Development of a vaccine against Staphylococcus aureus mastitis in cattle and buffalo

Mastitis, the inflammation of the mammary gland, is the most significant cause of economic loss to the dairy industry. Staphylococcus aureus is major problem for milk production all over the world, and the number one cause of mastitis in both India and No rway. India has approximately 300 million cows and buffalos kept primarily for milk production. The average herd size is low, most animals are kept to produce milk for the extended family. It is generally agreed that S. aureus mastitis in cattle is bes t controlled through hygienic measures to limit transmission of bacteria, the use of antibiotics, and culling of infected animals. However, control is difficult because S. aureus may reside on healthy animals and often causes subclinical disease. Hence, i t is virtually impossible to eliminate this bacteria from the environment. Furthermore, the use of antibiotics must be limited in order to avoid antibiotic residues in milk, which may be potentially harmful for consumers. In addition, the culling of cattl e is generally not possible in India for religious and cultural reasons. Previous studies have demonstrated a benefit of S. aureus vaccines against mastitis in cattle, but strain diversity with respect to antigenic properties and geographical differences in geno- and phenotypes of S. aureus have limited the possibility of commercialising such vaccines. Suffice to say, Indian farmers with a few cows or buffalo would benefit tremendously if a vaccine could reduce the morbidity and mortality of S. aureus mastitis in their animals, but also larger Indian dairy farms and the Norwegian dairy industry would benefit from such a vaccine. The success of the proposed study would also contribute greatly to increased knowledge of bacterial properties, and, importan tly, to the pathogenesis and immunological responses in S. aureus mastitis.