Experimental Staphylococcus aureus arthritis in mice

Staphylococcus aureus arthritis is usually caused by bacteremia and is highly destructive. Controlled studies on septic arthritis in humans are difficult to perform, because the time of onset of the infection is unknown. Animal models of bacterial arthritis make it possible to control important variables in experimental studies. We present a mouse model of S. aureus arthritis in which the intravenous administration of 10(7) cells of S. aureus LS-1 induced arthritis or osteitis or both within 3 weeks in 80 to 90% of the mice. Signs of arthritis emerged within the first few days after the injection. An interesting finding was that the S. aureus strain used in this study binds bone sialoprotein, a glycoprotein known to be specifically localized to bone tissue. This new model of S. aureus arthritis enables the study of the kinetics of joint destruction and the host-bacterium relationship as well as therapeutical approaches to septic arthritis and osteomyelitis.