Environmental spread of mecA-carrying Staphylococcaceae in a Brazilian veterinary teaching hospital: A phenotypic and molecular epidemiological investigation.

Antimicrobial resistance significantly threatens human, animal, and environmental health, necessitating coordinated surveillance and intervention strategies. This study aimed to assess the presence of antimicrobial-resistant Staphylococcaceae on high-contact surfaces within the dermatology sector of a Brazilian veterinary teaching hospital. Thirty-eight high-touched surfaces were swabbed. Staphylococcus spp. was isolated from two sampling moments - after cleaning (M1) and after attendance activities (M2) using mannitol salt agar. Isolates were identified using MALDI-TOF, and an antimicrobial susceptibility test (AST) was performed using a disk-diffusion test. Results were described as absolute and relative frequencies. Antimicrobial susceptibility results were compared to the sampling moment and sampling group using the Chi-square or Fisher's Exact tests. The correlation between PCR positivity and MDR was evaluated. Eighty-seven Staphylococcaceae strains were isolated from surfaces, including examination tables, furniture, and cleaning facilities. The most frequently identified species were S. schleiferi, S. pseudintermedius, and S. simulans. AST revealed that 80.5% of the isolates were resistant to at least one drug, with penicillin resistance (71.3%) being the most prevalent. Resistance was also observed against gentamicin (26.4%), erythromycin (25.3%), and tetracycline (13.8%), as well as other clinically relevant antimicrobials. Multidrug-resistant (MDR) isolates were also detected in 24.1% of the samples, mostly in areas with a lot of contact, like exam tables for patients. The mecA gene was identified in 16.7% of tested isolates, while the blaZ gene was found in 19.6% of penicillin-resistant isolates. These findings highlight the urgent need for enhanced hospital infection control measures to prevent the spread of antimicrobial-resistant Staphylococcaceae. Considering the role of hospital environmental settings as pathways for acquiring MDR bacterial pathogens, biosecurity policies, antimicrobial stewardship programs, and strengthened epidemiological surveillance should be implemented in veterinary hospitals to mitigate antimicrobial resistance and reduce cross-contamination risks between animals, staff, and the hospital environment.