These three proteins are suitable targets to develop preventive therapies against STEC infections because: (i) their encoding genes are conserved, widely distributed and highly frequent in both LEE-positive (OmpT, Cah) and LEE-negative STEC strains (Hes, Cah and OmpT) [27]; (ii) they are expressed in vivo during infection in humans and are reactive to hyperimmune sera from HUS patients; and (iii) they have been shown to participate in different colonization-associated phenotypes in vitro assays and in infections of human epithelial cells [5,35,36]. This evidence concerns the gene RRBP1 and infection.