gálvez, A., 2011. Enterococci
AC
as probiotics and their implications in food safety. International Journal of Food Microbiology 151, 125–140. Fraqueza, M.J., Barreto, A.S., 2014. HACCP: Hazard Analysis and Critical Control Points, In: Toldra, F., Hui, Y. H., Astiasaran, I., Sebranek, J., Talon, R., (Eds.). Handbook of Fermented Meat and Poultry, 2nd Edition. Wiley-Blackwell. ISBN: 978-1-118-52269-1, 469p. Galloway-Penã, J., Roh, J.H., Latorre,M., Qin, X., Murray, B.E., 2012. Genomic and SNP analyses demonstrate a distant separation of the hospital and communityassociated clades of Enterococcus faecium. PLoS One 7:e30187.
35
ACCEPTED MANUSCRIPT Gevers, D., Buys, G., Devlieghere, F., Uyttendaele, M., Debevere, O., Swings, E., 2000. Isolation and identification of tetracycline resistant Lactic Acid Bacteria from Pre-
T
packed sliced meat products. Systematic Applied Microbiology 23, 279-284.
IP
Gevers, D., Huys, G., Swings, J., 2003. In vitro conjugal transfer of tetracycline
SC R
resistance from Lactobacillus isolates to other Gram-positive bacteria. FEMS Microbiology Letters 225, 25-130.
Gfeller, K.Y., Roth, M., Meile, L.,Teuber, M., 2003. Sequence and genetic organization
NU
of the 19.3-kb erythromycin- and dalfopristin-resistance plasmid pLME300 from
MA
Lactobacillus fermentum ROT1. Plasmid 50, 190–201. Gueimonde, M., Sánchez, B., Reyes-Gavilán, C.G., Margolles, A., 2013. Antibiotic resistance in probiotic bactéria. Frontiers in Microbiology 4, 202, pp.6. 2011.
TE
D
Guilbaud, M., Zagorec, M., Chaillou, S., Champomier-Vergès, M.C.,
Intraspecies diversity of Lactobacillus sakei response to oxidative stress and
CE P
variability of strain performance in mixed strains challenges. Food Microbiology 29 (2), 197-204.
AC
Haug, M.C., Tanner, S.A., Lacroix, C., Stevens, M.J., Meile, L., 2011. Monitoring horizontal antibiotic resistance gene transferin a colonic fermentation model. FEMS Microbiology Ecology 78, 210-219. Hebert, E. M., Saavedra, L. Taranto, M. P., Mozzi, F., Magni, C., Nader, M. E. F., Font de Valdez, G., Sesma, F. Vignolo, G., Raya, R. R., 2012. Genome Sequence of the Bacteriocin-Producing Lactobacillus curvatus Strain CRL705. Journal of Bacteriology 194 (2), 538-539. Henriques, A.R., Telo da Gama, L., Fraqueza, M.J., 2014. Assessing Listeria monocytogenes presence in Portuguese ready-to-eat meat processing industries based on hygienic and safety audit. Food Research International 63, 81–88.
36
ACCEPTED MANUSCRIPT Holzapfel, W.H., Haberer, P., Geisen, R., Bjorkroth, J., Schillinger, U., 2001. Taxonomy and important features of probiotic microorganisms in food and
T
nutrition. The American Journal of Clinical Nutrition 73, 365S-73S.
IP
Hummel, A. S., Hertel, C., Holzapfel, W. H., Franz, C. M. A. P., 2007. Antibiotic
SC R
Resistances of Starter and Probiotic Strains of Lactic Acid Bacteria. Applied Environmental Microbiology 73(3), 730-739.
Hurtado, A., Reguant, C., Bordons, A., Rozès, N., 2012. Lactic acid bacteria from
NU
fermented table olives. Food Microbiology 31, 1-8.
coagulase-negative
MA
Janssens, M., Myter, N., De Vuyst, L., Leroy, F., 2013. Community dynamics of staphylococci
during
spontaneous
artisan-type
meat
fermentations differ between smoking and moulding treatments. International
TE
D
Journal of Food Microbiology 166 (1), 168–175. Klare, I., Konstabel, C., Werner, G., Huys, G., Vankerckhoven V., Kahlmeter, G.,
CE P
Hildebrandt, B., Muller-Bertling, S., Witte, W., Goossens, H., 2007. Antimicrobial susceptibilities of Lactobacillus, Pediococcus and Lactococcus
AC
human isolates and cultures intended for probiotic or nutritional use. Journal Antimicrobial Chemotheraphy 59, 900-912. Kozacinski, L., Drosinos, E., Caklovica, F., Cocolin, L., Gasparik-Reichardt, J., Slavica Veskovi, S., 2008. Investigation of Microbial Association of Traditionally Fermented Sausages. Microflora in Traditionally Fermented Sausages, Food Technology Biotechnology 46, 1, 93–106. Kumar, A., Schweizer, H. P., 2005. Bacterial resistance to antibiotics: Active efflux and reduced uptake. Advanced Drug Delivery Reviews 57, 1486-1513.
