Figure 8

Histopathology of the lung and brain of the immunized mice infected with S. suis serotypes 2, 7, 9 and ½. Microscopic pathological observations of lung and brain of mice after challenge with S. suis serotypes 2, 7, 9 and 1/2. For lung (A), neutrophilic infiltration and interstitial thickening are shown with a black arrow. For brain (C), meningeal thickening and neutrophilic infiltration are shown with a black arrow. The experiment was performed twice. A representative figure of each group is shown (n = 10). The results from both experiments were similar and the data were pooled for analysis. Histology scores in the lung (B) and brain (D). Horizontal lines show the mean, and error bars represent the SD (n = 10). *P < 0.05; **P < 0.01.