title: Experimental and clinical studies on fluoroquinolone-insusceptible Escherichia coli isolated from patients with urinary tract infections from 1994 to 2007.
abstract: Urinary tract infections (UTIs) due to fluoroquinolone-insusceptible Escherichia coli have become increasingly common in recent years. We investigated the potential relationships between clinical measures to combat fluoroquinolone-insusceptible E. coli and experimental analyses on E. coli isolates. Over a 14-year period from 1994 through 2007, a total of 828 E. coli isolates were collected from patients (one isolate per patient) with UTI at the urology ward of Okayama University Hospital. We analyzed the mutations in quinolone resistance-determining regions of DNA gyrase (gyrA) and topoisomerase IV (parC). The production of biofilm by these isolates was also examined and the associated medical records were retrospectively reviewed. Seven of 189 (3.7%) strains from uncomplicated UTIs and 82 of 639 (12.8%) strains from complicated UTIs were insusceptible to fluoroquinolones. Amino acid replacements of type II topoisomerases were frequently observed at positions 83 and 87 in GyrA and at positions 80 and 84 in ParC. No significant difference in the biofilm-forming capabilities was observed between fluoroquinolone-susceptible and -insusceptible E. coli. Our study suggests that biofilm formation of fluoroquinolone-insusceptible E. coli isolates is not a major mechanism of resistance in patients with UTI.
authors.affiliation: Department of Urology, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama 700-8558, Japan.
authors.forename: Koichiro
authors.initials: K
authors.lastname: Wada
authors.forename: Reiko
authors.initials: R
authors.lastname: Kariyama
authors.forename: Ritsuko
authors.initials: R
authors.lastname: Mitsuhata
authors.forename: Shinya
authors.initials: S
authors.lastname: Uehara
authors.forename: Toyohiko
authors.initials: T
authors.lastname: Watanabe
authors.forename: Koichi
authors.initials: K
authors.lastname: Monden
authors.forename: Hiromi
authors.initials: H
authors.lastname: Kumon
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D019943:Amino Acid Substitution; D000900:Anti-Bacterial Agents / Q000494:pharmacology / Q000627:therapeutic use; D018441:Biofilms; D002648:Child; D004250:DNA Topoisomerases, Type II / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects / Q000201:enzymology / Q000235:genetics; D004927:Escherichia coli Infections / Q000188:drug therapy*; D005260:Female; D024841:Fluoroquinolones / Q000494:pharmacology / Q000627:therapeutic use; D006801:Humans; D008297:Male; D008875:Middle Aged; D009154:Mutation; D014552:Urinary Tract Infections / Q000188:drug therapy / Q000382:microbiology; D055815:Young Adult
chemical_list: D000900:Anti-Bacterial Agents; D024841:Fluoroquinolones; D004250:DNA Topoisomerases, Type II