FIG. 4.

(A) Intracellular survival of B. suis 1330 wild type (filled bars) and three MSM-resistant mutants (mut 1, mut 4, and mut 6; open, hatched, and crosshatched bars, respectively) in human macrophage-like THP-1 cells. The experiment was performed twice, in triplicate. (B) Relative AHAS activity in the wild type (WT), the ilvI::Tn5 mutant, and the same three MSM-resistant mutants of B. suis mentioned above. This experiment was performed three times, in duplicate. Standard deviations of the means were calculated (**, significant for P < 0.005; ***, significant for P < 0.0001).