title: Activity of clinafloxacin, compared with six other quinolones, against Acinetobacter baumannii clinical isolates.
abstract: The in vitro activity of clinafloxacin was studied in comparison with ciprofloxacin, levofloxacin, moxifloxacin, nalidixic acid, sparfloxacin and trovafloxacin against Acinetobacter baumannii clinical isolates. Clinafloxacin showed a MIC(90) of 4 mg/L, whereas the remaining quinolones showed a MIC(90) equal to or higher than 16 mg/L. MIC(50) determination in the presence of reserpine resulted in a two-fold decrease, except for trovafloxacin, which decreased four-fold, and for moxifloxacin and nalidixic acid, which did not change. The effect of reserpine was most pronounced among strains with a low level of resistance to quinolones. The MIC of clinafloxacin for strains with no mutation in either gyrA or parC genes ranged from 0.008 to 0.25 mg/L. In strains with a single mutation at amino acid codon Ser83 of the gyrA gene, the MIC of clinafloxacin ranged from 0.12 to 1 mg/L, whereas strains with a double mutation, one in the gyrA gene and another in the parC gene, showed a range of MIC of clinafloxacin from 1 to 8 mg/L. Therefore, clinafloxacin shows good activity against strains carrying a single mutation in the gyrA gene, and hence a second mutation is required for the microorganism to express resistance.
authors.affiliation: Institut Clinic d'Infeccions i Immunologia, IDIBAPS, Facultat de Medicina, Universitat de Barcelona, Villarroel 170, 08036 Barcelona, Spain. vila@medizina.ub.es
authors.forename: Jordi
authors.initials: J
authors.lastname: Vila
authors.forename: Anna
authors.initials: A
authors.lastname: Ribera
authors.forename: Francesc
authors.initials: F
authors.lastname: Marco
authors.forename: Joaquim
authors.initials: J
authors.lastname: Ruiz
authors.forename: Josep
authors.initials: J
authors.lastname: Mensa
authors.forename: Josep
authors.initials: J
authors.lastname: Chaves
authors.forename: Gonzalo
authors.initials: G
authors.lastname: Hernandez
authors.forename: M Teresa
authors.initials: MT
authors.lastname: Jimenez De Anta
mesh_terms: D000150:Acinetobacter / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification; D000151:Acinetobacter Infections / Q000382:microbiology; D000890:Anti-Infective Agents / Q000494:pharmacology*; D024881:Drug Resistance, Bacterial / Q000235:genetics; D024841:Fluoroquinolones; D005798:Genes, Bacterial; D006801:Humans; D008826:Microbial Sensitivity Tests; D012110:Reserpine / Q000494:pharmacology
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D012110:Reserpine; C057477:clinafloxacin