Antimicrobial Susceptibility Testing For Escherichia Coli Strains To Fluoroquinolones, in Urinary Tract Infections

Background: urinary tract infect ions (utls) are one of the most common infectious diseases diagnosed all over the world .meanwhile most episode of utls are caused by escherichia coli (up to 85%) and frequently tluoroquinolones are preferredas initial agents for empiric therapy of utis. widespread use of tluoroquinolones has resulted in an increa sing incidence ofresistance these agents all over the world. the aim of this study was to assess, susceptibility of escherichia coli strains fromuti patients against common tluoroquinolones. methods: antimicrobial susceptibility testing was determined by disk agardiffusion (dad) and minimal inhibitory concentration methods as described by the national corrunittee for clinicallaboratory standards (nccls). results: one hundred sixty four clinical isolates of e. coli were collected by urine culturesfrom patients with uti. the extent of resistant to nalidixic acid, ofloxacin, nortloxacin and ciprotloxacin, by disk diffusionmethod was 49.3%,44.5%,41.4% and 40.2%, respectively. resistance to ciprotloxacin by mic method was 42.1%. conclusion:this study represents high level resist ant of e. coli isolates from uti patients. it is becau se of inappropriate and incorrectadministration of antimicrobial agents in blind cases. this problem remarks significance of performing antimicrobialsusceptibility testing before empiric antibiotic therapy. to overcome this problem use of unnec essary antibiotics therapyshould be limited.