37
ACCEPTED MANUSCRIPT Landeta, G., Curiel, J.A., Carrascosa, A.V., Muñoz, R., de las Rivas, B., 2013. Technological and safety properties of lactic acid bacteria isolated from Spanish
T
dry-cured sausages. Meat Science 95, 272–280.
antibiotics
by
target
modification.
Antimicrobial
Agents
SC R
streptogramin
IP
Leclercq, R., Courvalin, P., 1991. Bacterial resistance to macrolide, lincosamide, and
Chemotheraphy 35(7), 1267–1272.
Leser, T. D., Amenuvor, J. Z., Jensen, T. K., Lindecrona, R. H., Boye, M., Moller, K.,
NU
2002. Culture-Independent Analysis of Gut Bacteria: the Pig Gastrointestinal
MA
Tract Microbiota Revisited. Applied Environmental Microbiology 68, 673-690. Levy, S.B., Marshall, B., 2004. Antibacterial resistance worldwide: causes, challenges and responses. Nature Medicine 10, S122 - S129.
TE
D
Lin, C. F., Fung, Z. F., Wu, C. L., Chung, T. C., 1996. Molecular characterization of a plasmid-borne (pTC82) chloramphenicol resistance determinant (cat-TC) from
CE P
Lactobacillus reuteri G4. Plasmid 36, 2, 116–124. Ludwig, W., Schleifer, K.H., and Whitman, W.B., 2009. Order II. Lactobacillales ord.
AC
nov." In: De Vos, P., Garrity, G.M., Jones, D., Krieg, N.R., Ludwig, W., Rainey, F.A., Schleifer, K.H., Whitman, W.B. (Eds). Bergey's Manual of Systematic Bacteriology, Second edition, vol. 3 (The Firmicutes), Springer, Dordrecht, Heidelberg, London, New York. p. 464. Marshall, B.M., Ochieng, D.J., Levy, S.B., 2009. Commensals: underappreciated reservoir of antibiotic resistance. Microbe 4, 231–238. Martín, B., Corominas, L., Garriga, M., Aymerich, T., 2009. Identification and tracing of Enterococcus spp. by RAPD-PCR in traditional fermented sausages and meat environment. Journal of Applied Microbiology 106(1), 66-77.
38
ACCEPTED MANUSCRIPT Martinez, J. L., 2009. Environmental pollution by antibiotics and by antibiotic resistance determinants. Environmental Pollution, 157, 2893-2902.
T
Martinez, J.L., Rojo, F., 2011. Metabolic regulation of antibiotic resistance. FEMS
IP
microbiology Review 35, 5, 768–789.
SC R
Marty, E., Buchs, J., Eugster-Meier, E., Lacroix, C., Meile, L., 2012. Identification of Staphylococci and dominant Lactic Acid Bacteria in spontaneously fermented Swiss meat products using PCR-RFLP. Food Microbiology 29, 157-166.
NU
Mayrhofer, S., Mair, C., Kneifel, W., Domig, K. J., 2011. Susceptibility of
MA
Bifidobacteria of animal origin to selected antimicrobial agents. Chemotherapy Research and Practice 2011, 989520, pp. 6. Medina, R.B., Oliszewski, R., Abeijón Mukdsi, M.C., Van Nieuwenhove, C.P.,
TE
D
González, S.N., 2011. Sheep and goat’s dairy products from South America: Microbiota and its metabolic activity. Small Ruminant Research 101, 84-91.
CE P
Muscariello, L., Marino, C., Capri, U., Vastano, V., Marasco, R., Sacco, M., 2013. CcpA and three newly identified proteins are involved in biofilm development in
AC
Lactobacillus plantarum. Journal of Basic Microbiology, 53(1):62-71. doi: 10.1002/jobm.201100456. Epub 2012 May 15. Nawaz, M., Wang, J., Zhou, A., Ma, C., Wu, X., Moore, J.E., Millar, B.C., Xu, J., 2011. Characterization and transfer of antibiotic resistance in lactic acid bacteria from fermented food products. Current Microbiology 62, 1081–1089. Oki, K., Rai, A. K., Sumie Sato, S., Watanabe, K., Tamang, J. P., 2011. Lactic acid bacteria isolated from ethnic preserved meat products of the Western Himalayas. Food Microbiology 28, 1308-1315. Palmer, K.L., Godfrey, P., Griggs, A., Kos, V.N., Zucker, J., Cerqueira, G., Gevers, D., Walker, S., Wortman, J., Feldgarden, M., Haas, B., Birren, B., Gilmore, M. S.,
39
ACCEPTED MANUSCRIPT 2012. Comparative genomics of Enterococci: variation in Enterococcus faecalis, clade structure in E. faecium, and defining characteristics of E. gallinarum and E.
T
casseliflavus. MBio. 3:e00318–00311.
