Figure 5

Protection conferred in mice against virulent B. ovis PA by the Brucella vaccines. Mice were inoculated with PBS (negative control), B. melitensis Rev 1, B. ovis PNV25dA, or B. ovis PNV22A (see strain abbreviations and inoculation doses in legend to Figure 1) and were challenged 28 days later with 10⁵ CFU/mouse of virulent B. ovis PA. Three weeks after infection, the CFUs of B. ovis PA in spleen were counted in five mice per vaccination group. Results are expressed as means ± SD (n = 5) of the log CFU/spleen of B. ovis PA. Significant differences (PLSD test) between vaccination groups are marked as described in the legend to Figure 4.