Extracellular proteins as a potential marker of active Staphylococcus aureus infection in bone

The potential of extracellular protein antigens of Staphylococcus aureus as markers of infection of bone was investigated by immunoblotting. Serum from patients with S. aureus bone infection showed levels of IgG antibodies to a preparation of soluble extracellular proteins of 17-81 kDa which were significantly higher than those found in serum from normal controls. By contrast, immunoblots of various whole cell or cell wall-derived antigens gave complex patterns of response which were unsuitable for positive diagnosis of S. aureus bone infection.