Diagnostic Approaches for Methicillin-Resistant Staphylococcus aureus (MRSA): Accuracy, Limitations, and Future Direction

Methicillin-resistant Staphylococcus aureus (MRSA) is a major global health threat responsible for significant morbidity and mortality, accounting for approximately 19,000 deaths annually in the United States. MRSA resistance is primarily mediated by the mecA and mecC genes, which are carried on the staphylococcal cassette chromosome mec (SCCmec) integrated at the OrfX locus of Staphylococcus aureus, resulting in reduced susceptibility to β-lactam antibiotics. Rapid and accurate diagnostic methods are therefore essential to improve clinical outcomes and limit disease transmission. This mini-review evaluates current MRSA diagnostic approaches, including polymerase chain reaction (PCR) and its variants, isothermal amplification techniques (LAMP and RPA), CRISPR-based diagnostics, and electrochemical biosensors. These methods are compared in terms of diagnostic accuracy, clinical utility, cost-effectiveness, and practical limitations. Overall, isothermal amplification demonstrated a more favorable balance in cost-effectiveness and practical limitations compared to other methods. However, when considering clinical utility and diagnostic accuracy, the results were context dependent. No single method was universally optimal, and the choice of diagnostic approach depends on the clinical context and resource availability.