鲍曼不动杆菌对碳青霉烯类药物的主动外排机制

Efflux mechanism on carbapenems of Acinetobacter baumannii

目的：研究主动外排泵抑制剂羰基氰氯苯腙（CCCP）对碳青霉烯类药物抗鲍曼不动杆菌活性的影响，探讨主动外排作用在鲍曼不动杆菌耐药中所起的作用。方法应用琼脂稀释法检测鲍曼不动杆菌耐药株和敏感株在加入主动外排泵抑制剂羰基氰氯苯腙（CCCP）后对亚胺培南（IMP）的最低抑菌浓度（MIC）变化情况。结果应用10 mg／L CCCP 后 IMP 的耐药率由64．39％降至34．38％，能明显增强 IMP 对鲍曼不动杆菌的敏感性，CCCP 在体外能增强 IMP 抗菌活性，主动外排机制既存在于 IMP 耐药株，也存在于 IMP 敏感株，对耐药株影响更大。结论 CCCP 在体外可部分逆转鲍曼不动杆菌对亚胺培南的耐药性，主动外排作用是鲍曼不动杆菌多重耐药的重要机制之一。

Objective To explore the drug fast mechanism on carbapenems of Acinetobacter baumannii,it is important for clinicians to choose appropriate antibiotics.Methods The influence of active efflux inhibitors carbonyl cyanide m -chlorophenylhydrazone （CCCP）on minimal inhibitory concentration （MIC）of Acinetobacter baumannii to imipenem（IMP）was measured by agar dilution method.Results At the concentration of 10mg/L,CCCP had obvi-ously effects on carbapenems MICs,the rate of resistance of imipenem decreased from 64.39% to 34.38%.In vitro CCCP enhanced the activities of imipenem.Efflux mechanism existed not only in IMP resistant strains,but also in IMP sensitive strains.But the affection of CCCP against IMP resistant strains was much stronger than that of IMP suscepti-ble strains.Conclusion Efflux pump may be one of the main mechanisms of Acinetobacter baumannii resistance to IMP,while efflux pump inhibitors may partly reduce the resistance.