Evaluation of a nonisotopically labeled oligonucleotide probe to detect the heat-stable enterotoxin gene of Escherichia coli by the DNA colony hybridization test

A commercially available, alkaline-phosphatase-conjugated oligonucleotide probe for detecting the heat-stable enterotoxin gene of Escherichia coli was compared with cloned gene probes by examining E. coli isolates from traveler's diarrhea by DNA colony hybridization tests. The oligonucleotide probe was useful in specifically identifying the so-called STh gene. No deproteinization of sample was necessary to prepare the colony blots.