Fig. 4

Survival rates (%) of Korl:ICR (a), A:ICR (b), and B:ICR (c) were observed after infection with 2 × 10⁶ CFU S. pneumoniae D39 serotype 2. These mice were treated with vancomycin single-dose or double-dose after 18 h, or 18 and 42 h. Treatment with vancomycin significantly improved the survival rate than that of the control mice in all the stocks (P < 0.05). Repetition of vancomycin injection enhanced the survival, while only A:ICR exhibited significantly improved survival rate in 18, 42 h than in the 18 h vancomycin treatment (P < 0.05). P values were calculated by the log-rank test. *P < 0.05, **P < 0.01 between the groups