STX2 and hemolytic-uremic syndrome: Shiga toxins (Stx1 and Stx2) are key virulence factors in the pathogenesis of gastroenteritis, HC and HUS, caused by STEC and other Stx-producing bacteria, including Citrobacter freundii, Enterobacter cloacae, Acinetobacter haemolyticus, Aeromonas sp., and Escherichia albertii22–26.