FIG. 6.
Histograms showing mean colonization levels in the tracheas of 4-week-old, female Wistar rats inoculated intranasally with 106 CFU (A) and intratracheally with 105 CFU (B) of B. bronchiseptica. Rats were inoculated with wild-type strain RB50 (hatched bars), the Bvg− phase-locked strain RB54 (open bars), and the ΔfimBCD strain RB63 (solid bars) and sacrificed after 24 h and 5 days. The lower limit of detection was four bacteria and is represented by the dashed line; ∗ indicates that colonization levels for RB63 were significantly lower than those of RB50 with a P value of ≤0.05. Error bars represent the standard error from the mean (SEM).