The pathogenic mechanisms of Shiga toxin and the Shiga-like toxins

Shiga and Shiga-like toxins.

In vivo formation of hybrid toxins comprising Shiga toxin and the Shiga-like toxins and role of the B subunit in localization and cytotoxic activity.

Shiga toxin, Shiga-like toxin I (SLT-I) and Shiga-like toxin II (SLT-II) are cell-associated cytotoxins that kill both Vero cells and HeLa cells, whereas Shiga-like toxin II variant (SLT-IIv) is an extracellular cytotoxin that is more cytotoxic for Vero cells than for HeLa cells. The basis for these differences in cytotoxin localization and host cell specificity were examined in this study. The...

Shiga toxins and apoptosis.

The enteric pathogens Shigella dysenteriae serotype 1 and Shiga toxin-producing Escherichia coli (STEC) cause bloody diarrheal diseases that may progress to life-threatening extraintestinal complications. Although the S. dysenteriae and STEC differ in the expression of a number of virulence determinants, they share the capacity to produce one or more potent cytotoxins, called Shiga toxins (Stxs...

Extraintestinal pathogenic Escherichia coli carrying the Shiga Toxin gene stx2.

The 2011 outbreak of infections with Escherichia coli with characteristics of both enteroaggregative E. coli (EAEC) and Shiga toxin-producing E. coli (STEC) caused a paradigm shift with regard to the human pathogenicity of STEC (1). Diarrheagenic E. coli (DEC) usually does not cause extraintestinal diseases such as urinary tract infections and bacteremia (2). The DNA of 193 E. coli isolates fro...

Immunochemical and cytotoxic activities of Shigella dysenteriae 1 (shiga) and shiga-like toxins.

Toxins in culture supernatants and bacterial lysates of S. dysenteriae 1 and S. flexneri were quantitated by a cytotoxicity assay and a newly developed radioimmunoassay. Cytotoxin titers paralleled toxin antigen levels. Thus, variations in cytotoxicity among shigellae probably reflect differences in toxin yield rather than specific activity (cytotoxicity per microgram of toxin antigen).