title: Characterization of enteroinvasive Escherichia coli strains isolated from children with diarrhea in Chile.
abstract: Analysis of stool samples from 912 cases of diarrhea among Chilean infants and 1,112 controls resulted in the isolation of 17 enteroinvasive Escherichia coli (EIEC) strains from diarrhea cases (1.9%) and 3 EIEC from the asymptomatic controls (0.3%). Biochemical analysis of the 20 isolates showed variability among them. However, the majority were lysine decarboxylase negative and nonmotile and utilized sodium acetate. The strains belonged to the O groups 28ac, 124, 143, or 144 or were untypable with the antisera used. Most of them had conjugative plasmids which mediated multiple antibiotic resistance. There was a strong correlation in this group of strains between a positive Sereny test, the presence of a plasmid of 120 megadaltons, and hybridization with the invasiveness probe, an HindIII fragment derived from the plasmid pPS15A. The isolates had a wide range of plasmid profiles. Bioassays and colony and Southern hybridization tests with iron uptake DNA probes indicated that 80% of the EIEC strains produced aerobactin and expressed its receptor, the genes for which are known to be chromosomally located.
authors.affiliation: Department of Microbiology and Immunology, New York Medical College, Valhalla 10595.
authors.forename: G
authors.initials: G
authors.lastname: Faundez
authors.forename: G
authors.initials: G
authors.lastname: Figueroa
authors.forename: M
authors.initials: M
authors.lastname: Troncoso
authors.forename: F C
authors.initials: FC
authors.lastname: Cabello
mesh_terms: D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001425:Bacterial Outer Membrane Proteins / Q000032:analysis; D002677:Chile; D004269:DNA, Bacterial / Q000032:analysis; D003967:Diarrhea / Q000382:microbiology*; D004352:Drug Resistance, Microbial / Q000235:genetics; D004591:Electrophoresis, Polyacrylamide Gel; D004926:Escherichia coli / Q000145:classification* / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D004927:Escherichia coli Infections / Q000453:epidemiology / Q000382:microbiology*; D006801:Humans; D006877:Hydroxamic Acids / Q000032:analysis; D007223:Infant; D009693:Nucleic Acid Hybridization; D011815:R Factors; D011971:Receptors, Immunologic / Q000235:genetics
chemical_list: D000900:Anti-Bacterial Agents; D001425:Bacterial Outer Membrane Proteins; D004269:DNA, Bacterial; D006877:Hydroxamic Acids; D011971:Receptors, Immunologic; C034506:aerobactin receptor; C031819:aerobactin