FIG. 5.

Histograms showing mean colonization levels in the noses, larynxes, and tracheas of 4-week-old, female Wistar rats inoculated intranasally with B. bronchiseptica. Rats were inoculated with the wild-type strain RB50 (hatched bars) and the ΔfimBCD strain RB63 (solid bars) and sacrificed after 10, 30, and 60 days. The lower limit of detection was four bacteria and is represented by the dashed line. Significantly different colonization levels are designated by ∗ for P values of ≤0.005. Error bars represent the standard error from the mean (SEM).