J Vet Med Sci. 2026 Jul 13. doi: 10.1292/jvms.26-0179. Online ahead of print.
ABSTRACT
Mastitis is one of the most common diseases in dairy cows, causing significant economic losses due to reduced productivity and the need for treatment. In recent years, MRSA (methicillin-resistant Staphylococcus aureus) has emerged as an important cause of chronic and recurrent mastitis, posing additional challenges for herd health management. The aim of this study was to conduct a comparative analysis of recurrent mastitis in Holstein-Friesian cows caused by MRSA and non-MRSA Staphylococcus aureus, with a particular focus on the number of recurrences, somatic cell count (SCC), milk production, and risk factors. The study included 120 cows, divided into two groups of 60, raised under identical conditions on a single farm. Milk samples were collected under sterile conditions, cultured on Blood agar and Mannitol Salt agar, and analyzed for the presence of MRSA using PCR for the mecA gene. Cows were monitored for the number of recurrences, SCC, daily milk yield, and response to therapy. Statistical analyses included t-tests, ANOVA, correlation analysis, and logistic regression. The results showed that MRSA-infected cows had significantly higher recurrence rates, along with elevated SCC and reduced milk yield compared to the non-MRSA group. MRSA was identified as the strongest independent risk factor for mastitis recurrence. These findings highlight the importance of regular bacteriological monitoring, appropriate therapy, and preventive measures to reduce economic losses and protect herd health.
PMID:42437984 | DOI:10.1292/jvms.26-0179
