鸡致病性E.coli地方株血清型的鉴定、毒力基因及致病性检测  

Analysis on serotypes,virulence genes and pathogenicity of local strains of pathogenic Escherichia coli from chicken

作　　者：张召兴[1] 张香斋[1] 李蕴玉[1] 张艳英[1] 常超越 贾青辉[1] 李佩国[1] 

机构地区：[1]河北科技师范学院河北省预防兽医学重点实验室,河北秦皇岛066604

出　　处：《中国兽医学报》2017年第12期2260-2265,共6页Chinese Journal of Veterinary Science

基　　金：河北省研究生创新资助项目(2016-2017);河北省现代农业产业技术体系技术研究岗位资助项目(HBCT2013090203)

摘　　要：为了研究河北秦皇岛地区鸡致病性大肠杆菌(Escherichia coli,E.coli)地方流行株的优势血清型、毒力基因和致病性,本研究采用常规鉴定方法和16SrRNA PCR方法,从采集自河北秦皇岛地区不同养鸡场的83份病鸡组织中分离鉴定出56株E.coli。人工感染1日龄雏鸡试验表明,46株分离株为致病性E.coli。采用玻片凝集试验、PCR方法分别测定致病性E.coli分离株的血清型分布和16种毒力基因携带情况。结果显示,定型的42株致病性E.coli分离株包括11种血清型,以O7 8、O89、O142及O1为优势血清型;46株致病性E.coli分离株中以irp2、fuyA、ompT、Iss a、iutA、iroN和hlyF毒力基因检出率较高,在89.1%~100.0%,其他毒力基因检出率为22.0%~72.0%。选择优势血清型代表株QH1(O78)、QH1(O89)、QH1(O142)和QH1(O1)人工感染1日龄雏鸡,计算半数致死量(LD50),确定其致病性。结果表明,QH1(O78)株致病性最强,对1日龄雏鸡的LD50为3.16×106 CFU/mL;对14,49日龄雏鸡的LD50分别为1.07×107,5×108 CFU/mL。本研究为河北秦皇岛地区鸡致病性E.coli地方流行株防控提供试验依据。In order to analyze the serotype,virulence genes and pathogenicity of the local epidemic strains of pathogenic Escherichia coli isolated from chicken in Qinhuangdao area,a total of 56 E. coli were isolated from 83 tissue of diseased chicken in chicken farms in Qinhuangdao area by bac teria characteristics and 16S rRNA PCR methods. The results of the artificial infection in 1-day-old chickens showed that 46 isolates were pathogenic;the serotype of 46 isolates were determined by direct agglutination test with specific antisera,42 pathogenic E. coli isolates belonged to 11 kinds of serotypes,and O78, O89, Ot4eand （）l were the predominant serotypes. The positive rate of the irp2 ,fuyA,ompT, Iss^a , iutA, iroN and hlyF genes was 89. 1% -100.0%, the other virulence genes were 22.0%-72.0%. To determine pathogenicity, the predominant serotype strains QH1 （O78）, QH1 （O89）,QHI（O142） and QHI（O1） were used to infect artificially 1 day-old chickens,and the LD50 was calculated,the results showed that pathogenicity of QH1 （O78） was the strongest,the LD50 at 1 day-old chickens was 3.16 × 10^6 CFU/mL. The LD50 at 14-and 49-day-old chickens were 1.07 × 10^7 CFU/mL and 5 × 10^8 CFU/mL, respectively. The research provides a experimental basis for the prevention and treatment of the local strains of pathogenic Escherichia coli.

关 键 词：鸡致病性大肠杆菌 分离鉴定 血清型 毒力基因 致病性 

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