肠聚集性大肠埃希菌在健康人群肠道中携带情况及其毒力基因和耐药性研究

Research on the carriage rate, virulence genes and drug resistance of enteroagglomerate Escherichia coli in intestinal tract of healthy population

目的研究健康人群肠道肠聚集性大肠埃希菌(Enteroaggregative E.coli,EAEC)的分布特点及其毒力基因和耐药性情况。方法留取健康体检者的粪便标本,接种SS平板和麦康凯平板,采用MALDI-TOF MS鉴定仪对疑似大肠埃希菌进行鉴定,检测分离到大肠埃希菌的3个EAEC毒力基因:astA、aggR、pic,采用K-B纸片扩散法检测EAEC对AMP、AMC、CTX、CAZ、CIP、IPM共6种抗生素的耐药性。结果共检出EAEC菌株78例,总携带率为8.6%;astA是EAEC最主要的毒力基因,有66株(84.6%)携带astA,其中41株(52.6%)单独携带astA;EAEC对AMP、AMC、CTX、CAZ、CIP、IPM的耐药率分别为65.4%、20.5%、29.5%、25.6%、55.1%、2.6%,老年组的耐药性高于青少年组和成年组。结论研究结果提示EAEC在健康人群中也具有较高的携带率和耐药性,且老年组的情况更严重,应引起重视。

Objective To study the distribution characteristics, virulence genes and drug resistance of enteroagglomerate Escherichia coli(EAEC) strains in intestinal tract of healthy population. Methods Stool specimens from healthy persons were inoculated with SS plates and MAC plates, the suspected E.coli strains were identificated by MALDI-TOF MS, three virulence genes(astA, aggR, pic) of EAEC were detected, and K-B disk diffusion method was used to detect the resistance of EAEC to AMP, AMC, CTX, CAZ, CIP, IPM. Results A total of 78 EAEC strains were detected with a total carrying rate of 8.6%;astA was the most virulence gene of EAEC. 66 strains(84.6%) carried astA, of which 41(52.6%) carried astA alone. The resistance rates of EAEC to AMP, AMC, CTX, CAZ, CIP and IPM were 65.4%, 20.5%, 29.5%, 25.6%, 55.1% and 2.6%. The resistance of the elderly group was significantly higher than that of the adolescent group and the adult group. Conclusion EAEC has a high carrying rate in the healthy population, and the situation is more severe in the elderly, which should be paid attention to.