IP
Panagou, E.Z., Nychas, G.-J.E., Sofos, J.N., 2013. Types of traditional Greek foods and
SC R
their safety. Food Control 29, 32–41.
Paramithiotis, S., Kagkli, D.-M.; Blana, V. A., Nychas, G.-J. E., Drosinos, E. H., 2008. Identification and characterization of Enterococcus spp. in Greek spontaneous
NU
sausage fermentation. Journal of Food Protection 6, 1244-1247.
MA
Patarata, L., 2002. Caracterização e avaliação da aptidão tecnológica de bactérias do ácido láctico e Micrococcaceae em produtos de salsicharia. Efeito da sua utilização em culturas de arranque e de formulação acidificante no fabrico de
TE
D
linguiça tradicional transmontana. PhD thesis, UTAD, Vila Real, 262 p. Pyörälä, S., Baptiste , K. E., Catry, B., van Duijkeren , E., Greko, C., Moreno, M. A.,
CE P
Pomba, M. C. M. F., Rantala, M., Ružauskas, M., Sanders, P. , E. Threlfall, J., Torren-Edo, J., Törneke, K., 2014. Macrolides and lincosamides in cattle and
AC
pigs: Use and development of antimicrobial resistance. The Veterinary Journal 200, 230-239. Reis, J.A., Paula, A.T., Casarotti, S.N., Penna, A.L.B., 2012. Lactic acid bacteria antimicrobial compounds: Characteristics and applications. Food Engineering Reviews 4, 124-140. Ribeiro, T., Oliveira, M., Fraqueza, M. J., Laukova, A., Elias, M., Tenreiro, R. Barreto, A. S., Semedo-Lemsaddek, T., 2009. Antibiotic resistance and virulence factors among enterococci isolated from chouriço, a traditional Portuguese dry fermented sausage. Journal of Food Protection 74, 465-469.
40
ACCEPTED MANUSCRIPT Rodríguez-Rojas, A., Rodríguez-Beltrán J., Couce, A., Blázquez, J., 2013. Antibiotics and antibiotic resistance: A bitter fight against evolution. International Journal of
T
Medical Microbiology 303, 293-297.
IP
Rojo-Bezares, B., Sáenz, Y., Poeta, P., Zarazaga, M., Ruiz-Larrea, F., Torres, C., 2006.
SC R
Assessment of antibiotic susceptibility within lactic acid bactéria strains isolated from wine. International Journal of Food Microbiology 111, 234–240 Sagoo, S.K., Little, C.L., Greenwood, M., Mithani, V., Grant, K.A., McLauchlin, J., de
NU
Pinna, E., Threlfall, E.J., 2009. Assessment of the microbiological safety of dried
MA
spices and herbs from production and retail premises in the United Kingdom. Food Microbiology 26 (1), 39-43.
Salyers, A.A., Gupta, A., Wang, Y., 2004. Human intestinal bacteria as reservoirs for
TE
D
antibiotic resistance genes. Trends Microbiology 12, 412-416. Sarmah, A.K., Meyer, M. T., Boxall, A.B.A., 2006. A global perspective on the use,
CE P
sales, exposure pathways, occurrence, fate and effects of veterinary antibiotics (VAs) in the environment. Chemosphere 65, 725–759.
AC
Schweiggert, U., Carle, R., Schieber, A., 2007. Conventional and alternative processes for spice production a review. Trends in Food Science & Technology 18, 260268.
Serrano, L.M., Molenaar, D., Wels, M., Teusink, B., Bron, P.A., de Vos, W.M., Smid, E.J., 2007. Thioredoxin reductase is a key factor in the oxidative stress response of Lactobacillus plantarum WCFS1. Microbial Cell Factory 28, 6:29. Shen, J., Wang, Y., Schwarz, S., 2013. Presence and dissemination of the multiresistance gene cfr in Gram-positive and Gram-negative bacteria. The Journal of Antimicrobial Chemotherapy 68, 1697-1706.
41
ACCEPTED MANUSCRIPT Singer, R.S., Finch, R., Wegener, H.C., Bywater, R., Walters, J., Lipsitch, M., 2003. Antibiotic resistance—the interplay between antibiotic use in animals and human
T
beings. The Lancet Infectious Diseases 3, 47-51.
IP
Talon, R., Leroy, S., 2011. Diversity and safety hazards of bacteria involved in meat
SC R
fermentations. Meat Science 89, 303–309.
Talon, R., Leroy, S., Lebert, I., 2007. Microbial ecosystems of traditional fermented meat products: The importance of indigenous starters. Meat Science 77, 55–62.
NU
Tannock, G.W., 2004. A special fondness for lactobacilli. Applied Environmental
MA
Microbiology 70, 3189-3194.
Teale, C.J., 2002. Antimicrobial resistance and the food chain. Journal Applied Microbiology 92 Suppl, 85S-9S.
