多黏菌素E联合比阿培南对耐碳青霉烯铜绿假单胞菌的体外抗菌活性研究

In vitro activity of colistin combination with biapenem against carbopenems-resistant Pseudomonas aeruginosa

目的评价多黏菌素E联合比阿培南对85株耐碳青霉烯铜绿假单胞菌(CRPA)的体外抗菌效应。方法用琼脂平板稀释法测定多黏菌素E和比阿培南对85株CRPA的最低抑菌浓度(MIC)值。用微量肉汤稀释法测定不同浓度组合的多黏菌素E和比阿培南对85株CRPA的MIC值,并计算部分抑菌浓度指数来判定联合效应。测定多黏菌素E与比阿培南单用或联用的时间杀菌曲线。结果多黏菌素E与比阿培南联合用药可显著降低CRPA的MIC(P<0.01)。多黏菌素E与比阿培南联合用药表现协同作用为11.76%、部分协同为17.65%、相加作用为34.12%、无关作用为36.47%、无拮抗作用。多黏菌素E联合比阿培南的细菌数量与单药相比降低>2 log_(10)CFU·mL^(-1)。结论多黏菌素E与比阿培南联合用药在体外对CRPA以协同作用和相加作用为主,杀菌曲线也显示了较好的协同作用。

Objective To evaluate the antibiotic effects of colistin conbined with biapenem against 85 isolates of Carbapenems- resistant Pseudomonas aeruginosa（CRPA） in vitro.Methods The minimal inhibitory concentration（MIC） of colistin or biapenem against 85 strains of CRPA was determined by agar dilution method.The broth microdilution and checkerboard method were used to determine the MICs of colistin or biapenem and fractional inhibitory concentration index（FICI） was calculated according to MIC results.The time- killing curves of colistin and biapenem alone or combination were determined.Results The MIC of all the combined antimicrobials was reduced significantly（P〈0.01）.Of85 isolates,11.76%synergism,17.65%section synergism,34.12%additive effect,36.47%indifference,no antagonism found.At 24 h the combination resulted in more than 2 log_（10） CFU·mL^-1 reduction in viable bacteria compared with colistin or biapenem alone.Conclusion The activities of colistin combined with biapenem are mainly synergistic and additive.