Occurrence of extended spectrum beta-lactamases among Enterobacteriaceae spp. isolated at a tertiary care institute.

Increasing resistance to third generation cephalosporins has become a cause for concern especially among Enterobacteriaceae that cause nosocomial infections. The prevalence of extended spectrum beta-lactamases (ESBLs) among members of Enterobacteriaceae constitutes a serious threat to current beta-lactam therapy leading to treatment failure and consequent escalation of costs. A detailed study was initiated to identify the occurrence of ESBLs among the Enterobacteriaceae isolates at a tertiary care hospital using the double disk potentiation technique. Antibiogram profiles were determined to commonly used antibiotics and confirmation of ESBLs production was carried out by the disk diffusion assay using ceftazidime and cefotaxime in the presence and absence of clavulanic acid. Our results indicate that the majority of ESBLs were expressed in Escherichia coli.