Fig 7.

Influence of Ifp and InvC on the colonization of intestinal lymphatic tissues and organs. (A) BALB/c mice were coinfected via the orogastric route with 2 × 10⁸ bacteria in an inoculum comprised of an equal mixture of Y. pseudotuberculosis YPIII (wt) and YP97 (Δifp) or YP98 (ΔinvC). Three days postinfection, the mice were sacrificed and the numbers of surviving bacteria in the small intestine (SI), PPs, MLNs, liver, and spleen determined as described in Materials and Methods. Data are presented as a scatter plot of numbers of CFU per gram of organ as determined by counts of viable bacteria on plates. Each spot represents the CFU count in the indicated tissue samples from one mouse. The levels of statistical significance for differences between test groups were determined by the Mann-Whitney test. Asterisks indicate results that differed significantly from those for YPIII: *, P < 0.05; **, P < 0.01. (B) Data are graphed as competitive index values for the tissue samples from one mouse. The bars represent the medians of the competitive index values. A competitive index score of 1 denotes no difference in virulence compared to that of YPIII. Asterisks indicate results that differed significantly from those for YPIII: **, P < 0.01; ***, P < 0.001.