Figure 2.

Transgenic BALB/c mice expressing human transferrin were infected by intraperitoneal injection of 1.5 × 10⁷ CFU of the bioluminescent N. meningitidis strain 24198LUX. Mice were examined before (A top) and after 24 h of infection (B top). Mice before infection showed no skin features but had signs of vasculitis after 24 h of infection that could be seen on the ears. Skin samples of the ear were collected in mice before infection (A middle) and after 24 h of infections (B middle) and were embedded in paraffin. Microscope examination at magnification ×200 are shown for H&E staining of 3 µm sections of paraffin embedded organ. The ear skin section of infected mice (B middle) showed haemorrhagic lesions outsides blood vessels. A 3 µm H&E stained section at magnification ×400 with of paraffin embedded omentum (fold of visceral peritoneum) with a longitudinal blood vessel in the filed showing signs of vasculitis (B bottom compared to A bottom). Note the haemorrhages around the vessel and endothelialisation (arrow heads) of leucocytes at the periphery of the vessels.