Propionibacterium acnes: A Teenager’s Worst Nightmare Defined

General Background

Magnified Magnified Image of Propionibacterium acnes. Photo credit: CDC.

By Megan Lydon

Propionibacterium acnes is a bacterium commonly found on human skin, particularly in sebaceous (oil) glands and hair follicles. It is gram-positive and a fairly slow-growing aerotolerant bacterium. A lower density of P. acnes is detected on the skin of adolescents, especially those prepubescent. The bacteria mainly live on fatty acids. The normal habitat of P. acnes is in the sebaceous follicle shared with the yeast Pityrosporum and aerobic staphylococci and micrococci on its surface .Despite its name, and its colloquial associations, P. acnes is not solely associated with acne .;it is a normal resident of the skin microbiota in most people. However, it can contribute to the development of acne vulgaris, the most common form of acne, when factors such as excess sebum production, hormonal changes, and inflammation are present. Age-related differences are also noted in which lower levels of P. acnes are found in young children before they hit puberty. Acne is one of the most common skin diseases affecting more than 45 million people in the United States. In addition, in a clinical context, it is estimated that nearly 20% of visits to dermatologists are related to acne and the treatment of the condition

Skin Microbiome

Skim Microbiome

Microbiomes, in general, serve a greater purpose than living organisms just existing in their habitat. Through a combination of commensal species of microbes and their interactions with their habitat, environments are formed where the host and bacteria can adapt and regulate processes either to their advantage or negative effects of competition. The skin microbiome works identically. There is mass variability in the skin microbiome. As for microbes involved fungi, bacteria, viruses, and small arthropods contribute to this relationship [1]. In addition, the microbiome is much more complex than once thought. Past research has tended to focus only on pathogens and opportunistic pathogens rather than the entire spread of microbes in general (even “harmless” to human hosts). In addition to the variability of the microbes present in the skin microbiome, locations of the skin and their own environments are also variable from person to person. However, even in these differences, homeostasis between the microbiome and host is imperative for continued healthy interactions on the epithelium and avoids the occurrence of disease. The skin ecosystem is continuously variable in humidity, temperature, pH, and composition of antimicrobial peptides and lipids [1]. In addition, the frequency of hair follicles can also determine the production of sebaceous materials and eccrine and apocrine glands. With this variety of environments, it establishes a separate niche for microbes to fill and thrive in. The abundance of certain bacteria is dependent on these niches.

Pathogenesis of P. acnes (Acne Vulgeris)

Pathogenesis of P. acnes (Acne Vulgeris)

Public Health Implications

Public Health Implications

Acne Vulgeris Treatments

Acne Vulgeris Treatments

References

Authored for BIOL 238 Microbiology, taught by Joan Slonczewski,at Kenyon College,2024