Spirochetes Flashcards
What are some characteristics of the spirochetes?
Helical morphology
Flexible peptidoglycan cell wall
One of more axial fibrils which wind around the cell wall of the organism
What can Treponema and Leptospira be visualized by?
Dark Field Microscopy
What can Borrelia be visualized by?
Stained preparations
What causes syphilis?
Treponema pallidum
How is syphilis transmitted?
Sexual Contact
Via the placenta congenitally
What is the pathogenesis of syphilis?
T. pallidum will pass through mucosa/skin and multiply locally before disseminating causing symptoms to appear after they reach a critical level
What are the stages of syphilis?
Primary -Latency Secondary -Latency Tertiary
Primary Syphilis
Primary syphilis consists of an ulcerative lesion at the site of inoculation with regional adenopathy called a chancre and it is painless due to the destruction of the nerves
Secondary Syphilis
Secondary syphilis - Systemic (flu-like) illness which may develop 2-10 weeks after primary lesion heals and moist area coalesce into condylomata lata
Latent Syphilis
Defined as the presence of a positive treponemal serologic test in the absence of clinical manifestations
Tertiary (Late) Syphilis
A. Neurosyphilis
i. Asymptomatic - evidence of infection in CSF without symptoms or signs
ii. Meningovascular - chronic meningitis which can affect major arteries to brain
iii. Paresis - cortical degeneration of the brain with mental changes
iv. Tabes dorsalis - Demyelination of posterior columns and dorsal roots resulting in loss of pain, temperature and position sense in limbs with or without ataxia
B. Cardiovascular involves the proximal aorta and its branches causing
aneurysms
C. Late benign “gummatous” –granulomatous lesions in skin, mucocutaneous areas, bones
What are the signs of congenital syphilis?
Normal at birth - multiorgan involvement becomes apparent later. Rhinitis, rash, bony and cartilaginous involvement (teeth), liver, spleen, lymph nodes and CNS
How is T. pallidum visualized?
Dark Field Microscopy
Nontreponemal Reaginic Tests
Syphilis reaginic antibodies are IgG & IgM directed against cardiolipin, a lecithin-cholesterol mixture present on mitochondrial membrane - extract of beef heart
NOT Ab against T. pallidum
VDRL - Venereal Diseases Research Laboratories
Only test done on cerebrospinal fluid
RPR - Rapid Plasma Reagin
Test done on the serum
Specific Treponemal Tests
Measure specific antibody against T. pallidum