Enzyme-linked immunosorbent assay of the detection of antibodies to exocellular proteins of Staphylococcus aureus in bone infection

An enzyme-linked immunosorbent assay (ELISA) was developed for measurement of the antibody response to exocellular protein antigens of Staphylococcus aureus. The wells of a microtitre plate were coated with the exocellular proteins present in the tryptic soya broth growth medium from a stationary phase culture of a bone infection strain of S. aureus. The wells were then reacted sequentially with patient sera, protein A-peroxidase conjugate and chromogenic substrate. Serum from patients with S. aureus bone infection gave a significantly higher IgG titre than sera from patients with Staphylococcus epidermidis or Streptococcus sanguis bone infection or healthy uninfected individuals. The assay therefore appears to have potential in the serodiagnosis of S. aureus bone infection.