Precipitating antibodies against Staphylococcus aureus in experimental rabbit osteomyelitis, investigated by means of quantitative immunoelectrophoretic methods.

Eight rabbits were infected with Staphylococcus aureus by injection of 1 X 10(8) colony-forming units into the marrow cavity of the tibia. Titres of precipitating antibodies against S. aureus in serum were followed by means of crossed immunoelectrophoresis. Four rabbits infected with the protein A-containing, alpha-toxin negative Cowan I strain developed no signs of infection and only a slight or no antibody response. All 4 rabbits infected with the protein A-free, alpha-toxin-producing Wood 46 strain developed local signs of infection, and 3 of 4 developed roentgenologic signs of osteomyelitis. All 4 rabbits developed a very high level of precipitating antibodies, but after 2-3 months the level of antibodies decreased, although the infection continued.