Evaluation of ehxA, stx1, and stx2 Virulence Gene Prevalence in Cattle Escherichia coli Isolates by Multiplex PCR



  Today, it is nearly 25 years past from investigation of Shiga toxigenic Escherichia coli (STEC) which is able to produce Shiga toxins and cause different gastroenteritis. Since incidence of gastroenteritis due to STEC is increasing, it's necessary to develop rapid, specific and accurate procedures like PCR. In this study, we used PCR method to detect and identify STEC in cultures of 55 Escherichia coli positive feces from cattle. The assay utilized three specific primer pairs to detect ehxA, stx1, and stx2 (including variants of Stx2) genes producing 321, 348, and 584 base pairs, respectively. Finally, about 21.8% of Escherichia coli isolates were positive for ehxA, stx1, and/or stx2 genes. According to other research, the prevalence of stx2 genes was higher than stx1 genes but not about ehxA genes.