Methicillin-resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) is a leading cause of antimicrobial-resistant infection worldwide. The spectrum of diseases caused by MRSA range from uncomplicated skin and soft-tissue infections to life-threatening invasive infections such as bacteraemia, pneumonia, osteomyelitis and endocarditis. MRSA commonly colonizes the skin and mucosal surfaces as an asymptomatic commensal but can transition to an invasive pathogen when host barriers are disrupted or immune defences are compromised. The shift from commensal to pathogen is facilitated by a broad repertoire of virulence factors that promote adhesion, immune evasion, tissue invasion and persistence within host tissues. Despite the development of several new antibiotics with activity against MRSA, clinical outcomes during invasive infections are poor, with many patients experiencing persistent or recurrent infection. Strategies to prevent MRSA infection include infection control measures, screening and targeted decolonization approaches; however, the effectiveness of these interventions varies and often depends on local MRSA prevalence and epidemiological context. Understanding the epidemiology, pathogenesis and clinical management of MRSA remains essential to guide effective prevention and treatment strategies.