Antimicrobial Peptides Among Emerging Strategies to Combat Canine MRSP Crisis

Staphylococcus pseudintermedius is the leading cause of canine pyoderma and a significant pathogen in various canine infections, including skin, soft tissue, and postoperative sites. The emergence of methicillin-resistant S. pseudintermedius (MRSP) has created a critical challenge, as these strains exhibit multidrug resistance, biofilm-associated persistence, and frequent treatment failure. Current standard-of-care options are increasingly limited, necessitating novel approaches to manage recurrent infections and reduce the reliance on systemic antimicrobials, which often exacerbates resistance.

This article reviews the escalating challenge of methicillin-resistant S. pseudintermedius (MRSP) in canine medicine. It systematically covers the pathogen's emergence, epidemiology, and the underlying mechanisms of resistance and recurrence. The review critically evaluates the limitations of current treatment options, highlighting why conventional antimicrobial strategies are failing. Furthermore, it explores a range of emerging therapeutic strategies, including phage-based therapies, microbiome-directed interventions, immune modulation, nanomaterials, photodynamic therapy, and antimicrobial peptides, positioning them as potential adjuncts to standard care to reduce systemic antimicrobial dependence.

The review underscores that MRSP represents a significant crisis in veterinary medicine, primarily due to its pervasive multidrug resistance, capacity for biofilm-associated persistence, and the resulting high rates of treatment failure. Existing systemic antimicrobial options are becoming increasingly ineffective, leading to a cycle of repeated exposure that further drives resistance development. The article identifies a critical gap in current treatment paradigms, emphasizing the urgent need for innovative solutions.

The most significant finding is the comprehensive overview of diverse emerging therapeutic strategies, such as phage-based therapies, microbiome-directed interventions, immune modulation, nanomaterials, photodynamic therapy, and antimicrobial peptides. These approaches offer promising avenues to bypass or overcome traditional antibiotic resistance mechanisms, providing potential alternatives or adjuncts to conventional antibiotics. The goal of these novel strategies is to reduce the overall reliance on systemic antimicrobials, thereby addressing the complex and persistent nature of MRSP infections.