四川自贡地区健康人群中艾伯特埃希菌的分离鉴定

Identification of Escherichia albertii from healthy carriers in Zigong,Sichuan Province,China

目的了解长期从事鸡鸭等家禽养殖及屠宰人员等健康人群艾伯特埃希菌的携带情况。方法收集家禽养殖、屠宰人群及其他健康人粪便,经EC肉汤增菌后PCR检测eae基因,阳性样品接种麦康凯琼脂,挑选不发酵乳糖菌落,通过16SrDNA序列分析和多位点序列分型(MLST)对菌株进行鉴定。分离株进行紧密粘附素亚型和cdtB亚型分析,并通过脉冲场凝胶电泳(PFGE)分析与动物来源艾伯特埃希菌菌株间的相关性。结果从189份从事鸡鸭宰杀人员的粪便中,分离到2株艾伯特埃希菌,从58份其他健康人群粪便中分离到1株菌,而138份家禽养殖场人员粪便中未分离到菌株。3株菌株的紧密粘附素亚型分别为sigma,iota 2,nu,cdtB亚型均为Ⅱ/Ⅲ/Ⅴ亚型。PFGE显示三株菌之间的带型相似性小于80%,并且与鸡鸭等来源的艾伯特埃希菌带型不同。结论从事鸡鸭屠宰等健康人员中存在一定程度的艾伯特埃希菌携带率,但其与家禽携带艾伯特埃希菌的关系,仍需进一步研究。

We investigated the carrying situation of Escherichia albertii from healthy people engaged in breeding and slaughtering poultry for a long time.We collected stool samples from people engaged in breeding and slaughtering poultry and other healthy people.After enriched with EC broth,eae-positive enrichment culture was directly streaked on MacConkey,and eaepositive lactose non-fermenting isolate was retained for further investigation.The 16 SrDNA sequencing and multilocus sequence typing（MLST）were applied in the identification of E.albertii from suspected strains.Intimin subtypes and cdtBtypes of E.albertii strains were detected.Pulsed-field gel electrophoresis（PFGE）was used to detected genetic polymorphism of strains from this study and animal source ones.Results showed that two isolates were identified as E.albertii from 189 stools of people exposed to slaughtering chickens and ducks and one from 58 stools in control groups.No isolate was identified as E.albertii from 138 stools samples of people exposed to breeding poultry.Intimin subtypes of three isolates from stool samples were subtyped as sigma,iota 2,nu,and cdtBtypes were closely related to types II/III/V.PFGE patterns of the three strains was distinguishable（80%similarity）,and appeared in different cluster with chickens,ducks and other sources of E.albertii strains.The rate of carrying E.albertii to a certain extent exist in healthy people engaged in slaughtering chickens and ducks,and the relationship between these strains and strains from poultry should be further investigated.