Wound culture is often helpful in cases of moderate or severe infection and when the concern for multidrug-resistant organisms is high. Ideally, samples for culture should be obtained prior to the initiation of empiric antibiotics. However, in cases of systemic toxicity or limb-threatening infections, antibiotic therapy should not be withheld before surgical cultures are obtained.
The preferred clinical specimens for reliable culture include aspirate from an abscess or curettage from the ulcer base following superficial debridement of necrotic tissue. Organisms cultured from superficial swabs are not reliable for predicting the pathogens responsible for deeper infection
In the setting of osteomyelitis, bone biopsy is the preferred method of sample collection for culture. If performed percutaneously, sampling through uninvolved tissue under radiographic guidance is preferred. Although sinus tract cultures may be of some use for prediction of osteomyelitis if Staphylococcus aureus or Salmonella species are identified, in general, such cultures are not worthwhile. Samples should be sent for both aerobic and anaerobic bacterial cultures
Surgical debridement is required for cure of infections complicated by abscess, extensive bone or joint involvement, crepitus, necrosis, gangrene or necrotizing fasciitis and is important for source control in patients with severe sepsis
In addition to surgical debridement, revascularization (via angioplasty or bypass grafting) and/or amputation may be necessary