粤北地区仔猪腹泻源大肠杆菌毒力基因检测及致病性初步研究  

Detection of virulence genes of Escherichia coli strains isolated from piglets with diarrhea in north Guangdong and preliminary study on their pathogenicity

作　　者：南文金[1,2] 黄健强 吴静波[1,2] 胡鸿惠 彭国良[2] 肖正中 

机构地区：[1]韶关学院动物疫病实验室,广东韶关512005 [2]粤北生猪生产及疫病防控协同创新发展中心,广东韶关512005

出　　处：《广东农业科学》2017年第6期129-134,共6页Guangdong Agricultural Sciences

基　　金：广东省科技计划项目(2017A020225044;2016A040402038);广东省现代农业科技创新联盟建设项目(2016LM1141);韶关市科技计划项目(2013CX/N09)

摘　　要：采用PCR方法对56株仔猪黄白痢源大肠杆菌肠毒素和耶尔森菌强毒力岛(HPI)相关毒力因子STa、STb、LT和irp2进行检测,进而根据毒力因子基因型对部分菌株进行致病性试验。结果显示,38株受试菌检测到毒力因子,其中STa基因阳性率为3.57%,STb基因阳性率为53.57%,LT基因阳性率为7.14%,irp2基因阳性率为21.43%,检测的毒力因子表现为5种基因型,主要的毒力因子基因型是STb和STb+irp2。致病性试验显示毒力基因阳性菌株均对小白鼠具有致病性。结果表明,粤北地区致仔猪黄白痢大肠杆菌流行的主要毒力因子为STb,其次为irp2、少数菌株携带STa和LT毒力因子,相关毒力基因检测可以作为快速确定大肠杆菌致病性的重要依据。Enterotoxin virulence-related gene （ STa, STb and LT ） and HPI gene （ irp2 ） of 56 strains of Escherichia coli isolated from piglets with diarrhea were detected by corresponding PCR, and part of strains were chosen according to virulence factors gene-type for animal pathogenicity test. The results showed that 38 strains had virulence genes, the positive rates of STa, STb, LT and irp2 genes respectively were 3.57%, 53.57%, 7.14% and 21.43%. There were 5 virulence factors genotypes, the major genotypes were STb and STb＋irp2. The pathogenicity test showed that positive strains had pathogenicity to mice. In north Guangdong, the major virulence factors of pathogenic E. coli from diarrhea piglets were STa and irp2, a few strains carried STa and LT, some isolates expressed two virulence factors. Detection of virulence genes was an important reference for rapid determining pathogenicity of E. coll.

关 键 词：大肠杆菌 肠毒素 强毒力岛 毒力基因 致病性 

分 类 号：S852.61[农业科学—基础兽医学]