(A) Silver-stained SDS-PAGE of whole-cell protein preparations of Rickettsia conorii, the ELB agent and R. typhi. Lane 1, R. conorii; lane 2. ELB agent; lane 3, R. typhi; lane 4, heated R. conorii; lane 5, heated ELB agent; lane 6, heated R. typhi. Molecular weights are indicated on the left. (B) Western blot of rickettsial proteins probed with various antisera. R. conorii antigens (lanes 2, 6, and 10), ELB agent antigens (lanes 3, 7, and 11) and R. typhi antigens (lanes 4, 8, and 12) were probe