Quinolone-resistance mutations in the topoisomerase IV parC gene of Acinetobacter baumannii.
Mutations in the parC gene, which encodes a subunit of topoisomerase IV, were determined in 21 epidemiologically unrelated clinical isolates of Acinetobacter baumannii. Our studies highlight the conserved sequences in the quinolone-resistance-determining region of the parC gene from A. baumannii and other bacteria. Nine of ten isolates with MICs of ciprofloxacin of > or = 32 mg/L showed a change of Ser80 to Leu and one showed a change of Glu84 to Lys. These results suggest that ParC from A. baumannii is a secondary target for quinolones and that mutations at residues Ser80 and Glu84, when combined with mutations at Ser83 of GyrA, may render A. baumannii highly resistant to quinolones.
Vila
J
J
Department of Microbiology, Hospital Clínic, School of Medicine, University of Barcelona, Spain. vila@microclinic.med.ub.es
Ruiz
J
J
Goñi
P
P
Jimenez de Anta
T
T
D000150:Acinetobacter / Q000187:drug effects / Q000235:genetics*; D000595:Amino Acid Sequence; D000890:Anti-Infective Agents / Q000494:pharmacology; D001483:Base Sequence; D002939:Ciprofloxacin / Q000494:pharmacology; D027101:DNA Topoisomerase IV; D004264:DNA Topoisomerases, Type I / Q000235:genetics*; D004250:DNA Topoisomerases, Type II / Q000235:genetics*; D004352:Drug Resistance, Microbial / Q000235:genetics; D005798:Genes, Bacterial / Q000235:genetics*; D008969:Molecular Sequence Data; D017354:Point Mutation; D017386:Sequence Homology, Amino Acid
D000890:Anti-Infective Agents; D002939:Ciprofloxacin; D027101:DNA Topoisomerase IV; D004264:DNA Topoisomerases, Type I; D004250:DNA Topoisomerases, Type II