Cutibacterium acnes (formerly Propionibacterium acnes) is the relatively slow-growing, typically aerotolerant anaerobic, gram-positive bacterium (rod) linked to the skin condition of acne; it can also cause chronic blepharitis and endophthalmitis, the latter particularly following intraocular surgery. Its genome has been sequenced and a study has shown several genes can generate enzymes for degrading skin and proteins that may be immunogenic (activating the immune system).
The species is largely commensal and part of the skin flora present on most healthy adult humans' skin. It is usually just barely detectable on the skin of healthy preadolescents. It lives, among other things, primarily on fatty acids in sebum secreted by sebaceous glands in the follicles. It may also be found throughout the gastrointestinal tract.
Originally identified as Bacillus acnes, it was later named Propionibacterium acnes for its ability to generate propionic acid. In 2016, P. acnes was taxonomically reclassified as a result of biochemical and genomic studies. In terms of both phylogenetic tree structure and DNA G + C content, the cutaneous species was distinguishable from other species that had been previously categorized as P. acnes. As part of restructuring, the novel genus Cutibacterium was created for the cutaneous species, including those formerly identified as Propionibacterium acnes, Propionibacterium avidum, and Propionibacterium granulosum. Characterization of phylotypes of C. acnes is an active field of research.
Role in diseases
Cutibacterium acnes bacteria predominantly live deep within follicles and pores, although they are also found on the surface of healthy skin. In these follicles, C. acnes bacteria use sebum, cellular debris and metabolic byproducts from the surrounding skin tissue as their primary sources of energy and nutrients. Elevated production of sebum by hyperactive sebaceous glands (sebaceous hyperplasia) or blockage of the follicle can cause C. acnes bacteria to grow and multiply.
Cutibacterium acnes bacteria secrete many proteins, including several digestive enzymes. These enzymes are involved in the digestion of sebum and the acquisition of other nutrients. They can also destabilize the layers of cells that form the walls of the follicle. The cellular damage, metabolic byproducts and bacterial debris produced by the rapid growth of C. acnes in follicles can trigger inflammation. This inflammation can lead to the symptoms associated with some common skin disorders, such as folliculitis and acne vulgaris. Acne vulgaris is the disease most commonly associated with C. acnes infection.
Acne vulgaris is a chronic inflammatory disease of the pilosebaceous unit, which includes the hair follicle, hair shaft, and sebaceous gland and about 650 million people are affected globally by this disease. C. acnes starts to colonize on the skin around 1 to 3 years prior to puberty and grows exponentially during this time. This is why so many teens and young adults struggle with acne. Prescriptions to treat acne are often antibiotics. However, with the rise of antibiotic resistance, antibiotics are now often combined with broad-spectrum antibacterial agents such as benzoyl peroxide, and other medications like isotretinoin (commonly known as Accutane) are being used on patients with severe or resistant acne.
The damage caused by C. acnes and the associated inflammation make the affected tissue more susceptible to colonization by opportunistic bacteria, such as Staphylococcus aureus. Preliminary research shows healthy pores are only colonized by C. acnes, while unhealthy ones universally include the nonpore-resident Staphylococcus epidermidis, amongst other bacterial contaminants. Whether this is a root causality, just opportunistic and a side effect, or a more complex pathological duality between C. acnes and this particular Staphylococcus species is not known. Current research has pointed to the idea that C. acnes and S. epidermidis have a symbiotic relationship. Both bacteria exist on the normal flora of the skin and a disrupt in balance of these bacteria on the skin can result in acne or other bacterial infection.
Cutibacterium acnes has been found in herniated discs. The propionic acid which it secretes creates micro-fractures of the surrounding bone. These micro-fractures are sensitive and it has been found that antibiotics have been helpful in resolving this type of low back pain.
Cutibacterium acnes can be found in bronchoalveolar lavage of approximately 70% of patients with sarcoidosis and is associated with disease activity, but it can also be found in 23% of controls. The subspecies of C. acnes that cause these infections of otherwise sterile tissues (prior to medical procedures), however, are the same subspecies found on the skin of individuals who do not have acne-prone skin, so are likely local contaminants. Moderate to severe acne vulgaris appears to be more often associated with virulent strains.
