AM-19226 strains were grown overnight in LB medium and were used to infect Caco2-BBE cells in the presence 0.2% bile at an MOI of ~10. After 3h of co-culture, percent cytotoxicity was determined by measuring LDH in co-culture supernatants. (A) Co-culture was performed with the parental AM-19226 strain, a strain deleted for vcsN2, strains deleted for individual effector protein genes (Δvop). (B) Co-culture was performed with the parental AM-19226 strain or a vopX truncation mutant strain (vopX’) (C) Co-culture was performed with the parental strain, ΔvopH, ΔvopA, ΔvopI, or ΔvopW carrying pBAD18, pBAD18-vopH, pBAD18-vopA, pBAD18-vopI, or pBAD18-vopW. Arabinose was added to the co-culture medium at the indicated concentrations to induce vop expression from the pBAD18 plasmids. For each panel, data are shown from one experiment using three colonies per strain. Each experiment was repeated twice and produced similar results.