ABSTRACT
PURPOSE: The increased use of antibiotics may be the main factor responsible for the development and spread of bacterial resistance. This study demonstrated the relation between quinolone use and the rate of isolating ciprofloxacin-resistant(CIPRO-R) Escherichia coli(E.coli) in patients with urinary tract infection(UTI). MATERIALS AND METHODS: From 2001 to 2006, we determined antimicrobial use for 2,803 in terms of the defined daily dose(DDD) and the antimicrobial use density(AUD), and we surveyed the isolation rates of CIPRO-R E.coli in UTIs in both inpatients and outpatients. We also analyzed the correlation between the number of prescriptions and the resistance rates. RESULTS: Of the 637(22.7%) CIPRO-R E.coli isolates, 297(46.6%) were from inpatients and 340(53.4%) were from outpatients. There was a statistically significant correlation between the rate of isolating CIPRO-R E.coli and the amount of quinolone use for the inpatients(r=0.815, p<0.05) as well as the outpatients(r=0.804, p<0.05). A logistic regression analysis identified previous quinolone use as the independent risk factor(odd ratio: 2.604 [95% confidence interval(CI): 1.639-4.137]) for CIPRO-R E.coli in inpatients. Also, these CIPRO-R E.coli showed low sensitivity to ampicillin and trimethoprim/sufamethoxazole(TMP/SMX) in the inpatients(10.4%, 27.3%) and outpatients(5.1%, 27.1%), respectively. CONCLUSIONS: Our study shows a significant correlation between ciprofloxacin resistance and quinolone use, and previous quinolone use seems to be the risk factor for CIPRO-R E.coli bacteriuria. It is necessary to keep antimictrobial therapy under constant surveillance for the prevention of CIPRO-R E.coli.