title: Linkage of genes for heat-stable enterotoxin, drug resistance, K99 antigen, and colicin in bovine and porcine strains of enterotoxigenic Escherichia coli.
abstract: Linkages among genes for production of Escherichia coli heat-stable enterotoxin (ST), drug resistance, K99 antigen, and colicin were investigated in 2 bovine and 3 porcine strains of enterotoxigenic E coli. In conjugation experiments, all 5 isolates transferred enterotoxigenicity and the ability to produce K99; 4 of the 5 isolates also transferred antibiotic resistance markers, and 3 colicinogenic strains transmitted the ability to produce colicin. In 2 of the 3 colicin-producing strains, the genes for colicin were located along with those for K99 and ST on a single plasmid. One of these 2 strains transferred the genes for tetracycline resistance and production of both mouse-active ST (STa) and mouse-inactive ST, whereas the other transmitted the gene(s) for STa only. Transformation studies with the 3rd strain revealed that the K99 determinant resided on a 22-megadalton (Mdal)R plasmid, and that STa and colicin production were on a 65-Mdal plasmid. Analysis of the plasmids from the transformation experiments revealed that the larger plasmid was conjugative and the smaller plasmid was nonconjugative; stable cointegrate formation occurred between these 2 plasmids. Genetic information coding for the production of STa and K99 were also present on a single plasmid of approximately 80 Mdal in both noncolicinogenic strains.
mesh_terms: D000818:Animals; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D000954:Antigens, Surface / Q000235:genetics*; D001427:Bacterial Toxins; D002417:Cattle / Q000382:microbiology*; D003087:Colicins / Q000235:genetics*; D003227:Conjugation, Genetic; D004768:Enterotoxins / Q000235:genetics*; D004926:Escherichia coli / Q000187:drug effects / Q000235:genetics*; D029968:Escherichia coli Proteins; D005798:Genes, Bacterial; D008040:Genetic Linkage; D010957:Plasmids; D011815:R Factors; D013045:Species Specificity; D013552:Swine / Q000382:microbiology*; D014169:Transformation, Bacterial
chemical_list: D000900:Anti-Bacterial Agents; D000954:Antigens, Surface; D001427:Bacterial Toxins; D003087:Colicins; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C031429:K99 antigen; C034151:heat stable toxin (E coli)