BSCI 424 — PATHOGENIC MICROBIOLOGY — Fall 2000

Propionibacterium Summary

 
  Anaerobic or aerotolerant nonmotile Gram-positive bacillus arranged in short chains or clumps (see WebLinked image; see WebLinked image; see WebLinked image)

  Normal flora of skin, conjunctiva, outer ear, oropharynx and female genital tract

   Catalase positive

  Major metabolic byproduct is propionic acid from fermentation of carbohydrates

  Produce array of enzymes that contribute to pathogenesis

  Lipases

  Proteases

  Neuraminidase

  Hyaluronidase

  Propionibacterium acnes:

  Acne in adolescents and young adults

  P. acnes colonize follicles of sebacious glands

  Stimulate host inflammatory response and rupture of sebacious follicles

1. Organisms produce a low molecular weight protein that is chemoattractive for leukocytes
2. Phagocytosis of bacteria leads to release of hydrolytic enzymes from phagocytic cells
3. Hydrolytic enzymes and bacterial enzymes (see above) lead to the inflammatory response and ultimately rupture of the follicle

  Treatment: difficult to rid organisms from the sebacious follicle niche

1. Topical cleansing agent (benzoyl peroxide)
2. Antibiotic (e.g., erythromycin, clindamycin)
   
   

 Opportunistic infections in patients with intravascular or prosthetic devices

   Propionibacterium can be grown on common laboratory medium but is a slow grower and often overgrown by contaminating flora

 

 

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