TE
D
Toldrá, F., Nip, W.-K., Hiu, Y.H., 2007. Dry-fermented sausages: an overview. In: Toldra F. (Ed.). Handbook of Fermented Meat and Poultry, 1st Edition. Blackwell
CE P
Publishing, USA. pp321-325. Toomey, N., Bolton, D., Fanning, S., 2010. Characterization and transferability of
AC
antibiotic resistance genes from lactic acid bacteria isolated from Irish pork and beef abattoirs. Research in Microbiology 161, 127-135. Trigo, M.J., Fraqueza, M.J., 1998. Effect of gamma radiation on microbial population of natural casings. Radiation Physics and Chemistry 52(1-6), 125-128. Tuohy, K.M., Gougoulias, C., Shen, Q., 2009 . Studying the human gut microbiota in the trans-omics era-focus on metagenomics and metabonomics. Current Pharmaceutical Design 15 (13), 1415-1427. Tynkkynen, S., Singh, K.V. and Varmanen, P., 1998. Vancomycin resistance factor of Lactobacillus rhamnosus GG in relation to enterococcal vancomycin resistance (van) genes. International Journal Food Microbiology 41, 195-204.
42
ACCEPTED MANUSCRIPT Urso, R., Comi, G., Cocolin, L., 2006. Ecology of lactic acid bacteria in Italian fermented sausages: isolation, identification and molecular characterization.
T
Systematic and Applied Microbiology 29, 8, 671-680.
IP
van Kranenburg, R.,Kleerebezem,M., van Hylckama Vlieg, J., Ursing, B. M.,
SC R
Boekhorst, J., Smit, B. A., Ayad, E.H.E., Smit, G., Siezen, R.J., 2002. Flavour formation from amino acids by lactic acid bacteria: predictions from genome sequence analysis. International Dairy Journal 12, 111–121.
NU
van Reenen, C. A., Dicks, L. M. T., 2011. Horizontal gene transfer amongst probiotic
MA
lactic acid bacteria and other intestinal microbiota: what are the possibilities? A review. Archives of Microbiology 193(3), 157-168. Vandamme, P., Bruyne1, K., Pot, B., 2014. Lactic acid bacteria : biodiversity and
TE
D
taxonomy Phylogenetics and systematics. In: Holzapfel, W. H., Wood, B.J.B. (Eds.). Lactic Acid Bacteria Biodiversity and Taxonomy. John Wiley & Sons, Ltd,
CE P
UK. pp.31-39.
Verluyten, J., Leroy, F., de Vuyst, L., 2004. Effects of Different Spices Used in
AC
Production of Fermented Sausages on Growth of and Curvacin A Production by Lactobacillus curvatus LTH 1174. Applied and Environmental Microbiology 70 (8), 4807-4813. Wanangkarn A., Liu, D.-C., Swetwiwathana, A., Jindaprasert, A., Phraephaisarn, C., Chumnqoen, W., Tan, F.-J., 2014. Lactic acid bacterial population dynamics during fermentation and storage of Thai fermented sausage according to restriction fragment length polymorphism analysis. International Journal of Food Microbiology 186, 61-67. Werner, G., 2012. Current Trends of Emergence and Spread of Vancomycin-Resistant Enterococci. In: Pana, M. (Edt.) Antibiotic Resistant Bacteria - A Continuous
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ACCEPTED MANUSCRIPT Challenge in the New Millennium. 306-357p. InTech, Available from: http://www.intechopen.com/books/antibiotic-resistant-bacteria-acontinuous-
T
challenge-in-the-new-millennium/current-trends-of-emergence-and-spread-of-
IP
vancomycinresistant-enterococci
SC R
WHO, 2014. Antimicrobial resistance: global report on surveillance. World Health Organization. Geneva, Switzerland. 232p. ISBN 978 92 4 156474 8. Wright, A. Von, Axelsson, L., 2012. In: Lahtinen, S.; Ouwehand, A.C., Salminen, S.,
NU
Wright, A. Von. (Eds). Lactic Acid Bacteria, Microbiological and Functional
MA
Aspects. 4th Edition. Edited by CRC Press Taylor & Francis Group, US. pp 2-14. Wright, G.D., 2007. The antibiotic resistome: the nexus of chemical and genetic diversity. Nature Reviews Microbiology 5 (3), 175-186.
TE
D
Zeuthen, P., 2007. A historical perspective of meat fermentation. In : Toldra F. (Ed.), Handbook of Fermented Meat and Poultry. 1st Edition. Blackwell Publishing,
CE P
USA. pp. 3-8.
Zhou, J.S., Pillidge, C.J., Gopal, P.K., Gill. H.S.,
2005. Antibiotic susceptibility
AC
profiles of new probiotic Lactobacillus and Bifidobacterium strains. International Journal of Food Microbiology 98, 211 – 217. Zonenschain, D., Rebecchi, A., Morelli, L., 2009. Erythromycin- and tetracyclineresistant lactobacilli in Italian fermented dry sausages. Journal of Applied Microbiology 107, 1559-1568.
