Surgical drainage is required for treatment and to obtain specimens for culture so that appropriate antibiotics can be selected. A variety of anaerobes and aerobes can be recovered from cutaneous abscesses and from cutaneous ulcers. These abscesses respond well to incision and drainage alone. Decubitus ulcers, however, can be the source of serious anaerobic or polymicrobial bacteremia. Multiple species of anaerobes and aerobes are present in infected feet of diabetic patients.
Aerobes predominate in bone and joint infections, but anaerobes can also be important.
Factors that predispose to the development of anaerobic osteomyelitis and septic arthritis include peripheral vascular disease, prosthetic devices, bites, and trauma. Anaerobic osteomyelitis can occur as an acute hematogenous infection in younger patients, as a superinfection of chronic staphylococcal osteomyelitis, or as an indolent infection of bone and joint prostheses. Bacteroides species cause most cases of anaerobic osteomyelitis, but other anaerobes may be implicated, including peptococci, Veillonella species, and even Propionibacterium species. Although P. acnes can occasionally cause endocarditis and bacteremia, this organism usually appears in blood cultures as a contaminant from the skin. Fusobacterium species and other anaerobes can also cause serious bacteremias.