FIG. 3.

Mortality and decreased bacterial clearance after post-traumatic brain injury (TBI) bacterial pneumonia are sex dependent. For all experiments, mice received TBI according to protocol. Twenty-four hours later, Pseudomonas aeruginosa K-strain (PAK) was instilled intratracheally, and either mortality or bacterial clearance was measured. (A) P. aeruginosa-pneumonia leads to increased mortality after TBI in male mice (blue line, n = 8) compared with female mice (pink line, n = 7), p < 0.05; *represents a significant difference compared with males. (B) P. aeruginosa pneumonia leads to increased mortality after TBI in oophorectomized female mice (blue line, n = 9) compared with wild-type female mice (pink line, n = 4), p < 0.05; *represents a significant difference compared with wild-type females. (C) Wild-type male, wild-type female, and oophorectomized female mice lungs were isolated 6 h after PAK instillation and colony-forming units/mL were measured. Wild-type females (pink diamonds) had improved bacterial clearance compared with wild-type males (blue circles); oophorectomized female mice (black triangles) had decreased bacterial clearance compared with wild-type females (pink diamonds); n = 4 for each group, p < 0.05; *represents a significant difference compared with wild-type males, **represents a significant difference compared with wild-type females.