title: Genetic profiles of Shiga toxin and intimin genes found in stool broth cultures: a 2-year reference laboratory study.
abstract: Shiga toxin (Stx)-producing Escherichia coli (STEC) are associated with potentially serious illness in humans. STEC detection is often based on the presence of Stxs, Stx(1) and/or Stx(2), and intimin, encoded by the eae gene. A 2-year collection of stool broth cultures was tested for variants of stx(1), stx(2), and eae. Approximately 80% (138 of 174) were positive for stx(1) and/or stx(2), with stx(1) as the most prevalent (66%). Of the stx(1) variants, stx(1) was the most common (76%) followed by stx(1c) (22%). Analysis of stx(2)-positive isolates found 20 (53%) stx(2), 13 (34%) stx(2)/stx(2v-ha), 3 (8%) stx(2v-ha), 1 (3%) stx(2v-hb), and 1 (3%) stx(2d-activatable). Findings of stx(2)/stx(2v-ha) and stx(2d-activatable) are noteworthy given associations with hemolytic uremic syndrome and increased cytotoxicity, respectively. Of the Stx positive, 94 (68%) were eae positive with 31 (33%) eae(varepsilon1), 19 (20%) eae(gamma1), and 18 (19%) eae(beta1). A predominance of eae(varepsilon1) may suggest a new pathogenic significance because, reportedly, eae(beta1) is one of the most widespread variants.
authors.affiliation: North Carolina State Laboratory of Public Health, Raleigh, NC 27601, USA.
authors.forename: Pierre A
authors.initials: PA
authors.lastname: Michel
authors.forename: Julie A
authors.initials: JA
authors.lastname: Kase
mesh_terms: D018829:Adhesins, Bacterial / Q000145:classification / Q000235:genetics*; D004269:DNA, Bacterial / Q000235:genetics* / Q000302:isolation & purification*; D029968:Escherichia coli Proteins / Q000145:classification / Q000235:genetics*; D005243:Feces / Q000382:microbiology*; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods; D022622:Shiga Toxin 1 / Q000145:classification / Q000235:genetics*; D022641:Shiga Toxin 2 / Q000145:classification / Q000235:genetics*; D054323:Shiga-Toxigenic Escherichia coli / Q000235:genetics*
chemical_list: D018829:Adhesins, Bacterial; D004269:DNA, Bacterial; D029968:Escherichia coli Proteins; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; C073819:eaeA protein, E coli