Figure 4.

Coinfected mice exhibit increased morbidity and mortality as well as decreased resistance and tolerance. Viral burden as measured by viral genome copies in lung tissue on days 1 and 3 (A). Bacterial burden as measured by colony-forming units (CFUs) in 1 mL of lung homogenate on days 1 and 3 (B). Percentage of mice with no detectable bacteria in their lungs at day 1 and 3 (C). Survival of naïve, singly-infected and coinfected mice was measured over the course of 2 weeks (D). Weights were monitored during this time and are expressed as percentages of the starting weight of each mouse prior to infection (E). Concentration of albumin in the BALF on days 1 and 3 post-K. oxytoca (F). In (E) # denotes P ≤ 0.05 between coinfected and IAV groups while * denotes P ≤ 0.05 between coinfected and K. oxytoca groups. † denotes day at which coinfected mice begin to exhibit decreased survival. In (C,D,F) * denotes P ≤ 0.05 between indicated groups. Data were analyzed with ANOVA followed by Tukey's multiple comparison tests (A,E,F), Mann-Whitney U-test on non-transformed data (B), Fisher's exact test (C), and log rank tests (D) where appropriate. Error bars represent SEM. Data are combined from at least three independent experiments with at least four mice per group.