Frequency of extended spectrum beta lactamase producing gram negative bacilli among clinical isolates

ABSTRACT

Extended-spectrum beta-lactamase [ESBL]-producing bacteria are emerging pathogens. They are descended by genetic mutation from native beta-lactamases found in gram negative bacteria, especially infectious strains of Escherichia coli and Klebsiella species. Clinicians, microbiologists, infection control practitioners, and hospital epidemiologists are concerned about ESBL-producing bacteria because of the increasing incidence of such infections, the limitations of effective antimicrobial drug therapy, and adverse patient outcomes. The present study was undertaken to determine the frequency of ESBL producing gram negative bacilli recovered from clinical specimens in our setup. A total of 3099 gram negative isolates recovered from various clinical samples during the period of January 2007 to December 2008 were processed for the detection of ESBL production. Among them 35.5% bacterial strains were found to be ESBL producers. The commonest ESBL producing organism isolated was Escherecia coli [44.8%], followed by Klebsiella pneumoniae [38.6%]. Production of ESBLs by gram negative bacteria is emerging as a widespread problem in our setup. Appropriate infection control and antibiotic management strategies are needed to stem the spread of this emerging form of resistance