Cutibacterium acnes is often considered an opportunistic pathogen, causing a range of postoperative and device-related infections e.g., surgical infections, post-neurosurgical infections, infected joint prostheses (especially shoulder), neurosurgical shunt infections and endocarditis in patients with prosthetic heart valves (predominantly men). C. acnes may play a role in other conditions, including SAPHO (synovitis, acne, pustulosis, hyperostosis, osteitis) syndrome, sarcoidosis and sciatica. It is also suspected a main bacterial source of neuroinflammation in Alzheimer's disease brains. It is a common contaminant in blood and cerebrospinal fluid cultures.
Cutibacterium acnes bacteria are susceptible to a wide range of antimicrobial molecules, from both pharmaceutical and natural sources. The antibiotics most frequently used to treat acne vulgaris are erythromycin, clindamycin, doxycycline, and minocycline. Several other families of antibiotics are also active against C. acnes bacteria, including quinolones, cephalosporins, pleuromutilins, penicillins, and sulfonamides.
The emergence of antibiotic-resistant C. acnes bacteria represents a growing problem worldwide. The problem is especially pronounced in North America and Europe. The antibiotic families that C. acnes are most likely to acquire resistance to are the macrolides (e.g., erythromycin and azithromycin), lincosamides (e.g., clindamycin) and tetracyclines (e.g., doxycycline and minocycline).
However, C. acnes bacteria are susceptible to many types of antimicrobial chemicals found in over-the-counter antibacterial products, including benzoyl peroxide, triclosan, chloroxylenol, and chlorhexidine gluconate.
Several naturally occurring molecules and compounds are toxic to C. acnes bacteria. Some essential oils such as rosemary, tea tree oil, clove oil, and citrus oils contain antibacterial chemicals. Natural honey has also been shown to have some antibacterial properties that may be active against C. acnes.
Cutibacterium acnes glows orange when exposed to blacklight, possibly due to the presence of endogenous porphyrins. It is also killed by ultraviolet light. C. acnes is especially sensitive to light in the 405–420 nanometer (near the ultraviolet) range due to an endogenic porphyrin–coporphyrin III. A total radiant exposure of 320 J/cm2 inactivates this species in vitro. Its photosensitivity can be enhanced by pretreatment with aminolevulinic acid, which boosts production of this chemical, although this causes significant side effects in humans, and in practice was not significantly better than the light treatment alone.
Cutibacterium acnes has been found to be an endophyte of plants. Notably, grapevine appears to host an endophytic population of C. acnes that is closely related to the human-associated strains. The two lines diverged roughly 7,000 years ago, at about the same time when grapevine agriculture may have been established. This C. acnes subtype was dubbed Zappae in honour of the eccentric composer Frank Zappa, to highlight its unexpected and unconventional habitat.
- "Genus: Cutibacterium". Prokaryotic Nomenclature Up-to-Date. DSMZ. Archived from the original on 17 August 2018. Retrieved 17 August 2018.
- Scholz CF, Kilian M (November 2016). "The natural history of cutaneous propionibacteria, and reclassification of selected species within the genus Propionibacterium to the proposed novel genera Acidipropionibacterium gen. nov., Cutibacterium gen. nov. and Pseudopropionibacterium gen. nov" (PDF). International Journal of Systematic and Evolutionary Microbiology. 66 (11): 4422–4432. doi:10.1099/ijsem.0.001367. PMID 27488827. Retrieved 17 August 2018.
- Dréno B, Pécastaings S, Corvec S, Veraldi S, Khammari A, Roques C (June 2018). "Cutibacterium acnes (Propionibacterium acnes) and acne vulgaris: a brief look at the latest updates". Journal of the European Academy of Dermatology and Venereology. 32 Suppl 2: 5–14. doi:10.1111/jdv.15043. hdl:2434/620522. PMID 29894579.
- "Genus Cutibacterium". LPSN. Retrieved 17 August 2018.
- Bhatia A, Maisonneuve JF, Persing DH (2004-01-01). Proprionibacterium acnes and Chronic Diseases. National Academies Press (US).
- Dali P, Giugliano ER, Vellozzi EM, Smith MA (October 2001). "Susceptibilities of Propionibacterium acnes ophthalmic isolates to moxifloxacin". Antimicrobial Agents and Chemotherapy. 45 (10): 2969–70. doi:10.1128/AAC.45.10.2969-2970.2001. PMC 90767. PMID 11583007.
