Fig. 4.

Competition of WT and sdiA mutant in the bovine rumen and RAJ. Eight 1.5-year-old fully ruminant and ruminally cannulated Charolais heifers were inoculated with equal cfus of WT and sdiA mutant. (A) As a control, equal cfus of WT and sdiA were grown in coculture in vitro, and their competitive indexes were determined throughout growth (early, mid, late, and stationary phases of growth). A competitive index of 1 means no difference, a competitive index <1 means that WT was in higher numbers than the sdiA mutant, and a competitive index >1 means that the mutant was in higher numbers than WT. The ratio of WT to mutant bacteria was determined in the (B) rumen and (C) RAJ. (D) Schematic model of SdiA-AHL–dependent EHEC gene expression in the bovine GI tract.