Figure 6

MR images of a footpad infection induced by iron-labeled S. aureus bacteria. Axial T2*-weighted MRI of the inflamed left footpad induced with (A) and without (B) iron-labeled bacteria, 24 h post infection. Bacteria were observed as hypointensities in the footpad (yellow arrow) when iron-labeled S. aureus were applied. (C, D) T2-weighted MRI of inflamed lymph nodes, Day 1 and Day 3 post infection. Bacteria were observed as hypointensities in the lymph nodes (yellow arrow) when iron-labeled S. aureus were applied. Electron microscopy (E, F), Prussian blue staining (G) and Gram staining (H) of the lymph node, 24 h post infection, showing iron-labeled bacteria.