In vitro kinetics of the activity of fusidic acid and fluoroquinolones combinations against staphylococci according to methicillin-resistance phenotype. Implications for the treatment of osteoarticular infections]

The kinetics of the effect of fusidic acid and of two fluoropiperazinyl quinolones (ofloxacin and pefloxacin), used alone or in combination, on ten methicillin-susceptible or methicillin-resistant strains of staphylococci were studied. Little or no bactericidal effects were seen with fusidic acid. With ofloxacin and pefloxacin, the bactericidal effect was delayed and occurred only with high concentrations. Used in combination, fusidic acid and the fluoroquinolones exhibited no synergistic effects and occasionally antagonized each other in vitro. The methicillin-resistance phenotype of organisms had no influence on results.