Double PCR for Detection of Virulence Genes K88 and K99 of Enterotoxigenic Escherichia coli Strains

To detect and identify two fimbriae genes(K88 and K99) of enterotoxigenic Escherichia coli(ETEC),a double PCR method was developed based on 2 pairs of primers for K88 and K99 genes amplification.2 different virulence genes of the reference E.coli strain which passed was detected and the double PCR was proved to be specificity and sensitivity.The PCR amplification conditions ultimately were determined that dNTP concentration were 0.4 mmol/L,K88 and K99 primers concentration were both 25 μmol/L and the annealing temperature was 52 ℃.Furthermore,a total of 23 samples of E.coli were tested by the double PCR assay and the results showed 2 samples were K88,3 samples were K99,and 5 samples were K88 and K99 positive.The double PCR assay provided a method to detect ETEC which caused diarrhea in piglets.