Overall, our data suggests that O157:H7Δstx2 infection greatly stimulated Stx2 passage through both paracellular and transcellular pathways, and that this stimulation is mainly due to O157:H7Δstx2 co-incubation with epithelial cells, and to a lesser extent, to soluble metabolites released by O157:H7Δstx2 to the culture supernatant. Here, STX2 is linked to infection.