spirochetes Flashcards
1
Q
spirochete morphology and structure
A
- elongated, flexible, motile
- spirally wound flagella anchored at poles
- binary fission
- gram-negative
2
Q
three groups of spirochetes
A
- treponema
- borrelia
- leptospira
3
Q
diseases caused by treponema
A
- syphilis
- yaws
- pinta
4
Q
diseases caused by borrelia
A
- relapsing fever
- Lyme Disease
5
Q
diseases caused by leptospira
A
leptospirosis
6
Q
how can treponema pallidum be viewed?
A
- too small for gram stain
- darkfield microscopy
- immunofluorescence
- silver salts
- electron microscopy
7
Q
treponema pallidum storage and culture
A
- can not be grown in culture
- can be kept alive in rich media under anaerobic condition
- survive in blood 24 hours
- survive in tissue for several days
8
Q
treponema pallidum transmission
A
- direct contact of genitalia/mucous membranes
- not transmissible in late stages
- mother to fetus (congenital syphilis), still birth, abortion
- rare: transfusion, or contact
9
Q
treponema pallidum pathogenesis
A
- incubation 2-6 weeks but bacteria present and replicating
- primary lesion - 1-4 weeks after infection on genitalia
- secondary lesion - after dissemination, generalized skin rash 2-20 weeks post primary lesion
- tertiary lesion - late in disease many years after infection in CNS, rubbery, called “gumma”
10
Q
treponema pallidum diagnosis
A
- pathogenic signs
- history of exposure
- organisms in lesion
- positive tests
11
Q
treponema pallidum tests
A
- nonspecific (VDRL, flocculation)
- FTA-ABS
- micro hemagglutination test
- ELISA
- TPI
12
Q
syphilis false positives and negatives
A
- may read positive in presence of mono or malaria
- ## VDRL has more false results than FTA-ABS
13
Q
what test is specifically not used for treponema pallidum?
A
PCR - no specific primers at diagnostic level
14
Q
antibiotics for treponema pallidum
A
- very sensitive to penicillin
- tetracycline, erythromycin
15
Q
vaccine for treponema pallidum?
A
no vaccine