MMRSA Guide
Microscopic illustration of MRSA (Staphylococcus aureus) bacteria
Reference · Treatment

Treating invasive MRSA wound infection

Surgical and traumatic wounds give MRSA direct access to fat, fascia, muscle, implants and bone. Treatment is a combination of surgery to remove infected material and weeks of targeted antibiotics.

Reviewed and updated by the MRSA Guide editorial team.

Recognising an infected wound

Signs include increasing pain after the second or third postoperative day, spreading redness beyond the incision, warmth and swelling, purulent or foul discharge, wound edges separating, fever, and rising inflammatory markers. Deep infection may show little on the surface, with pain, fever and a raised CRP as the only clues; ultrasound, CT or MRI is used to look for a collection.

Diagnosis rests on deep tissue samples taken at exploration rather than a superficial swab, which often grows colonising skin flora instead of the true pathogen.

Source control

Source control means physically removing what the antibiotic cannot reach: opening the wound, excising necrotic tissue, washing out collections, removing infected sutures or mesh, exchanging or removing a prosthesis, and taking out infected intravascular lines. It may be staged, with repeat debridement every 24–72 hours until the tissue bed is clean. Negative pressure dressings and delayed closure are used afterwards.

Necrotising infection — severe pain, skin blistering or blackening, crepitus, rapid progression — is a surgical emergency needing immediate exploration alongside linezolid or clindamycin for toxin suppression.

Antibiotic choice by depth

  • Superficial surgical site infection: after drainage, oral co-trimoxazole or doxycycline for 7–14 days.
  • Deep or complicated wound infection: intravenous vancomycin or daptomycin, with ceftaroline or teicoplanin as alternatives, for 2–4 weeks.
  • Bone involvement (osteomyelitis): six weeks or more of intravenous therapy, or an equivalent oral regimen with good bone penetration.
  • Implant or prosthetic joint infection: a companion drug plus rifampicin for its activity in biofilm, typically 3–6 months, with debridement or implant exchange.

Long outpatient courses are increasingly delivered with dalbavancin where keeping an intravenous line is impractical.

Preventing wound MRSA in the first place

Pre-operative screening and decolonisation, chlorhexidine showering, appropriate surgical prophylaxis, and strict dressing hygiene all cut the rate of MRSA surgical site infection. See hospitals and surgery and decolonisation.

Frequently asked questions

How is an MRSA surgical wound infection treated?
The wound is opened and explored, dead and infected tissue is removed, and any collection is drained. Intravenous antibiotics — usually vancomycin or daptomycin — are started, then narrowed once culture and susceptibility results return. Infected implants or mesh often have to be removed or exchanged for the infection to clear.
Why does an infected wound need surgery as well as antibiotics?
Antibiotics reach living, well-perfused tissue. Dead tissue, pus and biofilm on foreign material are effectively out of reach, so bacteria survive there and the infection relapses when treatment stops. Removing that material — debridement and source control — is what makes the antibiotic work.
How long does treatment last?
A superficial surgical site infection that has been fully debrided may need only 7–14 days. Deeper infection involving fascia or muscle usually needs 2–4 weeks. If bone is involved (osteomyelitis) treatment runs 6 weeks or longer, and prosthetic joint infection is often 3–6 months with rifampicin added to a companion drug.
When can intravenous treatment change to tablets?
Usually once the patient is afebrile and stable, the source has been controlled, any blood cultures are negative, inflammatory markers are falling, and a well-absorbed oral option is available. Linezolid, tedizolid, co-trimoxazole with rifampicin, or doxycycline are the usual oral step-down choices.
Can an MRSA wound infection cause sepsis?
Yes. If MRSA breaches the wound bed and enters the bloodstream it can cause bacteraemia and sepsis. Fever, a fast heart rate, low blood pressure, confusion or severe pain out of proportion to the wound all need emergency assessment.
What is negative pressure wound therapy?
A sealed dressing connected to controlled suction that removes exudate, reduces oedema and encourages granulation tissue. It is used after debridement in large or deep wounds. It supports healing but does not replace debridement or antibiotics.
References
  1. Infectious Diseases Society of America. Clinical practice guidelines for the treatment of MRSA infections (2011)
  2. Infectious Diseases Society of America. Diagnosis and management of prosthetic joint infection (2013)
  3. World Health Organization. Global guidelines for the prevention of surgical site infection (2018)
  4. The Lancet. Adjunctive rifampicin for Staphylococcus aureus bacteraemia (ARREST trial) (2018)

Treatment hub

How MRSA treatment is chosen by site and severity.

Skin & soft-tissue infection

Drainage first, then which oral antibiotics and for how long.

Bloodstream infection

Bacteraemia and endocarditis, source control and duration.

Decolonisation

Mupirocin and chlorhexidine protocols to clear carriage.

Every MRSA antibiotic

All 12 drugs used against MRSA, with route and role.

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