Virulence of Shiga Toxin-Producing Escherichia coli (STEC) in Orally-Infected Mice Correlates with the Type of Toxin Produced by the Infecting Strain

In this chapter, we will provide a brief review of the attributes of the Shiga toxin (Stx) family with emphasis on the importance of these toxins in the pathogenesis of disease caused by E. coli O157: H7 and other Shiga toxin-producing E. coli (STEC).We will also describe a modification of our streptomycin (str)-treated, orally-infected mouse model (23, 24) that permits the assessment of the relative virulence of various E. coli O157:H7 strains.In addition, we will illustrate how the type (s) of Stx produced by an E. coli strain is linked to virulence of that isolate when fed to str-treated mice.Lastly, we will underscore the role that activation of Stx2d by intestinal mucus plays in enhancing the pathogenicity of an infecting STEC strain that produces Stx2d.