Prevalence of extended-spectrum beta-lactamase producing gram negative isolates in Enterobacteriaceae group of bacteria in clinical samples from a tertiary care hospital

Abstract

Introduction: Extended spectrum β-lactamases (ESBLs) are enzymes that intervene resistance to extended-spectrum (third generation) cephalosporins (e.g., ceftazidime, cefotaxime, and ceftriaxone) and but do not affect carbapenems (e.g., meropenem or imipenem). Though the number of ESBLs producing organism has been increasing day by day, the detection methods and treatment option for them are extremely limited. Objective: Objective of the study was to investigate the rate of ESBLs production and their antibiotic susceptibility pattern. Materials and method: A total 200 Gram negative isolates from various clinical samples received in microbiology laboratory, Sir Takhtsinhji General Hospital, Bhavnagar were studied and Antibiotic susceptibility test was done for commonly used antibiotics. A hospital-based study was conducted in microbiology laboratory, Sir Takhtsinhji General Hospital, Bhavnagar from February 2012 to August 2012. A total of 200 Gram negative isolates from various clinical samples were collected and identified using the conventional biochemical tests following the Clinical and Laboratory Standard Institute (CLSI) guidelines. Antimicrobial susceptibility testing (AST) was performed using the standardized Kirby-Bauer disk diffusion method. Results: Among the total isolates 89(44.5%) were ESBLs producer, and the rate of ESBLs positivity was 39.8% for E. coli (33 out of 83), 10% for Proteus mirabilis (1 out of 10), 51.4% for Klebsiella spp (55 out of 107). ESBLs producing organisms were resistant to most of the antibiotics but 100% were sensitive to imipenem, meropenem, and cefoperazone + sulbactam. Conclusion: Screening for ESBLs production requires to be carried out regularly in all clinical diagnostic laboratories to direct clinicians in appropriate selection of antibiotics.

Keywords

• β-lactamases
• esbls
• multidrug resistance
• kirby-bauer disk diffusion
• e. coli
• k. pneumonia
• proteus mirabilis