gyrA mutations in ciprofloxacin-resistant Bartonella bacilliformis strains obtained in vitro.
We isolated and characterized mutants of Bartonella bacilliformis that are resistant to the fluoroquinolone antibiotic ciprofloxacin, which targets the A subunit of DNA gyrase. Mutants had single point mutations in the gyrA gene that changed either Asp-90 to Gly or Asp-95 to Asn and had 3- or 16-fold higher resistance, respectively, to ciprofloxacin than did wild-type B. bacilliformis. Asp-95 is homologous to Asp-87 of Escherichia coli GyrA and is a common residue mutated in fluoroquinolone-resistant strains of other bacteria. This is the first report of a mutation at an Asp-90 homologue, which corresponds to Asp-82 in E. coli GyrA.
Minnick
Michael F
MF
Division of Biological Sciences, The University of Montana, Missoula, Montana 59812, USA. mike.minnick@mso.umt.edu
Wilson
Zachary R
ZR
Smitherman
Laura S
LS
Samuels
D Scott
DS
D000595:Amino Acid Sequence; D001473:Bartonella / Q000187:drug effects / Q000235:genetics*; D002939:Ciprofloxacin / Q000494:pharmacology*; D027081:DNA Gyrase / Q000187:drug effects / Q000235:genetics*; D004352:Drug Resistance, Microbial / Q000235:genetics*; D017354:Point Mutation / Q000187:drug effects*
D002939:Ciprofloxacin; D027081:DNA Gyrase