Screening of vancomycin resistance-associated genes in methicillin-resistant Staphylococcus aureus isolates from cattle, sheep and goats in northwestern Iran

Staphylococcus aureus is an important pathogen causing a wide range of diseases in both humans and animals. The aim of this research was to screen the vancomycin resistance-associated genes in methicillin-resistant Staphylococcus aureus (MRSA) isolates from animals. A total of 400 nasal swab samples were collected from cattle, goats and sheep between February and August 2022 from both industrial and traditional livestock farms in West Azerbaijan province, Iran. Then, nasal swabs were cultured on mannitol salt agar and molecular analysis was performed after bacteriological examination to confirm the presence of S. aureus. The MecA gene was used to detect MRSA isolates, and two important vancomycin resistance-associated genes, namely vanA and vanB, were searched in the isolates. Out of 400 nasal swabs, 69 samples had S. aureus; of which seven isolates were resistant against methicillin. No vancomycin resistance-associated genes were detected in the MRSA isolates. Based on these findings, vancomycin could be used to treat infections caused by this bacterium.