Protective Staphylococcal species (CoNS)

Protective Staphylococcal species refers to a specific subset of commensal, coagulase-negative bacteria (CoNS), most notably certain strains of Staphylococcus epidermidis and Staphylococcus hominis, that provide an essential innate defense against pathogenic colonization on human skin (Nakatsuji et al., Sci Transl Med, 2017). These organisms maintain skin homeostasis by producing selective antimicrobial peptides (AMPs) that target and inhibit the growth and virulence of Staphylococcus aureus without harming the broader resident microbiome. In conditions like atopic dermatitis, a significant depletion of these protective species is associated with S. aureus overgrowth, which contributes to skin inflammation and barrier dysfunction. Therapeutic strategies currently in development, such as live biotherapeutic products (LBPs) like MSB-01 (S-005151) and autologous microbiome transplants, aim to restore these protective populations to treat chronic inflammatory skin diseases (Nakatsuji et al., Nat Med, 2021). Beyond direct antimicrobial activity, these species interact with the host by modulating the innate immune response and strengthening the skin barrier through the secretion of diverse metabolites and signaling molecules (NCT02144142).

Other names

Commensal StaphylococciCoagulase-negative StaphylococciSkin-protective StaphylococciAntimicrobial CoNSAntimicrobial Staphylococci

Protective Staphylococcal species produce strain-specific antimicrobial peptides (AMPs) that selectively inhibit Staphylococcus aureus growth; interfere with S. aureus virulence via the accessory gene regulator (agr) quorum-sensing system; and engage in competitive exclusion for nutritional niches (Nakatsuji et al., 2017; 2021).