Phylogenetic population genomics study of CC97 Staphylococcus aureus isolated from livestock and humans

Since the Neolithic era, interactions between humans and domesticated animals have led to episodes of zoonotic infectious disease, but the capacity for livestock to act as a reservoir for new bacterial pathogens which are epidemic in human populations has not previously been demonstrated. Here, using a high-resolution phylogenetic approach, we report the discovery of emergent clones of human epidemic community-associated methicillin-resistant S. aureus (CA-MRSA) which originated from independent livestock-to-human host jumps followed by transmission among global human populations. These findings have important public health implications highlighting the importance of surveillance for early identification of emergent clones, and improved transmission control measures at the human-livestock interface.