Evidence of common and genus-specific epitopes on Ornithodoros spp. Tick (Acari: Argasidae) salivary proteins.

New Zealand White rabbits were repeatedly infested with Ornithodoros turicata (Duges), Ornithodoros talaje (Guérin-Méneville), and Ornithodoros coriaceus (Koch) at 2-wk intervals. Blood samples were taken from each animal 10 d after each infestation and the titer of anti-tick antibody was determined by enzyme-linked immunosorbent assay. Subsequent cross-reactivity studies demonstrated that the antitick antisera nonspecifically bound to salivary gland extract proteins prepared from several other tick genera and species' Amblyomma maculatum (Koch), Dermacentor andersoni (Stiles), Dermacentor variabilis (Say), and Ornithodoros moubata (Murray). Absorption of the antisera against an immobilized extract of A. maculatum substantially increased specificity at the genus level. Western blots of electrophoretically separated Ornithodoros salivary gland extract samples were used to further compare the specificity of absorbed and nonabsorbed antitick antisera. The blots demonstrated that many of the Ornithodoros salivary gland extract proteins bear genus specific epitopes. Some differences were noted among the Ornithodoros species examined with respect to the degree of antigenic relatedness with the ixodid ticks.