Comparative analyses of abscess formation and bacterial burden in tissue from Fibγ^Δ5 and wild-type mice following intravenous S. aureus infection. (A) Representative hematoxylin/eosin-stained sections of heart, kidney, and liver from wild-type and Fibγ^Δ5 mice collected 48 hours after intravenous infection with 2.5 × 10⁸ CFUs wild-type S. aureus. Images were captured using an Axioplan 2 microscope with Axiovision Image analysis software (version 4.8.1; Carl Zeiss Microimaging). Scale bar represents 100 μm (upper panels) and 50 μm (lower panels). (B) Bacterial lesion counts in tissue sections prepared from heart, kidney, and liver of wild-type and Fibγ^Δ5 mice 48 hours after intravenous infection. Data are presented as the mean number of lesions per tissue midline section ± standard error of the mean (SEM) with N = 5 per group. (C) Bacterial burdens observed in major organs of Fibγ^Δ5 and control mice at 48 hours (left panel), 24 hours (middle panel), and 30 minutes (right panel) following intravenous injection of 2.5 × 10⁸ CFUs S. aureus (N = 5 per group per time point). Values in solid tissues are the total mean CFUs ± SEM within the entire organ as determined by serial plating aliquots of tissue homogenates. Values in blood are the mean CFUs ± SEM per milliliter in whole blood as determined by plating serial dilutions of whole blood collected from the inferior vena cava. The data were analyzed using the Student t test.