大型奶牛养殖环境源大肠埃希菌毒力基因与系统进化分群  

Virulence genes and phylo-grouping of Escherichia coli from large dairy breedings

作　　者：唐敏嘉 张雪婧 何卓琳 蒲万霞[1] TANG Minjia;ZHANG Xuejing;HE Zhuolin;PU Wanxia(Gansu Province Key Laboratory of New Animal Drug Project,Ministry of Agriculture and Rural Affairs Key Laboratory of Veterinary Drug Discovery/Lanzhou Institute of Husbandry and Pharmaceutical Sciences of Chinese Academy of Agriculture Sciences,Lanzhou 730050,China)

机构地区：[1]中国农业科学院,兰州畜牧与兽药研究所,农业农村部兽用药物创制重点实验室/甘肃省新兽药工程重点实验室,甘肃兰州730050

出　　处：《中国兽医学报》2022年第8期1612-1619,共8页Chinese Journal of Veterinary Science

基　　金：国家重点研发计划资助项目(2016YFD0501305);中国农业科学院创新工程基金资助项目(25-LZIHPS-03)。

摘　　要：对甘肃2个大型奶牛养殖环境的大肠埃希菌(Escherichia coli,E.coli)分离株进行系统进化分群和毒力基因分布情况研究,分析系统群与E.coli主要毒力基因之间的潜在关联,以期为E.coli的研究和防治提供参考。利用PCR方法对281株E.coli分离株进行系统进化分群鉴定和毒力基因检测。281株E.coli分离株被分为8个系统进化群,B1、A、E、F、D、C、B2群和隐支Ⅰ或Ⅱ的占比分别为51.96%,28.47%,11.39%,2.85%,1.78%,1.07%,0.71%,0.36%,有4株为未知系统群。毒力基因检测结果显示,ompA、ibeB、ompT、iroN、traT、iucD、fyuA和irp2的阳性率分别为100%,98.58%,76.16%,71.53%,68.33%,64.06%,30.96%,30.25%。不同年份和养殖环境的部分毒力基因的分布存在明显差异,携带8个所鉴定的毒力基因的菌株在B1、B2群和粪土源中的分布较多;traT在2017年的分布明显低于2018和2019年;traT和iroN在粪土源分离株中的分布高于污水源。系统群与毒力基因的关联性分析结果显示,A群与ompT和traT存在负相关性;B1群与ompT、irp2、fyuA和iucD存在正相关性;E群与irp2、fyuA和iucD存在负相关性,与iroN存在正相关性。系统进化分群以B1群为主,不同年份和养殖环境的部分毒力基因的分布有明显的差异;部分毒力基因的分布与系统群存在联系。To provide a reference for the research and prevention of Escherichia coli(E.coli),the phylogenetic grouping and virulence genes of E.coli,which isolated from two large-scale dairy farms in Gansu Province were identified,and the correlation between phylo-groups and virulence genes of E.coli was analyzed.The phylogenetic grouping and virulence genes detection of the E.coli strains were carried out by PCR.Two hundred and eighty-one E.coli strains were assigned to eight phylo-groups,and the phylo-groups B1,A,E,F,D,C,B2 and cladesⅠorⅡwere 51.96%,28.47%,11.39%,2.85%,1.78%,1.07%,0.71%and 0.36%,respectively.The detection rates of ompA,ibeB,ompT,iroN,traT,iucD,fyuA and irp2 were 100%,98.58%,76.16%,71.53%,68.33%,64.06%,30.96%and 30.25%,respectively.There were significant differences in the distribution of some virulence genes in different years and dairy breedings.The strains carrying all identified virulence genes were mainly distributed in B1 and B2 phylo-groups and fecal-soil sourced samples.The distribution of traT in 2017 was significantly lower than that in 2018 and 2019.The distribution of traT and iroN in fecal-soil sourced isolates was higher than that of sewage sourced isolates.Phylo-group A was negatively correlated with ompT and traT,whereas phylo-group B1was positively correlated with ompT,irp2,fyuA,and iucD.Phylo-group E had a negative correlation with irp2,fyuA,and iucD,and a positive correlation with the iroN.Phylo-group B1 was more prevalent than other phylo-groups.There were significant differences in the distribution of some virulence genes in different years and breeding environments.The distribution of some virulence genes was associated with phylo-groups.

关 键 词：大肠埃希菌 奶牛养殖环境 毒力基因 系统进化分群 

分 类 号：S852.61[农业科学—基础兽医学] R535[农业科学—兽医学]