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

Abstract

A commercially available, alkaline-phosphatase-conjugated oligonucleotide probe for detecting the heatstable 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.

Identification of Escherichia coli that produces heat-stable enterotoxin STA by a commercially available enzyme-linked immunoassay and comparison of the assay with infant mouse and DNA probe tests

“…The NEP-010 nucleotide probe for STA (11) is 26 bases long and constitutes part of the STA2 gene sequence but differs in two bases from the analogous region of the STAI sequence. Previous reports have shown that this probe is satisfactory in colony hybridization tests for the detection of strains with the STA2 gene but does not identify all strains carrying the STAI gene (18,25). A mixed probe incorporating both STAl and STA2 enzyme-linked oligonucleotides was provided by Du Pont, NEN Research Products, Boston, Mass., at our request and was used to test the 200 strains.…”

Specific DNA Fragments Coding for ST1 and LT1 Toxins, and K88 (F4) Adhesin in Enterotoxigenic Escherichia coli

“…The purpose of this study was to characterize porcine ETEC strains belonging to different serogroups but all possessing the F4 fimbriae, with regard to enterotoxin and fimbrial adhesin encoding genes, by using enzyme-labelled and 32P-labelled oligonucleotide probes. The use of such probes has been shown to be an appropriate method for detecting ETEC, both from faecal specimens, on colony blots, and on Southern blots of plasmid profiles (HILL et al, 1986; JABLONSKI et a]., 1986; LI et a]., 1987; NISHIBUSHI et al, 1988;SOMMERFELT et al, 1988;WASTESON et al, 1988). As indicated from multilocus enzyme electrophoresis, the chromosomal gene diversity among E. coli isolates sharing single antigenic determinants, can approach or equal that observed by randomly chosen strains (CAUGANT et al, 1985).…”

Development of enzyme-labeled oligonucleotide probe for detection of mecA gene in methicillin-resistant Staphylococcus aureus

“…Although hybridization tests using radioisotope-labeled DNA fragments may be useful for research laboratories, radioisotope management in routine clinical laboratories is difficult. To avoid this problem, various enzyme-labeled oligonucleotide probes are under investigation (8,18,29). In this study, we have developed a DNA hybridization method with an enzyme-linked oligonucleotide probe to detect mecA, mecA-ELONP.…”