Fig. (2) Invasion of differentiated intestinal Caco-2 and T84 cells by aEPEC and tEPEC strains. Experiments were performed in triplicates at least three times; error bars indicate standard deviation. ** indicates statistically significant difference between aEPEC 1711-4 and 3991-1 or tEPEC E2348/69 in Caco-2 cells; (P = 0.006); * indicates statistically significant differences between aEPEC 1711- 4 and 3991-1 and tEPEC E2348/69 in T84 cells (P < 0.001).