Figure 5.

Immunohistochemistry of Rickettsia parkeri antigen in tissues from intravenously infected C3H/HeN mice and by tick transmission. A and B: Presence of rickettsiae in brain of intravenously infected mice 6 days after infection, showing endothelial and perivascular rickettsial antigen. Inset shows individual rickettsial antigen. C and D: Identification of rickettsial infection in lung of intravenously infected mice. Inset shows individual rickettsial antigen. E: Axillary lymph node infected with rickettsiae in intravenously inoculated mice 6 days after infection. F–I: Skin area of tick transmission with a massive presence of rickettsial antigen in many cell types 6 days after tick attachment, including perivascular infection. J–L: Rickettsial antigen present within areas of inflammatory infiltration in liver during tick transmission (day 6 after tick attachment). M and N: Infection of lungs with visualization of individual bacteria in the lungs of R. parkeri infection by tick transmission 6 days after tick attachment. O: Draining axillary lymph node related to the site of tick attachment on day 6 after tick attachment, showing the presence of rickettsial antigen.