Kinetics of the neutralization of the cytotoxic effects on HEp-2 cells after previous incubation of the bacterial strains with anti-Pet IgG (125 μg/mL and 250 μg/mL) or with PMSF at the concentrations of 0.3, 0.6, and 1.25 mM. Light microscopy of the cells incubated with aEPEC strain BA 3160; magnification: 100x (a). Cytotoxic effect on cells incubated with aEPEC strains BA 2775, BA 3160, BA 2923, and BA 2991 and EAEC strains 40 A5, 215 A3, and 252 A2. Positive controls were EAEC 042 and Pet. Negative controls were aEPEC BA 3170 and cells alone incubated with PMSF. Statistically significant difference when compared to the control (bacteria) as determined using the Friedman with Dunn nonparametric test, (b) or incubated with the anti-Pet IgG. Statistically significant difference when compared to the control (bacteria) as determined using one-way analysis of variance (ANOVA) with Tukey’s test, (c). The results refer to the mean values of three independent experiments performed in triplicate.
