Molecular-Based Investigation of Methicillin-Resistant Staphylococcus Aureus from Bovine Mastitis in Kasur

Methicillin-resistant Staphylococcus aureus (MRSA) poses a significant threat to the dairy industry through mastitis, causing substantial economic losses. MRSA is a zoonotic pathogen that transmits between livestock and humans through direct contact, contaminated environments, or animal products. Its prevalence is further exacerbated by inadequate research and the misuse of antibiotics. Objectives: To find molecular-based investigation of methicillin-resistant Staphylococcus aureus from bovine mastitis in Kasur. Methods: This study characterized MRSA isolates from bovine mastitis using biochemical tests and genotypic analysis of the Staphylococcal Cassette Chromosome mec (SCCmec), which carries the mecA gene that makes the bacteria resistant to β-lactam antibiotics. SCCmec typing distinguishes hospital-associated (HA-), community-associated (CA-), and livestock-associated (LA-) MRSA strains, the latter (notably CC398) exhibiting rising zoonotic concern. Results: Among 100 mastitic milk samples, 85% (85/100) carried mecA, confirming MRSA. Alarmingly, 78% (78/100) co-harbored the Panton-Valentine Leukocidin (PVL) gene, a key virulence determinant linked to severe infections in humans. Conclusions: The high co-occurrence of mecA (mediating multidrug resistance) and PVL (enhancing pathogenicity) in LA-MRSA isolates underscores a critical one health challenge, necessitating urgent interventions in antibiotic resistance and farm hygiene to mitigate transmission risks.