Identification of enterotoxigenic Escherichia coli with synthetic alkaline phosphatase-conjugated oligonucleotide DNA probes.

Alkaline phosphatase-conjugated (AP) 26-base oligonucleotide DNA probes were compared with the same probes labeled with gamma-32P for the identification of heat-labile (LT) and heat-stable (ST) enterotoxigenic Escherichia coli (ETEC). The AP oligonucleotide probes were as sensitive as the radiolabeled (RL) probes in detecting LT and STA-2 target cell DNA, but the AP ST probe, which differed from STA-1 by two bases, was less sensitive than the RL probe in detecting STA-1 DNA (6.25 versus 0.

A comparative study of enterotoxin gene probes and tests for toxin production to detect enterotoxigenic Escherichia coli.

Escherichia coli isolated from children with diarrhea were tested for enterotoxin production and for hybridization with gene probes for heat-labile (LT) and heat-stable (ST-H and ST-P) enterotoxin. Fecal specimens were also examined directly for genes coding for enterotoxins. E.

Identification of enterotoxigenic Escherichia coli by colony hybridization using three enterotoxin gene probes.

The applicability of examining clinical specimens with a DNA hybridization technique for genes encoding enterotoxins was examined using enterotoxigenic Escherichia coli (ETEC) that produced both heat-labile toxin (LT) and heat-stable toxin (ST) (24 isolates), ETEC that produced LT only (17 isolates), and ETEC that produced ST only (22 isolates) from Thailand. ETEC was identified with Y-l adrenal cell and suckling mouse assays. All were homologous with radiolabeled fragments of DNA encoding LT or ST of porcine origin (ST-P) or of human origin (ST-H).