Comparative analysis of extended-spectrum beta-lactamases producing uropathogens in outpatient and inpatient departments

Abstract

INTRODUCTION: Since its discovery in 1980, extended-spectrum beta-lactamases (ESBL) have been prevalent throughout the world. Several new and more complicated resistance mechanisms have emerged and have driven the focus away from ESBLs. The present study was conducted to know the isolated prevalence and resistance profile of ESBL-producing Gram-negative uropathogens and outline an empirical therapy for management of urinary tract infections. MATERIALS AND METHODS: A study was conducted over a period of 3 months (April to June 2015) in the microbiology department of our 500-bedded tertiary care referral hospital. Urine specimens were processed as per standard guidelines. Antimicrobial susceptibility and ESBL detection were performed by Kirby–Bauer Disc diffusion method and results were interpreted as per CLSI 2015 guidelines. Production of other beta-lactamases was not studied. Klebsiella pneumoniae ATCC 700603 (ESBL positive) and Escherichia coli ATCC 25922 (ESBL negative) strains were used as quality control. P RESULTS: Of the 111 Gram-negative urinary isolates, 60 were ESBL positive (54%). ESBL prevalence was highest in E. coli (73.3%), followed by Klebsiella spp. (11.7%), Morganella spp. (6.7), Proteus mirabilis (5%), Pseudomonas spp. (1.6%), and Citrobacter spp. (1.6%). Most of the ESBL isolates were from outpatient department (OPD) (76.7%) while only 23.3% were from inpatient department (IPD), P CONCLUSION: ESBLs can cause therapeutic failure even when host appears to be susceptible in vitro. Hence, it is important to know its prevalence and antimicrobial susceptibility profile to formulate appropriate antibiotic policy.