Staphylococcus aureus (S. aureus) is a well-known mastitis pathogen in cattle causing great financial loss. According to our previous study, there are various bovine subtypes of S. aureus. One of them, genotype B, is highly contagious and pathogenic, causing serious problems in dairy farming. Together with Prof. Ph. Moreillon, University of Lausanne, we demonstrated that GTB is identical to CC8, based on „multilocus sequence typing“. The CC8 subtype is known to be a pathogen which may cause severe cases of purulent infection and bacteraemia in humans. Furthermore, a considerable number of these isolates are resistant to methicillin (MRSA). The present grant application proposes, therefore, to analyze the identity of the 2 strains at a molecular level. In particular, we plan to sequence and compare the entire genomes of a GTB and a CC8 strain. In the case of identity, the disease would need to be considered as a novel zoonosis, requiring epidemiological control to keep the risk of transmission from cattle to humans to a minimum. Identity of the 2 strains would also have serious consequences for the dairy industry such as abolishing products made with raw milk.
