Prevalence, risk factors, and antimicrobial resistance of Staphylococcus aureus in equines in Egypt.

Staphylococcus aureus is a common commensal organism in both humans and animals, frequently colonizing the skin and nasal cavities of healthy individuals, although it can also cause a wide range of severe infections. The present study investigated the prevalence and risk factors of S. aureus in equines, along with antimicrobial resistance patterns of methicillin-resistant S. aureus (MRSA) isolates. The results revealed a prevalence of 38.6% in nasal samples collected from equines, highlighting the organism's significant presence and potential to cause infections in these animals. A genotypic prevalence of 8.2% was also recorded. Horses showed a significantly higher prevalence compared to donkeys and mules, indicating species-related differences in susceptibility and management practices. Risk factor analysis demonstrated higher infection rates in young animals, those in poor body condition, animals showing respiratory signs, and those with a history of prior antibiotic therapy. Antimicrobial susceptibility testing of MRSA isolates revealed high resistance to cefoxitin, cefotaxime, and meropenem, indicating the emergence of multidrug-resistant strains. These findings emphasize the role of antimicrobial misuse and microbial adaptation in resistance development. Overall, the study highlights the epidemiological importance of S. aureus in equines and underscores the need for improved management, hygiene practices, and prudent antibiotic use.