title: Immunological properties of Rickettsia rickettsii purified by zonal centrifugation.
abstract: The properties of Rickettsia rickettsii purified from infected chicken yolk sacs or mouse L cell cultures by sucrose density gradient centrifugation in a zonal rotor were examined in various ways. Rickettsiae derived from both L cells and yolk sacs had similar compositions: about 12% nitrogen, 1.5% phosphorus, 5% carbohydrate, and 30% fatty acids. On a dry-weight basis, purified rickettsiae were at least 2,000 times as effective as a commercial spotted fever vaccine in protecting guinea pigs against infection with spotted fever rickettsiae and mice against death from toxin of R. rickettsii. Gradient-purified rickettsiae (0.6 mug) induced a serological response in guinea pigs of the same magnitude as that stimulated by 1,600 mug of the commercial vaccine. Gradient-purified rickettsiae had little group reactivity in complement fixation tests but became anti-complementary upon storage. Microagglutination and hemagglutination tests with the purified antigen gave promise of usefulness in diagnosis of spotted fever. These results suggest that zonal centrifugation may be a valuable procedure for the preparation of R. rickettsii vaccine and diagnostic reagent.
mesh_terms: D000818:Animals; D000917:Antibody Formation; D000942:Antigens, Bacterial / Q000032:analysis; D001426:Bacterial Proteins / Q000032:analysis; D001428:Bacterial Vaccines; D002241:Carbohydrates / Q000032:analysis; D002501:Centrifugation, Zonal; D003168:Complement Fixation Tests; D005227:Fatty Acids / Q000032:analysis; D005260:Female; D006168:Guinea Pigs; D006386:Hemagglutination Tests; D007106:Immune Sera; D007114:Immunization; D007117:Immunization, Secondary; D007739:L Cells; D009584:Nitrogen / Q000032:analysis; D010758:Phosphorus / Q000032:analysis; D012284:Rickettsia rickettsii / Q000276:immunology* / Q000302:isolation & purification; D012373:Rocky Mountain Spotted Fever / Q000276:immunology*; D014817:Vitelline Membrane
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D001428:Bacterial Vaccines; D002241:Carbohydrates; D005227:Fatty Acids; D007106:Immune Sera; D010758:Phosphorus; D009584:Nitrogen