title: Determination of ciprofloxacin and nalidixic acid resistance in Campylobacter jejuni with a fluorogenic polymerase chain reaction assay.
abstract: A fluorogenic polymerase chain reaction assay for the gyrA gene was used to determine the frequency of a Thr-86 mutation in Campylobacter jejuni isolates from food animals and humans in northern Thailand and to investigate the correlation between this mutation and bacterial resistance to fluoroquinolones. Eighty-four isolates of C. jejuni were used: 65 from healthy chickens on farms, 16 from chickens at the slaughterhouse, 1 from chicken meat at the market, and 1 from a healthy farm worker. The microbroth dilution technique was used for in vitro susceptibility testing. MIC breakpoints established by the National Antimicrobial Resistance Monitoring System were used to categorize the resistance of C. jejuni to ciprofloxacin and nalidixic acid. Sixty of the 84 C. jejuni isolates tested carried the Thr-86 mutation in the gyrA gene. All isolates with ciprofloxacin MICs of > or = 2 mg/liter carried the mutation, and no isolates with nalidixic acid MICs of < or = 16 mg/liter carried the Thr-86-to-Ile mutation. There was a very strong association between ciprofloxacin resistance and the presence of the mutation (kappa = 0.971, P < 0.01). The association between the presence of the Thr-86-to-Ile mutation and nalidixic acid resistance was weaker (kappa 0.859: P < or = 0.01).
authors.affiliation: Population Medicine Center, A109 Veterinary Clinical Center, Michigan State University, East Lansing, Michigan 48824-1314, USA.
authors.forename: Pawin
authors.initials: P
authors.lastname: Padungtod
authors.forename: John B
authors.initials: JB
authors.lastname: Kaneene
authors.forename: David L
authors.initials: DL
authors.lastname: Wilson
authors.forename: Julia
authors.initials: J
authors.lastname: Bell
authors.forename: John E
authors.initials: JE
authors.lastname: Linz
mesh_terms: D000003:Abattoirs; D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology*; D016123:Campylobacter jejuni / Q000187:drug effects* / Q000235:genetics; D002939:Ciprofloxacin / Q000494:pharmacology*; D027081:DNA Gyrase / Q000235:genetics; D017931:DNA Primers; D004269:DNA, Bacterial / Q000032:analysis; D024881:Drug Resistance, Bacterial; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D009268:Nalidixic Acid / Q000494:pharmacology*; D017354:Point Mutation; D016133:Polymerase Chain Reaction
chemical_list: D000890:Anti-Infective Agents; D017931:DNA Primers; D004269:DNA, Bacterial; D009268:Nalidixic Acid; D002939:Ciprofloxacin; D027081:DNA Gyrase