After being taken in by phagosomes, Shigella bacteria can escape and live inside or move to other intestinal epithelial cells. Multiplying organisms can possess intesinal epithelium that can become ulcerated. S. dysenteriae type 1 can produce a toxin (Shiga toxin) that binds to a glycosphingolipid and enters endothelial cells of blood vessels in the large intestine. The Shiga toxin then attacks the large ribosomal subunit, affecting protein synthesis leading to conditions such as HUS.