Tissue morphology following infection with <i>N. meningitidis</i>.

<p>(A) Tissue morphology 6 h post infection with <i>N. meningitidis</i> (H&E). Thrombosis and mild inflammation can be seen in a vessel (arrow). (B) Bacteria (green) at 6 h infection, human endothelium labeling (huCD31; red), indicates loss of continuous staining (arrow). Cell nuclei are labeled with DAPI (blue). (C) Platelet aggregation (red) in close proximity to bacteria (green), 6 h post infection. (D) Inflammation, vascular leak (arrow) and congestion (arrowheads) at 24 h post infection (H&E). (E) Bacteria (green) filling a vessel in close proximity to the basement membrane (Collagen IV, red). (F) Disruption of Collagen IV (red) in a heavily infected vessel at 24 h. (G) Thrombosed vessel (arrow) 24 h post infection (H&E). (H) Small vascular hemorrhage (arrow) in a congested vessel also showing neutrophil infiltration (*). (I) Extensive vascular leak, red/brown color shows large lake of RBCs at the dermal/epidermal border at 24 h (H&E). (J) RBC (red) leakage in the dermis (d). Leakage occurs at the epidermal (e) border. (K) Human skin graft prior to infection. (L) The same mouse as (K) 24 h post infection showing <i>purpura</i>, seen as dark areas (arrow).