集约化猪场PWD病原性大肠杆菌毒力因子分析  

Serological and virulence factors analysis of Escherichia coli isolates causing post-weaning diarrhea in intensive pig farms

作　　者：姜中其[1] 王娜[1] 方维焕[1] 孙建华[1] 李洪州[2] 

机构地区：[1]浙江大学动物科学学院,浙江杭州310029 [2]浙江杭州萧山区农业局畜牧兽医站,浙江杭州311200

出　　处：《浙江大学学报（农业与生命科学版）》2006年第5期520-526,共7页Journal of Zhejiang University:Agriculture and Life Sciences

基　　金：浙江省科技厅资助项目(2003C32002);浙江省教育厅资助项目(20000240)

摘　　要：探索浙江省集约化猪场仔猪断奶腹泻(PWD)病原性大肠杆菌血清型和毒力因子特征,为PWD防治及耐药性研究提供资料.从10个规模化猪场以直肠棉拭子采集PWD病料,经细菌分离纯化、革兰氏染色、生化试验和小鼠致病性试验等,对病原进行鉴定.采用11种猪源大肠埃希氏菌常见O型抗原血清、应用K88及F18菌毛单因子血清对分离菌进行玻板凝集试验和PCR方法分析黏附素及肠毒素类型.分离鉴定的56株病原性大肠杆菌O抗原定型了33株,共覆盖了11种血清型,其中O149、O139、O8为优势血清型,共17株,占定型菌株的51.5%;菌毛单因子血清玻板凝集试验和PCR测得病原性大肠杆菌中产肠毒素大肠杆菌(ETEC)比例较高,占病原性大肠杆菌分离总数的67.92%(36/53),肠毒素中含STa、STb、STa+STb、LT和SLT-2 e分别占总检测菌株数的30.19%(16/53)、35.85%(19/53)、18.9%(10/53)、1.89%(1/53)和9.43%(5/53).黏附素类型主要有K88和F18两种,分别占总检测菌株数的24.53%(13/53)和28.30%(15/53).结果表明,浙江省PWD病原性大肠杆菌至少覆盖了包括优势血清型O149、O139、O8在内的11种血清型;大肠杆菌中以产肠毒素型为主,主要毒力因子包括黏附素F18及K88和肠毒素STa、STb、SLT-2 e等.In order to determine the prevalent serotypes and virulence factors of pathogenic Escherichia coli isolates from piglets with post-weaning diarrhea （PWD） in intensive pig farms of Zhejiang Province, rectum swabs from piglets with PWD in intensive pig farms were collected for isolations of pathogenic Escherichia coll. The isolations were identified by gram stain, biochemical reactions and pathogenicity tests in mice. The O serotyping and pill typing were conducted by slide agglutination with antiserum against 11 commonly seen swine Escherichia coli O antigens and anti-K88 and anti-F18 monoclonal antibodies, respectively. The types of adhesins and enterotoxins were further verified by Polymerase chain reactions （PCR） with specific primer pairs. Among 56 Escherichia coll isolates, 33 were typable and distributed in 11 serotypes. The prevalent serotypes included O149, O139 and O8, amounted to 51.5% （17/33） of the total typable ones. Slide agglutination tests and PCR analysis showed that the enterotoxigenic Escherichia coli accounted for 67. 92% （36/53）, of which harbored the genes for enterotoxin STa, STb, STa＋STb, LTand SLT-2e amounted to 30. 19%（16/53）, 35.85%（19/53）, 18.9%（10/53）, 1.89%（1/53）and 9. 43%（5/53）, respectively. Isolations with F18 and K88 adhesins contributed 28.30 % （ 15/53 ）, 24.53% （13/53）, respectively. It is concluded that pathogenic Escherichia coli isolates collected from piglets with PWD of Zhejiang Province covered at least 11 O serotypes and the predominant serotypes are O149, O139, and O8. Escherichia coli causing PWD are mostly enterotoxigenic, with the predominant enterotoxins STa, STb, SLT-2e. The toxins and adhesins F18 and K88 are the most important virulence factors involved.

关 键 词：仔猪断奶腹泻(PWD) 产肠毒素大肠杆菌(ETEC) 血清型 黏附素(菌毛) 肠毒素 

分 类 号：S852.61[农业科学—基础兽医学]