Prevalence of extended spectrum β-lactamase (ESBL) producing E. coli and Klebsiella species in urinary isolates

Introduction: Bacterial resistance to β-lactam antibiotics has risen dramatically, with extended spectrum βlactamase (ESBL) contributing to this increase. Early identification of ESBL production is becoming increasingly important. Methodology: A total of 367 consecutive, urine samples from patients suspected to have UTI, were processed. All Escherichia coli and Klebsiella species isolated in significant numbers were included. The isolates were identified by standard microbiological procedures and AST was done according to CLSI guidelines. The isolates were tested for susceptibility to third generation cephalosporins and then tested for Double disc synergy test (DDST) & Phenotypic confirmatory disc diffusion test (PCDDT). Result: Out of 367 urine samples processed in the study, 271 yielded various bacterial isolates. Of these, 96 were Escherichia coli and 58 were Klebsiella species. Out of these total 154 isolates, 117 showed resistance to any one of the three cephalosporins tested. ESBL production was observed in 89(57.79%) isolates by PCDDT. DDST failed to detect ESBLs in four isolates of E.coli and two isolates of Klebsiella spp. Conclusion: The practice of routine ESBL testing for uropathogens along with conventional antibiogram would be useful for all cases which will help in the proper treatment of the patients and also prevent further development of bacterial drug resistance.