Isolation of the novel phage SAP71 and its potential use against Staphylococcus aureus in an atopic dermatitis mouse model.

Atopic dermatitis (AD) is accompanied by changes in skin microbiota, in which abnormal colonization of Staphylococcus aureus is particularly common. The antibiotic treatment is prone to destroy the commensal bacterial community, further exacerbating the microbiome dysbiosis. Elimination of S. aureus through phage-targeted therapies presents a promising method in the treatment strategy of AD. In this study, we isolated a novel phage SAP71, which specifically lysed S. aureus. Genome sequencing showed that SAP71 contained no virulence, lysogenic, or antimicrobial resistance genes, making this lytic phage a potential agent for phage therapy. Moreover, we demonstrated that phage SAP71 was able to significantly improve the skin lesions, reduce the bacterial loads in the skin, and prevent the development of AD-like skin pathological changes in an AD model. In short, phage SAP71 was demonstrated to effectively treat S. aureus infection in AD, which provided a theoretical basis for the clinical phage therapy of AD.