Staphylococcus aureus Panton-Valentine Leukocidin Targets Muscle Tissues in a Child with Myositis

The incidence of myositis has been increasing since the ad-vent of the epidemic of community-associated methicillin-resistant Staphylococcus aureus infection, and Panton-Val-entine leukocidin has been implicated as a factor contrib-uting to more-severe muscle injury. We report a case of severe myositis accompanying septic osteomyelitis and necrotizing fasciitis caused by a Panton-Valentine leukocidin–positive S. aureus strain. Immunostaining showed strong binding of the Panton-Valentine leukocidin toxin to necrotic muscle tissues. Staphylococcus aureus myositis, pyomyositis, and necrotizing fasciitis are severe but uncommon infections in the United States [1]. Epidemiologic studies suggest that the incidence of these infections is increasing [2, 3]. It has been proposed that Panton-Valentine leukocidin (PVL), a toxin that induces cy-tolysis of human phagocytes, could play a major role in path