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Indian Journal of Medical Microbiology, (2014) 32(1): 68-71

Brief Communication

Intravascular catheter related infections and antimicrobial susceptibility pattern of isolated bacteria in a tertiary care hospital of Bangladesh FJ Mansur, L Barai, MM Karim, JA Haq*, K Fatema, MO Faruq

Abstract The aim of this study was to evaluate the rate of bacterial colonisation and catheter related blood stream infections (CRBSI) together with the antibiotic susceptibility patterns in a tertiary care hospital. CRBSI was detected with semi-quantitative and quantitative methods. The antimicrobial susceptible patterns of the isolated organisms were performed by Kirby Bauer disk diffusion method. The rate of catheter colonisation and CRBSI were 42.1% and 14% (16.1/1000 catheter days) respectively. The most common causative pathogens were Pseudomonas sp. (23.7%), Acinetobacter sp. (18.4%), Staphylococcus aureus (13.2%) and Enterobacteriaceae (10.5%). The rate of isolation of methicillin resistance S. aureus, imipenem resistant Pseudomonas sp. and extended spectrum β lactamase producing Enterobacteriaceae were 60%, 44.0% and 100%. The result of this study would be useful for control and treatment of CRBSI. Key words: Antimicrobial susceptibility, catheter related blood stream infections, central venous catheter, tertiary care hospital

Introduction Vascular catheter related infections are the leading cause of nosocomial blood stream infections and are associated with significant mortality and morbidity.[1] Prevention of catheter related blood stream infections (CRBSI) is an essential objective when these devices are required. The type of catheter, reason for its use and manner in which it is used, as well as the specific characteristics of the patient in whom it is placed, are all factors affecting the risk of infection. Therefore, it is not surprising that CRBSI rates differ according to the institution and health-care unit under study.[2] Knowledge of the CRBSI in a particular centre *Corresponding author (email: [email protected]) Department of Microbiology, Stamford University Bangladesh, Department of Biological Chemistry, Yamaguchi University, 1677-1 Yoshida, Yamaguchi 753-8515, Japan, (FJM, MMK), Department of Microbiology, Bangladesh Institute of Research and Rehabilitation of Diabetes, Endocrine and Metabolic Disorders, Dhaka, (JAH, LB), Department of Biotechnology and Genetic Engineering, Islamic University, Kushtia -7003, Bangladesh, (MMK), Department of Critical Care Medicine of Microbiology, Bangladesh Institute of Research and Rehabilitation of Diabetes, Endocrine and Metabolic Disorders, Dhaka (KAF, MOF) Received: 24-05-2013 Accepted: 10-10-2013 Access this article online Quick Response Code:

Website: www.ijmm.org PMID: *** DOI: 10.4103/0255-0857.124321

is the first-step toward assessing the success of existing measures to prevent these infections and the need for further corrective measures.[3] The aim of this study was to evaluate the rate of bacterial colonisation of intravascular catheters and CRBSI by quantitative and semi-quantitative methods of catheter culture, together with the antibiotic susceptibility patterns of the isolated bacteria in a tertiary care hospital of Dhaka city, Bangladesh. Materials and Methods This study was conducted in a tertiary care hospital of Bangladesh. During a 6-month period (March to August 2010), 57 intravascular catheter (5 cm long tip) segments from 50 admitted patients in hospital were enrolled in the study. When a patient with a central venous catheter presented fever or a clinical process of sepsis of unknown origin, blood culture was performed, the catheter was removed and the tip was cultured. Microbiological procedures Blood cultures were performed by lytic centrifugation method.[4] Catheter cultures were carried out by using both the semi-quantitative method (proposed by Maki et al.,[5] in 1977) and the other quantitative method (modified Brun-Buisson method).[6] Bacterial and fungal isolates were identified by conventional standard methods.[7] Antibiotic susceptibility studies were performed by Kirby Bauer disc diffusion method.[8] The criteria for positivity in the semi-quantitative method was >15 CFU/plate[7] and for the quantitative method, it was >103 CFU/mL.[9] Extended spectrum production was detected

β lactamase by double disk

(ESBL) diffusion

January-March 2014 Mansur, et al.: Catheter related blood stream infections in a tertiary care hospital of Bangladesh

synergy test[10] and methicillin resistance of isolated Staphylococcus aureus (MRSA) was detected by 1 μg oxacillin disc.[11] Diagnostic criteria CRBSI CRBSI was defined as isolation of the same organism from semi-quantitative (more than 15 CFU) or quantitative culture (>103 CFU/mL) of a catheter tip and a peripheral blood culture with systemic inflammatory response syndrome, after exclusion of other infection sources.[12] Colonisation Colonisation of the catheter tip was defined as the finding of >15 CFU of bacteria in semi-quantitative culture or >103 CFU/mL in quantitative culture from the catheter tip in a patient without clinical symptoms of sepsis.[5] Result