- Liu J, Cheng A, Bangayan NJ, Barnard E, Curd E, Craft N, Li H (August 2014). "Draft Genome Sequences of Propionibacterium acnes Type Strain ATCC6919 and Antibiotic-Resistant Strain HL411PA1". Genome Announcements. 2 (4): e00740–14. doi:10.1128/genomeA.00740-14. PMC 4132614. PMID 25125638.
- Brüggemann H, Henne A, Hoster F, Liesegang H, Wiezer A, Strittmatter A, et al. (July 2004). "The complete genome sequence of Propionibacterium acnes, a commensal of human skin". Science. 305 (5684): 671–3. Bibcode:2004Sci...305..671B. doi:10.1126/science.1100330. PMID 15286373. S2CID 26252335.
- Perry A, Lambert P (December 2011). "Propionibacterium acnes: infection beyond the skin". Expert Review of Anti-Infective Therapy. 9 (12): 1149–56. doi:10.1586/eri.11.137. PMID 22114965. S2CID 42012357.
- Gilchrist TC (1900). "A bacteriological and microscopical study of over 300 vesicular and pustular lesions of the skin, with a research upon the etiology of acne vulgaris". Johns Hopkins Hospital Report. 9: 409–430.
- Douglas HC, Gunter SE (July 1946). "The Taxonomic Position of Corynebacterium acnes". Journal of Bacteriology. 52 (1): 15–23. doi:10.1128/JB.52.1.15-23.1946. PMC 518134. PMID 16561149.
- "Propionibacterium Cutibacterium - late breaking news and a new name". Shoulder Arthritis / Rotator Cuff Tears: causes of shoulder pain. April 2, 2017. Retrieved 17 August 2018.
- Dagnelie MA, Khammari A, Dréno B, Corvec S (November 2018). "Cutibacterium acnes molecular typing: time to standardize the method". Clinical Microbiology and Infection. 24 (11): 1149–1155. doi:10.1016/j.cmi.2018.03.010. PMID 29544912. Retrieved 17 August 2018.
- Zeller VA, Letembet VA, Meyssonnier VA, Heym B, Ziza JM, Marmor SD (July 2018). "Cutibacterium (Formerly Propionibacterium) avidum: A Rare but Avid Agent of Prosthetic Hip Infection". The Journal of Arthroplasty. 33 (7): 2246–2250. doi:10.1016/j.arth.2018.02.008. PMID 29544969. Retrieved 17 August 2018.
- Zouboulis CC (2011). "Acne and sebaceous gland function". Clinics in Dermatology. 22 (5): 360–6. doi:10.1016/j.clindermatol.2004.03.004. PMID 15556719.
- Holland C, Mak TN, Zimny-Arndt U, Schmid M, Meyer TF, Jungblut PR, Brüggemann H (August 2010). "Proteomic identification of secreted proteins of Propionibacterium acnes". BMC Microbiology. 10: 230. doi:10.1186/1471-2180-10-230. PMC 3224659. PMID 20799957.
- Kim J (2005). "Review of the innate immune response in acne vulgaris: activation of Toll-like receptor 2 in acne triggers inflammatory cytokine responses". Dermatology. 211 (3): 193–8. doi:10.1159/000087011. PMID 16205063. S2CID 21459334.
- Zouboulis CC (2004). "Acne and sebaceous gland function". Clinics in Dermatology. 22 (5): 360–6. doi:10.1016/j.clindermatol.2004.03.004. PMID 15556719.
- "Understanding Acne - News in Health, January 2010". Newsinhealth.nih.gov. Retrieved 2012-06-14.
- Tuchayi, Sara Moradi; Makrantonaki, Evgenia; Ganceviciene, Ruta; Dessinioti, Clio; Feldman, Steven R.; Zouboulis, Christos C. (2015-09-17). "Acne vulgaris". Nature Reviews Disease Primers. 1 (1): 1–20. doi:10.1038/nrdp.2015.29. ISSN 2056-676X.
- "Cutibacterium (Propionibacterium) Infections Clinical Presentation: History, Complications". emedicine.medscape.com. Retrieved 2022-04-22.
- Ross; et al. (2003). "Antibiotic-resistant acne: lessons from Europe". British Journal of Dermatology. 148 (3): 467–78. arXiv:0706.4406. doi:10.1046/j.1365-2133.2003.05067.x. hdl:10454/3069. PMID 12653738. S2CID 20838517.
