title: Activity and postantibiotic effect of marbofloxacin, enrofloxacin, difloxacin and ciprofloxacin against feline Bordetella bronchiseptica isolates.
abstract: The minimum inhibitory concentration (MIC) and postantibiotic effect (PAE) of marbofloxacin, enrofloxacin, difloxacin and ciprofloxacin were evaluated in vitro against 43 feline-source Bordetella bronchiseptica strains. All strains tested were susceptible to marbofloxacin and enrofloxacin (MIC90 0.5mg/l), while 93 and 84% of the strains were susceptible, respectively, to ciprofloxacin and difloxacin with MIC(90) values of, respectively, 1 and 8mg/l. The PAE was studied in 10 strains by exposure of bacteria to marbofloxacin, enrofloxacin, difloxacin and ciprofloxacin at 5 and 10 times minimum inhibitory concentration (MIC) for 1 and 2h. Regrowth was determined by measuring the viable counts after drug removal by a 10(3) dilution procedure. PAEs increased as a function of concentration and exposure time. The mean duration of PAEs varied between 1.1 and 8.2h, showing the following order: marbofloxacin>enrofloxacin>ciprofloxacin>difloxacin. These data are encouraging since fluoroquinolones have a possible role in the clinical treatment of B. bronchiseptica infections, and the strong PAE caused by quinolones may contribute to the in vivo efficacy of these drugs.
authors.affiliation: Istituto di Microbiologia, Facoltà di Medicina e Chirurgia, Policlinico Universitario, Torre Biologica, 2 degrees piano, Università di Messina, 98125, Messina, Italy. mtfera@www.unime.it
authors.forename: M
authors.initials: M
authors.lastname: Carbone
authors.forename: M G
authors.initials: MG
authors.lastname: Pennisi
authors.forename: M
authors.initials: M
authors.lastname: Masucci
authors.forename: A
authors.initials: A
authors.lastname: De Sarro
authors.forename: M
authors.initials: M
authors.lastname: Giannone
authors.forename: M T
authors.initials: MT
authors.lastname: Fera
mesh_terms: D000818:Animals; D000890:Anti-Infective Agents / Q000494:pharmacology* / Q000627:therapeutic use; D001885:Bordetella Infections / Q000188:drug therapy / Q000382:microbiology / Q000662:veterinary; D016950:Bordetella bronchiseptica / Q000187:drug effects*; D002371:Cat Diseases / Q000188:drug therapy / Q000382:microbiology; D002415:Cats; D002939:Ciprofloxacin / Q000031:analogs & derivatives* / Q000494:pharmacology* / Q000627:therapeutic use; D000077422:Enrofloxacin; D005260:Female; D024841:Fluoroquinolones; D008297:Male; D008826:Microbial Sensitivity Tests / Q000662:veterinary; D015363:Quinolones / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D000890:Anti-Infective Agents; D024841:Fluoroquinolones; D015363:Quinolones; D000077422:Enrofloxacin; D002939:Ciprofloxacin; C047225:difloxacin; C080260:marbofloxacin