Exam 4: Topic 22

Question 1

Describe the following characteristics of Treponema pallidum (causative agent ofsyphilis): gram stain, shape, dominant virulence factor

Answer 1

• spirochete Treponema pallidum.
• gram negative, but does not show up on gram stain.
• Spirochetes do not stain on gram stain.
• Darkfield microscopy or negative stain to identify by microscopy.
• virulence factors: a tip that digs into our cell membranes, which allows for colonization.
Can also penetrate epithelial lining and travel to any other tissue.

Question 2

Describe the three stages of syphilis infections (and two latency periods). Atwhich stage is syphilis the most contagious

Answer 2

1. Sore: 2-3 weeks after exposure
   LATENCY:
   a. sore resolves, spirochetes disseminate (~few weeks)
   
   2. Body rash:
      a. 1-2 months after initial infection
      b. fever, fatigue, sores (painful), in mucous membranes.
      c. Copper colored rash permeating thick skin
      LATENCY:
      i. May be for life
   3. affects internal organs:
      a. 3-15 years after initial infection
      spirochetes enter CSF

Question 3

Provide two reasons that syphilis is difficult to diagnose. (Hint: one has to do withthe bacteria itself, and the other has to do with the symptoms)

Answer 3

• because gram stains are blank; signs are not definitive enough. If syphilis is suspected, a negative stain or darkfield microscopy can be used.

Question 4

Briefly discuss the treatment and epidemiology of syphilis

Answer 4

Three stages; lifelong without antibiotics. (can be treated with penicillin in early stages).

Question 5

What are some consequences to a fetus if the mother is infected withTreponema?

Answer 5

fetus can develop “congenital syphilis,” which can lead to serious consequences like stillbirth, premature birth, low birth weight, deformities

Question 6

Describe the characteristics of Neisseria gonorrheae (causative agent ofgonorrhea).

Answer 6

• Neisseria gonorrhaeav G- diplococcus v Intracellular Puss discharge

Question 7

Describe the virulence factors of N. gonorrheae and briefly describe the processof disease in the urogenital tract of males and females.

Answer 7

• Male urogenital tract can introduce scarring and blocked, which causes infertility
• Female urogenital tract (Fallopian tube becomes engorged and loses structure).

Question 8

Describe the characteristics of Chlamydia trachomatis

Answer 8

Chlamydia trachomatis
v Penicillin/cephalosporins do not clear a chlamydia infection
v Intracellular pathogen
v Symptoms: milder form of gonorrhea
v Females more likely to be asymptomatic

Question 9

Which of the three sexually transmitted bacteria should be susceptible topenicillin? Which pathogen cannot be treated with penicillin?

Answer 9

• Penicillin does not clear chlamydia infection.
Syphilis and gonorrhea can be treated in early stages