ABSTRACT
Introduction: Treatment of extended spectrum betalactamase (ESBL) producing strains of Enterobacteriaceae has emerged as a major challenge in hospitalized critical as well as community based patients. Infections due to ESBL producers range from uncomplicated urinary tract infection to life threatening sepsis. Methods: We conducted a study to detect the presence of these enzymes in isolates in tertiary care hospital. A total 318 non-repetitive isolates were screened for resistance to any of five screening agents by CLSI (formerly NCCLS) disc diffusion method. Those with suspicious profile were checked for ESBL production by phenotypic confirmation test as recommended by CLSI Disc potentiation method. Various cephalosporin- b-lactamase inhibitor combinations were also tested. Results: Of the 269(84.59%) screen-positive isolates, only 219(81.41%) were identified as ESBL producers. From 219, only 136(62.10%) of Escherichia coli and 83(37.89%) Klebsiella pneumoniae were ESBL producers. Conclusion: Tests for the detection of ESBL producing Escherichia coli and Klebsiella pneumoniae should be carried out in all diagnostic centres routinely because drug resistance patterns are constantly changing.