Spirochetes 1

• What type of bacteria are spirochetes?

  Gram negative, long, slender, helically tightly coiled bacteria
• What types of environments can spirochetes thrive in?

  Spirochetes can be aerobic, microaerophilic, or anaerobic
• How do spirochetes exhibit motility?

  Spirochetes exhibit corkscrew motility
• What is the function of the axial filament in spirochetes?

  The axial filament acts like flagella and enables movement
• What are the best-known diseases caused by spirochetes?

  The best-known diseases are syphilis and Lyme's disease
• What are the characteristics of Treponema pallidum, the causative agent of syphilis?

  • No natural reservoir in the environment
  • Requires a living host
  • Cannot be cultured from clinical specimens
• How is Treponema pallidum transmitted?

  It is primarily transmitted through sexual contact with open lesions
• What happens to Treponema pallidum when exposed to heat, cold, and drying?

  The organism is very fragile and is destroyed rapidly
• Can Treponema pallidum be transmitted to a fetus?


  Yes, it can be transmitted to a fetus
• What are the stages of syphilis disease?

  The stages are primary, secondary, latent, tertiary, and congenital syphilis
• What occurs during primary syphilis?

  • Organism enters through skin or mucosal tissue
  • Carried by blood throughout the body
  • Organisms multiply at the site of entry
• What is a chancre in primary syphilis?

  A chancre is a primary lesion that forms at the entrance site
• What is the incubation period for a chancre?

  The incubation period is variable, ranging from 10 days to several months
• How does a chancre appear and progress?

  A chancre begins as a small nodule and enlarges into a painless ulcer
• Where is a chancre most frequently seen?

  It is most frequently seen on the external genitalia
• How does a chancre heal?

  The lesion heals spontaneously after 1-5 weeks
• How can spirochetes be detected in a chancre?

  By examining a swab of the chancre under a dark-field microscope
• What percentage of patients become serologically positive after one week of chancre appearance?


  Thirty percent become serologically positive one week after appearance
• What percentage of patients become serologically positive after three weeks of chancre appearance?

  Ninety percent become serologically positive after three weeks
• What are the symptoms of secondary syphilis?

  • Occurs 6-8 weeks after initial chancre
  • Systemic infection, patient highly infectious
  • Pale red rash on palms, soles, or body
  • Flu-like illness, headache
  • Generalized lymphadenopathy
  • Sores secrete infectious fluids
• How long does secondary syphilis last?

  This stage lasts 2-6 weeks
• What characterizes latent syphilis?

  • No obvious symptoms
  • Lasts for 3-30 years
  • Decreased infectious ability
  • Organisms dormant in liver or spleen
  • Lifetime latency in 70% of cases
  • Re-awakening in 30% of cases
• What are the manifestations of tertiary syphilis?

  • Gummatous syphilis
  • Cardiovascular syphilis
  • Neurosyphilis
• What is congenital syphilis?

  • Transmitted from mother to fetus
  • Affects fetus during second or third trimester
  • Can result in syphilitic stillbirth
• What percentage of congenital syphilis cases result in stillbirth?

  Forty percent result in syphilitic stillbirth
• What are the effects of congenital syphilis on the fetus?

  • Bone deformities
  • Blindness
  • Deafness
  • Deformed faces
  • Dental deformities
  • Skin rashes
  • Neonatal death
• What are the diagnostic methods for syphilis?

  • Darkfield microscopy and fluorescence microscopy
  • RPR (rapid plasma reagin)
  • TPPA (T. pallidum particle agglutination assay)
  • TPHA (T. pallidum hemagglutination assay)
  • Micro-hemoagglutination assays for antibodies to Treponema pallidum
• What causes Yaws and how is it characterized?

  • Caused by Treponema pallidum pertenue
  • Tropical infection of skin, bones, and joints
  • Begins with a round, hard swelling of the skin
• How is Yaws transmitted?

  Yaws is spread by direct contact with the fluid from a lesion of an infected person
• What causes Pinta and how is it characterized?

  • Caused by Treponema pallidum carateum
  • The least severe of treponemal infections
  • Limited to the skin
  • Transmitted by skin-to-skin contact
• What is the incubation period for Pinta?

  The incubation period is two to three weeks
• What does Pinta produce after its incubation period?

  Pinta produces a raised papule that enlarges and becomes hyperkeratotic