2015-2016年江阴市致泻性大肠埃希菌监测及其毒力基因分析

Etiological surveillance of diarrheagenic Escherichia coli in Jiangyin from 2015 to 2016 and its virulence genes

目的了解2015-2016年江阴市致泻性大肠埃希菌[肠致病性大肠埃希菌(EPEC)、肠产毒性大肠埃希菌(ETEC)、肠侵袭性大肠埃希菌(EIEC)、肠出血性大肠埃希菌(EHEC)、肠聚集性大肠埃希菌(EAEC)]的感染、分布及其毒力基因的携带情况。方法对2015-2016年哨点医院提供的感染性腹泻样本进行实时荧光定量PCR检测,确定其致病型别及其携带的毒力基因。结果359份腹泻标本中,检出致泻性大肠埃希菌31份,检出率8.64%,其中EAEC 15份,检出率4.18%,EPEC 13份,检出率3.62%,ETEC 3份,检出率0.84%,未检出EIEC及EHEC。15株EAEC中,携带astA基因8株,携带aggR+pic基因6株,携带astA+aggR+pic基因1株。13株EPEC均携带eae基因,3株ETEC均携带estI基因。致泻性大肠埃希菌主要集中在夏秋季节高发,2015年主要以EPEC为主,2016年主要以EAEC为主。结论江阴市致泻性大肠埃希菌主要以EAEC和EPEC两个型别为主,携带的毒力基因呈多态性,显示其致病力和侵袭力具有多样性和复杂性,应加强监测。

OBJECTIVE To understand the prevalence of infections caused by 5 species of diarrheagenic E.coli:enteropathogenic E.coli(EPEC),enterotoxic E.coli(ETEC),enteroinvasive E.coli(EIEC),enterohemorrhagic E.coli(EHEC),enteroaggregative E.coli(EAEC)in Jiangyin from 2015 to 2016 and observe the virulence genes in the strains.METHODS Real-time fluorescence quantification PCR was performed to detect the infectious diarrhea samples that were obtained from sentry hospitals during 2015-2016 so as to determine the pathogenic types and the virulence genes.RESULTS Among the 359 cases of diarrhea specimens,31 were detected with diarrheagenic E.coli,with the isolation rate 8.64%,15(4.18%)of which were EAEC,13(3.62%)were EPEC,3(0.84%)were ETEC,while,neither EIEC nor EHEC were detected.Of the 15 strains of EAEC,8 carried with astA gene,6 carried with aggR+pic genes,and 1 carried with astA+aggR+pic genes.All of the 13 strains of EPEC carried with eae genes,and 3 strains of ETEC carried with estI gene.The diarrheagenic E.coli was highly prevalent in summer and autumn,the EPEC was dominant in 2015,and EAEC was dominant in 2016.CONCLUSION The EAEC and EPEC are dominant among the diarrheagenic E.coli in Jiangyin,the virulence genes that are carried by the strains show polymorphism,indicating that the pathogenicity and invasion are diversified and complex,and it is necessary to strengthen the surveillance.