title: Resistance mechanism of Acinetobacter spp. strains resistant to DW-116, a new quinolone.
abstract: DW-116 is a new fluoroquinolone antimicrobial agent with a broad spectrum. In order to elucidate the resistance mechanism to DW-116 in Acinetobacter spp. bacteria, total chromosomal DNA was isolated from 10 strains of Acinetobacter spp. resistant to DW-116. Quinolone resistance determinant region (QRDR) of DNA gyrase gene was amplified by PCR. The 345 bp nucleotide fragment yielded was inserted into pKF 3 which was used as the vector. Comparisons of the DNA sequences of 8 strains with that of the wild type strain revealed a Ser-83 to Leu mutation in mutants and all ten strains contained one silent mutation(T-->G) in QRDR. From Acinetobacter MB4-8 strain, DNA gyrase was isolated and purified, through no-vobiocin-sepharose, heparin-sepharose affinity column chromatography. The enzyme was composed of two subunits and the molecular mass of subunits A and B were 75.6 and 51.9 kDa, respectively. The supercoiling activity of the reconstituted DNA gyrase composed of subunit A from Acinetobacter MB4-8 and subunit B from E. coli was not inhibited by 128 micrograms/ml of ciprofloxacin. It might be said that one of the resistance mechanisms to DW-116 in A-cinetobacter MB4-8 was subunit A alteration of DNA gyrase.
authors.affiliation: College of Pharmacy, Seoul National University, Korea.
authors.forename: K H
authors.initials: KH
authors.lastname: Choi
authors.forename: M C
authors.initials: MC
authors.lastname: Baek
authors.forename: B K
authors.initials: BK
authors.lastname: Kim
authors.forename: E C
authors.initials: EC
authors.lastname: Choi
mesh_terms: D000150:Acinetobacter / Q000187:drug effects* / Q000201:enzymology / Q000235:genetics; D000151:Acinetobacter Infections / Q000382:microbiology; D000890:Anti-Infective Agents / Q000494:pharmacology*; D001483:Base Sequence; D004591:Electrophoresis, Polyacrylamide Gel; D024841:Fluoroquinolones; D008826:Microbial Sensitivity Tests; D008969:Molecular Sequence Data; D009154:Mutation; D010879:Piperazines / Q000494:pharmacology*; D016133:Polymerase Chain Reaction; D015363:Quinolones / Q000494:pharmacology*; D059005:Topoisomerase II Inhibitors
chemical_list: D000890:Anti-Infective Agents; C097673:DW-116; D024841:Fluoroquinolones; D010879:Piperazines; D015363:Quinolones; D059005:Topoisomerase II Inhibitors