- Hiramatsu J, Kataoka M, Nakata Y, Okazaki K, Tada S, Tanimoto M, Eishi Y (October 2003). "Propionibacterium acnes DNA detected in bronchoalveolar lavage cells from patients with sarcoidosis". Sarcoidosis, Vasculitis, and Diffuse Lung Diseases. 20 (3): 197–203. PMID 14620162.
- Fournière M, Latire T, Souak D, Feuilloley MG, Bedoux G (November 2020). "Staphylococcus epidermidis and Cutibacterium acnes: Two Major Sentinels of Skin Microbiota and the Influence of Cosmetics". Microorganisms. 8 (11): 1752. doi:10.3390/microorganisms8111752. PMC 7695133. PMID 33171837.
- Lim, Sung A.; Na, Kyung-Sun; Joo, Choun-Ki (September 2017). "Clinical Features of Infectious Keratitis Caused by Propionibacterium Acnes". Eye & Contact Lens. 43 (5): 330–333. doi:10.1097/ICL.0000000000000281. ISSN 1542-233X.
- Capoor MN, Ruzicka F, Schmitz JE, James GA, Machackova T, Jancalek R, et al. (2017-04-03). "Propionibacterium acnes biofilm is present in intervertebral discs of patients undergoing microdiscectomy". PLOS ONE. 12 (4): e0174518. Bibcode:2017PLoSO..1274518C. doi:10.1371/journal.pone.0174518. PMC 5378350. PMID 28369127.
- Albert HB, Sorensen JS, Christensen BS, Manniche C (April 2013). "Antibiotic treatment in patients with chronic low back pain and vertebral bone edema (Modic type 1 changes): a double-blind randomized clinical controlled trial of efficacy". European Spine Journal. 22 (4): 697–707. doi:10.1007/s00586-013-2675-y. PMC 3631045. PMID 23404353.
- Inoue Y, Suga M (February 2008). "[Granulomatous diseases and pathogenic microorganism]". Kekkaku. 83 (2): 115–30. PMID 18326339.
- Lomholt HB, Kilian M (August 2010). Bereswill S (ed.). "Population genetic analysis of Propionibacterium acnes identifies a subpopulation and epidemic clones associated with acne". PLOS ONE. 5 (8): e12277. Bibcode:2010PLoSO...512277L. doi:10.1371/journal.pone.0012277. PMC 2924382. PMID 20808860.
- Haidar R., Najjar M., Boghossian A.D., Tabbarah Z., "Propionibacterium acnes causing delayed postoperative spine infection: Review." Scandinavian Journal of Infectious Diseases. 42 (6-7) (pp 405-411), 2010
- Nisbet, M.; Briggs, S.; Ellis-Pegler, R.; Thomas, M. ;Holland, D. "Propionibacterium acnes: an under-appreciated cause of post-neurosurgical infection" Journal of Antimicrobial Chemotherapy. 60(5). NOV 2007. 1097-1103.1103..
- Levy PY, Fenollar F, Stein A, Borrione F, Cohen E, Lebail B, Raoult D (June 2008). "Propionibacterium acnes postoperative shoulder arthritis: an emerging clinical entity". Clinical Infectious Diseases. 46 (12): 1884–6. doi:10.1086/588477. PMID 18462110.
- Sohail MR, Gray AL, Baddour LM, Tleyjeh IM, Virk A (April 2009). "Infective endocarditis due to Propionibacterium species". Clinical Microbiology and Infection. 15 (4): 387–94. doi:10.1111/j.1469-0691.2009.02703.x. PMID 19260876.
- Perry A., Lambert P. " Propionibacterium acnes: Infection beyond the skin." Expert Review of Anti-Infective Therapy. 9 (12) (pp 1149-1156), 2011
- Emery DC, Shoemark DK, Batstone TE, Waterfall CM, Coghill JA, Cerajewska TL, et al. (2017). "16S rRNA Next Generation Sequencing Analysis Shows Bacteria in Alzheimer's Post-Mortem Brain". Frontiers in Aging Neuroscience. 9: 195. doi:10.3389/fnagi.2017.00195. PMC 5476743. PMID 28676754.
- Portillo ME, Corvec S, Borens O, Trampuz A (2013). "Propionibacterium acnes: an underestimated pathogen in implant-associated infections". BioMed Research International. 2013: 804391. doi:10.1155/2013/804391. PMC 3838805. PMID 24308006.
