title: Role of gyrA mutation and loss of OprF in the multiple antibiotic resistance phenotype of Pseudomonas aeruginosa G49.
abstract: A clinical isolate of Pseudomonas aeruginosa G48, became resistant during fluoroquinolone treatment giving rise to the post-therapy isolate, G49. To determine whether mutation in gyrA gave rise to fluoroquinolone resistance, G49 was transformed with a plasmid encoding gyrA (pNJR3-2); this reduced the MIC of fluoroquinolones for G49 two-fold. DNA sequencing of gyrA of G49 demonstrated a mutation at Thr-83, substituting with isoleucine. The outer membrane of G49 was shown to lack OprF, suggesting that loss of this protein may be involved in the multiple antibiotic resistance phenotype; however, when G49 was transformed with a plasmid encoding oprF (pRW5), expression of oprF was shown to have no effect upon the phenotype.
authors.affiliation: Department of Infection, Medical School, University of Birmingham, UK.
authors.forename: L
authors.initials: L
authors.lastname: Pumbwe
authors.forename: M J
authors.initials: MJ
authors.lastname: Everett
authors.forename: R E
authors.initials: RE
authors.lastname: Hancock
authors.forename: L J
authors.initials: LJ
authors.lastname: Piddock
mesh_terms: D000890:Anti-Infective Agents / Q000494:pharmacology; D001483:Base Sequence; D027081:DNA Gyrase; D004250:DNA Topoisomerases, Type II / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics; D018432:Drug Resistance, Multiple / Q000235:genetics*; D024841:Fluoroquinolones; D005798:Genes, Bacterial; D006801:Humans; D009154:Mutation; D010641:Phenotype; D010957:Plasmids / Q000235:genetics; D018272:Porins / Q000235:genetics*; D011552:Pseudomonas Infections / Q000188:drug therapy / Q000382:microbiology; D011550:Pseudomonas aeruginosa / Q000187:drug effects* / Q000235:genetics* / Q000302:isolation & purification; D014170:Transformation, Genetic
chemical_list: D000890:Anti-Infective Agents; D004269:DNA, Bacterial; D024841:Fluoroquinolones; D018272:Porins; D027081:DNA Gyrase; D004250:DNA Topoisomerases, Type II