Activity of Meropenem with and without Ciprofloxacin and Colistin against Pseudomonas aeruginosa and Acinetobacter baumannii

Abstract

ABSTRACT Time-kill synergy studies showed that at 24 h, subinhibitory meropenem and ciprofloxacin concentrations of 0.06 to 128 and 0.03 to 32 μg/ml, respectively, showed synergy against 34/51 Pseudomonas aeruginosa strains; subinhibitory concentrations of meropenem (0.06 to 8 μg/ml) and colistin (0.12 to 1 μg/ml) showed synergy against 13 isolates. Subinhibitory meropenem and ciprofloxacin concentrations of 0.25 to 2 and 0.12 to 16 μg/ml, respectively, showed synergy against 18/52 Acinetobacter baumannii strains at 24 h. Subinhibitory meropenem and colistin concentrations of 0.03 to 64 and 0.06 to 8 μg/ml, respectively, showed synergy against 49 strains at 24 h.