Figure 4.

Production of pro-inflammatory cytokines IL-6 (A) and TNF-α (B) in sera and bacterial loads (C–F) of C57BL/6 mice infected with 1 × 10⁷ CFU of S. suis strain P1/7 and S. parasuis strain BS26. Median values with interquartile ranges of each group were used to express cytokine levels in sera. Bacterial counts of individuals, including median with interquartile ranges, were presented. Colonies were expressed as CFU/0.1 g for organ samples or CFU/mL for blood samples. Significant differences in bacterial counts and cytokine data between the two infected groups were determined by Wilcoxon’s two-sample test. * Cytokine levels and bacterial counts of mice infected with S. suis strain P1/7 were statistically higher than those of mice infected with S. parasuis strain BS26 (p < 0.05). § Cytokine levels of mice infected with S. parasuis strain BS26 were statistically higher than those of mice infected with S. suis strain P1/7 (p < 0.05).