Livestock-associated Staphylococcus aureus: origin, evolution and public health threat.

Staphylococcus aureus is a major pathogen responsible for severe nosocomial and community-associated infections of humans and infections of economically important livestock species. In recent years, studies into livestock-associated S. aureus including methicillin-resistant (MRSA) strains have provided new information regarding their origin and host adaptation, and their capacity to cause zoonotic infections of humans. Furthermore, a potential role for human activities such as domestication and industrialisation in the emergence of S. aureus clones affecting livestock has been highlighted. Here, I summarise recent developments in this emerging field and suggest questions of importance for future research efforts.