title: Protective role of O antigen in Salmonella typhi-murium infection.
abstract: Mice were actively immunized with preparations produced from different Salmonella strains. They were challenged with 2 LD50 of a virulent S. typhi-murium strain and examined for viable cell counts in the liver 4, 7 and 11 days postinfection. Whole cell vaccines, ribosomal extracts and endotoxin preparations of the O antigen-deficient variant of S. typhi-murium strain LT2-MI failed to protect the mice or did so in a much lower degree than preparations of the corresponding O antigen-bearing variant. Preparations from other salmonellae exerted a protective action only if the strain had an O-antigen identical with that of S. typhi-murium. The results pointed to a considerable protective role of the O antigen.
mesh_terms: D000818:Animals; D000941:Antigens / Q000276:immunology*; D001428:Bacterial Vaccines / Q000276:immunology*; D005260:Female; D008297:Male; D051379:Mice; D019081:O Antigens; D012480:Salmonella Infections / Q000276:immunology*; D012486:Salmonella typhimurium / Q000276:immunology*; D014611:Vaccination
chemical_list: D000941:Antigens; D001428:Bacterial Vaccines; D019081:O Antigens