Cutibacterium

Cutibacterium is a genus of Gram-positive, non-spore-forming rods that are predominantly anaerobic. Members are part of the normal human skin and mucosal microbiota, with a particular association to sebaceous gland–rich areas. The best known species is Cutibacterium acnes, historically named Propionibacterium acnes, which has been the primary focus of acne-related research. The genus also includes other skin-associated species, such as Cutibacterium avidum and Cutibacterium granulosum, and taxonomic reclassification has moved several Propionibacterium species into Cutibacterium.

Ecology and biology: Cutibacterium species are slow-growing and lipophilic, often utilizing sebum components as nutrients. They contribute to the skin’s microbial ecology by occupying oily regions and can interact with the host immune system. In healthy individuals, they are part of the resident microbiota, but imbalances in sebum production and inflammation can promote pathogenic activity, particularly by C. acnes.

Clinical relevance: Cutibacterium acnes is most commonly associated with acne vulgaris, where inflammatory processes are amplified in sebaceous-rich skin. The genus also includes opportunistic pathogens that can cause device- or prosthesis-related infections, including chronic biofilm-associated infections of implants and, less frequently, endocarditis or other deep-seated infections. Diagnosis relies on culture under anaerobic conditions and clinical correlation. Treatment considerations emphasize topical and systemic therapies for acne, and, for invasive infections, culture-guided antibiotics and, when applicable, removal of foreign material.