44
Men
Drying
Time
CR
Health status
TE D
cold
Bacteriostatic effect
Contact material
CE P
Maintenance status
Dryfermented sausage Temperature/time
Smoke nature
Hygiene status
AC
Ingredients
Temperature/Humidity
MA N
Training
US
Initial fecal contamination
Initial contamination
IP
Raw meat material
T
ACCEPTED MANUSCRIPT
Smoking
Figure 1. Sources and factors involved on selection and spread of antibiotic resistant LAB in dry-fermented sausages.
45
ACCEPTED MANUSCRIPT
Name product
Composition
Main process Conditions
Major known function
LAB Level
pork
short-ripened fermented sausage 30days 20-25°C, cold smoked 2 days
Microorganisms inhibition by acidification
Northeastern region of Thailand
Thai fermented sausage
Beef , bovine liver spleen , roasted rice powder garlic , salt , spices and seasonings
fermented sausage 3 days at room temperature
Acidification pH 4.1
Spain
Dry fermented sausage
pork
Fermented sausage
Swiss
Dry Fermented sausages not named
Western Himalayas/ India and Nepal
Jamma or Geema /Kargyong
wildlife meat (deer, wild boar, chamois) or meat from cattle, sheep and pork ethnic chevron (goat) meat
nd
US
Ciauscolo salami
MA N
Italy
CR
(log cfu/g)
Identification Method
IP
Region/ Country
T
Table 1: Overview of Lactic acid bacteria (LAB) species diversity of dry- fermented meat sausages from different geographical origins.
Species identification by 16S rRNA gene sequencing
Reported LAB species diversity
References
L. sakei/ P. pentosaceus/ L. plantarum/ L. paraplantarum/ E. faecalis/ L. paracasei /L. lactis /L. johnsonii /L. brevis/Lactococcus spp./Carnobacterium spp/ W. helénica/Leuconostoc mesenteroides L. sakei/L. plantarum/ L. mesenteroides L. brevis /P. pentosaceus /Lc. lactis / L. fermentum
Federici et al., 2014
Species identification by 16S rRNA gene sequencing
Acidification, Nitrate reduction activity,Lipolyti c activity
nd
Species identification by 16S rRNA gene sequencing
L. sakei /L. plantarum /L. paracasei/ L.coryniformi/E. faecium
Landeta et al., 2013
Fermentation and ripening conducted at 9-17 ºC, 15 days, cold smoking on last stage
Microorganisms inhibition by acidification (pH 4.6–6.6),
4.6–9.1
L. sakei /L. curvatus / E. faecalis/E. faecium /Pediococcus pentosaceus and others Streptococcus
Marty et al., 2012
Boiling, 15 min. Smoking, 15-20 days uncontrolled temperature and humidity
Acidification (pH 5.5), flavor
7.8-7.5
16S rRNA, genebased PCR – restriction fragment length polymorphism (RFLP) 16S rRNA and phenylalanyltRNA synthase (pheS) genes sequencing
E. durans/E. faecalis/E. faecium/E. hirae, Leuconostoc citreum, Leuc. mesenteroides, P. pentosaceus, and Weissella cibaria
Oki et al., 2011
AC
CE P
TE D
nd
Wanangkarn et al., 2012, 2014
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Composition
Main process Conditions
Major known function
LAB Level (log cfu/g)
Smoking, max. 8 days at temperatures below 37 ºCand with uncontrolled humidity
Aroma and taste, extension of shelf life
Italy
Piacentino salami
Pork meat
Aroma and taste
South-east Europe (Greece, Bosnia and Herzegovina, Croatia, Hungary, Italy and Serbia).
Sudzuk, Sremska, Friuli
pork and beef meat
Fermentation 8 days(RH= 40% to 90% at 15–25°C) Ripening (45 days) at RH =70–90% and 12–19°C. Ripening (28 days)
Italy
Fermented sausage
Spain
Fuet, Chorizo and Salchichon Chouriço
pork meat, lard, sodium chloride, nitrite and nitrate, and black pepper. pork meat
Trás-os-Montes, North Portugal
Pork meat and fat; salt, wine, garlic, bay, eventually paprika
species- and genus-specific primers and 16S rRNA gene sequencing Species identification by 16S rRNA gene sequencing
3-5
phenotypic identification API 50 CHL
Acidification pH=5.62-5.65
8–9
species-specific PCR and DGGE analysis followed by16S rRNA gene sequencing species-specific PCR and 16S rRNA gene sequencing Phenotypic and species specific PCR
MA N
3-9
CE P
Acidification (pH 4.7 to 5.7), aroma and taste
AC
Ripening (2845 days).
