鸭源致病性大肠杆菌的血清型鉴定及其相关毒力基因分析  

Serotype Identification and Virulence-associated Genes Analysis of Pathogenic E.coli Isolated from Ducklings

作　　者：于学辉[1] 程安春[1] 汪铭书[1] 王英[2] 王远微[2] 汤承[2] 

机构地区：[1]四川农业大学动物医学院禽病防治研究中心,雅安625014 [2]西南民族大学生命科学与技术学院,成都610041

出　　处：《畜牧兽医学报》2008年第1期53-59,共7页ACTA VETERINARIA ET ZOOTECHNICA SINICA

基　　金：国家科技攻关重大项目(2004BA901A03);国家“十一五”科技支撑计划(2007Z06-017);教育部“新世纪优秀人才支持计划”项目(NCET-04-0906/NCET-06-0818);四川省重大基础研究项目(04JY029-006-1);四川省重点建设学科项目(SZD0418)

摘　　要：自规模化养鸭场患典型大肠杆菌败血症雏鸭分离的282株致病性大肠杆菌(E.coli)中鉴定出210株(包含37种血清型),其中O93、O78、O92、O76占43.8%(92/210)为优势血清型,O46、O32&O93混合型、O60&O93混合型为首次从鸭群中分离到。应用PCR结合核酸序列测定对210株致病性E.coli(鸭大肠杆菌病分离株)和28株自健康雏鸭泄殖腔拭子分离的E.coli(临床健康鸭大肠杆菌分离株)进行包括强毒力岛(HPI)中的鼠疫菌素受体基因(fyuA)和铁调节蛋白基因(irp2)、I型菌毛必需蛋白基因(fimC)、P型菌毛结构基因(papA)和血清耐受基因(iss)检测,结果表明:fyuAi、rp2、fimC、papA和iss基因在鸭大肠杆菌病分离株的携带率分别为41.0%、43.3%、92.9%、97.6%和96.7%,在临床健康鸭大肠杆菌分离株的携带率分别为21.4%、25.0%、92.9%、100%和92.9%,患病鸭和临床健康鸭大肠杆菌分离株iss、fimC和papA携带率差异不显著(P>0.05),但papA的携带率均显著高于其他宿主(鸡、猪和人)源E.coli;HPI毒力岛在鸭源E.coli中分布较广,其携带率表现为鸭大肠杆菌病分离株极显著高于临床健康鸭大肠杆菌分离株。HPI毒力岛的携带率与菌株的致病性呈明显的正相关,与O78等特定的血清型有一定的关系。鸭大肠杆菌病分离株有37.6%(79/210)同时携带fyuAi、rp2、fimCi、ss和papA基因,极显著高于健康鸭大肠杆菌分离株的14.3%(4/28)(P<0.01)。Among the 282 E.coli strains isolated from ducklings typically showing E.coli septicemia in large-scale duck farms in Southwest China,the serotypes of 210 strains were identified.The results showed that totally 37 serotypes were obtained,of which serotypes of O93,O78,O92 and O76 accounted for 43.8% and were the prevalent serotypes,and serotypes of O46,O32＆O93,O60＆O93 were isolated from ducks at the first time.The pesticin receptor gene（fyuA） within the highly pathogenecity islands（HPI）,iron regulatory protein gene（irp）,type 1 pilus essential protein gene（fimC）,the pap pilus structural protein gene（papA） and serum tolerance associated gene（iss） of the 210 pathogenic E.coli strains isolated from ducks showing clinical signs and the 28 E.coli strains isolated from cloacal swab of clinically healthy ducklings were detected by the method of polymerase chain reaction（PCR） and nucleic acid sequence analysis.The results demonstrated that the genes of fyuA,irp2,fimC,papA and iss were detected from pathogenic E.coli strains isolated from ducks showing clinical signs and account for 41.0%,43.3%, 92.9%,97.6% and 96.7% respectively,and the corresponding genes detected from E.coli strains isolated from clinically healthy ducklings account for 21.4%,25.0%,92.9%,100% and 92.9% respectively.The results showed that there were no significant difference（P〉0.05） of iss,fimC and papA gene between the E.coli strains isolated from ducklings showing clinical signs and that isolated from clinically healthy ducklings.With the respects of papA gene detection,there were significant difference（P〈0.05） between the E.coli strains isolated from ducks showing clinical signs and that isolated from other hosts of chickens,swine and humans.The fyuA gene was widely distributed in ducklings and its detection rate in ducklings showing clinical signs was significantly higher（P〈0.05） than that in clinically healthy duckling.There was a close positive correlation between the fyuA gene and the pathogenicity

关 键 词：鸭 致病性大肠杆菌 血清型 毒力基因 分子流行病学 

分 类 号：S852.612[农业科学—基础兽医学]