Staphylococcus aureus membrane vesicles confer resistance to antimicrobial fatty acids

S. aureus is a common commensal inhabitant of skin and nares of healthy individuals. In these environments, S. aureus overcomes colonisation barriers deployed by the innate immune system, which include long chain unsaturated free fatty acids with known potent anti-staphylococcal activity. S. aureus resistance mechanisms to these antimicrobial fatty acids (AFAs) remain elusive. However, it is well-documented that AFAs target S. aureus membrane, and increase its fluidity. This is associated with a drastic change in secreted proteins. The most abundantly secreted proteins in response to AFAs were recently identified to be components of S. aureus membrane vesicles (MVs), as revealed by proteomics analyses. Here, we demonstrate that MVs are decoys that trap AFAs. Importantly, MV release and composition are modulated by AFAs to promote bacterial survival.