FIG. 6.
Lethal challenge of FBP54-immunized mice with S. pyogenes strain SSI-1. Mice (n = 15) were injected intraperitoneally with 106 CFU of strain SSI-1 (M3) on day 51 after the first immunization. Mortality was monitored every day. χ2 analysis was employed to analyze the significance of differences between the means of FBP54-immunized and nonimmunized mice on day 8. ∗, P < 0.05; ∗∗, P < 0.001. p.o., peroral; i.n., intranasal.