Treponema Flashcards
Classification
Family: spirochaetaceae
Genus: treponema
Species: pallidum
Morphology
Gram-negative
Actively motile
Slender spirals
The spirals are so thin that they are only readily seen with IF stain or dark-field illumination
Outer membrane protein differs from other gram-negative bacteria:
- lack Lipopolysaccharide
- has less cytoplasm
Growth characteristics
- slow growth rate (30 - 33 hrs generation time)
- survive better in microaerophillic conditions than anaerobic
- so far has not been cultured on artificial media
Antigenic structure
endoplasmic flagellum in periplasmic space
Outer membrane protein
Virulence factors
Outer membrane protein (promote adherence to host)
Fibronectin (prevent phagocytosis by macrophages)
Hyaluronidase
Motility
Diseases:
I) acquired syphillis
- Primary- local nontender ulcer (chancre)
- Secondary- maculopapar rash or organ involvement
- Tertiary- skin and bones, CNS involvement (e.g tabes) or cardiovascular lesions (e.g. aneurysm)
II) congenital syphilis
Passes through the placenta
- causes mental retardation and blindness
Microbiological diagnosis
Specimen:
Materials from chancre or secondary lesions
Blood for serologic tests
- after 2nd week
DME:
- dark field microscopy: long slender, tightly coiled spirals, moving slowly
- silver impregnantion
- IFA
Culture: none
Specific tests:
Serologic tests
Serologic tests
I) Non specific
Non-treponemal assays
Principle: T.pallidum infection leads to production of reagin
Reagin- antibodies to substances related from cell damaged by T. Pallidum
Reagin reacts with cardiolipin
Cardiolipin- a phospholipid component of certain eukaryotic and prokaryotic membranes
Example of non-trepenem test:
Rapid plasma reagin (RPR)
Venereal disease research laboratory (VDRL)
II) specific tests:
treponema antibody tests
Treatment and prevention
Penicillin
- no immunization
