Prophages in Skin Pathogens: From Virulence to Therapy.

Prophages are bacteriophage genomes that are part of bacterial chromosomes. They are not just dormant passengers; they actively shape pathogen biology. For example, in skin-infecting pathogens such as Staphylococcus aureus, Streptococcus pyogenes, and Pseudomonas aeruginosa, prophages carry important virulence factors, cytotoxins, superantigens, immune evasion clusters, and epigenetic regulators that directly affect the course of skin and soft tissue infections. This same prophage biology provides a therapeutic strategy: prophage-derived molecules, including endolysins, holins, spanins, and polysaccharide depolymerases, demonstrate potent antimicrobial and antibiofilm activity against drug-resistant skin pathogens, with several candidates now in clinical development. Engineered chimeric lysins, CRISPR-encoded prophage delivery systems, and the systematic mining of the skin microbiome phageome collectively enhance the translational potential of this biology. This review integrates mechanistic insights into prophage-mediated virulence. It assesses the translational landscape of prophage-derived therapeutics, delineating the conceptual and clinical frontiers that characterize the forthcoming chapter in this domain.