多黏菌素联合替加环素对多重耐药鲍曼不动杆菌的作用

Synergistic effect of a combination of colistin and tigecycline against multidrug-resistant Acinetobacter baumannii

目的探讨多黏菌素联合替加环素(tigecyclin)对多重耐药鲍曼不动杆菌体外抗菌的效果。方法收集临床分离的50株多重耐药鲍曼不动杆菌,采用微量肉汤稀释法、棋盘法分别检测替加环素、多黏菌素单独及联合使用的最低抑菌浓度(MIC),并计算药物联合使用抑菌浓度(FIC)指数,利用FIC指数判定替加环素和多黏菌素联用时对多重耐药鲍曼不动杆菌体外抗菌的效果。荧光定量PCR检测外排泵基因表达水平。结果替加环素联合多黏菌素能显著降低各自MIC值,表现为协同作用的菌株占70%,表现为相加作用的占14%,表现为无关作用的占6%,拮抗作用则为10%。对联合用药不敏感的菌株,其外排泵基因(abe B,abe J,abe G,abe M)表达水平显著高于敏感型(P<0.05)。结论替加环素联合多黏菌素可对多重耐药鲍曼不动杆菌的感染进行治疗。

Objective The objective of this study was to evaluate the combination of colistin and tigecycline in vitro antibacterial effect of multidrug resistant baumanus. Methods Collect clinical separation 50 multiple drug-resistant strains of acinetobacter baumannii, trace broth dilution method, board method is used respectively for ring element, polymyxin b alone and combination of the minimum bacteriostatic concentration（MIC）, and calculate the drug combination of bacteriostatic concentration（FIC） index, using the FIC index determination for ring element and polymyxin b when the combination of multiple drug resistance of acinetobacter baumannii in vitro antibacterial effect. Results The interaction between colistin and tigecycline, when used in combination, was 70% synergistic, 14% additive, 6% indifferent, and 10% antagonistic. For strains that are not sensitive to combination therapy, the expression level of efflux pump gene（abe B, abe J, abe G, abe M） was significantly higher than that of sensitive type（P〈0.05）. Conclusion Our results suggest that the synergistic effect of the colistin-tigecycline combination is suffcient to make it an optimal treatment choice.