Bovine mastitis is a major disease of dairy cattle, causing inflammation of the udder, reduced milk yield, and significant economic losses. In Switzerland alone, annual losses exceed 129 million Swiss francs. This study focuses on strain characterization of two important pathogens, Streptococcus uberis and Staphylococcus aureus. S. uberis, traditionally considered environmental, has also shown contagious strains, while S. aureus is a contagious pathogen with biofilm-forming ability and virulence factors such as enterotoxins. Strains will be analyzed from milk and environmental sources to clarify herd-level epidemiology and assess emerging genotypes.
Given the rising problem of antimicrobial resistance (AMR) in mastitis pathogens, the project also investigates resistance mechanisms, their spread through bedding systems, and co-selection by environmental contaminants. Additional work will explore resistant bacteria in small ruminants, where antibiotic use is lower. The ultimate goal is to develop new technologies and on-farm screening methods, integrating a One Health approach to reduce mastitis impact and limit AMR dissemination.