nd
CR
pork and poultry
US
Alheira
TE D
North Portugal
Identification Method
Reported LAB species diversity
References
T
Name product
IP
Region/ Country
Cold Ripening
Acidification (pH 5.3 to 6.2), aroma and taste
6.86- 8.99
Cold smoked, 1 to 4 weeks drying at a low temperature
Acidification (pH=5.5), aroma and taste
8
L. plantarum/L. paraplantarum/ L. brevis/ L. rhamnosus/ L. sakei/ L. zeae/ L. paracasei/ Leuconostoc mesenteroides, P. pentosaceus, P. acidilactici, Weissella cibaria/W. viridescens and E.faecium/ E. faecalis L. sakei/ L. curvatus/ L. plantarum/L.brevis/L.rhamnosus, L. paracasei and L. reuteri
Albano et al., 2009
L.sakei/L.curvatus/L.plantarum/L. pentosus/L.rhamnosus/L. brevis/L. paracasei/L. alimentarius/L. fermentum/L. bavaricus; Lac. lactis; P. pentosaceus/P. acidilactici; Leuc. mesenteroides; E. faecium L.sakei/ L.plantarum/ L. curvatus /L. casei/ L. brevis/L.paraplantarum/ Lactococcus garvieae/L. lactis/ Leuconostoc carnosum/ L.mesenteroides Weisella helénica/W. paramesenteroides L. sakei/L.plantarum/L. curvatus Leuconostoc mesenteroides E. faecium
Kozacinski et al., 2008
L. sakei/ L. plantarum
Patarata, 2002
Zonenschain et al., 2009
Urso et al., 2006
Aymerich et al., 2003, 2006
47
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Gene(s)
Localization
Ampicilin Penicillin
L. plantarum, L. casei, L. salivarius, L. leishmannii, L. acidophilus Lactobacilli
Point mutations
Chromosome
blaZ
E. faecalis
Reference
Not transferable
Reduced penicillin binding to the expressed protein
Danielsen and Wind, 2003
Transposon
transferable
Antibiotic hydrolysis by β lactamases
blaZ
Transposon
transferable
Aquilanti et al., 2007 Werner, 2012
E. faecium
pbp5 gene mutated
chromosome Transposon
Not transferable Transferable
Werner, 2012
Lactobacilli, (L. plantarum) and Leuconostoc mesenteroides E. faecium and E. faecalis
ddl vanX-like gene aad
Chromosome
Not transferable
vanA, vanB, vanD and vanM vanC, vanE, vanL and vanG cat
Transposons Plasmids Chromosome
Transferable
Plasmid
Transferable
Plasmid, Transposons Chromosome
Transferable
Plasmid, transposon
Transferable
Reduced penicillin binding to the expressed protein D-alanine ligase-related enzymes, d- Ddl (alanine:d-alanine) ligase vancomycine D-Ala-D-Lac mediated resistance; D-Ala-D-Ser mediated resistance chloramphenicol acetylation by acetyltransferases ribosomal protection proteins tet(O)/(M)(S) or efflux pump proteins tet(K)/(L) rRNA methylases (Ribosomal methylation
Cloranfenicol
L. acidophilus, L. plantarum
Tetracycline
Lactobacilli E. faecium and E. faecalis
tetM, tetO, tetS tetK, tetL
Lactobacilli Lactococcus
ermB,
MLSR phenotype Erytromycin
MA N
TE D CE P
AC
Vancomycin
Resistance mechanisms
CR
Species
US
Antibiotics
IP
T
Table 2: LAB antibiotic resistance determinants identified.
Risk of transmission
Not transferable
Not transferable
Elisha and Courvalin, 1995, Deghorain et al., 2007 Werner, 2012
Hummel et al., 2007 Ahn et al., 1992 Gevers et al., 2003, Ammor et al., 2008 Werner, 2012 Leclercq and Courvalin, 1991 48
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lnu(A)
Chromosome
Not transferable
Lincosamide transferase
Transferable
Antibiotic acetylation Transferases
Cauwerts et al., 2007 Gfeller et al., 2003
Quinupristin– dalfopristin Streptogramin
Lactobacilli Lb. fermentum
vat (E)
Plasmid
Enterococcus
lsa
Chromosome
Not transferable
Chromosome
Not transferable
ABC transporter rRNA methylases Enzymatic modification
Dina et al., 2003, Werner, 2012 Klare et al., 2007 Rojo-Bezares et al., 2006
Streptomycin Spectinomycin
Lactobacill, L. plantarum Pediococcus
ant(6) , mutations in genes encoding ribosomal proteins
StreptomycinStreptothricinKanamycin
E. faecium and E. faecalis
aadE-sat4-aphA
Transposon
Transferable
Enzymatic modification
Werner, 2012
GentamicinKanamycin
Lactobacilli, L. plantarun, L.casei, L.delbrueki E. faecium and E. faecalis Lactobacilli
aac(6)-aph(2), ant(6), aph(3)-IIIa
Chromosome
Not transferable
Enzymatic modification
Rojo-Bezares et al., 2006
aac(6')-Ii, aph(2”)-Ie, and ant(6)-Ia Gene mutations on A subunits of TopoisomeraseIV
Transposon
Transferable
Enzymatic modification
Werner, 2012
Chromosome
Not transferable
Hummel et al., 2007
gyrA, gyrB and parE genes qnr gene
Chromosome
Not transferable
Topoisomerases II and IV targets unknown resistance mechanism Topoisomerases II and IV targets
E. faecium
Chromosome
Not transferable
T
Lactobacilli
IP
Lincosamide
E.faecalis
Werner, 2012 Shen et al., 2013
CR
plasmids Chromosome
Fluoroquinolones
Transferable Not transferable
by methylases) Modification of nucleotide A2058
CE P
TE D
MA N
US
E. faecalis
ermA, ermC erm(T) Cfr msrA-C
AC
E. faecium and
Arsene et al., 2007
MLS phenotype- macrolides, lincosamides and streptogramins.
