仔猪致泻性大肠杆菌毒力因子多重PCR检测方法的建立与应用

Establishment of multiplex PCR detection method for diarrhea-causing Escherichia coli virulence factor in piglets in Jilin Province

本研究以致泻性大肠杆菌(DEC)的4种毒力因子EAST1、LT、STa和STb为模板设计特异性引物并优化各项反应条件,以建立仔猪DEC的多重PCR检测方法。该方法具有较好的特异性,只对DEC产生特异性条带,对非DEC及其他病菌则呈阴性。利用所建立的多重PCR方法对吉林省各猪场采集的样本进行检测,结果表明,在测定的猪场中,携带EAST1毒力基因的阳性菌株引起的大肠杆菌感染广泛存在,携带STb毒力基因的阳性菌株次之,携带STa及LT毒力基因的阳性菌株引起的大肠杆菌感染相较于以上2个毒力因子在所测猪场中占比略低。综上所述,本方法的建立为DEC中常见毒力因子的快速检测及分子流行病学调查提供了新的手段。

In this study, four virulence factors of diarrhea-causing Escherichia coli(DEC),EAST1,LT,STa and STb were used as templates to design specific primers and optimize various reaction conditions to establish a multiplex PCR detection method for piglet DEC. This method has good specificity and only produces specific bands for DEC,but is negative for non-DEC and other pathogens.The established multiplex PCR method was used to detect samples collected from pig farms in Jilin Province.The results showed that E.coli infections caused by positive strains carrying EAST1 virulence genes were widespread in the tested pig farms, and they carried STb virulence genes.Strains were followed by E.coli infections caused by positive strains carrying STa and LT virulence genes.Compared with the above two virulence factors, the proportion of the tested pig farms was slightly lower.In summary, the establishment of this method provides a new method for the rapid detection and molecular epidemiological investigation of common virulence factors in DEC.