title: Mutation rate of avian intestinal coliform bacteria when pressured with fluoroquinolones.
abstract: The purpose of this study was to determine the rate at which resistance developed in avian coliform bacteria when exposed to nalidixic acid, sarafloxacin, or enrofloxacin. In in vitro studies, the rates of mutation of avian isolates of Escherichia coli and Salmonella were determined following nalidixic acid, sarafloxacin, or enrofloxacin pressure. The rates of mutation were similar for nalidixic acid and sarafloxacin, whereas a lower rate of mutation was seen after enrofloxacin pressure. In in vivo studies, the quinolones were administered in the drinking water to broiler chickens at a concentration of 40 ppm for five consecutive days. Samples of feces were inoculated onto appropriate media and the frequency of resistance was determined. The frequency rates of resistance to nalidixic acid and sarafloxacin were similar. Enrofloxacin-medicated birds did not develop enrofloxacin-resistant coliform bacteria. The in vitro and in vivo data appear to correlate.
authors.affiliation: Department of Medical Microbiology, College of Veterinary Medicine, University of Georgia, Athens 30602, USA.
authors.forename: W M
authors.initials: WM
authors.lastname: Medders
authors.forename: R E
authors.initials: RE
authors.lastname: Wooley
authors.forename: P S
authors.initials: PS
authors.lastname: Gibbs
authors.forename: E B
authors.initials: EB
authors.lastname: Shotts
authors.forename: J
authors.initials: J
authors.lastname: Brown
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D002645:Chickens; D002939:Ciprofloxacin / Q000031:analogs & derivatives / Q000494:pharmacology / Q000627:therapeutic use; D000077422:Enrofloxacin; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics*; D004927:Escherichia coli Infections / Q000517:prevention & control / Q000662:veterinary*; D024841:Fluoroquinolones; D008826:Microbial Sensitivity Tests; D016296:Mutagenesis; D009152:Mutagenicity Tests; D009268:Nalidixic Acid / Q000494:pharmacology / Q000627:therapeutic use; D011201:Poultry Diseases; D015363:Quinolones / Q000494:pharmacology / Q000627:therapeutic use; D012475:Salmonella / Q000187:drug effects / Q000235:genetics*; D012481:Salmonella Infections, Animal / Q000517:prevention & control*
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D015363:Quinolones; D009268:Nalidixic Acid; D000077422:Enrofloxacin; D002939:Ciprofloxacin; C047224:sarafloxacin