Prevalence and Fluoroquinolone Resistance Pattern in Escherichia coli Isolates of Urinary Tract Infection (UTI) Patients

Background: Urinary tract infections (UTIs) are among the most common infectious diseases all over the world. Recent studies reported an increased antibiotic resistance in Escherichia coli, primary causative agent of UTI. The resistance has emerged even to more potent antimicrobial agents like fluoroquinolones. Objectives: The present study was undertaken to evaluate the prevalence and resistance pattern of E. coli causing UTIs in patients admitted to a tertiary care hospital in South India, with reference to fluoroquinolones. Material and Methods: A total of 278 selected urine samples of urinary tract infections were processed for E. coli culture using standard methods. For these urinary E. coli isolates, susceptibility to various antibiotics including fluoroquinolones was checked by Kirby Bauer disk diffusion method according CLSI criteria. Final resistance to fluoroquinolones isolates was analyzed. Results: Out of the 278 selected UTI clinical isolates 148 (54%) showed ciprofloxacin sensitive and 130 (46%) clinical isolates are ciprofloxacin resistant. Of the 130 ciprofloxacin resistant urinary isolates of E. coli subjected to susceptibility test for increased generation of fluoroquinolone drugs, the pattern of resistance noticed as levofloxacin (2nd generation) 79%, gatifloxacin (3rd generation) 77% and moxifloxacin (4th generation) 75%, respectively. The fluoroquinolone resistance in UTI clinical isolates was decreasing with increasing generations of fluoroquinolone. Quinolone drug resistance in clinical isolates was increasing with age and hospitalized patients. Conclusion: Study showed an increased fluoroquinolone resistance among uropathogenic E. coli isolates of UTI. These increased antibiotic resistance trends in UTI patients indicated that it is imperative to rationalize the use of antimicrobials and to use them conservatively.