Acne
Acne is linked to skin biofilms formed by certain bacteria.
Cutibacterium acnes is one of the most abundant bacteria on the skin. It prefers to live in sebaceous and moist areas of the skin like the forehead, neck and back. It is particularly abundant in the sebaceous follicles where it feeds on the sebum produced by these glands.
Although usually harmless, under the right conditions, Cutibacterium acnes can be an opportunistic pathogen and some strains are particularly linked to acne. The ones that cause acne can grow in biofilms inside the follicles and induce inflammation. It is now thought that being protected in biofilms is one of the reasons why acne is so difficult to treat and so often resistant to antibiotics.
Clinicians and scientists have now acknowledged the existence of C. acnes biofilms and are beginning to report on the complexity of the glue-like matrix that holds the bacteria together.
On skin, Cutibacterium acnes (formerly Propionibacterium acnes) can behave as an opportunistic pathogen, depending on strain and environmental conditions. Acneic strains of C. acnes form biofilms inside skin–gland hollows, inducing inflammation and skin disorders. The biproducts of C. acnes growth accumulate in the extracellular matrix of the biofilm. However, little is known about the actual composition of the biofilm matrix of C. acnes. We have developed a new technique for extraction of the biofilm matrix without the use of chemical or enzymatic digestion which are known to be a source of artefacts. Our results show the complexity of the biofilm matrix composition and will provide insight into the development of new anti-C. acnes treatments and potential new antibiofilm drugs.
Further reading on acne biofilms
Composition of the Biofilm Matrix of Cutibacterium acnes Acneic Strain RT5 https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6598116/