Use of Molecular epidemiology of bovine Staphylococcus aureus and Streptococcus agalactiae to guide vaccine development and improved control measures for contagious mastitis in Brazil

Project summary

Brazil is one of the largest milk producers worldwide, but its dairy industry has suffered great economic losses due to contagious bovine mastitis (CBM), an infectious disease caused mainly by the bacterial species Streptococcus agalactiae (GBS) and Staphylococcus aureus (SAU). CBM control in Brazil is difficult because most dairy farms run small family farms with limited professional training. Farmers often use antibiotics for treatment and prevention of mastitis without proper guidance. This practice contributes to the risk of antimicrobial resistance in the bacteria, which can infect people as well as cows. Not all GBS and SAU are equal. There is variability in certain bacterial structures, including those that are present on their outer surface (e.g. carbohydrates and proteins). These polymorphic cell surface structures allow the classification of SAU and GBS strains into different types. Knowledge of the distribution of those types is essential for development of disease control tools, such vaccines and management strategies. Currently, there is a lack of knowledge on CBM-causing SAU and GBS in Brazil, partly because current diagnostic and typing methods are expensive and usually restricted to research laboratories. There is an urgent need for the development of faster and cheaper methods, improved surveillance, better CBM control measures and vaccine development studies. We aim to collect unprecedented information on SAU and GBS types on Brazilian dairy farms, to evaluate new diagnostic and typing methods, and to inform future studies for vaccine design. Our analysis of SAU and GBS strains from Southeastern and Northern Brazil will provide better understanding of their potential to cause CBM, and it will guide mastitis control policies, public health recommendations, including the rational use of antimicrobials, and inform vaccine design. Moreover, our international scientific collaboration will foster the scientific and professional development of a promising young LMIC-based female scientist.