Detection of surface antigen in Rickettsia tsutsugamushi infected mouse reticuloendothelial cells

Antibody produced by immunizing CBA/CaJ mice with RE cells from C57B1/6J mice infected 14 days earlier with R. tsutsugamushi Gilliam strain bound readily to Gilliam strain non-cell associated rickettsiae and less readily to the periphery of infected RE cells. Conversely, antibody produced by immunizing with RE cells infected 21 days earlier did not bind to Gilliam rickettsiae but bound to the surface of RE cells from mice infected 21 days earlier. This binding was not related to alloantibodies because these were absorbed prior to testing. The demonstration of rickettsial antibody staining of infected cell associated antigen(s) in this assay system provides a new method for the detection of R. tsutsugamushi infection.