529 UVB inhibits staphylococcus aureus growth through action on skin commensals

Staphylococcus aureus (S.aureus) plays a crucial role in the pathogenesis of atopic dermatitis (AD) via secretion several virulence factors that can exacerbate disease. S.aureus growth and inhibition is one potential therapeutic approaches AD treatment. Ultraviolet radiation (UVR)-based phototherapy widely used treatment options for with favourable benefit-risk ratio. UVR has been shown being able inducing antimicrobial peptides (AMP). We therefore hypothesize efficacy at least partly due to its ability induce AMP not only from host cells, but also certain skin resident microbes. To test hypothesis, we first investigated supernatants obtained common commensal bacteria isolated human inhibit growth. The microbes were grown overnight tryptic soy broth followed by centrifugation sterile filtration. supernatant was added suspension changes calculating area under curve (AUC) OD600 values measured 24 hours. Intriguingly, S. hominis, S.xylosus S.simulans showed slight significant further examined if action on these commensals. this end, commensals exposed different doses UVR. as described above suspension. found UVB altered their inhibitory when compared respective unirradiated controls. Taken together, our preliminary results indicate UV exposure arm increased producing antimicrobials exert efficacy.