Journal of Hospital Infection 86 (2014) 244e249 Available online at www.sciencedirect.com
Journal of Hospital Infection journal homepage: www.elsevierhealth.com/journals/jhin
Review
Elizabethkingia meningoseptica: an important emerging pathogen causing healthcare-associated infections S.S. Jean a, W.S. Lee b, F.L. Chen b, T.Y. Ou b, P.R. Hsueh c, * a
Department of Emergency Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan Division of Infectious Diseases, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan c Departments of Laboratory Medicine and Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan b
A R T I C L E
I N F O
Article history: Received 6 August 2013 Accepted 28 January 2014 Available online 25 February 2014 Keywords: Contamination source Elizabethkingia meningoseptica Environmental cleaning Infection control Outbreak
S U M M A R Y
Elizabethkingia meningoseptica has been deemed a potentially important threat to patients in critical care areas because of its multidrug-resistant phenotype and its ability to adapt to various environments. This review considers the incidence, factors which predispose to, and clinical features of, E. meningoseptica sepsis, along with antimicrobial susceptibility patterns of clinical E. meningoseptica isolates and reportedly successful measures for the prevention and control of infections caused by this bacterium. The English-language literature from the PubMed database was reviewed. The incidence of E. meningoseptica bacteraemia has increased over the last decade. Patients at high risk of E. meningoseptica infection include preterm children, the immunocompromised and those exposed to antibiotics in critical care units. Vancomycin, rifampicin, newer fluoroquinolones, piperacillinetazobactam, minocycline and possibly tigecycline are preferred empirical choices for E. meningoseptica infection according to in-vitro susceptibility data. Combination therapy has been used for infections not responding to single agents. Saline, lipid, and chlorhexidine gluconate solutions as well as contaminated sinks have been implicated as sources of infection following outbreak investigations. In addition to reinforcement of standard infection control measures, actions that have successfully terminated E. meningoseptica outbreaks include pre-emptive contact isolation, systematic investigations to identify the source of the bacterium and thorough cleaning of equipment and environmental surfaces. As the clinical complexity and incidence of E. meningoseptica infections increase, there is a need for heightened awareness of the potential for this bacterium to cause outbreaks. This will permit timely initiation of active surveillance for infected/colonized patients as well as investigations to identify the likely source of the bacterium, which will, in turn, allow implementation of appropriate infection control measures. ª 2014 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.
* Corresponding author. Address: Departments of Laboratory Medicine and Internal Medicine, National Taiwan University Hospital, No. 7 Chung-Shan South Road, Taipei 100, Taiwan. Tel.: þ886 2 23123456x65355; fax: þ886 2 23224263. E-mail address: [email protected] (P.R. Hsueh). 0195-6701/$ e see front matter ª 2014 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jhin.2014.01.009
S.S. Jean et al. / Journal of Hospital Infection 86 (2014) 244e249
Introduction Elizabethkingia meningoseptica (formerly Chryseobacterium meningosepticum or CDC II-a), an important member of the genus Chryseobacterium, is a non-motile, non-fastidious, catalase- and oxidase-positive, aerobic glucose-non-fermentative Gram-negative bacillus first defined by King in 1959.1,2 She used serological techniques to type strains isolated in epidemiological studies. Of the six serotypes (AeF) King described, type C was responsible for the majority of cases of meningitis.2 Among the Chryseobacterium spp., both E. meningoseptica and C. indologenes are most frequently isolated from soil, saltwater and freshwater and from dry and moist clinical environmental and equipment surfaces, intravenous lipid solutions, and municipal water supplies including those which have been adequately chlorinated. The latter sources greatly contribute to extensive contamination of healthcare settings.1,3e7 The clinical significance of C. indologenes is often questioned.8 Additionally, the fact that Chryseobacterium spp. have occasionally been cocultured with Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp. or meticillin-resistant Staphylococcus aureus with E. meningoseptica from clinical samples complicates our understanding of the exact pathogenic role of E. meningoseptica.6,9,10 However, numerous studies have shown that E. meningoseptica infections tend to occur in patients with particular clinical characteristics in healthcare settings, and that those predisposing factors are similar to those seen in patients with C. indologenes infections.3,6,9,11e18 Cases of communityacquired sepsis caused by E. meningoseptica have also been reported.17,19e23 E. meningoseptica infections are associated with high mortality rates (23e52%), partly because of multidrug resistance.9,11,12 With continuing advances in healthcare, patients in intensive care units (ICUs) are increasingly at risk of E. meningoseptica infections and there should be heightened awareness of this emerging opportunistic pathogen in these settings. This review considers current knowledge on virulence factors and antimicrobial susceptibility of the bacterium; incidence, clinical characteristics, and predictors of clinical outcome of E. meningoseptica infection; and measures to prevent and control such infection.
