Mice were vaccinated with the indicated strains or inoculated with saline alone were challenged with (A and C) B. abortus 2308, (B and D) B. melitensis 16M and (E) B. suis 1330, and 2 weeks post-challenge, the mice were euthanized and the Brucella CFU in their spleens were determined. Results are shown as mean ± standard deviation (n = 5) of the log CFU of Brucella recovered from spleens. Horizontal broken line above the x-axis indicates the lower limit of detection (<20 CFU/spleen). Asterisks indicate statistically significant differences from the corresponding saline group. *, P < 0.05; **, P < 0.01; ***, P < 0.001. α: no bacteria were recovered on plating the entire homogenate.