Prevalence and antimicrobial resistance pattern with special reference to extended spectrum β-lactamase producing klebsiella isolates in a tertiary care hospital

Extended spectrum β- lactamases (ESBLs) are a group of enzymes which confer resistance to cephalosporins, monobactams and related oxyimino β-lactams. ESBLs are encoded by transferable conjugative plasmids which may also carry resistant determinants to other antimicrobials like aminoglycosides, limiting treatment options. ESBL’s are more prevalent in Klebsiella spp. than any other members of family enterobacteriaceae. The present study was carried out to determine the antimicrobial susceptibility pattern and to detect ESBL production in Klebsiella spp. from clinical isolates in a tertiary care hospital. 100 isolates of Klebsiella spp. derived from various clinical specimens processed as per the standard guidelines were considered for the present study. Antimicrobial susceptibility testing by Kirby-Bauer technique was done according to Clinical Laboratory Standards Institute (CLSI) 2011 guidelines. 41 Klebsiella isolates which were considered presumptively positive for ESBL production by Kirby-Bauer method were later confirmed by the phenotypic double disc diffusion test using cefotaxime & cefotaxime/clavulanic acid discs. An increase of >/= 5 mm in the latter disc was considered as confirmatory. A majority of these isolates were also resistant to aminoglycosides. All isolates were found to be susceptible to carbapenems. The study revealed a high prevalence of ESBL producing Klebsiella spp. in our hospital. Enhanced infection control, coupled with antibiotic stewardship programs backed by simple and effective detection methods are required to limit the spread of ESBL-producers.