Use of a LightCycler gyrA mutation assay for identification of ciprofloxacin-resistant Campylobacter coli.

A fluorescence resonance energy transfer-based assay has been employed to detect mutations at the 86 codon in the DNA gyrase A (gyrA) gene in Campylobacter coli strains. These mutations were associated with ciprofloxacin resistance in strains isolated in Italy in 2000. The mutations in the gyrA gene were detected by real-time PCR amplification followed by hybridization with two fluorescent probes designed with sequences complementary to the wild-type C. coli gyrA gene. Mutation detection was performed by melting peak analysis of the probe-PCR product hybrid performed on a LightCycler (Roche Diagnostic). This gyrA mutation assay allows a rapid and reproducible screening method of ciprofloxacin-resistant C. coli strains.