FIG 7.

Impact of NTHi on P. aeruginosa (Pa) infection is independent of bacterial viability. BALBc/J mice were intratracheally infected with HK NTHi (NTHi Hi-1r) 24 h prior to introduction of mPA (mPA 08-31) and assessed 72 h after sequential infection. (A) Bacterial counts of NTHi and P. aeruginosa in the lung homogenates enumerated by viable colony counting (n = 10). (B and C) Severity of disease indicated by semiquantitative grading by a pathologist (L.N.) (B) and H&E-stained lung sections (×200 magnification) (C) (n = 8 to 10). (D) Total cell counts in BALF samples quantified by differential counting. (E) Percentage of PMNs in the BALF samples (n = 9 or 10). Values are mean ± SEM. LOD, limit of detection. *, P < 0.05; **, P < 0.01; ***, P < 0.001; ****, P < 0.0001, Kruskal-Wallis test with Dunn’s multiple-comparison test.