主动外排系统AcrAB-TolC与肺炎克雷伯菌耐药性关系研究

Study of the AcrAB-TolC efflux pump system and resistance of Klebsiella pneumoniae

目的探讨主动外排系统AcrAB-TolC与肺炎克雷伯菌耐药性的关系。方法运用琼脂稀释法检测抗生素和消毒剂对肺炎克雷伯菌的最小抑菌浓度;PCR扩增肺炎克雷伯菌acrA、acrB和toiC基因,分析AcrAB-TolC与肺炎克雷伯菌耐药的关系。结果肺炎克雷伯菌82.55%检出acrA基因,85.37%检出acrB基因,81.60%检出toiC基因,三基因均阳性,三基因均阴性、部分基因阳性分别占71.22%、9.91%和18.87%;AcrAB-TolC阳性组对阿奇霉素、四环素、氯霉素、苯扎溴胺(1︰49)、碘伏(1︰4)、消佳净(1︰49)的耐药率与AcrAB-TolC缺陷组、AcrAB-TolC阴性组比较差异有统计学意义(P<0.05)。结论肺炎克雷伯菌对阿奇霉素、四环素、氯霉素及中间工作浓度的消毒剂产生耐药性与携带主动外排系统AcrAB-TolC关系密切。

Objective To investigate the relationship between the AcrAB-TolC efflux pump system and resistance of Klebsiella pneumoniae. Methods Minimum inhibitory concentration testing of antibiotics and disinfectants was done u- sing the agar dilution method. The genes AcrA, AcrB, and TolC were detected with PCR and a chi-squared test was used to analyze data. Results Of Klebsiella pneumoniae samples, 82.55% had the AcrA gene, 85.37% had the AcrB gene, and 81. 60% had the TolC gene. All 3 genes were detected in 71.22% of strains, some of the 3 were detected in 9.91% of strains, and none of the genes were detected in 18.87% of strains. Strains with AcrAB-TolC had a statistically signifi- cant rate of resistance compared to strains missing AcrAB or TolC and strains lacking AcrAB and TolC. Strains with Ac- rAB-TolC were resistant to azithromycin, tetracycline, chloramphenicol, and benzalkonium bromide （1 ： 49）, iodophors （1 ： 4）, and sodium hypochlorite （1 ： 49） . Conclusion K. pneumoniae developed resistance to azithromycin, tetra- cycline, and chloramphenicol and intermediate working concentrations of disinfectants. This resistance was closely linked to the AcrAB-TolC efflux pump system.