Spirochetes

• Borrelia spp.


  • Helically coiled bacteria
  • Transmitted through arthropod vectors
• Arthropod vectors

  • Lice
  • Ticks
• Borrelia spp.


  Flexible twisted organisms resembling stretched spiral
• Borrelia recurrentis


  Agent of Louse-borne relapsing fever
• Vector of Borrelia recurrentis

  Human louse (Pediculus humanus)
• Borrelia hermsii/Borrelia parkeri


  Tick-borne relapsing fever
• Vector of Borrelia hermsii/Borrelia parkeri

  Ornithodoras ticks
• Borrelia burgdorferi


  Agent of Lyme Disease
• Vector of Borrelia burgdorferi

  Ixoda ticks and Deer ticks
• Stages of Lyme Disease

  1. Appearance of lesion; erythema chronicum migrans [bull's eye rashes]

  2. Dissemination through blood; bones, CNS, heart, and liver

  3. Neurological abnormalities, arthritis, and skin lesion (chronic stage)
• Kelly's medium


  Culture medium used for Borrelia
• Barbour Stoenner-Kelly's (BSK)


  Culture medium used for Borrelia
• ELISA


  Serological test for Borrelia
• Western blot


  Gold standard serological test for Borrelia
• DNA: WB


  Western Blot for DNA
• RNA: NB


  Northern Blot for RNA
• Treponema spp.


  Tightly twisted organism resembling cork screw
• Treponema pallidum subsp. pallidum

  Agent of syphilis (sexually transmitted infection)
• Other names for syphilis

  • Great pox
  • Evil pox
  • Italian Pox
  • Spanish Disease
• Transmission of syphilis

  1. Sexual contact

  2. Direct transmission

  3. Transplacental route (baby is affected; vertical transmission; congenital syphilis)
• Stages of syphilis

  • Primary syphilis: hard chancre (painless and firm)
  • Secondary syphilis: condylomata lata (wart-like lesions)
  • Latent syphilis: absence of clinical symptoms (+ serological tests)
  • Tertiary syphilis: gummas, neurosyphilis
• Laboratory diagnosis for Treponema

  • Direct Microscopic examination using Dark field microscope
  • Serological Tests
• Treatment for Treponema

  • Heavy Metals (Ex: Arsenic, Arsphenamine, Salvarsan)
  • Drug of choice: Penicillin
• Jarisch-Herxheimer reaction


  Large quantities of toxins are released as the bacterium dies during treatment process
• Treponema pallidum subsp. pertenue


  Agent of yaws (chronic nonvenereal disease of skin and bones)
• Transmission of yaws


  Direct contact of traumatized skin with infected lesion
• Treponema pallidum subsp. endemicum


  Agent of Bejel [Non-vereal syphilis and endemic syphilis] (lesion in oral cavity, oral mucosa, skin, bones and nasopharynx)
• Transmission of Bejel


  Mouth to mouth by utensils
• Treponema carateum


  Agent of pinta (ulcerative skin disease)
• Transmission of pinta


  Direct contact of traumatized skin with infected lesion
• Leptospira spp.


  Tightly twisted with one or both ends bent into a hook
• Leptospira biflexa


  Non-pathogenic, found in water and soil
• Leptospira interrogans


  Agent of leptospirosis (human and animals)
• Leptospirosis


  Zoonosis (Parasitic in vertebrates other than human)
• Animals that shed Leptospira in urine

  • Rodents
  • Cattle
  • Dogs
  • Cats
  • Raccoons
  • Bats
• Transmission of leptospirosis

  Direct contact with urine of animals
• Organs affected in leptospirosis

  • Kidney
  • Liver
  • Central nervous system
• Weil's disease


  Severe form of leptospirosis
• Principle leptospiral diseases

  • icterohemorrhagiae – Weil's Disease
  • canicola – Infectious Jaundice
  • autumnalis – Fo'rt Bragg or Pretibial Fever
  • grippotyphosa – Marsch Fever
  • hebdomadis – 7-day Fever
  • mitis/Pomona – Swine-herd's disease
• Specimen for culture

  • Blood (early infection)
  • Urine (2nd week)