FIG 1.

S. suis serotype 2 causes meningitis and mortality in complement-deficient (C3^−/−) but not in wild-type (WT) mice after mucosal infection. (A) Kaplan-Meier diagram for mortality of WT and C3^−/− mice intranasally infected with 2 × 10⁸ CFU of S. suis WT (strain 10) as described in Materials and Methods. ***, Significant difference between WT and C3^−/− mice (P < 0.001; log-rank test). (B) Immunolabeling of extracellular leukocyte-associated bacteria in the meninges of a C3^−/− mouse infected with S. suis WT (strain 10) using an antiserum raised against S. suis serotype 2. Scale bar, 200 μm.