大肠杆菌F18菌毛及其亚型的PCR鉴定

PCR Identification of Escherchia coli F18 and It's Subtypes

F18菌毛是产肠毒素大肠杆菌 (ETEC)与产vero细胞毒素大肠杆菌 (VTEC)的重要致病因子 ,可介导细菌对小肠细胞的黏附 ,并具有F18ab和F18ac 2个抗原亚型。根据已发表的F18ab菌毛A亚单位 (FedA ab)的基因 (fedA ab)设计 3条引物 ,建立了 2种聚合酶链式反应 (PCR)扩增方法。通过对F18ab+ 大肠杆菌、F18ac+ 大肠杆菌、K88+ 大肠杆菌、K99+ 大肠杆菌、987P+ 大肠杆菌、F4 1+ 大肠杆菌的试验 ,结果表明所建立的PCR方法可特异性鉴定F18+

The fimbrial adhesin F18 is frequently found on the surface of enterotoxigenic Escherichia coli (ETEC) and vero- toxigenic E. coli (VTEC) strains which are responsible for diarrhea and edema disease in weaned piglets, and it have been implicated as possible virulence factors that mediated bacterial colonization on small intestinal epithelial cells. The F18 adhesin occurs in two serological variants, F18ab and F18ac. Three synthetic oligonucleotide primers derived from the fedA gene of F18ab fimbriae were used in polymerase chain reaction (PCR) amplification procedure to detect some enteric pathogens, such as F18ab^+ strains, F18ac^+ strains, K88^+ strains, K99^+ strains, 987P^+ strains and F41^+ strains. The results showed that the established PCRs were not only able to identify F18^+ E. coli strains, but also to distinguish F18ab^+ and F18ac^+ strains.