Fig. 2. S. typhimurium does not alter epithelial permeability to macromolecules. T84 model epithelia were colonized as in Fig. 1 with S. typhimurium and/or E. coli in the presence of 10 mg/ml FITC or 40 kDa FITC-dextran. (A) Transepithelial electrical resistance (TEER), (B) FITC or (C) FITC-dextran concentrations in the basolateral media were measured as described in Materials and Methods. , no bacteria; , S. typhimurium; , E. coli. Data are the means±s.e.m. of three parallel experiments.