PHENOTYPIC DETECTION OF FLUOROQUINOLONE RESISTANCE AMONG URINARY ISOLATES OF ENTEROBACTERIACEAE

Abstract

BACKGROUND - Fluoroquinolones are the preferred antimicrobial agents for empirical therapy of UTI. Resistance among the different classes of antimicrobials including   fluoroquinolones has arisen in a multitude of bacterial species in the hospitals and in the community. AIM - The main purpose of the study was 1) To evaluate the antibiotic susceptibility pattern of urinary isolates. 2) To evaluate the ciprofloxacin resistance. 3) To determine the ESBL production among the ciprofloxacin resistant isolates. MATERIALS AND METHODS - A total of 100 Enterobacteriaceae isolates from urine samples over a period of three months were subjected to antibiotic susceptibility testing. Isolates with decreased susceptibility to ciprofloxacin were then subjected to minimum inhibitory concentration (MIC)  determination by E-test and macrobroth dilution method. The ESBL production among ciprofloxacin resistant isolates were confirmed by phenotypic confirmatory double disc diffusion method as per CLSI guidelines. Multi- Drug Resistant strains were identified among the isolates. RESULTS - Out of 100  isolates,34 percentage of isolates were resistant to ciprofloxacin and 38 percentage of isolates to norfloxacin. The MIC of these isolates ranged from 4 to 128 micro gram per ml. Results of the disc diffusion and MIC by macrobroth dilution ,E-test method correlated well with each other. All of these ciprofloxacin  resistant isolates were ESBL producers. MDR was found in 21 percentage of the isolates. CONCLUSION - This study   demonstrates a high incidence of ciprofloxacin resistance among urinary isolates and the association of multi-drug                resistance among these isolates. Therefore this study illustrates the need for a continuous evaluation of the commonly used antibiotics in the therapy of uropathogens and rational use of antibiotics.