FIG 3.

Epithelial damage of infected HIOs. HIOs were microinjected with 10³ CFU of Nissle, EHEC, or UPEC and harvested at the indicated times postinjection. Cryosections of infected HIOs were stained for DNA (blue; DAPI), bacteria (green; anti-E. coli for Nissle and UPEC, anti-O157 for EHEC), and F-actin (red; phalloidin) and assessed by confocal microscopy. The lumen is labeled. Bars, 20 μm. Representative images of experiments performed in triplicate are shown. (A) Nissle at 18 hours; (B) EHEC at 18 hours; (C) Nissle at 72 hours; (D) UPEC at 72 hours.