Spirochetes

• How many genera of spirochetes cause human infection?


  Three
• What is the genus of spirochetes that causes syphilis?

  Treponema
• Which spirochete causes Lyme disease?

  Borrelia
• What disease is caused by Leptospira?


  Leptospirosis
• What are the diseases caused by the three genera of spirochetes?


  • Treponema: Syphilis and nonvenereal treponematoses
  • Borrelia: Lyme disease and relapsing fever
  • Leptospira: Leptospirosis
• What are the characteristics of spirochetes of medical importance?


  • Species: T. pallidum, B. burgdorferi, B. recurrentis, L. interrogans
  • Disease: Syphilis, Lyme disease, relapsing fever, leptospirosis
  • Mode of Transmission: Various (e.g., sexual contact, tick bite, contaminated food)
  • Diagnosis: Microscopy, serologic tests
  • Morphology: Thin, tight spirals or large, loosely coiled
  • Growth in Bacteriologic Media: Some can grow, others cannot
  • Treatment: Penicillin G, Tetracycline, Amoxicillin
• What is the mode of transmission for Treponema pallidum?


  Intimate (sexual) contact; across the placenta
• How is Treponema pallidum diagnosed?


  Microscopy and serologic tests
• What is the morphology of Treponema pallidum?


  Thin, tight spirals
• What is the treatment for Treponema pallidum infection?


  Penicillin G
• What disease does Borrelia burgdorferi cause?


  Lyme disease
• How is Lyme disease diagnosed?


  Clinical observation and microscopy
• What is the morphology of Borrelia burgdorferi?


  Large, loosely coiled
• What is the treatment for acute Lyme disease?

  Tetracycline or amoxicillin
• What disease is caused by Borrelia recurrentis?


  Relapsing fever
• How is relapsing fever transmitted?


  By louse bite
• What is the morphology of Borrelia recurrentis?


  Large, loosely coiled
• What is the treatment for relapsing fever?

  Tetracycline
• What disease does Leptospira cause?


  Leptospirosis
• How is Leptospira transmitted?


  Through food or drink contaminated by urine of infected animals
• What is the morphology of Leptospira interrogans?


  Thin, tight spirals
• What is the treatment for leptospirosis?


  Penicillin G
• What are the characteristics of spirochetes?


  Thin-walled, flexible, spiral rods
• How do spirochetes move?


  Through the undulation of axial filaments that lie under the outer sheath
• What microscopy techniques are used to see spirochetes?


  Darkfield microscopy, silver impregnation, immunofluorescence
• What is the significance of Borreliae in microscopy?


  They are larger and can be seen with Giemsa and other blood stains
• What is the primary disease caused by Treponema pallidum?


  Syphilis
• What are the important properties of Treponema pallidum?


  Has not been grown on bacteriologic media or in cell culture, can induce specific antibodies, can be detected in the laboratory
• How is Treponema pallidum transmitted?


  From spirochete-containing lesions of skin or mucous membrane of an infected person
• Where does Treponema pallidum occur?


  Worldwide
• What is the pathogenesis of Treponema pallidum?


  Infects the small blood vessels and causes endarteritis
• What occurs during primary syphilis?


  Spirochetes multiply at the site of inoculation, forming a local nontender ulcer called a chancre
• What are the clinical findings of secondary syphilis?


  Maculopapular rash, moist papules, patchy alopecia, constitutional symptoms
• What are the characteristics of lesions in secondary syphilis?


  Moist lesions on the genitals rich in spirochetes and highly infectious
• What is the latent stage of syphilis?


  No lesions appear, but the infection continues, divided into early and late stages
• What happens during the early period of latent syphilis?


  Can last for a year or two after the secondary stage, with symptoms of secondary syphilis potentially reappearing
• What happens during the late period of latent syphilis?


  Can last for many years with no symptoms, and patients are not infectious
• What are the characteristics of tertiary syphilis?


  May show granulomas (gummas), CNS involvement, and cardiovascular lesions
• How is congenital syphilis transmitted?


  Transmitted across the placenta, typically after the 3rd month of pregnancy
• What are the potential outcomes of untreated congenital syphilis?


  Stillbirth and multiple fetal abnormalities