title: 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.
abstract: 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-Leu. 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.
authors.affiliation: Antimicrobial Agents Research Group, Division of Immunity and Infection, University of Birmingham, Birmingham B15 2TT, United Kingdom.
authors.forename: Deborah J
authors.initials: DJ
authors.lastname: Eaves
authors.forename: Luke
authors.initials: L
authors.lastname: Randall
authors.forename: Douglas T
authors.initials: DT
authors.lastname: Gray
authors.forename: Antony
authors.initials: A
authors.lastname: Buckley
authors.forename: Martin J
authors.initials: MJ
authors.lastname: Woodward
authors.forename: Allan P
authors.initials: AP
authors.lastname: White
authors.forename: Laura J V
authors.initials: LJ
authors.lastname: Piddock
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology*; D002939:Ciprofloxacin / Q000494:pharmacology; D003062:Codon / Q000235:genetics; D027081:DNA Gyrase / Q000235:genetics* / Q000502:physiology; D017931:DNA Primers; D027101:DNA Topoisomerase IV / Q000235:genetics* / Q000502:physiology; D004264:DNA Topoisomerases, Type I; D024881:Drug Resistance, Bacterial / Q000235:genetics*; D016521:Electrophoresis, Gel, Pulsed-Field; D008826:Microbial Sensitivity Tests; D015363:Quinolones / Q000494:pharmacology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D019779:Salmonella enterica / Q000187:drug effects* / Q000235:genetics*
chemical_list: D000900:Anti-Bacterial Agents; D003062:Codon; D017931:DNA Primers; D015363:Quinolones; D002939:Ciprofloxacin; D027101:DNA Topoisomerase IV; D004264:DNA Topoisomerases, Type I; D027081:DNA Gyrase