Commensal Staphylococci Influence Staphylococcus aureus Skin Colonization and Disease

Emerging evidence shows that cutaneous host defense relies upon extensive host/commensal cooperation. Resident commensals serve as the 'true' first line of defense at the skin’s surface. Skin commensals, including coagulase-negative staphylococci (CoNS), fortify cutaneous immune competence by broadening the functional repertoire of the skin’s innate and adaptive immune cell networks in a manner that bolsters effector responses against pathogenic microbes, while sparing members of the normal flora. CoNS can employ a diverse array of tactics that directly counter both the carriage and invasion of the common dermatopathogen S. aureus. The therapeutic efficacy of quorum-sensing inhibition has emerged as a promising paradigm for both pharmacologic and probiotic interventions aimed at mitigating S. aureus-induced disease. Commensal organisms that constitute the skin microbiota play a pivotal role in the orchestration of cutaneous homeostasis and immune competence. This balance can be promptly offset by the expansion of the opportunistic pathogen Staphylococcus aureus, which is responsible for the majority of bacterial skin infections. S. aureus carriage is also known to be a precondition for its transmission and pathogenesis. Recent reports suggest that skin-dwelling coagulase-negative staphylococci (CoNS) can prime the skin immune system to limit the colonization potential of invaders, and they can directly compete through production of antimicrobial molecules or through signaling antagonism. We review recent advances in these CoNS colonization resistance mechanisms, which may serve to aid development of pharmacologic and probiotic intervention strategies to limit S. aureus skin colonization and disease. Commensal organisms that constitute the skin microbiota play a pivotal role in the orchestration of cutaneous homeostasis and immune competence. This balance can be promptly offset by the expansion of the opportunistic pathogen Staphylococcus aureus, which is responsible for the majority of bacterial skin infections. S. aureus carriage is also known to be a precondition for its transmission and pathogenesis. Recent reports suggest that skin-dwelling coagulase-negative staphylococci (CoNS) can prime the skin immune system to limit the colonization potential of invaders, and they can directly compete through production of antimicrobial molecules or through signaling antagonism. We review recent advances in these CoNS colonization resistance mechanisms, which may serve to aid development of pharmacologic and probiotic intervention strategies to limit S. aureus skin colonization and disease.