S. Treponema pallidum

• What type of pathogen is S. Treponema?


  • pathogen of humans only
• What does S. Treponema cause?


  • syphilis
• What type of microscope is used to visualize S. Treponema?


  • Phase contrast or dark field microscope
  • difficult to visualize under regular light microscope due to its flattened helical cells
  • special stains or dyes also used
• What does S. Treponema produce?


  • hyaluronidase (break down connective tissue) and glycocalyx
  • Helps in infiltrating interstitial spaces and protects it from phagocytosis
• How can the bacteria be destroyed? (easy to kill)


  • exposure to heat
  • disinfectants
  • soap
  • drying
  • pH change
• What type of media can S. Treponema be grown in?


  • Grow in rabbits, monkeys, and rabbit epithelial cells
  • Unable to culture in cell-free media
• How is S. Treponema transmitted?


  • solely via sexual contact
  • cannot spread through fomite
• Who is S. Treponema endemic among?


  • sex workers
  • homosexuals
  • users of illegal drugs
• What can occur when infection spreads from infected mother to fetus?

  • Congenital syphilis
• What can result from Congenital syphilis?

  • fetal death
  • mental retardation
  • malformation
• Where does the disease occur?

  • throughout the US, particularly, the Southeast
• What are the four stages of untreated syphilis?


  • Primary
  • secondary
  • latent
  • tertiary
• What is primary syphilis?


  • Starts with painless, reddened lesions called chancre at the site of infection 10-21 days after exposure
  • Chancres typically form around external genitalia, but can also form in mouth, anus, fingers
• What is secondary syphilis?


  • Starts with the invasion of bacteria in the bloodstream
  • Sore throat, fever, myalgia, lymphadenopathy, and rashed that include palms, and soles of the feet
• What is the latent phase of syphilis?


  • clinically inactive phase
  • Commences after several weeks; may last up to 30 years
• What is tertiary syphilis?


  • Syphilitic lesions called gummas- rubbery, painfully swollen lesions due to inflammation and hyperimmune responses, and cause dementia, blindness
• How can S. Treponema be diagnosed?


  • Antibody tests against bacteria antigens of T. pallidum
  • Spirochetes can be observed in fresh discharge from lesions, but only when observed immediately
  • Tertiary syphilis is difficult to diagnose
• What is the treatment for S. Treponema?


  • Penicillin
  • ineffective against tertiary syphilis
• How can S. Treponema be prevented?


  • Abstinence
  • Safe sex