title: Chromosomal DNA, iron-transport systems, outer membrane proteins, and enterotoxin (heat labile) production in Salmonella typhi strains.
abstract: We examined a representative collection of Salmonella typhi strains from Chile, Peru, Mexico, India, and England for the presence of several properties. All strains had a conserved pattern of outer membrane proteins, as determined by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The electrophoresis profiles of chromosomal DNA digested with EcoRI and PstI restriction enzymes were similar for all the strains. A conserved pattern of hybridization was observed when digested chromosomal DNA was hybridized with DNA probes for the 36-kilodalton porin, enterobactin synthesis, and enterobactin receptor genes. All the strains produced enterobactin but not aerobactin in bioassays. None of the strains produced heat-labile toxin, as measured by an enzyme-linked immunosorbent assay. Colony and Southern hybridizations with DNA probes for aerobactin synthesis and its receptor and heat-labile toxin genes were negative. These results indicate that S. typhi strains from different origins have similar phenotypic and genetic properties and, as has been suggested, constitute a clone.
authors.affiliation: Department of Microbiology and Immunology, New York Medical College, Valhalla 10595.
authors.forename: G
authors.initials: G
authors.lastname: Faundez
authors.forename: L
authors.initials: L
authors.lastname: Aron
authors.forename: F C
authors.initials: FC
authors.lastname: Cabello
mesh_terms: D001425:Bacterial Outer Membrane Proteins / Q000378:metabolism; D001427:Bacterial Toxins / Q000096:biosynthesis; D001693:Biological Transport, Active; D004269:DNA, Bacterial / Q000235:genetics*; D004768:Enterotoxins / Q000096:biosynthesis; D029968:Escherichia coli Proteins; D006801:Humans; D007501:Iron / Q000378:metabolism; D012150:Polymorphism, Restriction Fragment Length; D012485:Salmonella typhi / Q000235:genetics* / Q000302:isolation & purification / Q000378:metabolism
chemical_list: D001425:Bacterial Outer Membrane Proteins; D001427:Bacterial Toxins; D004269:DNA, Bacterial; D004768:Enterotoxins; D029968:Escherichia coli Proteins; C027538:heat-labile enterotoxin, E coli; D007501:Iron