Propionibacterium acnes: Current Researches

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1. Classification

Domain: Bacteria Phylum: Actinobacteria Class: Actinobacteria Order: Actinomycetales Family: propionibacteriaceae Species: propionibacterium acnes

2. Description and significance

Propionibacterium acnes is a non-pathogenic, commensal bacterium that can be found in various locations of the body and in food such as dairy and cheese. P. acnes is a Gram-positive anaerobic bacillus that is slow-growing in nature, requiring a minimum of 6 days of culture growth (2). While P. acnes is most commonly associated with the inflammatory skin infection acne vulgaris, a skin condition commonly known as acne, research studies have demonstrated that it also plays a significant role in many other diseases such as in the lungs and lymph nodes and delayed surgical and implantation infections (3). However, due to its slow growth, P. acnes continues to be an under-recognized cause of diseases other than acne vulgaris and failure to diagnose can lead to serious consequences including mortality (3). Because of P. acnes’ broad association with a variety of disease, treatment options can vary. In most cases, P. acnes is susceptible to antibiotics or through a combination of either antibiotics and/or surgical option (3,4). Although a wide variety of research has been conducted on P. acnes, many questions are unanswered such as its symbiotic relationship in humans, and its antibiotic resistance role. Future research interest includes expanding on treatment options, novel diagnoses criteria specific to P. acnes in relation to different diseases, and its role as a disease-causing agent to further prevent infections and morbidity.

3. Genome structure

P. acnes stores its genetic information in a single circular chromosome. The chromosome encodes for approximately 2333 genes, with a 60% guanine-cytosine nucleotide ratio, containing various enzymes and proteins (6). For instance, P. acnes’ genes code for the Christie-Atkins-Munch-Petersen (CAMP) factors that act as toxins creating pores and allowing entry in the host’s membranes. The CAMP factors, along with enzymes that degrade body tissues, can ultimately lead to tissue inflammation. Moreover, the genome of P. acnes also encodes for proteins such as adhesins, heat shock proteins, and those that contribute in the formation of biofilms (6).

4. Cell structure and Metabolic Processes

P. acnes is a Gram-positive, non-spore forming, bacillus, or rod-like, bacterium. As a bacillus, P. acnes can be found living as individuals or in chains. In addition, as an aerotolerant anaerobic bacterium, the bacterium does not utilize oxygen for electron source, but is able to tolerate the presence of oxygen in the environment (3,4). Since P. acnes is an anaerobic microorganism, it can perform metabolic processes such as Embden-Meyerhof pathway and the pentose phosphate pathway, which allows for metabolization of sugars such as glucose, ribose, and mannose (5). Through the process of fermentation, P. acnes can also utilize lactose to produce propionic acid (4).

6. Ecology

Habitat; symbiosis; contributions to the environment.

7. Pathology

How does this organism cause disease? Human, animal, plant hosts? Virulence factors, as well as patient symptoms.

7. Key microorganisms

Include this section if your Wiki page focuses on a microbial process, rather than a specific taxon/group of organisms

8. Current Research

Include information about how this microbe (or related microbes) are currently being studied and for what purpose

9. References

It is required that you add at least five primary research articles (in same format as the sample reference below) that corresponds to the info that you added to this page. [Sample reference] Faller, A., and Schleifer, K. "Modified Oxidase and Benzidine Tests for Separation of Staphylococci from Micrococci". Journal of Clinical Microbiology. 1981. Volume 13. p. 1031-1035.