In rabbit knees 600 Staphylococcus aureus organisms produced progressive
infection in 50 per cent of the knees injected, whereas 5.3 times 10-7
Micrococcus species caused only transient colonization of the joints.
Methicillin, cephacetrile, and clindamycin administered before injection of
the staphylococci gave protection. Stainless-steel particles in the knee
did not increase susceptibility to infection from injected micrococci but
did make established micrococcal infections more persistent. Knees
containing steel debris failed to become infected during prolonged
staphylococcal bacteremia. Injected autologous blood, either fresh or three
days old, did not increase susceptibility to infection. Large doses of
steroids, given systemically or intraarticularly, decreased resistance to
micrococcal infection and increased the destruction caused by infection due
to this organism.