Fig. 1

Cytotoxic effect of different concentrations of S. suis serotype 31 (SS31) and S. suis serotype 2 (SS2 (P1/7)) on cell viability after (A) 2, (B) 4, or (C) 18 h of treatment. Cell cytotoxicity rate (%) is expressed as the mean ± SD.*p < 0.05 or *** p < 0.001 indicates significant difference between the cytotoxicity rate of cells after infection with S. suis serotype 31 strain compared to that after infection with the S. suis serotype 2 (P1/7) strain.