Preparation and Preliminary Utilization ofGene Probe of Heat stable Enterotoxin I(STI) of Enterotoxigenic E. coli (ETEC) by Polymerase Chain Reaction (PCR)
Abstract:The Heat stable enferotoxin I(ST) recombination plasmid pSLM004 of ETEC was cleaved with restriction endonuclease Taq I,the fragment of Taq I was labled with α-32p-DATP by PCR to be utilized as STI gene probe.Hybridization of colony in situs on filters indicated that the probe wsa highly specific and sensitive.Amount of 180 strains of E.coli which isolated from children's diarrhea and 52 strains from piglets,28 standard strains of E.coli serum types were identified,11,2 and 2 were positive,respectively,the hybridization positive rate was 6%,4% and 7% respectively,but 84 strains E.coli which isolated from calf with diarrhea disease,none was positive when detected with the STI probe.Among 15 STI gene probe hybridization positive E.coli strains,13 of them showed positive in suckling mouse bioassay,the coincidence ratio of the two assay was 87%.