title: The Shiga toxin genotype rather than the amount of Shiga toxin or the cytotoxicity of Shiga toxin in vitro correlates with the appearance of the hemolytic uremic syndrome.
abstract: Shiga toxins (Stx) are believed to play a key role in the pathogenesis of diseases caused by Stx-producing Escherichia coli (STEC), including the potentially life-threatening hemolytic uremic syndrome (HUS). In this study, 201 STEC strains collected from patients and environmental sources were investigated with regard to the stx genotypes and pathogenicity. The stx(2) and stx(2c) alleles were associated with high virulence and the ability to cause HUS, whereas stx(2d), stx(2e,)stx(1), and stx(1c) occurred in milder or asymptomatic infections. Quantification of Stx using an enzyme immunoassay and the Vero cell cytotoxicity assay showed no significant differences between the strains associated with HUS and those causing milder diseases. We hypothesize that the stx genotype and perhaps other yet unknown virulence factors rather than the amount of Stx or the in vitro cytotoxicity correlate with the development of HUS.
authors.affiliation: Austrian Reference Centre for Enterohaemorrhagic Escherichia coli, Department of Hygiene, Microbiology and Social Medicine, Innsbruck Medical University, A-6020 Innsbruck, Austria. dorothea.orth@i-med.ac.at
authors.forename: Dorothea
authors.initials: D
authors.lastname: Orth
authors.forename: Katharina
authors.initials: K
authors.lastname: Grif
authors.forename: Abdul B
authors.initials: AB
authors.lastname: Khan
authors.forename: Asma
authors.initials: A
authors.lastname: Naim
authors.forename: Manfred P
authors.initials: MP
authors.lastname: Dierich
authors.forename: Reinhard
authors.initials: R
authors.lastname: Würzner
mesh_terms: D018829:Adhesins, Bacterial / Q000378:metabolism; D000818:Animals; D002522:Chlorocebus aethiops; D029968:Escherichia coli Proteins / Q000378:metabolism; D005516:Food Microbiology; D005517:Foodborne Diseases; D005838:Genotype; D006463:Hemolytic-Uremic Syndrome / Q000382:microbiology*; D006801:Humans; D007124:Immunoenzyme Techniques; D022622:Shiga Toxin 1 / Q000145:classification / Q000235:genetics*; D022641:Shiga Toxin 2 / Q000145:classification / Q000235:genetics*; D054323:Shiga-Toxigenic Escherichia coli / Q000145:classification / Q000235:genetics* / Q000472:pathogenicity; D014709:Vero Cells / Q000382:microbiology; D014774:Virulence / Q000235:genetics
chemical_list: D018829:Adhesins, Bacterial; D029968:Escherichia coli Proteins; D022622:Shiga Toxin 1; D022641:Shiga Toxin 2; C073819:eaeA protein, E coli