title: Immunological response to a strain of Staphylococcus epidermidis in the rabbit: production of protective antibody.
abstract: A rabbit was immunised with a heat-killed vaccine prepared from strain 1142 of Staphylococcus epidermidis. The HA titres of the antisera against a surface-polysaccharide antigen extracted from the homologous strain were highest in the 2nd-4th weeks after immunisation and subsequently declined. Only a minor amount of 2-ME-resistant antibody was formed, and this at a late state of the reaction. After a booster injection of the vaccine at the 10th week, there was a significantly greater HA-antibody response and a greater amount of 2-ME-resistant antibody was formed. The relative passive-protective activity of the sera in mice corresponded to their content of 2-ME-sensitive HA antibody. The protective activity of the sera was 2-ME sensitive and was not removed by absorption with anti-rabbit IgG goat serum. Further, 280 microgram of IgM-rich serum fraction obtained by sucrose-density-gradient ultracentrifugation passively protected against homologous challenge infection in mice, but even 910 microgram of IgG-rich fraction did not. These results indicated that the protective antibody was of the IgM class.
mesh_terms: D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis* / Q000276:immunology; D000918:Antibody Specificity; D007112:Immunity, Maternally-Acquired; D007114:Immunization; D007074:Immunoglobulin G / Q000276:immunology; D007075:Immunoglobulin M / Q000276:immunology; D051379:Mice; D011817:Rabbits; D013203:Staphylococcal Infections / Q000276:immunology*; D013210:Staphylococcus / Q000276:immunology*
chemical_list: D000907:Antibodies, Bacterial; D007074:Immunoglobulin G; D007075:Immunoglobulin M