外排泵抑制剂羰酰氰间氯苯腙对多重耐药大肠埃希菌的耐药性影响

Effect of efflux pump inhibitor CCCP on antibiotic resistance of multidrug resistant Escherichia coli

目的探讨外排泵抑制剂羰酰氰间氯苯腙(carbonyl cyanide m-chloro phenylhydrazone,CCCP)对多重耐药大肠埃希菌的耐药性影响。方法采用纸片扩散法(K-B法)进行71株大肠埃希菌对6种抗菌药物的药物敏感性检测,用PCR技术检测受试菌株携带的acrA和acrB基因,用常量肉汤稀释法测定2种氟喹诺酮类抗菌药物对大肠埃希菌的最低抑菌浓度(minimum inhibitory concentrations,MICs),并对比加入CCCP前后的MICs值。结果 71株大肠埃希菌对3类6种抗菌药物耐药,其中对环丙沙星耐药率最高(73.24%),对氨曲南耐药率最低(30.99%),耐药模式以多重耐药为主(52.11%);外排泵基因acrA和acrB在多重耐药菌株中阳性率高达91.89%和81.03%;加入CCCP前后多重耐药菌株和敏感菌株的MICs值变化差异有统计学意义。结论主动外排泵抑制剂CCCP能够降低氟喹诺酮类抗菌药物对多重耐药大肠埃希菌的MICs。

Objective To investigate the effect of carbonyl cyanide m-chlorophenylhydrazone （CCCP） on drug resistance of muhidrug resistant Escherichia coli. Methods Disk diffusion （Kirby-Bauer test method） was used to detect the susceptibility of 71 strains of E. coli to 6 kinds of antibiotics, PCR assay to detect the acrA and acrB genes in E. coli strains, and constant broth dilu- tion method to determine minimum inhibitory concentrations （MICs） of 2 fluoroquinolones to E. coli. MICs detected before and after CCCP was added were compared. Results Totally 71 strains were found resistant to 6 kinds of antibiotics （3 categories）. The resis- tant rate of E. coli to ciprofloxacin was the highest （73.24%）, and that of E. coli to aztreonam was the lowest （30.99%）. Multidrug re- sistance （52.11%） was the main resistance pattern. AcrA/acrB positive rates were high （91.89% and 81.03%, respectively） in muhidrug resistant strains. Variations of MICs detected before and after CCCP was added in muhidrug resistant and sensitive strains were sig- nificantly different. Conclusion Efflux pump inhibitor CCCP can reduce the MICs of fluoroquinolone antibiotics to multidrug resistant E. coli.