Propionibacterium Acnes: These types of acnes are comparatively slow growing, normally aerotolerant anaerobic gram positive bacterium which is associated with the skin condition acne. It may as well cause chronic endophthalmitis and blepharitis, with endophthalmitis normally following surgery that is intraocular. The genome of this bacterium has been determined and studies have shown numerous genes that may generate enzymes for degradation of the skin as well as proteins that can activate the immune system.

This bacterium is a portion of the normal skin flora that is found on healthy adults. It is normally only barely detectable on the skin of pre-adolescents. It primarily lives on acids that are secreted by follicles in the sebaceous glands. It can also be found in the human gastrointestinal tract. It is named by its capacity to produce propionic acid.