- Gharamti AA, Kanafani ZA (December 2017). "Cutibacterium (formerly Propionibacterium) acnes infections associated with implantable devices". Expert Review of Anti-Infective Therapy. 15 (12): 1083–1094. doi:10.1080/14787210.2017.1404452. PMID 29125405. S2CID 205850559.
- "Prescription Medications for Treating Acne". Skincarephysicians.com. 2007-02-16. Archived from the original on 2012-06-20. Retrieved 2012-06-14.
- "The Cause Of Acne and Natural or Medical Acne Treatment". Archived from the original on 2017-10-11. Retrieved 2019-11-18.
- Strauss JS, Krowchuk DP, Leyden JJ, Lucky AW, Shalita AR, Siegfried EC, et al. (April 2007). "Guidelines of care for acne vulgaris management". Journal of the American Academy of Dermatology. 56 (4): 651–63. doi:10.1016/j.jaad.2006.08.048. PMID 17276540.
- Hoeffler U, Ko HL, Pulverer G (September 1976). "Antimicrobiol susceptibility of Propinibacterium acnes and related microbial species". Antimicrobial Agents and Chemotherapy. 10 (3): 387–94. doi:10.1128/aac.10.3.387. PMC 429758. PMID 984781.
- Wang WL, Everett ED, Johnson M, Dean E (January 1977). "Susceptibility of Propionibacterium acnes to seventeen antibiotics". Antimicrobial Agents and Chemotherapy. 11 (1): 171–3. doi:10.1128/aac.11.1.171. PMC 351938. PMID 836012.
- "Antibiotic Susceptibility of Propionibacterium acnes". ScienceOfAcne.com. 2011-07-15. Retrieved 2012-08-08.
- Tzellos T, Zampeli V, Makrantonaki E, Zouboulis CC (June 2011). "Treating acne with antibiotic-resistant bacterial colonization". Expert Opinion on Pharmacotherapy. 12 (8): 1233–47. doi:10.1517/14656566.2011.553192. PMID 21355786. S2CID 26957816.
- Ross JI, Snelling AM, Eady EA, Cove JH, Cunliffe WJ, Leyden JJ, et al. (February 2001). "Phenotypic and genotypic characterization of antibiotic-resistant Propionibacterium acnes isolated from acne patients attending dermatology clinics in Europe, the U.S.A., Japan and Australia". The British Journal of Dermatology. 144 (2): 339–46. arXiv:1510.02343. doi:10.1046/j.1365-2133.2001.03956.x. hdl:10454/3311. PMID 11251569. S2CID 44614220.
- Ross JI, Snelling AM, Carnegie E, Coates P, Cunliffe WJ, Bettoli V, et al. (March 2003). "Antibiotic-resistant acne: lessons from Europe". The British Journal of Dermatology. 148 (3): 467–78. doi:10.1046/j.1365-2133.2003.05067.x. hdl:10454/3069. PMID 12653738. S2CID 20838517.
- Coates P, Vyakrnam S, Eady EA, Jones CE, Cove JH, Cunliffe WJ (May 2002). "Prevalence of antibiotic-resistant propionibacteria on the skin of acne patients: 10-year surveillance data and snapshot distribution study". The British Journal of Dermatology. 146 (5): 840–8. doi:10.1046/j.1365-2133.2002.04690.x. PMID 12000382. S2CID 5725343.
- Leyden JJ, Wortzman M, Baldwin EK (December 2008). "Antibiotic-resistant Propionibacterium acnes suppressed by a benzoyl peroxide cleanser 6%". Cutis. 82 (6): 417–21. PMID 19181031.
- "Q&A for Health Care Professionals: Health Care Antiseptics". U.S. Food and Drug Administration. December 19, 2017. Retrieved 17 August 2018.
- Emsley J (July 1, 2004). Vanity, Vitality, and Virility: The Chemistry Behind the Products You Love to Buy. Oxford University. p. 130. ISBN 978-0-19-280509-6. Retrieved 17 August 2018.
- Yamakoshi T, Makino T, Matsunaga K, Yoshihisa Y, Rehman MU, Seki T, et al. (July 2012). "Efficacy of chlorhexidine gluconate ointment (Oronine H(®)) for experimentally-induced comedones". Clinical, Cosmetic and Investigational Dermatology. 5: 79–83. doi:10.2147/CCID.S33361. PMC 3426266. PMID 22936850.
