Cutibacterium acnes

Cutibacterium acnes is a Gram-positive, rod-shaped microbe that thrives in mesophilic temperatures, categorizing it as a chemoheterotroph, and can be found on all body sites in nearly all humans, residing on the skin of various species, and is an obligate anaerobe. The Gram-positive characteristic indicates that its cell wall contains a thick peptidoglycan layer, which retains the crystal violet stain used in the Gram staining procedure, appearing purple under a microscope. Its rod shape, also known as bacillus, allows it to inhabit small pores and follicles on the skin. As a mesophile, Cutibacterium acnes grows best in moderate temperatures, typically between 20-40°C, which is consistent with human body temperature. As a chemoheterotroph, it relies on external sources of organic compounds for energy and carbon, breaking down molecules such as triglycerides and fatty acids. Its presence on all body sites, including the face, chest, and back, makes it a ubiquitous microbe. The obligate anaerobic nature of Cutibacterium acnes means it requires a low-oxygen environment to survive, which is often found in the depths of pores and sebaceous glands. Cutibacterium acnes plays a significant role in the development of acne, as it breaks down sebum and other skin oils, producing compounds that can lead to inflammation and comedone formation. It has been found that certain strains of Cutibacterium acnes can produce enzymes that contribute to the severity of acne, while others may have anti-inflammatory properties.