Human Escherichia coli O157:H7 genetic marker in isolates of bovine origin

Abstract

The antiterminator Q gene of bacteriophage 933W (Q933) was identified upstream of the stx2 gene in 90% of human disease-origin Escherichia coli O157:H7 isolates and in 44.5% of bovine isolates. Shiga toxin production was higher in Q933-positive isolates than Q933-negative isolates. This genetic marker may provide a useful molecular tool for epidemiologic studies.