Exam #6: STD II Flashcards
What causes syphilis?
Treponema pallidum (spirochete)
List the characteristics of Treponema pallidum.
Thin Gram (-) spirochete
Motile
Microaerophilic
*Does NOT grow in cell free culture, very difficult to grow
Describe the structure of Treponema pallidum.
Gram (-) cytology, but DOES NOT gram stain
Flexible
Peptidoglycan surrounds axial fibrils
Wound endoflagella
Cell wall & axial fibrils are covered by an outer bilayered membrane
How is syphilis diagnosed?
Dark-field micrscopy
Direct fluorescence
Antibody/ serology is most common
How is primary syphilis characterized?
1+ skin lesions (chancres)
Hard
Indurated
Painless
What causes the lesion & how long does it last?
Inflammation causes the lesion
Onset is 10-90 days post initial infection
Lasts 2 weeks–>2 months
How is secondary syphilis charactertized?
Disseminated disease
- Flu-like syndrome
- Prominent skin lesions on plams & soles
- “Condylomata lata”
What are Condylomata lata?
Raised lesions in skin folds associated with secondary syphilis
How is latent syphilis characterized?
Asymptomatic period
- Lasts years to decades
- Can relapse into secondary syphilis
- Transmission possible esp. from mother to child
How is tertiary syphilis characterized?
Diffuse, chronic inflammation
Can cause devastating destruction of virtually any organ/ tissue
Gumma
What is a gumma?
Granulomatous lesions that may be found in bone, skin, & other tissues i.e. brain & heart associated with tertiary syphilis
What were the outcomes of the Tuskegee syphilis experiment?
IRB
Informed consent
What is congenital syphilis?
Mother-to-child transmitted syphilis
- Often terminates pregnancy, but when it doesn’t:
- Chronic rhinitis–>saddle nose
- “Condylomata lata”
- Teeth & bone malformation, blindness, deafness, & cardiovascular syphilis
What is Hutchinson’s triad?
Small
Malformed
Widely spaced teeth
What are the serologic tests for syphilis? What are their targets?
Treponemal test= detects antibody specific to T. pallidum
Nontreponemal= measures antibody directed against cardiolipin
When will a person start to exhibit a positive response to serologic tests through the infectious process?
Four weeks
How is syphilis treated?
PCN
What is NGU?
Non-gonococcal urethritis
i.e. when Gonorrhea & Chlamydia don’t cause urethritis
What are the most common causes of NGU?
Mcoyplasma genitalium & Ureaplasma urealyticum
List the characteristics of Mcoyplasma genitalium & Ureaplasma urealyticum.
DO NOT have a cell wall
Not stained
Pleomorphic
Plasma membrane contains sterols
What is the characteristics morphology of Mycoplasma genitalium?
“Fried-egg” appearance
What is Mycoplasma genitalium resistant to?
Doxycycline
What is Mycoplasma genitalium susceptible to?
Azithromycin
How is Ureaplasma treated?
Doxycycline
What is Chancroid caused by?
Haemophilus ducreyi
List the characteristics of Haemophilus ducreyi.
Gram (-) pleomorphic coccobacillus
What is required for the growth of Haemophilus ducreyi ?
X & V factor
What are the symptoms of Chancroid?
Genital ulcers
- Painful chancre (vs. painless)
- Soft (vs. hard)
- Multiple vs. 1 lesion
- Lymphadenopathy
“You do cry with ducreyi”
*Note that diagnosis is challenging because labs are NOT set up to detect b/c of low prevalence
How is Haemophilus ducreyi i.e. Chancroid treated?
Macrolides
What causes Donovanosis or Granuloma inguinale?
Klebsiella granulomatis
What are the symptoms of Donovanosis?
- Primary lesion is ulcerated
- Lesions are painless & bleed easily
- Significant genital damage can occur
- Hard
How is Donovanosis diagnosed?
Donovan bodies
Describe the medical decision making process when a patient presents with a genital ulcer.
1) Syphilis vs. Genital Herpes?
2) IF NOT, then chancroid or donovanosis
M. genitalium vs. Ureaplasma & doxycycline?
M. genitalium is resistant!
Ureaplasma is susceptible
