Cif increases the number of colony-forming units (CFUs) recovered from mice in an acute pneumonia model. A: immunoblots for Cif from PA14 and PA14 Δcif strains grown with or without an epoxide inducer. B: ratio of recovered CFUs at 6 h postinfection to input CFUs from bronchoalveolar lavage fluid (BALF) of mice treated with epoxide-induced PA14 or PA14 Δcif (n = 2 experiments, 6 mice for each treatment group/experiment). C: immunoblots for Cif from strain PAO1 grown with or without an epoxide inducer. D: immunoblots from one experimental set of mice for Cif in BALF (E) and lung homogenate (LH) (F) samples. Blots generated at the same time and processed in parallel. E and F: ratio of recovered CFUs at 6 h postinfection to input CFUs from BALF (E, n = 3 experiments, 4–8 mice for each treatment group/experiment) or LH (F, n = 4 experiments, 4–8 mice for each treatment group/experiment) of mice treated with PAO1 in combination with either exogenous, purified CifWT, or CifD129S protein. A and C: panels derived from a single blot. B, E, and F: black bars, medians; significance calculated using a one-tailed exact Wilcoxon-Mann-Whitney test from the R package “coin.”