Figure 2. HP0197 contributes significantly to S. suis virulence in mice and pigs.

(A) The survival of experimental mice inoculated with WT, Δhp0197 and cΔhp0197 strains. Ten mice in each group were inoculated by intraperitoneal injection with 10⁹ CFU of WT, Δhp0197 or cΔhp0197 respectively and the mice were monitored for clinical signs of infection three times a day during 7 days. “*” represents P value <0.05 of WT versus Δhp0197 group or Δhp0197 versus cΔhp0197 group respectively. (B) The loss of body weight of mice inoculated with the WT, Δhp0197 and cΔhp0197 strains, which usually reflects the health status of mice. “*” represents P value <0.05 of WT versus Δhp0197 group. (C) The kinetics of bacterial clearance from the blood of mice inoculated with the WT, Δhp0197 and cΔhp0197 strains. “*” represents P<0.05 of WT versus Δhp0197 group at given time course. (D) The survival of experimental pigs inoculated with WT and Δhp0197 strains. Eight pigs in each group were inoculated intranasally with 2×10⁷ CFU of WT and Δhp0197 strains respectively. Four pigs were inoculated with PBS and served as a control. “*” represents P<0.05 of WT versus Δhp0197 group. (E) Clinical scores (daily means and standard deviations) of pigs after inoculation. “*” represents P value <0.05 of WT versus Δhp0197 group at given time course.