An assessment for comparing virulent factors of enterotoxigenic E.coli k99 isolates by PCR and SDS- PAGE methods

Since E. coli K99 is a causative agent of diarrhea and casualties in calf, it has adverse impacts on economy. This research studied the pathogenic factors of the E. coli by Multiplex PCR, and determined protein pattern of different E. coli isolates by SDS-PAGE (sodium dodsil sulfate polyacryl amid gel electroforesis).

300 rectal swabs were collected from 1-30 days-old calf during a period between 2010 to 2011. One part of the samples was studied with Multiplex PCR method for determination of the K99, F41 as well as STa genes, and another part was cultured for E. coli isolation and SDS-PAGE assay.

The PCR results indicated that 16 of the 200 isolated E. coli had K99, F41, and STa pathogenic factors. LT was not found in the isolates. SDS-PAGE results showed different protein pattern in the isolated E. coli strains. The results of SDS-PAGE column showed only one band for K99 antigen.

Based on the found virulent factors in the isolated E. coli K99, it has been shown that the isolates contain at least three pathogenic genes (K99, F41, and STa). Although no significant difference has been seen between the isolates in terms of gene investigations, there was a meaningful difference in the protein patterns of the isolates. As a conclusion, different bacteria showed different protein patterns and consequently had different pathogenic ability.