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• Spirochetes

  Gram negative unicellular organisms with coiled shape
• Spirochetes

  • Can be visualized only by darkfield or phase microscopy
  • Multiply by transverse fission
  • Motile with axial fibrils
• “Spiro” means “coiled,” and “chaete” means “hair”
• Filamentous flagella


  Axial filaments that run lengthwise between the cell membrane and outer membrane
• Spirochetes are bacteria with helically coiled cells
• Genera of spirochetes causing human disease

  • Treponema
  • Borrelia
  • Leptospira
• Diagnosis often relies upon the demonstration of a patient’s serologic response to the offending agent
• Clinical course of human disease caused by spirochetes

  1. Early local proliferation

  2. Spirochetemia with systemic dissemination

  3. Persistence at immune privileged sites
• Characteristics of the Genera Within the Order Spirochaetales

  • Number of axial fibrils
  • Number of insertion disks
  • Biochemical and Metabolic features

  
• Insertion disk


  A plate-like structure where fibrils are attached, found near the terminal end of the cell
• Treponema


  Genus name came from the Greek word meaning "turning thread"
• Treponema


  • Best observed with dark-field microscopy
  • Thin spiral organisms with three axial filaments and one insertion disk
  • Corkscrew motility

  
• Species of Treponema responsible for disease in humans

  • T. pallidum
  • T. carateum
• Subspecies of T. pallidum

  • T. pallidum subspecie pallidum
  • T. pallidum subspecie pertenue
  • T. pallidum subspecie endemicum
• Serologically & morphologically indistinguishable

  Species of Treponema
• Causative agents and diseases

  • T. pallidum subspecie pallidum - Venereal syphilis
  • T. pallidum subspecie pertenue - Yaws
  • T. pallidum subspecie endemicum - Endemic syphilis
  • T. cuniculi - Rabbit syphilis
  • T. carateum - Pinta
• Dark Field Microscopy

  Most definite & earliest means of diagnosis for Treponema
• Dark Field Microscopy procedure

  1. Cleanse lesion with sterile H2O

  2. Abrade gently

  3. Apply pressure & collect exudates
• DFM is not recommended for oral lesions
• DFM should be done 10 minutes after acquiring the sample
• T. pallidum subspecie pallidum is non-culturable in artificial medium
• T. pallidum subspecie pallidum causes syphilis
• Other names for syphilis

  • Lues venera
  • Italian disease
  • French disease
  • Great pox
  • Evil pox
• T. pallidum subspecie pallidum is a disease of blood vessels
• Stages of Syphilis

  • Primary
  • Secondary
  • Latent
  • Tertiary
• Primary Stage of Syphilis

  Develops 10-90 days after infection with a hard chancre
• Secondary Stage of Syphilis

  Develops 2 to 12 weeks after the appearance of the primary chancre
• Latent Stage of Syphilis


  Period in which the disease becomes subclinical but not dormant
• Tertiary Stage of Syphilis

  Tissue-destructive phase with lesions seen 10-25 years after the primary stage
• Lesions in Tertiary Stage of Syphilis

  • Gummas in CNS
  • Cardiovascular system
  • Eyes
• Gummata


  Soft, tumor-like balls of inflammation