Virginia Research Day 2025

Medical Student Research Biomedical

26 Virulence Factors, Genetic Lineages, and Clinical Implications of Staphylococcus Aureus vs. Staphylococcus Pseudintermedius: A Comparative Analysis in Human and Veterinary Medicine

Paige O’Brien Daly, MA¹; Erin Onken, BS¹; Douglas Pluta²; Kaylie Ward¹; Jessica Gilbertie, MS, DVM, PhD² Corresponding author: eonken@vcom.edu

1 Edward Via College of Osteopathic Medicine - Virginia Campus ² Virginia Polytechnic Institute and State University – Blacksburg, VA

study emphasizes the interconnectedness of human and veterinary health systems and the critical role of pets in facilitating the spread of resistant pathogens. These findings underscore the need for a One Health approach that integrates human, animal, and environmental health. Enhanced surveillance systems, rapid diagnostic tools, and targeted interventions are essential to mitigate the threats posed by these pathogens and address the global challenges of antimicrobial resistance and zoonotic transmission effectively. Recognizing S. pseudintermedius as a potential zoonotic pathogen demands a coordinated response to protect both public and animal health.

Staphylococcus aureus (S. aureus) and Staphylococcus pseudintermedius (S. pseudintermedius) are significant pathogens with substantial impacts on human and animal health. This study undertakes a comparative analysis of their epidemiology, molecular characteristics, virulence factors, genetic lineages, and clinical implications to address critical questions about their behavior and risks. It explores the similarities and differences in their pathogenic mechanisms, the influence of their distinct genetic lineages on host adaptation and clinical outcomes, and the zoonotic potential of S. pseudintermedius . An extensive review of current research reveals that S. aureus is predominantly a human pathogen, while S. pseudintermedius primarily infects canines. However, the zoonotic potential of S. pseudintermedius is an

emerging public health concern as human-animal interactions intensify. Both species share virulence strategies, including biofilm formation and immune evasion, and exhibit alarming levels of antimicrobial resistance, particularly methicillin resistance, which complicates treatment and control strategies in both human and veterinary medicine. These shared resistance mechanisms highlight the growing threat of cross species transmission and the challenges posed by the rise of multidrug-resistant strains. The zoonotic risks of S. pseudintermedius , combined with its increasing recognition as a human pathogen, underline the urgent need for proactive measures. The

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