Shiga toxin 2-specific but not shiga toxin 1-specific human monoclonal antibody protects piglets challenged with enterohemorrhagic Escherichia coli producing shiga toxin 1 and shiga toxin 2.

Shiga toxin 2 (Stx2) producing Escherichia coli (STEC) strains are more frequently isolated from hemolytic-uremic syndrome cases than strains that produce Stx1 and Stx2, and rarely the strains that produce only Stx1. Studies have implicated Stx2 as the sole contributor to acute kidney failure and other systemic complications in humans, and our study adds further support to this assumption since Stx2- and Stx1-specific antibodies protected 100% and 0% of piglets, respectively, against an oral challenge with a Stx1- and Stx2-producing STEC strain. We conclude that Stx2-specific antibody is sufficient to protect piglets, and possibly humans, against STEC producing both toxins.