In vitro efficacy of Meropenem and Sulbactam combination against Acinetobacter baumannii / 中华检验医学杂志

ABSTRACT

Objective To evaluate the synergy effect of Meropenem and Sulbactam combination against Meropenem-resistant and Meropenem-susceptible A.baumannii in vitro and optimize combination ratio of Meropenem and Sulbactam to achieve best synergy effect.Methods Evaluating the synergy effect of Meropenem and Sulbaetam combination through microdilution checkerboard method against Meropenemresistant and Meropenem-susceptible A.baumannii,isolated from inpatients of Chinese hospitals.Assessing the synergy effect of combination in different ratios of Meropenem to Sulbactam.Results The checkerboard method with the combination of Meropenem and Sulbactam demonstrated 25.0％ ( 10/40 ) synergism,67.5％ (28/40) partial synergism,7.5％ (3/40) additive,no indifference and antagonism in Meropenemsusceptible isolates,and 27.5％ (11/40) synergism,40.0％ (16/40) partial synergism,25.0％(10/40) additive,no indifference and antagonism in Meropenem-resistant isolates.Eleven Meropenemresistant isolates which showed synergism in synergy test were tested for MICs of combination of Meropenem and Sulbactam,using ratios of 4∶ 1,2∶ 1,1∶1 and 1∶2,and the MIC90 were 64∶ 16,64∶ 32,32∶32,32∶64 μg/ml,respectively.Conclusions Meropenem and Sulbactam combination show synergism or partial synergism against most A.baumannii isolates.The optimal ration of combination for clinical use may be 1∶ 1.