Prevalence of mutations within the quinolone resistance-determining region of gyrA, gyrB, parC, and parE and association with antibiotic resistance in quinolone-resistant Salmonella enterica

Eaves, D. J., Randall, L., Gray, D. T., Buckley, A., Woodward, M. J., White, A. P. and Piddock, L. J. V. (2004) Prevalence of mutations within the quinolone resistance-determining region of gyrA, gyrB, parC, and parE and association with antibiotic resistance in quinolone-resistant Salmonella enterica. Antimicrobial Agents and Chemotherapy, 48 (10). pp. 4012-4015. ISSN 1098-6596 doi: 10.1128/aac.48.10.4012-4015.2004

Abstract/Summary

Salmonella enterica isolates (n = 182) were examined for mutations in the quinolone resistance-determining region of gyrA, gyrB, parC, and parE. The frequency, location, and type of GyrA substitution varied with the serovar. Mutations were found in parC that encoded Thr57-Ser, Thr66-Ile, and Ser80-Arg substitutions. Mutations in the gyrB quinolone resistance-determining region were located at codon Tyr420-Cys or Arg437-Len. Novel mutations were also found in parE encoding Glu453-Gly, His461-Tyr, Ala498-Thr, Val512-Gly, and Ser518-Cys. Although it is counterintuitive, isolates with a mutation in both gyrA and parC were more susceptible to ciprofloxacin than were isolates with a mutation in gyrA alone.