C. acnes's passport

CLASSIFICATION 

Name : Cutibacterium acnes (formerly Propionibacterium acnes)

Type : Cutibacterium

Family : Propionibacteriaceae

Habitat : Human skin, sebaceous glands

Main phylotype : 

• C. acnes subsp. acnes (Phylotype I)
• C. acnes subsp. defendens (Phylotype II)
• C. acnes subsp. elongatum (Phylotype III)

FEATURES

Morphology : Gram-positive bacterium

Metabolism : Aerotolerant anaerobic

Growth : Very slow (5 to 7 days)

Envelope & Cell Wall : Lipid-rich cell wall

Distinctive feature : Pleomorphism (Variable shapes)

KEY VIRULENCE FACTORS

Antibiotic resistance :  biofilm formation 

Inflammation & Development of pimples : 

• Lipases (GehA) that produce irritating free fatty iiiacids
• cAMP factors capable of activating the host’s iiiiinflammatory defenses
• Porphyrins that, when exposed to light (UV rays), iiirelease toxic and irritating compounds

PATHOGENESIS

Dermatosis : 

• Acne Vulgaris: Loss of phylotype diversity in favor of the virulent IA1 type ¹  

Opportunistic infections : 

• Infections of surgical instruments ²

• Association with other conditions (SAPHO* syndrome) ²

  *SAPHO = synovitis-acne-pustulosis-hyperostosis-osteitis

1. Cavallo, I. et al. Skin dysbiosis and Cutibacterium acnes biofilm in inflammatory acne lesions of adolescents. Sci. Rep. 12, 21104 (2022).

2. Mayslich, C., Grange, P. A. & Dupin, N. Cutibacterium acnes as an Opportunistic Pathogen: An Update of Its Virulence-Associated Factors. Microorganisms 9, 303 (2021).