The ProU glycine betaine ABC transporter (proVWX) contributes to K. pneumoniae fitness during acute pneumonia. (A) Adult male C57BL/6J mice were infected via oropharyngeal aspiration with either K. pneumoniae KPPR1 WT or KPPR1 ΔproV. The numbers of CFU per lung were measured at 24 h following instillation. (B) The white blood cells within the bronchoalveolar lavage fluid collected from each infected mouse were enumerated. The total white blood cell, macrophage, and PMN counts are shown. The data shown summarize those from four independent experiments, with statistical significance being determined through an unpaired t test. In each panel, the arithmetic mean is depicted for each strain, with the counts from individual mice being represented by individual points.