Nucleotide sequence of the gyrA gene of Arcobacter species and characterization of human ciprofloxacin-resistant clinical isolates

The nucleotide sequence of the gyrA gene of Arcobacter butzleri, Arcobacter cryaerophilus, Arcobacter cibarius, and Arcobacter skirrowii was determined. The deduced GyrA proteins are closely related to those of Wolinella succinogenes and Helicobacter pullorum, whereas those of Campylobacter species showed less sequence identity. The phylogenetic analysis of GyrA sequences provides a result similar to 16S rRNA gene sequence phylogenetic analysis and allows the discrimination among A. butzleri species. In addition, a Thr -> Ile mutation at amino acid 85 in the quinolone resistance-determining region was associated with ciprofloxacin resistance for two A. butzleri and one A. cryaerophilus ciprofloxacin-resistant strains.