TABLE 2.
Protective immunity induced by immunization with a B. abortus S19, RB51, Δmfp, or Δomp19 strain in C57BL/6 mice
| Vaccine | Log10 CFU of B. abortus S2308 in spleen (mean ± SD)a | Protection (log10 U) |
|---|---|---|
| PBS control | 6.67 ± 0.13 | |
| B. abortus S19 | 4.94 ± 0.41 | 1.73b,c |
| B. abortus RB51 | 5.90 ± 0.42 | 0.77b |
| B. abortus Δmfp::kan | 5.20 ± 0.42 | 1.47b,c |
| B abortus Δomp19::kan | 5.94 ± 0.35 | 0.73b |
a
Mice were inoculated with PBS, 107 CFU of RB51, or 105 CFU of the other strains. Six weeks later, mice were challenged i.p. with 106 CFU of S2308, and spleen CFU were enumerated 2 weeks after challenge. Results are representative of two independent experiments.
b
Significantly different compared to the PBS control group (P ≤ 0.0004).
c
Significantly different compared to the Δomp19::kan strain and RB51 (P ≤ 0.003).