Evaluation of a Visual DNA Probe for Enterotoxigenic E. coli Detection in Foods and Wastewater by Colony Hybridization

Abstract

A visual DNA probe for the detection of enterotoxigenic E. coli (LT EEC) by colony hybridization was evaluated to determine its efficacy as a more restrictive, routine indicator method for foods and wastewater. The E. coli heat labile enterotoxin (LT) gene was used as the DNA probe to detect LT EEC. In control experiments the reliability of the probe was demonstrated with food spiked with LT EEC. Raw oysters and wastewater examined for naturally occurring LT EEC showed significant levels of probe positive isolates. Despite some problems, for example background noise associated with food type, the DNA probe proved satisfactory as a method for indicating the presence of enterotoxigenic Enterobacteriaceae.