title: Association between alpha-hemolysin production and HeLa cell-detaching activity in fecal isolates of Escherichia coli.
abstract: Escherichia coli isolates that cause detachment of cell monolayers during in vitro adherence assays (cell-detaching E. coli [CDEC]) were recently reported as a potential new group of enteropathogenic bacteria. In the present study, 269 E. coli isolates from feces of children 1 to 5 years of age were identified as CDEC in a detaching assay developed with HeLa cells. The great majority of these isolates were hemolytic within 3 h of growth on blood agar plates and hybridized with a DNA probe for alpha-hemolysin (93.7%), while most of the non-detaching isolates were hemolytic within 24 h (3.6%) or nonhemolytic (94.8%). E. coli isolates that produced alpha-hemolysin were found in 60 (30%) of 200 children with diarrhea and 47 (24%) of 200 age-matched controls. No statistical significance was found for the differences in alpha-hemolysin production among the matched pairs (P = 0.2). These data suggest that CDEC isolates are not associated with diarrhea in the population studied.
authors.affiliation: Secção de Bacteriologia, Instituto Adolfo Lutz, São Paulo, Brazil.
authors.forename: L R
authors.initials: LR
authors.lastname: Marques
authors.forename: C M
authors.initials: CM
authors.lastname: Abe
authors.forename: P M
authors.initials: PM
authors.lastname: Griffin
authors.forename: T A
authors.initials: TA
authors.lastname: Gomes
mesh_terms: D001426:Bacterial Proteins / Q000096:biosynthesis*; D001938:Brazil / Q000453:epidemiology; D002448:Cell Adhesion; D002675:Child, Preschool; D003967:Diarrhea / Q000150:complications / Q000453:epidemiology / Q000382:microbiology*; D004926:Escherichia coli / Q000302:isolation & purification / Q000472:pathogenicity*; D004927:Escherichia coli Infections / Q000150:complications / Q000453:epidemiology / Q000382:microbiology*; D029968:Escherichia coli Proteins; D005243:Feces / Q000382:microbiology*; D006367:HeLa Cells; D006460:Hemolysin Proteins / Q000096:biosynthesis*; D006801:Humans; D007223:Infant; D018675:Toxicity Tests
chemical_list: D001426:Bacterial Proteins; D029968:Escherichia coli Proteins; D006460:Hemolysin Proteins; C036507:Hlya protein, E coli