Microbiome precision editing: Using PEG as a selective fermentation initiator against methicillin-resistant Staphylococcus aureus.

Recent creation of a Unified Microbiome Initiative (UMI) has the aim of understanding how microbes interact with each other and with us. When pathogenic Staphylococcus aureus infects the skin, the interplay between S. aureus and skin commensal bacteria occurs. Our previous data revealed that skin commensal bacteria can mediate fermentation against the growth of USA300, a community-acquired methicillin-resistant S. aureus MRSA. By using a fermentation process with solid media on a small scale, we define poly(ethylene glycol) dimethacrylate (PEG-DMA) as a selective fermentation initiator which can specifically intensify the probiotic ability of skin commensal Staphylococcus epidermidis bacteria. At least five short-chain fatty acids including acetic, butyric and propionic acids with anti-USA300 activities are produced by PEG-DMA fermentation of S. epidermidis. Furthermore, the S. epidermidis-laden PEG-DMA hydrogels effectively decolonized USA300 in skin wounds in mice. The PEG-DMA and its derivatives may become novel biomaterials to specifically tailor the human skin microbiome against invading pathogens.