20 Flashcards
List the three causes of ulcerative STDs
- Syphilis
- Chancroid
- Genital herpes
List the three causes of Nonulcerative STDs
- Gonorrhea
- Trichomoniasis
- Chlamydia
Where are the genus treponema normally found
- normal flora on mucosal surfaces
what pathogen causes syphilis
Treponemia pallidum
Treponemia pallidum
- gram status
- shape
- motility
- gram negative
- spirochete
- slow rotational motility
what does Treponemia pallidum require to grow
- exclusively a human pathogen
- obligate internal parasite
Treponemia pallidum will grow in a primary cell culture. what animal model is used
rabbits
virulence factors of Treponemia pallidum
- hyaluronidase -> perivascular infiltration
- Fibronectin coat: antiphagocytic
what causes lesions from Treponemia pallidum infection
the result of the inflammatory process
how is Treponemia pallidum transmitted
- direct sexual contact with person who has active 1º or 2º lesion
- lesion near mouth
- needle sharing
- transplacental transmission
what is the principle lesion of primary syphilis? what does it look like
the syphilis chancre
- begins as papule
- superficial erosion
- formation of hemorrhagic crust
- base is smooth and border is raised
what is the typical dormancy period between primary and secondary syphilis
2-10 weeks
what signs are characteristic of secondary syphilus
- superficial lesions of high infectivity -> maculopapular rash
- mucosal warty lesions (condylomata lata)
- immune complexes form in arteriolar walls
What is latent syphilis? What two categories can it be broken into?
- absence of clinical signs and symptoms
- early latency: within 1 yr of infection
- late latency: > 1 yr after infection
- immunity to relapse and reinfection
When does tertiary syphilis manifest
5-20 yrs after infection
what signs are characteristic of tertiary syphilis
- neurosyphilis
- cardiovascular syphilis
- granulomata
- typically seen in skin, bones, and joints
what signals poor prognosis in congenital syphilis
- earlier onset of symptoms after birth signals poor prognosis
- most infants are born apparently healthy and develop signs and symptoms at 3 weeks of age
what signs are characteristic of congenital syphilis
- maculopapular cutaneous lesions
- nasal obstruction with mucoid discharge
- osteitis of nasal bones
- hutchinson’s triad
what is Hutchinson’s triad
- notched incisors
- interstitial keratitis
- 8th nerve deafness
how is syphilis diagnosed
- presence of chancre, and/or genital lesion
- darkfield microscopy
- most cases diagnosed serologically
- nontreponemal tests: VDRL, RPR: nonspecific, screening
- treponemal tests: specific antibody test
tx of syphilis
pencillin
what pathogen causes gonorrhea
Neisseria gonorrhoeae
Neisseria gonorrhoeae
- gram status
- shape
- growth requirementsdfffxxf
- gram negative
- diplococcus with kidney bean shaped cell
- fastidious growth requirements
virulence factors of Neisseria gonorrhoeae
- antigenic variation of pili
- nonpiliated phase variants
- IgA proteases
- Plasmid-and chromosome- mediated resistance to PCN, tetracyclines, spectinomycin, and fluoroquinolones
highest rate of gonorrhea is in what patient population
adolescents
major reservoir of gonorrhea
asymptomatic patient
transmission of gonorrhea
- genital
- oral-genital
- rectal intercourse
how does N. gonorrhoeae lead to injury of cells
released Lipooligosaccharide and peptidoglycan
entry and exit of N. gonorrhoeae is via
- mucosal surfaces
- eyes
- mouth
- urethra
- vagina
- rectum
where does N. gonorrhoeae tend to colonize in males and females
- females: endocervix and urethra -> cevicitis
- males: anterior urethra -> urethritis -> mucopurulent discharge
List the complications of gonorrhea
- various local effects
- acute salpingitis or pelvic inflammatory disease
- disseminated gonococcal infection
features of disseminated gonococcal infection
- fever rash
- endocarditis, meningitis
- **purulent arthritis
how is gonorrhea diagnosed
- culture
- nucleic acid amplification -> PCR *gold standar
tx of gonorrhea
3rd gen cephalosporin
