Phenotypic detection of extended spectrum, AmpC, Metallo beta-lactamases and their coexistence in clinical isolates of commonly isolated gram negativebacteria in GKGH hospital, Bhuj

Abstract Broad-spectrum beta lactam antibiotics are the most commonly used antibiotics in the clinical setting. Resistance to these beta lactam antibiotics mediated by extended spectrum beta lactamases (ESBLs), AmpC beta lactamases and Metallo beta lactamases (MBLs) enzymes is an increasing common public health problem. Determination of their prevalence is essential for epidemiological purpose and to formulate an effective antibiotic policy to avoid treatment failure. A total of 934 clinical isolates comprising of Escherichia coli, Klebsiella pneumoniae, Proteus spp. And A cinetobacter baumannii, which were recovered from various clinical specimens over a period of a year i.e., from January 2017 to December 2017, were studied. Antibiogram profile was determined by Kirby-Bauer disc diffusion method and was interpreted by using CLSI guidelines. Detection of ESBL was done using ceftazidime and ceftazidime-clavulanic acid combination discs method, AmpC producers were detected by AmpC disc test and MBL production was done using Imipenem-EDTA combined disc test. Among 934 isolates 246(26.3%) strains were ESBL producers, 91(9.7%) AmpC producers and 143(15.3%) were MBL producers. The co-production of ESBL/AmpC/MBL beta lactamases was observed in 160(17.1%). The study emphasizes the need for the early detection of isolates that produce these enzymes to avoid therapeutic failures and nosocomial outbreaks. Keywords: Extended spectrum beta-lactamases, AmpC beta-lactamases, Metallo beta-lactamases, Prevalence, Co-production. Introduction There are many mechanisms for beta lactam antibiotics becoming resistance in treating the bacterial infections one of the most important mechanism involved is the production of beta lactamases enzymes, such as extended-spectrum beta-lactamases (ESBL), AmpC beta-lactamases and carbapenemases.[1] ESBLs are enzymes capable of cleaving third-generation cephalosporins and aztreonam.[2] ESBLs are inhibited by clavula