Study of Urinary Isolates With Reference to Extended Spectrum Beta Lactamases Detection and Antibiogram

BACKGROUND: Extended spectrum beta lactamases continue to be major problem in clinical setups world over, conferring resistance to extended spectrum cephalosporins and are associated with significant morbidity and mortality.Urinary tract infections (UTIs) are one of the most common infectious diseases encountered in the clinical practice.Extended spectrum beta lactamases (ESBLs) production in gram negative bacteria, have emerged as a major problem in hospitalized as well as community based patients.ESBLs producing bacteria may not be detected by routine disc diffusion susceptibility test, leading to inappropriate use of antibiotics and treatment failure.The objective of this study was to determine the resistance patterns of the micro-organisms isolated from cases of UTI and to detect ESBLs production in gram negative bacteria.METHODS: Urinary isolates from symptomatic UTI cases (both in patients and out patients) attending the, Kesarsal Medical College and Hospital Ahmadabad were identified by conventional methods.Antimicrobial susceptibility testing was performed by Kirby Bauer's disc diffusion method gram negative isolates resistant to third generation cephalosporins were tested for ESBL production by two methods.RESULTS: Number of urinary isolates from patients with symptomatic UTI was 350 over a study period of one year.E.coli was the predominant isolate (57.7%) both in IPD and OPD patients.A total of 171 gram negative isolates resistant to third generation cephalosporins were tested for ESBL production by two methods-Modified Double Disc Synergy Test (CLSI) Phenotypic Confirmatory Test (PCT).ESBL production was seen in 36 (21.05%) isolates.Maximum ESBL production was seen in K. pneumoniae (22.41%) isolates followed by E.coli (13.26%).CONCLUSION: This study showed E.coli to be the predominant urinary pathogen isolated from UTI cases.Overall incidence of ESBL producing microorganisms was 21.05%.