FIG. 2.

Inflammation in the lungs of mice infected with an ExoU⁺ or ExoU⁻ strain of P. aeruginosa. (A to F) H&E staining of lung sections from mice inoculated with PA99U (A and B), PA99null (C and D), or PBS alone (E and F) at 18 h postinfection. Scale bars, 100 μm. (G and H) Flow cytometry analysis of inflammatory cells in the lungs of mice infected with an ExoU⁺ or ExoU⁻ strain at 18 h postinfection. (G) Number of CD45⁺ cells (leukocytes) per lung for mice infected with PA99U or PA99null. (H) Number of neutrophils per lung for mice infected with PA99U or PA99null and number of macrophages per lung for mice infected with PA99U or PA99null. The data are means ± standard errors of the means for at least three independent experiments. *, P < 0.05; †, P < 0.01. PMN, neutrophils; Mac, macrophages.