FIG. 2.

The level of cytokines in serum and organs at day 4 postinfection increases in the typhoid fever model when mice are treated with the aflagellate mutant. (A) Level of IFN-γ and IL-12 in the serum of noninfected (NI) mice or mice infected with WT S. enterica serovar Typhimurium or an aflagellate mutant (C⁻B⁻). Data are representative of at least six individually analyzed mice. (B) PP, MLN, and spleen cells were dissociated with collagenase, and the level of cytokines was determined in the cell supernatant (see Materials and Methods). Data are representative of at least seven individually analyzed mice. *, P < 0.05; **, P < 0.01; ***, P < 0.001.