Abstract:

The in-hospital mortality rate of methicillin-resistant Staphylococcus aureus (MRSA) can reach 20%-30%, which has attracted global attention. However, the clinical treatment options for MRSA infections are still very limited. The drug resistance mechanisms of MRSA can be divided into intrinsic and acquired types. Intrinsic drug resistance is mainly achieved through the secretion of β-lactamase and the activation of efflux pumps. MRSA can acquire drug resistance through gene mutations or plasmid transformation involving drug-resistant genes. Additionally, the formation of biofilms and the emergence of small colony variants are also important mechanisms for acquired drug resistance. In clinical practice, traditional antibiotics are still the main approach for treating MRSA bacteremia. As MRSA tolerance to traditional antibiotics gradually increases, research on new therapeutic methods has also made great progress. Among these, quorum-sensing system (QS) inhibitors, antimicrobial peptides, small-molecule compounds, antimicrobial photodynamic therapy, phage therapy, and combination therapy have shown great potential in the treatment of MRSA infections. These novel approaches not only provide more effective, low-toxicity, and sustainable solutions for clinical practice but also offer new ideas for the exploration of new antibiotics with mechanisms of action different from those of traditional antibiotics.

Key words: Methicillin-resistant Staphylococcus aureus, Drug resistance mechanism, β-lactamase