Outer membrane vesicles (OMVs) secreted by enterohemorrhagic Escherichia coli (EHEC) O157 contain Shiga toxin 2 (Stx2), the major virulence factor involved in the pathogenesis of EHEC-associated hemolytic uremic syndrome (EHEC-HUS). Here, STX2 is linked to hemolytic-uremic syndrome.