An exploration of mechanisms underlying Desemzia incerta colonization resistance to methicillin-resistant Staphylococcus aureus on the skin.

Methicillin-resistant causes significant healthcare burden and can be spread to the human population via livestock transmission. Members of the skin microbiome can prevent MRSA colonization via a poorly-understood phenomenon known as colonization resistance. Here, we studied colonization resistance of by bacterial inhibitors previously identified from a porcine skin model. We identify a pig skin commensal, , that reduced MRSA colonization in a murine model. We employ a combination of genomic, proteomic, and transcriptomic analyses to explore the mechanisms of inhibition between and . We identify 24 candidate antimicrobial proteins secreted by that could be responsible for its antimicrobial activity. We also find that exposure to leads to decreased biofilm formation. These findings show that the livestock transmission of MRSA can be exploited to uncover novel mechanisms of MRSA colonization resistance.