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T
Table 3: LAB antibiotic resistance profile isolates from dry fermented meat sausages and their genetic determinants. Origin
Main antibiotic resistance (%)
Resistance profile
Method (MIC or disc diffusion)
Antibioticresistant genes (PCR)
Antibiotic-resistant genes detected (%)
Reference
L. sakei (N=15)
Ciauscolo salami
L. sakei, (100% S resistant N=15; 93% CN resistant N=14; 33% Amp resistant N=5; 13% Tet resistant N=2); 7% Ery resistant N=1)
S-CN-AmpTet- Ery
tet(M), tet(W), tet(K), tet(L), tet(S), erm(A), erm(B), van(A), van(B),
ND
Federici et al., 2014
P. pentosaceus (100% S resistant N=9; 100% CN resistant N=9; 100% Tet resistant N=9); 100% Amp resistant N=9; 98% C resistant N=8; 33% Ery resistant N=3, 11% CD resistant N=1)
S-CN-AmpTet- C-EryCD
ampicillin (64–0.032 mg/ml), chloramphenicol (256– 0.125 mg/ml), clindamycin (32–0.032 mg/ml), erythromycin (32–0.016 mg/ml), gentamycin (2048–1 mg/ml), streptomycin sulfate (4096–2 mg/ml), tetracycline (128–0.064 mg/ml) vancomycin (256–0.125 mg/ml)
L. plantarum (N=5) L. plantarum (80% Tet resistant N=4; 60% S resistant N=3; 40% Ery resistant N=2; 40% C resistant N=2)
Lactococcus (N=1) L. sakei (N=20)
1
L. plantarum (N=4)
Dry fermented sausage
CR
US
MA N
L. paraplantarum (100% Tet resistant N=2; 100% S resistant N=2; 50% Ery resistant N=1; 50% CD resistant N=1; C resistant N=1; 50% CN resistant N=1)
Tet- S- EryAmp-CD-CCN
E. faecalis (100% CD resistant N=2; 100% Ery resistant N=2; 50% C resistant N=1; 50% CN resistant N=1)
CD- Ery- CCN
Lactococcus (100% Amp-C-CN-S-TetVan resistant N=1) L. sakei, (100% Van resistant N=20; 30% Rif resistant N=6; 20% Ai resistant N=4; 15% Tet resistant N=3) L. plantarum (100% Van resistant N=4; 100% Rif resistant N=4; 75% Tet
Amp-C-CNS-Tet-Van Van-Rif -AiTet
AC
E. faecalis (N=2)
1
Tet- S-Ery-C
CE P
L. paraplantarum (N=2)
TE D
P. pentosaceus (N=9)
IP
Species name and number
Van-Rif - Tet
P. pentosaceus tetM (n=4, 44%) ermB (n=1, 11%)
ND
MIC breackpoints from FEEDAP Panel (EFSA, 2005)
L. paraplantarum erm(B) (n=1, 50%)
E. faecalis erm(B) (n=1, 50%)
ampicillin (10 μg), penicillin G (10 U), vancomycin (30 μg), amikacin (30 μg)1, gentamicin (10 μg),
tetM gene
Lactococcus tet(M) (n=1, 100%) L. sakei, tet(M) (N=2, 67%)
Landeta et al. 2013
L. plantarum, tet(M) (N=0, 0%)
50
ACCEPTED MANUSCRIPT
1
resistant, N=3)
1
L.coryniformis (N=1)
E. faecium (N=19)
L. plantarum (N=12)
E. faecalis (N=20)
Dry fermented sausages Northern Italy: Salame Piacentino PDO
13% Tet resistance (N=4)
Dry fermented sausages North Italy: Piacentino salami (45days of ripening)
L. sakei, (70% Tet resistant N=17; 29% Ery resistant N=7)
Portuguese “chouriço” dry fermented sausage
E. faecalis 65% Ery resistant (N=13), 65% Gen resistant (13 of 20), 60% Tet resistant (N=12), , and 45% Van resistant (9 of 20)
Tet-Rif-CipP-Nit
Tet Tet-Ery
TE D
7% Ery resistance (N=2)
CE P
L. curvatus (N=16)
E. faecium (100% Tet resistant N=19; 100% Rif resistant N=19; 100% Cip resistant N=19, 68% P resistant N=13, 16% Nit resistant N=3)
Tet-Ery
L. curvatus, (62% Tet resistant N=10; 62% Ery resistant N=10)
AC
L. sakei (N=24)
