How MRSA is diagnosed and treated
MRSA treatment depends on where the infection is, how severe it is, and whether the organism is community- or hospital-acquired. Source control is as important as the antibiotic.
Diagnosis
Diagnosis rests on culture of the infected site — wound swab, blood, sputum, or tissue — followed by susceptibility testing. Rapid PCR assays for mecA and mecC can identify MRSA in positive blood cultures within hours, shortening time to effective therapy.
Skin and soft-tissue infection
Most simple abscesses are treated with incision and drainage. When antibiotics are added, oral options include trimethoprim- sulfamethoxazole, doxycycline, or clindamycin. Linezolid is reserved for severe or refractory disease.
Invasive infection
Bacteremia, endocarditis, pneumonia, and bone or joint infection are treated with intravenous vancomycin or daptomycin as first-line agents, with ceftaroline, dalbavancin, or oritavancin used in selected cases. Therapy is typically two to six weeks depending on source and complication.
Echocardiography, source-control imaging, and infectious-disease consultation are recommended for all S. aureus bacteremia.
Decolonisation
Selective decolonisation with intranasal mupirocin and chlorhexidine body wash reduces recurrence in selected patients and reduces ICU bloodstream infections when applied universally.