Shiga Toxin Interactions with the Intestinal Epithelium

Many different types of Escherichia coli are known to cause gastrointestinal disease, including enteroaggregative, enteropathogenic, enterotoxigenic, and enteroinvasive E. coli . However, none cause the severe morbidity that is sometimes seen in patients infected with Shiga toxin-producing E. coli (STEC). Although the majority of STEC infected patients have non-life-threatening diarrhea, STEC infection can result in serious gastrointestinal and systemic complications such as hemorrhagic colitis and hemolytic uremic syndrome (HUS) (1 ). STEC produces a potent toxin that is biochemically, biologically, and genetically very similar to the Shiga toxin produced by Shigella dysenteriae type 1. Shiga toxins are considered to be the principal virulence factors involved in the systemic complications that follow STEC infection; however, the precise mechanisms by which Shiga toxins cause such disorders remain unclear.