Fig 6. Rickettsial dissemination within fleas.

Fleas were exposed to a R. felis WT- (top panels) or R. felis sca1::tn-infected (middle panels) bloodmeal for 48 hours and female flea sections were stained for rickettsiae (green), nuclei (blue), and Evans blue (red) at 7 dpe (left panels) and 28 dpe (right panels). White arrows indicate rickettsiae. An uninfected flea (bottom left panel) and control lacking primary antibody (bottom right panel) served as negative controls. Image is representative of 4 sectioned fleas at each time point from independently exposed flea cohorts. MG: midgut, PV: proventriculus, OV: ovaries. Scale bar = 100 μm.