- Fu Y, Zu Y, Chen L, Efferth T, Liang H, Liu Z, Liu W (October 2007). "Investigation of antibacterial activity of rosemary essential oil against Propionibacterium acnes with atomic force microscopy". Planta Medica. 73 (12): 1275–80. doi:10.1055/s-2007-981614. PMID 17893831.
- Raman A, Weir U, Bloomfield SF (October 1995). "Antimicrobial effects of tea-tree oil and its major components on Staphylococcus aureus, Staph. epidermidis and Propionibacterium acnes". Letters in Applied Microbiology. 21 (4): 242–5. doi:10.1111/j.1472-765x.1995.tb01051.x. PMID 7576514. S2CID 5687026.
- Fu Y, Chen L, Zu Y, Liu Z, Liu X, Liu Y, et al. (January 2009). "The antibacterial activity of clove essential oil against Propionibacterium acnes and its mechanism of action". Archives of Dermatology. 145 (1): 86–8. doi:10.1001/archdermatol.2008.549. PMID 19153353.
- Lang G, Buchbauer G (January 2012). "A review on recent research results (2008–2010) on essential oils as antimicrobials and antifungals. A review". Flavour and Fragrance Journal. 27 (1): 13–39. doi:10.1002/ffj.2082.
- Baik JS, Kim SS, Lee JA, Oh TH, Kim JY, Lee NH, Hyun CG (January 2008). "Chemical composition and biological activities of essential oils extracted from Korean endemic citrus species". Journal of Microbiology and Biotechnology. 18 (1): 74–9. PMID 18239420.
- Albietz JM, Lenton LM (October 2006). "Effect of antibacterial honey on the ocular flora in tear deficiency and meibomian gland disease". Cornea. 25 (9): 1012–9. doi:10.1097/01.ico.0000225716.85382.7b. PMID 17133045. S2CID 12053077.
- Bayston R, Vera L, Mills A, Ashraf W, Stevenson O, Howdle SM (February 2010). "In vitro antimicrobial activity of silver-processed catheters for neurosurgery". The Journal of Antimicrobial Chemotherapy. 65 (2): 258–65. doi:10.1093/jac/dkp420. PMID 19942617.
- Libenson L, Hadley FP, Mcilroy AP, Wetzel VM, Mellon RR (1953). "Antibacterial effect of elemental sulfur". The Journal of Infectious Diseases. 93 (1): 28–35. doi:10.1093/infdis/93.1.28. PMID 13069766.
- McLean RJ, Hussain AA, Sayer M, Vincent PJ, Hughes DJ, Smith TJ (September 1993). "Antibacterial activity of multilayer silver-copper surface films on catheter material". Canadian Journal of Microbiology. 39 (9): 895–9. doi:10.1139/m93-134. PMID 8242490.
- Papageorgiou P, Katsambas A, Chu A (May 2000). "Phototherapy with blue (415 nm) and red (660 nm) light in the treatment of acne vulgaris". The British Journal of Dermatology. 142 (5): 973–8. doi:10.1046/j.1365-2133.2000.03481.x. PMID 10809858. S2CID 9237317.
- Togsverd-Bo K, Wiegell SR, Wulf HC, Haedersdal M (February 2009). "Short and limited effect of long-pulsed dye laser alone and in combination with photodynamic therapy for inflammatory rosacea". Journal of the European Academy of Dermatology and Venereology. 23 (2): 200–1. doi:10.1111/j.1468-3083.2008.02781.x. PMID 18452529. S2CID 30935383.
- Wan MT, Lin JY (May 2014). "Current evidence and applications of photodynamic therapy in dermatology". Clinical, Cosmetic and Investigational Dermatology. 7: 145–63. doi:10.2147/CCID.S35334. PMC 4038525. PMID 24899818.
- Campisano A, Ometto L, Compant S, Pancher M, Antonielli L, Yousaf S, et al. (May 2014). "Interkingdom transfer of the acne-causing agent, Propionibacterium acnes, from human to grapevine". Molecular Biology and Evolution. 31 (5): 1059–65. doi:10.1093/molbev/msu075. PMID 24554779.
- Media related to Propionibacterium acnes at Wikimedia Commons
- Propionibacterium+acnes at the US National Library of Medicine Medical Subject Headings (MeSH)
- Propionibacterium (Kenyon College)
- Type strain of Propionibacterium acnes at BacDive - the Bacterial Diversity Metadatabase