Bacteria

Spirochete

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Spirochete, Spirochaetaceae, Borrelia

  • See Also
  1. Treponema
  2. Syphilis
  3. Leptospira
  4. Gram Negative Bacteria
  5. Lyme Disease
  • Pathophysiology
  1. Spirochetes
    1. Tiny (sub-microscopic) Gram Negative, corkscrew (helical) shaped Bacteria
  2. Replication
    1. Spirochetes replicate via transverse fission (asexual reproduction)
    2. Cell divides into two equal halves
  3. Cell Wall
    1. Phospholipid outer membrane
      1. Exposes few Proteins, reducing immune cell detection
      2. Unique layer to Spirochetes
    2. Lipoprotein membrane containing lipopolysaccharides (LPS)
    3. Peptidoglycan Layer (thin)
    4. Cytoplasmic membrane (thin, inner most layer)
  4. Motility
    1. Axial filaments (thin endoflagella)
    2. Axial filaments are attached to the ends of the Spirochete cell wall
    3. Filaments do not protrude through the outer membrane (unique to Spirochetes)
      1. Filaments instead course along the Spirochete cell body (periplasmic flagella)
    4. Axial filaments rotate
      1. Spin the entire Spirochete, pushing it forward
  1. See Treponema
  2. Background
    1. Treponema are highly fragile outside the human host
      1. Organisms are easily killed with heating, drying or soap and water
    2. Treponema induce disease via host immune mediated inflammation
      1. Treponema species lack their own toxins
  3. Treponema pallidum: Sexually Transmitted Infection
    1. Treponema pallidum (Syphilis)
  4. Treponema pallidum Subspecies: Non-venereal Disease (primarily skin lesions)
    1. These organisms were previously classified as specific Treponema species
      1. Following DNA analysis, they were all reclassified as subspecies of Treponema pallidum
    2. Subspecies
      1. Bejel or Endemic syphilis (Treponema Pallidum Subspecies Endemicum)
      2. Yaws (Treponema Pallidum Subspecies Carateum)
      3. Pinta (Trpeonema palldium subspecies pertenue)
  • Types
  • Borrelia
  1. Background
    1. Unlike Treponema, Borrelia are large enough to be seen under light microscopy (Giemsa or Wright Stain)
  2. Borrelia species that cause Relapsing Fever (18 species total worldwide)
    1. Louse Borne: Borrelia Recurrentis
    2. Tick Borne: Borrelia Hermsii, Borrelia Miyamotoi, Borrelia Turicate (primary causes in North America)
  3. Borrelia Burgdorferi (Lyme Disease)
    1. Ixodes Tick Bite transmits Borrelia Burgdorferi
    2. Natural reservoir in white tailed deer and rodents (e.g. white-footed mouse)
  1. See Leptospira
  2. Leptospira interrogans: Weil's Disease, Leptospirosis
  • Labs
  1. Specific organism Serology
  2. Microscopy
    1. Spirochetes are too small to be seen on standard light microscopy without specific techniques
    2. May be identified on dark microscopy, silver stains or with immunofluorescence
  • References
  1. Gladwin, Trattler and Mahan (2014) Clinical Microbiology, Medmaster, Fl, p. 128
  2. Paster (2000) J Mol Microbiol Biotechnol 2(4):341-4 +PMID: 11075904 [PubMed]