婴幼儿腹泻致泻大肠埃希菌PCR毒力基因检测  

Detection of virulence genes by PCR in diarrheagenic Escherichia coli isolated from infants in Zhejiang

作　　者：叶菊莲[1] 占利[1] 程苏云[1] 罗芸[1] 余昭[1] 王复甦[1] 

机构地区：[1]浙江省疾病预防控制中心,杭州310051

出　　处：《中国卫生检验杂志》2009年第9期2055-2057,共3页Chinese Journal of Health Laboratory Technology

摘　　要：目的:了解引起2007年浙江省婴幼儿腹泻的致泻性大肠埃希菌EIEC、EPEC、ETEC血清型分布情况及其毒力基因携带状况。方法:将粪便接种到不加新生霉素的EC肉汤中,增菌后用EMB分离培养,可疑菌经生化鉴定后,进行血清学分型;根据不同血清型,以PCR检测相应的毒力基因。结果:200份腹泻粪便标本中共分离出EIEC 6株、EPEC 25株、ETEC 20株,其检出率分别为3.0%、12.5%、10.0%。其中EIEC侵袭质粒抗原H基因(ipaH)阳性1株,检出率为16.7%(1/6);EPEC束状菌毛A基因(BfpA)阳性9株,检出率为36.0%(9/25),其中携带紧密粘附素(eaeA)的2株,检出率为8.0%(2/25);ETEC耐热肠毒素(ST)阳性1株,检出率为5.0%(1/20),不耐热肠毒素(LT)未检出。结论:我省2007年引起婴幼儿腹泻的主要致泻性大肠埃希菌为携带BfpA毒力基因的O1、O126型EPEC;因此,有必要在传统细菌鉴定的基础上,增加对致泻大肠埃希菌进行PCR毒力基因检测,为进一步确诊和防控致泻大肠埃希菌引起的婴幼儿腹泻提供更有力的实验室依据。Objective： To comprehend the main serotypes and carriage status of virulence genes of EIEC, EPEC, ETEC causing diarrhoea among infants in Zhejiang. Methods：Fecal samples were inoculated to EC broth（ without novobiocin） and after enrichment, then diarrheagenic Escherichia coli（ E. coli） were isolated and identified with biochemical reactions and serum agglutination test. Finally all these isolates were screened for their virulence genes including ipaH gene in EIECs, BfpA （ bundle - forming pilus） and eaeA genes in EPECs, ST and LT genes in ETECs. Results：Out of 200 fecal samples from diarrhea infants,6 EIECs,25 EPECs and 20 ETECs were obtained ,with detective rates of 3.0% , 12.5% and 10. 0% respectively. 1 EIEC was detected possessing ipaH with carriage rate of 16. 7% （1/6） ; 9 EPECs were detected possessing Bfpa gene with carriage rate of 36. 0% （9/25） and 2 EPECs possessing eaeA gene with carriage rate of 8.0% （ 2/25 ） ; And 1 ETECs were detected possessing ST gene with carriage rate of 5. 0%, no LT gene was detected. Conclusion ： Because of its speediness and accuracy, PCR can be used to detect virulence genes of diarrheagenic Escherichia coli on the basis of classic bacterial identification, thus providing supportive evidences for diarrhoea diagnosis in infants.

关 键 词：致病性大肠杆菌(EPEC) 侵袭性大肠杆菌(EIEC) 产肠毒素大肠杆菌(ETEC) 毒力基因 

分 类 号：R446.5[医药卫生—诊断学]