Development of Multiplex PCR Assay for Detection of Four Fimbrial Genes of Enterotoxigenic Escherichia coli From Piglets with Diarrhoea

The fimbriae are the important virulence factors in enterotoxigenic E.coli(ETEC).To detect and identify the four main fimbriae genes(K88,K99,F41,987p) of ETEC from diarrhoeal piglets,a multiplex PCR assay was developed.Firstly,four pairs of primers were designed.And the multiplex PCR protocol were developed with four references E.coli strain which possess different four fimbriae genes.The results demonstrated that this protocol could amplify 201,314,380 and 459bp DNA segments of K88,K99,F41 and 987p fimbriae respectively.The four PCR products were further identified with AfaⅠ,DraⅠ,SspⅠand SspⅠ restriction enzyme digestion respectively.This assay has been proved to be specific and sensitive for diagnosis of piglet diarrhoea caused by ETEC and ifentification of the fimbriae type of ETEC.