Acne Vulgaris

Question 1

Proprionibacterium acnes

Answer 1

Acne Vulgaris
• Gr+ pleomorphic rod, short chains or clumps
• normal microbiota *hair follicles, *sebaceous glands, oral cavity, large intestine, conjunctiva
• *“glycocalyx” : can mean either capsule or slime layer
• nonsporeforming, nonmotile
• *microaerophile to anaerobe 
• ferments carbs→ major product *propionic acid
• catalase +
• *slow grower
 • *common contaminant in blood
• *opportunist
   o *prosthetic joint infection, esp. shoulder
VIRULENCE
• forms *biofilms 
• lipases
• proteases
• neuraminidase
• hyaluronidase
• “glycocalyx”→biofilms
• stimulates inflammation!
DISEASE
- ACNE VULGARIS
- severe cystic acne= *acne conglobata)
4 primary factors:  
– Propionibacterium acnes colonization of pilosebaceous follicle
– inflammation
– excess sebum production
– follicular hyperkeratinization
Noninflammatory lesions
– open comedo (blackhead)
– closed comedo (whitehead) 
Inflammatory lesions
– *papules 
- *pustules (pimples)
– *nodules
– *cysts