Detection ofstaphylococcus aureusinfection by enzyme-linked immunosorbent assay and immunoblotting, using high molecular weight staphylococcal proteins

Abstract

Two high molecular weight staphylococcal proteins, fibronectin‐binding protein and a M 200 000 protein, were investigated as antigens for serodiagnosis of staphylococcal infections. Sera from patients with staphylococcal infections and from controls were subjected to immunoblot analysis with staphylococcal lysate proteins to identify staphylococcal antigens to which patients with staphylococcal infections specifically exhibited antibodies. On such protein was found in the M 200 000 region. This protein was purified and used as antigen in ElISA and compared with other antigens, namely fibronectin‐binding protein(s) (FNBP, M, 185 000), α‐toxin and teichoic acid. Sera from patients with staphylococcal infections contained antibodies to the high molecular weight proteins in higher titers than sera from patients with non‐staphylococcal infections or healthy subjects. Based on their amino‐acid compositions and different abilities to bind fibronectin it was concluded that the M 200 000 protein and FNBP were not identical.