Fig 5. The exoR mutation in B. abortus 2308W does not affect its infection capacity.

(A, B) Murine RAW 264.7 macrophages or HeLa epithelial cells were cultivated and infected with B. abortus strains (2308W and exoR mutant) in the exponential phase. The number of intracellular viable B. abortus CFU was determined at different hours post-infection. Each point is the average of three independent trials. (C) Virulence assays of B. abortus 2308W and exoR mutant in mice. Mice were intraperitoneally inoculated with 10⁶ CFU of either B. abortus 2308W or B. abortus 2308W exoR mutant. CFU per gram of spleen was determined at 3- and 9-weeks post-infection. For these experiments, no significant difference was shown between the wild-type and the mutant (Mann-Whitney test).