FIG. 3.

(A) Clusters of adherent bacteria associated with the villi of pig ileal loops inoculated with wild-type EHEC O157:H7 strain 86-24N^S, grown in BHI plus NaHCO₃ without shaking. Adherence was quantified as the percentage of villi that had clusters of ≥5 adherent bacteria per villus. Arrowheads point to clusters of bacteria. The sections were stained with Giemsa stain. Magnification, ×200. (B and C) Transmission electron micrographs of AE lesions in pig ileal loops inoculated with wild-type EHEC O157:H7 strain 86-24N^S. Arrowheads show bacteria intimately adherent to epithelial cells. The arrow shows bacterial invasion of the epithelium. Bars, 1 μm.