Virulence factors Virulence factors of E. meningoseptica responsible for invasive disease are not fully understood. The bacterium produces an elastase which causes ophthalmia when injected into the eyes of rabbits, and death following intracerebral injection in mice.24 Despite in-vitro evidence of pathogenicity, this may not always correlate with in-vivo outcome. For example, one study found that Chryseobacterium spp. (C. indologenes, C. gleum, and E. meningoseptica) isolated from respiratory tract specimens from patients with cystic fibrosis were not significantly associated with compromised pulmonary function.25 Moreover, only a small percentage (
Journal of Hospital Infection journal homepage: www.elsevierhealth.com/journals/jhin
Review
Elizabethkingia meningoseptica: an important emerging pathogen causing healthcare-associated infections S.S. Jean a, W.S. Lee b, F.L. Chen b, T.Y. Ou b, P.R. Hsueh c, * a
Department of Emergency Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan Division of Infectious Diseases, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan c Departments of Laboratory Medicine and Internal Medicine, National Taiwan University Hospital, National Taiwan University College of Medicine, Taipei, Taiwan b
A R T I C L E
I N F O
Article history: Received 6 August 2013 Accepted 28 January 2014 Available online 25 February 2014 Keywords: Contamination source Elizabethkingia meningoseptica Environmental cleaning Infection control Outbreak
S U M M A R Y
Elizabethkingia meningoseptica has been deemed a potentially important threat to patients in critical care areas because of its multidrug-resistant phenotype and its ability to adapt to various environments. This review considers the incidence, factors which predispose to, and clinical features of, E. meningoseptica sepsis, along with antimicrobial susceptibility patterns of clinical E. meningoseptica isolates and reportedly successful measures for the prevention and control of infections caused by this bacterium. The English-language literature from the PubMed database was reviewed. The incidence of E. meningoseptica bacteraemia has increased over the last decade. Patients at high risk of E. meningoseptica infection include preterm children, the immunocompromised and those exposed to antibiotics in critical care units. Vancomycin, rifampicin, newer fluoroquinolones, piperacillinetazobactam, minocycline and possibly tigecycline are preferred empirical choices for E. meningoseptica infection according to in-vitro susceptibility data. Combination therapy has been used for infections not responding to single agents. Saline, lipid, and chlorhexidine gluconate solutions as well as contaminated sinks have been implicated as sources of infection following outbreak investigations. In addition to reinforcement of standard infection control measures, actions that have successfully terminated E. meningoseptica outbreaks include pre-emptive contact isolation, systematic investigations to identify the source of the bacterium and thorough cleaning of equipment and environmental surfaces. As the clinical complexity and incidence of E. meningoseptica infections increase, there is a need for heightened awareness of the potential for this bacterium to cause outbreaks. This will permit timely initiation of active surveillance for infected/colonized patients as well as investigations to identify the likely source of the bacterium, which will, in turn, allow implementation of appropriate infection control measures. ª 2014 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved.
* Corresponding author. Address: Departments of Laboratory Medicine and Internal Medicine, National Taiwan University Hospital, No. 7 Chung-Shan South Road, Taipei 100, Taiwan. Tel.: þ886 2 23123456x65355; fax: þ886 2 23224263. E-mail address: [email protected] (P.R. Hsueh). 0195-6701/$ e see front matter ª 2014 The Healthcare Infection Society. Published by Elsevier Ltd. All rights reserved. http://dx.doi.org/10.1016/j.jhin.2014.01.009
S.S. Jean et al. / Journal of Hospital Infection 86 (2014) 244e249
Introduction Elizabethkingia meningoseptica (formerly Chryseobacterium meningosepticum or CDC II-a), an important member of the genus Chryseobacterium, is a non-motile, non-fastidious, catalase- and oxidase-positive, aerobic glucose-non-fermentative Gram-negative bacillus first defined by King in 1959.1,2 She used serological techniques to type strains isolated in epidemiological studies. Of the six serotypes (AeF) King described, type C was responsible for the majority of cases of meningitis.2 Among the Chryseobacterium spp., both E. meningoseptica and C. indologenes are most frequently isolated from soil, saltwater and freshwater and from dry and moist clinical environmental and equipment surfaces, intravenous lipid solutions, and municipal water supplies including those which have been adequately chlorinated. The latter sources greatly contribute to extensive contamination of healthcare settings.1,3e7 The clinical significance of C. indologenes is often questioned.8 Additionally, the fact that Chryseobacterium spp. have occasionally been cocultured with Acinetobacter baumannii, Pseudomonas aeruginosa, Enterobacter spp. or meticillin-resistant Staphylococcus aureus with E. meningoseptica from clinical samples complicates our understanding of the exact pathogenic role of E. meningoseptica.6,9,10 However, numerous studies have shown that E. meningoseptica infections tend to occur in patients with particular clinical characteristics in healthcare settings, and that those predisposing factors are similar to those seen in patients with C. indologenes infections.3,6,9,11e18 Cases of communityacquired sepsis caused by E. meningoseptica have also been reported.17,19e23 E. meningoseptica infections are associated with high mortality rates (23e52%), partly because of multidrug resistance.9,11,12 With continuing advances in healthcare, patients in intensive care units (ICUs) are increasingly at risk of E. meningoseptica infections and there should be heightened awareness of this emerging opportunistic pathogen in these settings. This review considers current knowledge on virulence factors and antimicrobial susceptibility of the bacterium; incidence, clinical characteristics, and predictors of clinical outcome of E. meningoseptica infection; and measures to prevent and control such infection.
Virulence factors Virulence factors of E. meningoseptica responsible for invasive disease are not fully understood. The bacterium produces an elastase which causes ophthalmia when injected into the eyes of rabbits, and death following intracerebral injection in mice.24 Despite in-vitro evidence of pathogenicity, this may not always correlate with in-vivo outcome. For example, one study found that Chryseobacterium spp. (C. indologenes, C. gleum, and E. meningoseptica) isolated from respiratory tract specimens from patients with cystic fibrosis were not significantly associated with compromised pulmonary function.25 Moreover, only a small percentage (
