FIG 8.

S. aureus mntE mutants isolated from murine organs exhibit reduced fitness. (A) Colony morphology of S. aureus strains isolated from murine hearts and kidneys compared to strains grown in a rich medium. Eight-hour liquid cultures of S. aureus strains grown in TSB were serially diluted in PBS and plated onto TSA. Organs from mice retro-orbitally infected with 1 × 10⁷ CFU were harvested 4 days postinfection and homogenized in PBS, and serial dilutions were plated onto TSA medium. Images were taken approximately 15 h following incubation at 37°C. (B) Growth as measured by OD₆₀₀ over time for murine heart and kidney homogenates in TSB medium treated with 0, 0.3, or 0.6 mM paraquat. Organs from mice retro-orbitally infected with 1 × 10⁷ CFU were harvested 4 days postinfection, homogenized in PBS, and added 1:100 to the media. The data are the representative of one of two independent experiments, each performed in biological triplicate with the standard deviation of the mean shown.