Figure 1. EPEC inhibits Cl^–/OH^– exchange activity.

(A) Caco-2 cells were infected with EPEC or nonpathogenic E. coli in the cell culture medium for 3 hours. Cl^–/OH^– exchange activity was measured in base-loaded cells as DIDS–sensitive (300 μM) ³⁶Cl^– uptake. Results represent mean ± SEM of 9 separate experiments performed in triplicate. *P < 0.05 compared with control. (B) Time course of Cl^–/OH^– exchange activity inhibition by EPEC in Caco-2 cells. Results represent mean ± SEM of 6 separate experiments performed in triplicate. *P < 0.05 compared with control. (C) Effects of EPEC are not cell line specific. T84 cells were infected with EPEC for 60, 90, or 120 minutes, and Cl^–/OH^– exchange activity was measured as DIDS-sensitive (300 μM) ³⁶Cl^– uptake. Results represent mean ± SEM of 3 separate experiments performed in triplicate. *P < 0.05 compared with control.