title: Identification of enterotoxigenic Escherichia coli by colony hybridization using three enterotoxin gene probes.
abstract: 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). Strains of ETEC that produced ST only from rural Thailand were homologous with the ST-H probe only, whereas strains isolated in Bangkok were homologous with the ST-H probe, the ST-P probe, or both probes. The hybridization technique detected ETEC in all stool samples of patients with diarrhea from whom ETEC was isolated and in ETEC-inoculated water containing other species of bacteria. The DNA hybridization assay is useful for characterizing and identifying environmental sources of ETEC.
mesh_terms: D000328:Adult; D001427:Bacterial Toxins; D002648:Child; D003967:Diarrhea / Q000382:microbiology; D004768:Enterotoxins / Q000235:genetics*; D004926:Escherichia coli / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism; D029968:Escherichia coli Proteins; D005243:Feces / Q000382:microbiology; D005798:Genes, Bacterial; D006801:Humans; D009693:Nucleic Acid Hybridization; D014871:Water Microbiology
chemical_list: D001427:Bacterial Toxins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C034151:heat stable toxin (E coli); C027538:heat-labile enterotoxin, E coli