Maki’s roll plate method were 75%, 89.8%, 54.5% and 91.7% where by using modified Brun-Buisson method were 87.5%, 91.8%, 63.7% and 97.8% respectively [Table 4]. Antibiotic resistance pattern for major isolated organisms was shown in [Table 5]. The rate of isolation of MRSA, imipenem resistant Pseudomonas sp. and ESBL producing Enterobacteriaceae were 60%, 44.4% and 100% among the respective isolated organisms. Discussion In this study, we investigate the rate of bacterial colonisation and infection associated with an intravascular catheter by quantitative and semi-quantitative method of catheter culture together with the antibiotic susceptibility patterns of the isolated bacteria in tertiary care hospital of Bangladesh. per

Of the 57 catheters studied, 32 (56.1%) of them had culture positive catheter tip by using two methods [Table 1]. Out of 50 patients, the incidence of colonisation was found 42.1% (48.3 cases/1000 catheter days) and CRBSI was 14% (16.1 cases/1000 catheter days) [Table 2]. Most common isolated pathogens associated with catheter colonisation and CRBSI were Pseudomonas sp., Aceinetobacter sp., S. aureus, Enterococcus, Staphylococcus epidermidis and Candida sp. percent of catheter associated with colonisation and CRBSI for respective organism was calculated as shown in [Table 3]. The sensitivity, specificity, positive predictive value and negative predictive value using Table 1: Catheter colonization and CRBSI by different catheter tip culture method Category Culture method Maki’s Modified Both Total roll plate Brun-Buisson Catheter 7 6 11 24 colonisation CRBSI 1 2 5 8 Total 8 8 16 32

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The incidence of colonisation was 42.1% (48.3 cases/1000 catheter days) and CRBSI was

Table 3: Isolated microorganisms associated with catheter colonisation and CRBSI Microorganism Catheters associated with (%)a Colonisation only CRBSI 20.0 37.5 Pseudomonas sp. 13.3 37.5 Acinetobacter sp. 16.7 Nil Staphylococcus aureus 10.0 Nil Staphylococcus epidermidis 6.7 12.5 Candida nonalbicans 6.7 Nil Enterococcus sp. 3.3 12.5 Flavobacterium sp. Others* 23.3 Nil *Others include Micrococcus sp., Klebsiella sp., Escherichia coli, and Cytobacter sp. a(%) catheters associated with colonisation or CRBSI: (Number of colonisation or CRBSI/Total number of colonisation or CRBSI)×100, CRBSI: Catheter related blood stream infection

Table 2: Rate of colonisation and CRBSI Variable Rate % Episodes/1000 catheter daysc Catheter colonisation 42.10a 48.3 16.1 CRBSI 14b

Table 4: Comparison of Maki’s roll plate and modified Brun-Buisson method for detection of CRBSI Parameter Diagnostic accuracy Maki’s roll Modified Brun-Buisson plate % method % a Sensitivity 75 87.5 89.8 91.8 Specificityb Positive 54.5 63.7 predictive valuec 91.7 97.8 Negative predictive valued

a Rate of colonisation: (Number of colonized catheter/Total catheter)×100, bRate of CRBSI: (Number of CRBSI/Total catheter)×100, CEpisodes/1000 catheter days: (Total episodes of CRBSI or colonisation/Total duration of catheter in situ)×1000, CRBSI: Catheter related blood stream infection

Sensitivity: (True positive×100)/(True positive+false negative), Specificity: (True negative×100)/(True negative+false positive), c Positive predictive value: True positive/(True positive+false positive), d Negative predictive value: True negative/(True negative+false negative), CRBSI: Catheter related blood stream infection

CRBSI: Catheter related blood stream infection

a

b

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Table 5: The antibiotic resistance pattern of major organisms isolated from the patients Percent isolates showing antibiotic resistance Pseudomonas sp. Acinetobacter sp. Enterobacteriace sp. Staphylococcus aureus Imipenem 44.0** 51.4 00 N Piperacillin 22.2 100 N N Piperacillin/Tazobactam 11.1 85.7 N N Amoxiclav N N 100* 60 Ceftriaxone 88.8 85.7 100 N Ceftazidime 55.5 85.7 100 N Cefotaxime 88.8 N N N Amikacin 66.6 71.4 00 60 Netilmicin 77.7 85.7 00 40 Gentamicin 66.6 85.7 00 60 Ciprofloxacin 55.5 85.7 25 80 Cotrimoxazole 44.4 71.4 N 40 Chloramphenicol 66.6 71.4 25 N Oxacillin N N N 60*** Vancomycin N N N 00 Clindamycin N N N 80 Antibiotics

N: Not studied, *100% Enterobacteriacae were ESBL producer, **44.0% Pseudomonas sp. were imipenem resistant, ***60% Staphylococcus aureus were resistant to methicillin, ESBL: Extended spectrum β lactamase

