From the Guidelines
For a wound culture showing MRSA after leg amputation for diabetic foot, I strongly recommend starting empiric antibiotic therapy directed against MRSA, as the patient has a confirmed history of MRSA infection, which is a key consideration in selecting an appropriate antibiotic regimen 1. The choice of antibiotic should be based on the severity of the infection and the likely etiologic agent(s), with consideration of the local prevalence of MRSA colonization or infection 1.
- The initial empiric therapy should cover MRSA, and options may include intravenous vancomycin, daptomycin, linezolid, or ceftaroline, with dosing adjustments based on renal function and trough levels 1.
- Treatment duration should typically be 2-4 weeks depending on clinical response and wound healing, with the goal of continuing antibiotic therapy until, but not beyond, resolution of findings of infection 1.
- The wound requires proper care including regular dressing changes, debridement of necrotic tissue if present, and monitoring for signs of spreading infection, as antibiotic therapy is often insufficient without appropriate wound care 1.
- Blood cultures should be obtained to rule out systemic infection or bacteremia, and close monitoring of the surgical site, glycemic control, and nutritional support are also essential components of management to promote healing and prevent further complications.
- Definitive therapy should be based on the results of an appropriately obtained culture and sensitivity testing of a wound specimen, as well as the patient’s clinical response to the empiric regimen 1.
From the FDA Drug Label
The cure rates in microbiologically evaluable patients with MRSA skin and skin structure infection were 26/33 (79%) for linezolid-treated patients and 24/33 (73%) for vancomycin-treated patients Methicillin-resistant S aureus12/17 (71%) Methicillin-resistant S. aureus16/17 (94%)
Treatment of MRSA infections: Linezolid is effective in treating MRSA infections, with cure rates of 71% to 94% in microbiologically evaluable patients.
- Cure rates: The cure rates for linezolid-treated patients with MRSA infections were 71% to 94%.
- Comparison to vancomycin: Linezolid has been compared to vancomycin in the treatment of MRSA infections, with similar cure rates. 2
From the Research
Wound Culture Post Leg Amputation for Diabetic Foot Showing MRSA
- The presence of MRSA in a wound culture post leg amputation for diabetic foot is a significant concern, as it can impede the healing process 3.
- MRSA is a common contaminant or infecting organism in diabetic foot wounds, and its presence can increase the time to healing twofold 3.
- The treatment of diabetic foot ulcers (DFUs) should follow the Infectious Diseases Society of America diabetic foot infection guidelines, which may include the use of antibiotics active against MRSA such as vancomycin or daptomycin 4, 5.
- In cases of severe MRSA infections, combination antibiotic treatment may be considered, although the evidence for this approach is still limited 6, 7.
- Source control is a critical component of treating MRSA infections, and may include removal of infected tissue, drainage of abscesses, and surgical debridement 5.
Management of MRSA Infections
- The management of MRSA infections typically involves the use of antibiotics active against MRSA, such as vancomycin or daptomycin 5.
- The choice of antibiotic should be guided by the results of antibiotic susceptibility testing, and adjusted as necessary 5.
- In addition to antibiotic treatment, source control and wound care are critical components of managing MRSA infections 5.
- The presence of MRSA in a wound culture should prompt a thorough evaluation of the wound and the patient's overall condition, to identify any underlying factors that may be contributing to the infection 3.