A Systematic Review of Methicillin‑Resistant Staphylococcus aureus (MRSA) Surgical Site Infections in Companion Animals and Their Human Contacts: A One Health Perspective

Background

Methicillin-resistant Staphylococcus aureus (MRSA) is one of the most important antibiotic-resistant pathogens. Surgical site infection (SSI) after surgery in companion animals is a veterinary therapeutic challenge, posing a potential zoonotic threat to animal owners and veterinary personnel. This systematic review aimed to investigate the epidemiology, resistance patterns, and evidence of interspecies transmission of MRSA in SSI of companion animals and their human contacts from a One Health perspective.

Methods

According to the PRISMA 2020 guidelines, a systematic search was conducted in the PubMed/MEDLINE, Web of Science, Scopus, and Google Scholar databases for studies published between January 2019 and December 2025. Eligible studies included observational designs (cohort, case-control, cross-sectional), case reports, and case series that reported concurrent MRSA surgical site infection in dogs or cats and at least one human contact (owner or veterinary staff). The resulting methodological heterogeneity is explicitly addressed in the interpretation of the findings.

Results

Of the 1,247 articles found, 18 studies met the inclusion criteria. The prevalence of MRSA in companion animal SSI ranged from 2.4% to 18.7%. The most important risk factors included previous hospitalization, previous antibiotic therapy, and orthopedic surgery with implants. In 12 studies (66.7%), MRSA strains isolated from animal SSIs and human contact were identical in molecular typing (SCCmec type IV and spa types t011 and t034), indicating cross-species transmission. Resistance to clindamycin (72%), erythromycin (68%), and tetracycline (55%) was common, while all isolates were susceptible to vancomycin and linezolid. In 5 studies, asymptomatic veterinary personnel were carriers of MRSA, and the same strain was found in the SSI of the animal they operated on.

Conclusion

Integrating preoperative MRSA screening, which suggests probable interspecies transmission, implementing infection control protocols in veterinary hospitals, and coordinating with the human health system are recommended as key One Health strategies to reduce MRSA antibiotic-resistant zoonoses.