tetracycline (30 μg), erythromycin (15 μg), clindamycin (2 μg)1, tobramycin (10 μg)1, rifampicin (5 μg) chloramphenicol (30 μg)2, penicillin G (10 U) 2, teicoplanin (30 μg) 2, nitrofurantoine (300 μg) 2, ciprofloxacin (5 μg) 2. Tetracycline MIC value of 32 μg/ml (n=1) Erythromycin MIC value of 64 μg/ml (n=3)
MA N
2
30 isolates Lactobacillus paracasei
Method (MIC or disc diffusion)
T
Resistance profile
Antibioticresistant genes (PCR)
Antibiotic-resistant genes detected (%)
Reference
CR
L. paracasei (N=2)
Main antibiotic resistance (%)
IP
Origin
US
Species name and number
Eritromycine MIC value of ≥1024 μg/ml (n=2) Tetracycline MIC values of 8 µg/ml, and 32 µg/ml for L. plantarum , Erythromycin MIC values of 4 µg/ml
tet(M), tet(W), tet(L), tet(S), erm(A), erm(B),
tet(M), tet(W), tet(L), tet(S), erm(B), erm(C)
L. plantarum (92% Tet resistant N=11; 50% Ery resistant N=6)
Ery- CN-TetVan
vancomycin 30 mg; ampicillin 10 mg; penicillin G 10 U; gentamicin 10 mg; tetracycline 30 mg; and erythromycin 15 mg (disk diffusion method)
erm(B), (pbp5), aac(69)-Ie-aph(299), tet(M), van(A) and van(B)
E. faecium, tet(M) (N=19, 100%) tet (M) (N=4; 100%) erm(B) (N=2; 100%)
L. sakei, tet(M) (N=11, 65%), tet(W) (N=1, 6%) erm(B) (N=5, 71%) L. curvatus, tet(M) (N=7, 70%), tet(W) (N=4, 40%), erm(B) (N=10, 100%) L. plantarum; tet(M) (N=5, 45%, tet(W) (N=4, 36%), tet(S) (N=1, 9%); erm(B) (N=3, 50%); erm(C) (N=2, 33%) erm(B) (n=9, 45%), tet(M) (n=8, 40%), aac(69)Ie-aph(299) (n=8, 40%), and van(A) (n=8, 40%), pbp5 (n=0, 0%)
Comunian et al., 2010
Zonenschain et al., 2009
Ribeiro et al., 2009
51
ACCEPTED MANUSCRIPT
Origin
Main antibiotic resistance (%)
Resistance profile
Method (MIC or disc diffusion)
Antibioticresistant genes (PCR)
Antibiotic-resistant genes detected (%)
Reference
L. sakei (N=185); L. curvatus (N=53); Leuconostoc mesenteroides (N=12)
Dry fermented sausages Spain: chorizo, fuet and salchichon
43.6% ampicillin 1.2% chloramphenicol (30 µg) 98.4% gentamicin (10 µg) 0% erythromycin (15 µg) 0.8% linezolid (30 µg) 29.2% penicillin G 4.4% quinupristin/dalfopristin (15µg) 12% tetracycline (30 µg) 100% vancomycin (30 µg) (disk diffusion method)
Van-CNAmp-P-Tet-C
nd
nd
Aymerich et al., 2006
LAB (N=100)
Dry fermented sausages
55% Tet resistant LAB
Strains were considered resistant if inhibition halos diameters were: ≤19 mm for ampicillin (10 µg), penicillin G (10 U) and linezolid, ≤18 mm for tetracycline, ≤15 mm for quinupristin/ dalfopristin, ≤14 mm for vancomycin, ≤13 mm for chloramphenicol and erythromycin and ≤12 mm for gentamicin. ampicillin (25 pg), erythromycin (10 pg), rifampicin (30 pg) and tetracycline (30 pg)
L. sakei 100%Tet resistant (N=10), L. plantarum 100%Tet resistant (N=8), L. alimentarius 100%Tet resistant (N=3), L. curvatus 100%Tet resistant (N=3)
IP
CR
US
MA N TE D
CE P
Tet
Gevers et al., 2000
tet(M),tet(O), tet(S), tet(K), and tet(L)
100% tet (M) L. sakei (n=10), L. plantarum (n=8), L. alimentarius (n=3), L. curvatus (n=3)
Gevers et al., 2003
AC
L. sakei (N=10), L. plantarum (N=8), L. alimentarius (N=3), L. curvatus (N=3)
42.8% resistant towards 3–4 antibiotics
T
Species name and number
Legend: 1or 2 respective antibiotic tested on the specie Amp: ampicillin; CD: clindamycin; C: chloramphenicol; CN: gentamycin; S: streptomycin sulfate; Ery: erythromycin; Tet: tetracycline; Van: vancomycin; Rif: rifampicin; Cip: ciprofloxacin; ND- not detected, nd- not determined.
52
