Antimicrobial usage for the management of mastitis in the USA: Impacts on antimicrobial resistance and potential alternative approaches

Authors: GELALCHA, BENTI - University Of Tennessee; Agga, Getahun; KERRO DEGO, OUDESSA - University Of Tennessee

Submitted to: Intech
Publication Type: Book / Chapter
Publication Acceptance Date: 11/8/2021
Publication Date: 12/29/2021
Citation: Gelalcha, B.D., Agga, G.E., Kerro Dego, O. 2021. Antimicrobial usage for the management of mastitis in the USA: Impacts on antimicrobial resistance and potential alternative approaches. Intech. https://doi.org/10.5772/intechopen.101533.
DOI: https://doi.org/10.5772/intechopen.101533

Interpretive Summary: Mastitis is an inflammation of the udder commonly caused by bacteria. It is a common disease of dairy cows. Mastitis affects the animal welfare through pain, causes milk loss with significant economic consequences to the dairy industry. To treat sick cows, control its occurrence and prevent future infections, dairy producers rely on antibiotics. However, the widespread use of antibiotics particularly for the blanket therapy of all cows at drying off is being scrutinized due to a rapid increase in antimicrobial resistance. The antibiotics that are commonly used for the management of mastitis on dairy farms are also used for medical purposes. This will lead to the transfer of resistance mechanisms from mastitis causing bacteria to human pathogens. Resistant bacteria can also infect humans when unpasteurized milk is consumed or used for the production of milk products. To reduce antibiotic use and maintain the effectiveness of the antibiotics both for animal and human use, alternative approaches are required. Some of such alternative approaches include herd health management, targeted dry cow therapy, identification of the causative bacteria before treatment, and the use of vaccines.

Technical Abstract: Mastitis is the most frequently diagnosed disease of dairy cattle responsible for the reduction in milk quantity and quality and major economic losses. Dairy farmers use antibiotics for the prevention and treatment of mastitis. Frequent antimicrobial usage (AMU) undeniably increased antimicrobial resistance (AMR) in bacteria from dairy farms. Antimicrobial-resistant bacteria (ARB) from dairy farms can spread to humans directly through contact with carrier animals or indirectly through the consumption of raw milk or undercooked meat from culled dairy cows. Indirect spread from dairy farms to humans can also be through dairy manure fertilized vegetables or run-off waters from dairy farms to the environment. The most frequently used antibiotics in dairy farms are medically important and high-priority classes of antibiotics. As a result, dairy farms are considered one of the potential reservoirs of ARB and antimicrobial resistance genes (ARGs). To mitigate the rise of ARB in dairy farms, reducing AMU by adopting one or more of alternative disease control methods such as good herd health management, selective dry-cow therapy, probiotics, and others is critically important. This chapter is a concise review of the effects of antimicrobials usage to control mastitis in dairy cattle farms and its potential impact on human health.