Figure 2.

GM-CSF−/− mice have increased bacterial burden in the lungs and increased bacterial dissemination into the blood and spleen compared with SPC-GM and WT mice. Lungs, spleen, and blood were harvested 24 h after intratracheal infection with P. aeruginosa (6.7 CFU log₁₀ scale) from GM-CSF−/−, SPC-GM, and WT mice and plated for CFU analysis. (A) There were increased CFU in the lungs of GM-CSF−/− mice (open bar) compared with the WT (closed bar) and SPC-GM mice (checkered bar) 24 h postinfection (P < 0.001). GM-CSF−/− mice (open bar) have increased bacterial dissemination as shown by higher CFU found in the spleen (B) and blood (C) compared with WT (closed bars) and SPC-GM (checkered bars) mice. Data represent n = 5 mice per group and are representative of two similar experiments. The dotted line represents the original inoculum dose (6.7 CFU log₁₀ scale). The GM-CSF−/− mice had increased bacterial burden in their lung (P < 0.001) and increased dissemination into the spleen (P < 0.05) and blood (P < 0.001).