FIGURE 6. Loss of the GAC GlcNAcSide Chain Attenuates GAS Virulence.
(A) Survival curve of rabbits infected with GAS WT or ΔGacI mutant bacteria. Rabbits were infected with 4 × 109 CFU intrabronchially and survival was monitored for seven days (n = 9 rabbits of either sex per group in three independent experiments; log-rank test). (B) Gross lung appearance and microscopic H&E stain of rabbit lungs after infection with GAS WT or ΔGacI mutant bacteria. (C) Body temperature, (D) lung bacterial counts, and (E) lung TNF-α levels in lungs of infected rabbits 12 hours after intrapulmonary challenge; n = 4 rabbits per group; t-test; mean and 95% confidence interval. (F) Survival curve of mice upon systemic infection with GAS WT or ΔGacI mutant bacteria; survival was monitored for 6 days (n = 11 per group; log-rank test). (G) Blood CFU of mice 24 hours post systemic infection (n = 10 mice per group; t-test; mean and 95% confidence interval). *p< 0.05, ***p< 0.001. See also Figure S5.