Postantibiotic effects of difloxacin on three marine Vibrio strains

The minimal inhibitory concentrations (MIC) of difloxacin against Vibrio anguillarum W-1, V. parahaemolyticus 1614 and V. alginolyticus 1833 were determined by twofold broth macrodilution method, and the postantibiotic effects (PAE) of difloxacin against the three Vibrio strains were determined by colony counting. It was shown that, at the concentrations of 1MIC, 2MIC and 4MIC, the PAE of difloxacin against Vibrio anguillarum W-1, V.parahaemolyticus 1614, V. alginolyticus 1833 was 0.64h, 1.09h and 2.16h; 0.74h, 1.73h and 2.64h ; 0.54h,1.08h and 2.05h, respectively. There were significant PAE of difloxacin against the three Vibrio strains, and the time of PAE was prolonged as the concentration of difloxacin increased.