Mastitis Resistance to Enhance Dairy Food Safety

NON-TECHNICAL SUMMARY: Mastitis is an inflammation of the dairy cow's mammary gland caused by pathogenic microorganisms that decreases milk quality as well as quantity. The disease causes significant economic losses to milk producers because of reduced yield, and may become a food safety issue for consumers of dairy products because of exposure to dangerous bacteria and drug resistant strains. Efforts will be made to develop and evaluate natural natural antimicrobial treatment products for mastitis to enhance food safety. Additionally, the goal of mastitis control is to prevent the disease; thus, the development and testing of vaccines to enhance immunity against mastitis, especially against Staphylococcus aureus, is warranted.<P>APPROACH: Mastitis is the most costly disease of dairy cattle, and accounts for 26% of the total cost of all dairy cattle diseases. Antibiotic treatment is the principle method for eliminating existing cases of mastitis, and is the primary reason for using drugs in dairy cows. Because of the widespread use of antibiotics, there is growing public concern that misuse and overuse, is contributing to decreasing effectivness (resistance) of antibiotics against potentially dangerous human pathogens. From a food safety standpoint, novel approaches utilizing alternatives to classical antibiotic therapeutics to treat mastitis are warranted and needed. Studies will be designed to evaluate alternatives that include efficacious, natural antimicrobial treatment products that leave no drug residues in meat and milk, can be labeled as GRAS (Generally Regarded as Safe) and marketed for human consumption, qualify for use on organic dairies, and safe for the target species. Additionally, mastitis vaccines against Staphylococcus aureus will be evaluated for efficacy in dairy heifers and nonlactating cows with and without concurrent use of conventional antibiotics and novel (GRAS) antimicrobial products.