Phenotypic detection of ESBL and MBL in Gram Negative bacilli isolated from clinical specimens

Abstract

Introduction: Antimicrobial resistance is a growing threat worldwide. The prevalence of Extended spectrum beta lactamases (ESBLs) and Metallobetalactamases (MBL) among Gram negative bacilli constitutes a serious threat to current beta-lactam therapy leading to treatment failure. Material and Methods: ESBL was detected by double disc diffusion test using ceftazidime alone and in combination with clavulanic acid. MBL detection was done by Imipenem EDTA combined disc diffusion test. Results: Out of 549 Gram negative bacilli resistant to 3G cephalosporin, 179(32.60%) were ESBL producers and out of 236 Gram negative bacilli resistant to carbapenem, 47(19.19%) were MBL producers. ESBL production was observed in E.coli, Klebsiella spp. Proteus spp and Citrobacter spp, while MBL production was observed in Pseudomonas aeruginosa, Acinetobacter spp, E.coli and Klebsiella spp isolated from various clinical samples. Conclusion: Simple disc method can be routinely employed to detect these common resistance mechanisms which will reduce the mortality and also spread of such resistant strains.