辽宁地区腹泻患者大肠杆菌分离株Ⅱ型不耐热肠毒素的检测及测序分析  

Sequence analysis on type Ⅱ heat labile enterotoxin of Escherichiacoli from diarrhaea patients in Liaoning Province,China

作　　者：袁超文[1] 江馗语 张力国 刘文鑫[3] 

机构地区：[1]东北大学生命科学与健康学院,沈阳110819 [2]辽宁省重大动物疫情应急中心,沈阳110161 [3]广东医学院附属医院,血液疾病研究中心,湛江524001

出　　处：《中国人兽共患病学报》2016年第7期644-650,共7页Chinese Journal of Zoonoses

摘　　要：目的对辽宁地区人源性腹泻样本中致病性大肠杆菌(Pathogenic Escherichia coli)的毒力因子进行检测,掌握产Ⅱ型不耐热肠毒素(Type Ⅱ heat labile enterotoxin,LT-Ⅱ)大肠杆菌在我国北方地区的流行现状并阐明LT-Ⅱ与其他致病因子间的关系。方法于2014年3月至2015年3月收集辽宁地区人源性腹泻粪便样品,用麦康凯培养基和生化试验的方法分离出大肠杆菌,并用多重PCR方法对毒力基因(elt-Ⅱ、elt-I、sta、stb、K88、K99等)进行检测,对分离到的LT-Ⅱ阳性大肠杆菌中elt-Ⅱ基因进行测序及分型。结果 354份腹泻样品中共分离到携带有毒力因子的大肠杆菌139株,检出率为39.2%。毒力因子阳性大肠杆菌中,有12株携带elt-Ⅱ(8.6%)基因。在12株携带elt-Ⅱ的大肠杆菌中,2株单独携带elt-Ⅱ,6株携带F1,1株携带K88,1株携带astA,2株携带irp2/astA;测序结果表明12株elt-Ⅱ阳性大肠杆菌中有10株携带elt-Ⅱc1亚型,2株携带elt-Ⅱc4亚型。结论在引起人源性腹泻的毒力因子中有大肠杆菌Ⅱ型不耐热肠毒的存在,且主要以LT-Ⅱc1为主要流行型。In this study,we aimed to investigate the prevalence of type Ⅱ heat labile enterotoxin（LT-Ⅱ）producing Pathogenic Escherichia coli,and to further analyzed the relationship between elt-Ⅱ and other virulence factors.From 2014 to 2015,a total of 354 human fecal samples were collected from Liaoning Province,and then 354 E.coli strains were isolated from the fecal samples by using MacConkey agar and biochemical test.The isolated strains were further detected by using PCR method for detecting the virulence factors（elt-Ⅱ,elt-I,sta,stb,K88,K99,etc.）,and the elt-Ⅱ gene was sequenced in LT-Ⅱ positive Escherichia coli.Results showed that 139（39.2%）virulence factor positive E.coli were isolated from 354 fecal samples.Of the 139 virulence factor positive E.coli,12（8.6%）harbored the elt-Ⅱ gene.Of the 12 elt-Ⅱ positive strains,2harbored the elt-Ⅱ as the only virulence factor,6harbored F1 besides the elt-Ⅱ gene,1harbored K88 besides the elt-Ⅱ gene,1harbored astAbesides the elt-Ⅱ gene,and 2harbored irp2/astAbesides the elt-Ⅱ gene.The result of sequencing showed that 10 of the 12 elt-Ⅱ positive strains harbored the elt-Ⅱc1 subtype,and 2of the 12 elt-Ⅱ positive strains harbored the elt-Ⅱc4 subtype.Results indicated that LT-Ⅱ existed in human resource fecal samples,and LT-Ⅱc1 was the mainly subtype.

关 键 词：大肠杆菌Ⅱ型不耐热肠毒素 PCR检测 测序分析 

分 类 号：R183.3[医药卫生—流行病学]