Fig. 5.
Early antibiotic treatment reduced lung barrier failure and VEGF levels. Mice were infected with S. pneumoniae and assigned equally to groups and analysis time points (a, d ntotal = 9, b, c ntotal = 4 per time point). Starting 24 h or 48 h p.i., intervention groups were treated with ampicillin. As controls, mice were sham infected (PBS; a, d ntotal = 7, b, c ntotal = 4 per time point) or treated with solvent (0.9% NaCl). Mice surviving until designated analysis time point were sacrificed for BAL and blood sampling (number analyzed per time point presented in Additional file 1: Table S1) or histopathological analysis (number analyzed per time point presented in Additional file 1: Table S2). a Ratios of mouse serum albumin (MSA) BALF/serum reflecting lung barrier integrity, calculated from ELISA readouts. b Lung edema score, calculated from specified histopathological parameters displaying perivascular and alveolar edema formation. Results pooled from two independent experiments per time point. Median and 25–75% interquartile range. c Representative H&E staining. *Perivascular edema, #alveolar edema. Scale bars: 100 μm. d VEGF levels measured in BAL fluid by multiplex analysis. a, d Results pooled from three independent experiments per time point. Mean ± SEM. Two-way ANOVA/Sidak’s multiple comparisons test for comparison of ampicillin versus solvent treatment. a, b Kruskal–Wallis test/Dunn’s multiple comparisons test and d one-way ANOVA/Dunnett’s multiple comparisons test for comparison to S. pneumoniae-infected mice at therapy start. *Significant difference between groups at time point, #significant difference from therapy start: a, b, d */#p < 0.05, **/##p < 0.01. Abx antibiotics, BALF bronchoalveolar lavage fluid, Ctr control, PBS phosphate buffered saline, p.i. post infection, S. pn. Streptococcus pneumoniae