Detection of stx₁ and stx₂ Genes in Pennsylvanian White-Tailed Deer

Abstract: Shiga toxin-producing E. coli carrying the stx₁ and/or stx₂ genes can cause multi-symptomatic illness in humans. A variety of terrestrial and aquatic environmental reservoirs of stx have been described. Culture based detection of microbes in deer species have found a low percentage of samples that have tested positive for Stx-producing microbes, suggesting that while deer may contain these microbes, their overall abundance in deer is low. In this study, quantitative PCR (qPCR) was utilized to test for the presence of stx genes in white-tailed deer fecal matter in western Pennsylvania. In this culture independent screening, nearly half of the samples tested positive for the stx₂ gene, with a bias towards samples that were concentrated with stx₂. This study, while limited in scope, suggests that deer may be a greater reservoir for stx than was previously thought.