Biting flies on dairy farms can spread bovine mastitis

Bovine mastitis is a disease which causes inflammation of the mammary glands, resulting in abnormal or reduced milk production in cattle. It can be fatal if left untreated. Bovine mastitis can be caused by pathogenic bacteria, and other microbes, though the exact mechanism of transmission was previously well understood.

In a recent study published in mSphere, researchers from the University of Wisconsin-Madison reported that Stomoxys flies (also known as ‘stable flies’) were a key carrier of bacteria that can cause bovine mastitis. The findings of this study suggest that pathogenic bacteria, including Escherichia, Klebsiella and Staphylococcus, can colonise the fly gut. Colonised flies can act as vectors, transferring bacteria between cattle, thereby increasing the risk of developing mastitis.

This finding is significant as it highlights an important transmission route. Further research may help identify new strategies to prevent transmission and protect cows from disease-causing pathogens.

Article: Sommer, A.J., Kettner, J. E., Coon, K. L., (2024) Stable flies are bona fide carriers of mastitis-associated bacteria. mSphere, 9:e00336-24. https://doi.org/10.1128/msphere.00336-24

For further information, see: The American Society for Microbiology’s recent press release.