Figure 7.
The Ess secretion system of strains RN6390 and COL contributes to nasal colonization and virulence in the murine pneumonia model. For the murine pneumonia model mice (n = 10 mice per experiment) were infected at time zero with 2 × 108 cfu of S. aureus strains RN6390 (A), COL (B) or SA113 (C) or the cognate Δess mutant strains as indicated. Survival was assessed for up to 48 h. (B) For the murine nasal colonization model, mice (n = 10 mice per experiment) were infected with 2 × 108 cfu per nostril of the indicated strains and colonization status determined following nasal excision at 48 h.