FIG 5.

(A through C) Anti-Rickettsia immunohistochemistry demonstrated the absence of “Ca. Rickettsia andeanae” at the tick feeding site 2 (A), 6 (B), and 10 (C) days postattachment. (D through F) Conversely, variable numbers of organisms were observed in the skin of rats at the feeding sites of R. parkeri-infected ticks. Inflammatory cells containing positive, brown-staining coccobacillary rickettsial organisms were present in one aggregate or scattered aggregates at 2 (D) and 10 (F) dpa. Inflammatory cells with positive, brown-staining organisms were widespread throughout the skin at 6 dpa (E). Bars, 200 μm (magnification, ×10) for panels and 20 μm (magnification, ×100) for insets.