Figure 3. Effects of enteroaggregative E. coli strain 042 on T84 cells in culture. Polarized T84 monolayers were washed and inoculated with 106 CFU of 042 and allowed to coincubate at 37°C for 6 hrs. Transmission electron microscopy reveals adherence of bacteria to the apical surface of the T84 cells without internalization. The apical brush border is effaced; cells are ballooning and will eventually be extruded from the monolayer. (J.P. Nataro and S. Sears, unpub. data). Bar, 1 mm.