长治地区腹泻患者致泻性大肠杆菌的检测与分析

摘要

目的 了解山西省长治地区感染性腹泻患者致泻性大肠杆菌分离情况及菌株特征.方法 收集腹泻患者粪便,EC肉汤增菌后,采用针对致泻性大肠杆菌7个毒力基因eaeA、aggR、ipaH、stx1、stx2、lt、stIb及16S rRNA基因rrs的多重PCR初筛后,阳性者作致泻性大肠杆菌分离,再对分离菌株行生化鉴定、毒力基因检测及血清群测定.结果 170份标本中分离到致泻性大肠杆菌20株,阳性率为12%.其中EPEC 11株,均为非典型EPEC,EAEC 7株,ETEC 2株.结论 长治地区致泻性大肠杆菌感染以5岁以下儿童为主,除EPEC外,EAEC占有很大比例;对致泻性大肠杆菌的检测及判断有赖于血清群与毒力基因检测的分子生物学方法相结合.%The diarrheagenic Escherichia coli from diarrhea patients in Changzhi area, Shanxi Province were detected and characterized in this study. Feces from diarrhea patients were enriched in EC broth. Diarrheagenic Escherichia coli were primary screened by multiple polymerase chain reaction (PCR) using 7 virulence genes of eaeA, aggR, ipaH, stx1, stx2, lt, stIb and the gene of 16S rRNA rrs. Then, the diarrheagenic Escherichia coli were isolated from positive enrichment medium. I-solates were conducted with biochemical identification, virulence genes detection and sero-groups testing. A total of 170 fecal specimens were collected and 20 diarrheagenic Escherichia coli were isolated, among which 11 strains were enteropathogenic Escherichia coli (EPEC) with all atypical EPEC, 7 strains were enteroaggregative Escherichia coli (EAEC) , and 2 strains were enterotoxigenic Escherichia coli (ETEC). Results showed that the infection of diarrheagenic Escherichia coli was mainly in children aged less than 5 years in Changzhi area. In addition to EPEC, EAEC occupied a large proportion. It's suggested that the test of virulence genes should combine with traditional sero-typing in the screening of diarrheagenic Escherichia coli infection.