Fig 5.

Pathology scores for WT and mutant bacteria at day 7 postinfection. The pathological scores were determined as described in Materials and Methods. Each column shows data for a single mouse. The rectum was assumed to be the most distal segment of the colon on the slide. The midportion was the closest area to one full turn beyond the cecum and was cut so at least some of the crypts were displayed longitudinally. The mean of the composite scores for the mutant salmonellae in each of the three segments was determined and compared to the mean of the WT infection scores (ANOVA with Dunnett's posttest modification). The ssaV pathology scores were all very much lower than the WT scores. The double mutant (spvB sifA) had a slightly lower score than the WT in the midsection of the colon (***, P < 0.001; *, P < 0.05).