Fig. 1

Effects of PA pneumonia on lung inflammation. a Schematic diagram showing experimental design. Animals were exposed to PA on day 0 and then experiments were performed 24 h, 7-days or 1-month post-infection. b Representative NIR fluorescence images of the left lung lobe obtained from control and PA infected mice at 24 h post-infection (OD₆₀₀ 0.3) showing the distribution of 70-kDa tracer within the lung tissue. c Summary data showing lung permeability of 70-kDa tracer. Mann–Whitney test, P = 0.016 vs. control (uninfected) group. d Plasma leakage indicated by increased levels of albumin in bronchoalveolar lavage fluid (BALF) obtained from control and PA-infected mice at different time points post-infection (6 h, 24 h, and 7 days). Kruskal–Wallis test, P = 0.0001, P = 0.001 vs. control (uninfected) group. e Histological analysis by conventional H&E staining of lung sections in control and PA-infected mice 24 h post-infection (OD₆₀₀ 0.3). f Representative confocal images of neutrophil immunodetection (red), lectin-positive brain endothelial cells (green) and DAPI (nuclei; blue) in the brain from a control (up) and a PA-lung infected mouse 24 h post-infection (bottom). In all graphs, each point indicates data from an individual animal, bar graphs (columns and error bars) show mean ± S.E.M