目的:研究天津地区大肠埃希菌外排泵AcrAB-TolC在临床株中的携带情况、与耐药的相关性及羰基氰氯苯腙(CCCP)对大肠埃希菌外排泵AcrAB-TolC的抑制作用.方法:纸片扩散法(Kirby-Bauer)检测大肠埃希菌临床株对3类6种抗菌药物的敏感性；PCR技术检测受试菌株携带acra、acrb基因的情况；微量肉汤稀释法检测10株多重耐药大肠埃希菌对5种抗菌药物的最低抑菌浓度(MIC),并对比加入CCCP前后MIC的变化.结果:本地大肠埃希菌对6种抗生素均存在不同程度耐药现象,氟喹诺酮类耐药率最高,阿米卡星耐药率最低为10％,耐药模式以双药耐药与多重耐药为主；acra,acrb基因在多重耐药模式中阳性率高达84.6％和80.8％,与全敏感组比较具有统计学差异；加入CCCP后,10株多重耐药菌对5种抗生素的MIC值均有不同程度的下降,最高下降达128倍,多数由耐药变为敏感.结论:本地大肠埃希菌普遍携带外排泵AcrAB-TolC基因,外排泵AcrAB-TolC可能是大肠埃希菌多重耐药的重要原因之一.多重耐药大肠埃希菌存在主动外排机制,CCCP能有效抑制细菌对抗菌药物的主动外排作用.%Objective: To investigate the earring situation of AcrAB-TolC efflux pump of E.coli detected in clinic in Tianjin, the correlation with drug resisitance, and the inhibitory ability of carbonyl cyanide 3 - chloropheny/hydrazone (CCCP) on efflux pump of E.coli. Methods: The susceptibility of 90 strains of E.coli to 6 antibiotics were detected by disk diffusion(Kirby-Bauer); acra, acrb were detected by PCR; The MIC of 10 multi-drug E.coli to 5 antibiotics were tested by constant broth dilution method, and compared the variation of MIC which CCCP has been added. Results: The resissitant to 6 antibiotics exist in varying degrees local E.coli. The resisitant rates of E.coli to fluoroquinolones were the highest, hut AMK was the lowest 10%. Two kinds of drug resistance and multi-drug resisitance were the main parts of resistant patterns. Acra, acrb positive rate were the highest, 84.6% and 80.8%, of multi-drug resistant pattern. After adding CCCP, 10 multi-drug resistant strains of the MICs values of 5 antibiotics were tested. The MIC values reduced by 0.78% when compared to the formers for instance. Most strains turn from drug resistant to sensitive. Conclusion: The earring of acra/acrb of local E.coli is common. AcrAB-TolC is important reason of multi-durg resistance, active efflux mechanism exists in multi-drug resistant E.coli. CCCP can inhibit the efflux system of bacteria to antibiotics effectively.
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