Serological Properties of Specific Immunoglobulin Against Smith Strain of Staphylococcus aureus Extracted from Human Sera

Abstract

With the addition of Smith surface antigen (SSA), extracted from the Smith strain of Staphylococcus aureus, to human pooled sera antigen antibody complex was obtained. Propionic acid (pH 3.0) containing 5% sucrose was added to this complex and an eluate was dialyzed against phosphate buffered saline containing 5% sucrose. Bacterial agglutination titers of the eluates by using the Smith strain differed depending upon the amounts of SSA used. The eluate exhibited the highest titer in bacterial agglutination was the highest protein content and total amount of IgG, IgA and IgM in the eluate was 97% of the protein. With intraperitoneal injection of 50 pg protein of this eluate in mice, they were protected against lethal infection with Smith strain. The eluate was further subjected to sucrose density gradient ultracentrifugation. Then, 23.5μg and 230μg protein amounts of IgM and IgG rich fractions, respectively, were capable to protect against similar infection.