title: DNA gyrase gyrA mutations in ciprofloxacin-resistant strains of Staphylococcus aureus: close similarity with quinolone resistance mutations in Escherichia coli.
abstract: The gyrA genes isolated from three ciprofloxacin-resistant clinical isolates of Staphylococcus aureus carried codon 84 (serine----leucine) and/or codon 85 (serine----proline) mutations that were absent in pretreatment susceptible strains. These substitutions occur in a region of the gyrase A protein wherein directly analogous mutations of serine 83----leucine and alanine 84----proline in Escherichia coli confer quinolone resistance. Thus, DNA gyrase A subunit mutations are implicated in resistance to ciprofloxacin in S. aureus.
authors.affiliation: Department of Cellular and Molecular Sciences, St. George's Hospital Medical School, University of London, United Kingdom.
authors.forename: S
authors.initials: S
authors.lastname: Sreedharan
authors.forename: M
authors.initials: M
authors.lastname: Oram
authors.forename: B
authors.initials: B
authors.lastname: Jensen
authors.forename: L R
authors.initials: LR
authors.lastname: Peterson
authors.forename: L M
authors.initials: LM
authors.lastname: Fisher
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D015139:Blotting, Southern; D002939:Ciprofloxacin / Q000494:pharmacology*; D004250:DNA Topoisomerases, Type II / Q000235:genetics*; D004352:Drug Resistance, Microbial; D004926:Escherichia coli / Q000235:genetics; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D015183:Restriction Mapping; D013211:Staphylococcus aureus / Q000187:drug effects / Q000235:genetics*
chemical_list: D002939:Ciprofloxacin; D004250:DNA Topoisomerases, Type II