title: Escherichia coli O157:H7 strains that express Shiga toxin (Stx) 2 alone are more neurotropic for gnotobiotic piglets than are isotypes producing only Stx1 or both Stx1 and Stx2.
abstract: Infection with Escherichia coli O157:H7 can lead to hemolytic uremic syndrome (HUS) in some children. Epidemiologic data suggest that Shiga toxin (Stx) 2-producing strains are more frequently associated with HUS than are Stx1-producing strains. Less clear is whether strains that express Stx2 alone are more frequently associated with HUS than strains that express Stx1 and Stx2. Isogenic mutants 933stx1- and 933stx2- were produced from strain 933 (Stx1 and Stx2 producer), and 86-24stx2- was produced from strain 86-24 (Stx2 producer). Neurologic lesions or symptoms developed in 18 (90%) of 20 gnotobiotic piglets orally infected with strain 86-24, in 15 (85%) of 18 infected with mutant 933stx1-, in 9 (31%) of 29 infected with strain 933, in 0 of 5 infected with mutant 86-24stx2-, and in 0 of 6 infected with mutant 933stx2-. It was concluded that strains expressing Stx2 alone are more neurotropic for piglets when fed orally than are those strains expressing Stx1 and 2, whereas Stx1-producing strains induce only diarrhea. It is also conceivable that strains that produce Stx2 may constitute a significant predictive risk factor for HUS in humans.
authors.affiliation: Division of Infectious Diseases, Tufts University School of Veterinary Medicine, North Grafton, Massachusetts 01536, USA.
authors.forename: A
authors.initials: A
authors.lastname: Donohue-Rolfe
authors.forename: I
authors.initials: I
authors.lastname: Kondova
authors.forename: S
authors.initials: S
authors.lastname: Oswald
authors.forename: D
authors.initials: D
authors.lastname: Hutto
authors.forename: S
authors.initials: S
authors.lastname: Tzipori
mesh_terms: D000818:Animals; D001427:Bacterial Toxins / Q000235:genetics*; D017931:DNA Primers; D004768:Enterotoxins / Q000235:genetics; D004927:Escherichia coli Infections / Q000382:microbiology* / Q000473:pathology; D019453:Escherichia coli O157 / Q000235:genetics* / Q000472:pathogenicity*; D005856:Germ-Free Life; D006463:Hemolytic-Uremic Syndrome / Q000382:microbiology; D016297:Mutagenesis, Site-Directed; D009876:Operon; D016133:Polymerase Chain Reaction; D020033:Protein Isoforms / Q000235:genetics; D017384:Sequence Deletion; D022603:Shiga Toxins; D013552:Swine
chemical_list: D001427:Bacterial Toxins; D017931:DNA Primers; D004768:Enterotoxins; D020033:Protein Isoforms; D022603:Shiga Toxins