Identity of pathogenic strains of spotted fever rickettsiae isolated in Shikoku District based on reactivities to monoclonal antibodies.

Three IgG (B2, C3 and F8) and two IgM (S3 and X1) monoclonal antibodies (Mab) were produced in BALB/c mice immunized with Aoki strain of spotted fever (SF) rickettsiae in Tokushima Prefecture, Japan. Of these, two (B2 and C3) reacted equally with six Japanese strains including YH strain, the prototype of R. japonica, but did not react with the foreign strains. These results indicate that SF rickettsial strains from Tokushima Prefecture were identified as R. japonica, and that the SF strains isolated at least in Shikoku District most likely belong to a common serotype.