Staphylococcal Phage in Combination with Staphylococcus Epidermidis as a Potential Treatment for Staphylococcus Aureus-Associated Atopic Dermatitis and Suppressor of Phage-Resistant Mutants.

Atopic dermatitis is accompanied by the abnormal overgrowth of Staphylococcus aureus, a common cause of skin infections and an opportunistic pathogen. Although administration of antibiotics is effective against S. aureus, the resulting reduction in healthy microbiota and the emergence of drug-resistant bacteria are of concern. We propose that phage therapy can be an effective strategy to treat atopic dermatitis without perturbing the microbiota structure. In this study, we examined whether the S. aureus phage SaGU1 could be a tool to counteract the atopic exacerbation induced by S. aureus using an atopic mouse model. Administration of SaGU1 to the back skin of mice reduced both S. aureus counts and the disease exacerbation caused by S. aureus. Furthermore, the S. aureus-mediated exacerbation of atopic dermatitis with respect to IgE plasma concentration and histopathological findings was ameliorated by the application of SaGU1. We also found that Staphylococcus epidermidis, a typical epidermal symbiont in healthy skin, significantly attenuated the emergence of SaGU1-resistant S. aureus under co-culture with S. aureus and S. epidermidis in liquid culture infection experiments. Our results suggest that phage therapy using SaGU1 could be a promising clinical treatment for atopic dermatitis.