Cooperative Behavior of Fluoroquinolone Combinations against Escherichia coli and Staphylococcus aureus

MAZZIERI MR

BIOL. PHARM. BULL.

PHARMACEUTICAL SOC JAPAN

Lugar: Tokyo; Año: 2017 vol. 40

0918-6158

he effects of different combinations of ciprofloxacin (CIP) and norfloxacin (NOR) against Escherichia coli and Staphylococcus aureus were studied using checkerboard, fractional inhibitory concentration (FIC) and time?kill analysis methods. Results obtained by the checkerboard method showed that themore effectives combinations against Escherichia coli were 0.0009 μg/mL CIP0.0312 μg/mL NOR and 0.0037 μg/mL CIP0.0075 μg/mL NOR with a FIC index of 0.62. For Staphylococcus aureus, the combination of 0.0625 μg/mL CIP0.2500 μg/mL NOR showed a synergistic effect, with a FIC index of 0.50. The results of the time?kill method demonstrated either indifference or additivity of the ombinations 0.0009 μg/mL CIP0.0312 μg/mL NOR, 0.0018 μg/mL CIP0.0312 μg/mL NOR, 0.0037 μg/mL CIP 0.0075 μg/mL NOR and 0.0037 μg/mL CIP0.0156 μg/mL NOR at 24 h against E. coli. The combination 0.0037 μg/mL CIP0.0312 μg/mL NOR showed synergis