Extraction of protective components of Rickettsia rickettsii with n-octyl-beta-D-glucopyranoside.

Two Rickettsia rickettsii proteins, with apparent molecular masses of 120 and 155 kilodaltons, have been implicated as important antigens in immunity to Rocky Mountain spotted fever. An n-octyl-beta-D-glucopyranoside-soluble fraction of R. rickettsii was found to be enriched for these proteins along with others. Vaccination of mice with the detergent-soluble fraction protected them against death caused by R. rickettsii and protected guinea pigs from developing Rocky Mountain spotted fever after being challenged with viable R. rickettsii.