14% (16.1 cases/1000 catheter days) in our study. Chen et al., performed a study in 281 patients of a hospital of China and reported that, the rate of colonization of the catheter tip was 5% and CRBSI was 6%.[13] As shown in Table 3, the most common isolates from colonisation of the catheter tip were Pseudomonas sp. (20%), Acinetobacter sp. (13.3%) and S. aureus (16.7%) etc., and from CRBSI were Pseudomonas sp. (37.5%) and Acinetobacter sp. (37.5%). The relative high frequencies of Pseudomonas sp. and Acinetobacter sp. as predominant agents of catheter colonisation and CRBSI was probably due to most of these studied catheter (>50%) were collected from intensive care unit where chance of getting of infection with these two offending organism was very high. Which test is best for diagnosis of CRBSI has remained controversial. Seligman first proposed the use of quantitative culture of the catheter segment in 1974. Several years later, Maki et al., demonstrated that semi quantitative catheter segment culture was more accurate than quantitative culture of the catheter.[5] This study demonstrated the comparison of quantitative method (modified Brun-Buisson method) with the semi-quantitative method (Maki’s roll plate method) and shows both semi-quantitative and quantitative method had high sensitivity, specificity, negative predictive value and positive predictive value as shown in Table 4. Antibiotic resistant pattern of major organism isolated was shown in Table 5. Rate of multidrug resistance bacteria (e.g., MRSA, ESBL positive organism etc.) was high among the isolates, as the risk of developing infections with the resistant bacteria in hospitalised patients was high. One factor that was not investigated in this study is the cost and time required for the staff to carry out prospective

catheter monitoring. Although it was not an objective of the study, we estimated a daily time expenditure of two working hours, which is acceptable in a hospital similar to ours in size and characteristics. Our findings will help to implement educational and training programs on CRBSI for health personnel working in the designated area and it will enable better management of these devices with regard to prevention, diagnosis and treatment. References 1. 2.

3.

4.

5.

6.

7.

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Chatzinikolaou L, Raad II. Catheter-related infections. Iran J Clin Infec Dis. 2006;1:79-97. Zingg W, Sax H, Inan C, Cartier V, Diby M, Clergue F, et al. Hospital-wide surveillance of catheter-related bloodstream infection: From the expected to the unexpected. J Hosp Infect 2009;73:41-6. Delgado-Capel M, Capdevila-Morell JA, Sauca-Subias G, Ballester-Joya L, Vidal-Diez E, Yébenes-Reyes JC. Incidence of catheter-related bloodstream infection in a general hospital using two different detection methods. Enferm Infecc Microbiol Clin 2012;30:613-7. Cheesbrough M. Microbiological tests. In: District Laboratory Practice in Tropical Countries Part 2. 1st ed. UK: Cambridge University Press; 2002. p. 127. Maki DG, Weise CE, Sarafin HW. A semiquantitative culture method for identifying intravenous-catheter-related infection. N Engl J Med 1977;296:1305-9. Gutiérrez J, Leon C, Matamoros R, Nogales C, Martín E. Catheter-related bacteremia and fungemia. Reliability of two methods for catheter culture. Diagn Microbiol Infect Dis 1992;15:575-8. Colle JG, Miles RS, Watt B. Tests for the identification of bacteria. In: Mackie and Mac Cartney Practical Microbiology.

January-March 2014 Mansur, et al.: Catheter related blood stream infections in a tertiary care hospital of Bangladesh 14th ed. New York: Churchill Livingstone Inc.; 1996. p. 131-49. Bauer AW, Kirby WM, Sherris JC, Turck M. Antibiotic susceptibility testing by a standardized single disk method. Am J Clin Pathol 1966;45:493-6. 9. Liñares J, Sitges-Serra A, Garau J, Pérez JL, Martín R. Pathogenesis of catheter sepsis: A prospective study with quantitative and semiquantitative cultures of catheter hub and segments. J Clin Microbiol 1985;21:357-60. 10. Emery CL, Weymouth LA. Detection and clinical significance of extended-spectrum beta-lactamases in a tertiary-care medical center. J Clin Microbiol 1997;35:2061-7. 11. National Committee for Clinical Laboratory Standards. Performance Standards for Antimicrobial Susceptibility Testing M100-S11 Eleventh Informational Supplement. 8.

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Vol. 21. NCCLS, Villanova, PA, USA; 2001. 12. Mermel LA. Defining intravascular catheter-related infections: A plea for uniformity. Nutrition 1997;13:2S-4. 13. Chen HS, Wang FD, Lin M, Lin YC, Huang LJ, Liu CY. Risk factors for central venous catheter-related infections in general surgery. J Microbiol Immunol Infect 2006;39:231-6.

How to cite this article: Mansur FJ, Barai L, Karim MM, Haq JA, Fatema K, Faruq MO. Intravascular catheter related infections and antimicrobial susceptibility pattern of isolated bacteria in a tertiary care hospital of Bangladesh. Indian J Med Microbiol 2014;32:68-71. Source of Support: Nil, Conflict of Interest: None declared.

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Intravascular catheter related infections and antimicrobial susceptibility pattern of isolated bacteria in a tertiary care hospital of Bangladesh.

The aim of this study was to evaluate the rate of bacterial colonisation and catheter related blood stream infections (CRBSI) together with the antibi...
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