25b Spirochetes Flashcards
What is the gram status of spirochetes?
Gram -
What is the shape and motility of Spirochetes?
Elongated, Motile, Spiral Shaped
Posses flagellum
What are the flagellum of Spirochetes like?
Axial filament or Internal flagellum (inside the periplasm)
Spirally wound around the cell and anchored through hook-like bases at the two poles of the cells
How do spirochetes multiply?
Binary fission
What are the three major groups of Spirochetes?
Treponema
Borrelia
Leptospira
What illnesses are associated with…
Treponema
Borrelia
Leptospira
T: causes syphilis, yaws, pinta, as well as normal flora in mouth, intestine, and genitalia
B: Lyme disease
L: lepotspirosis
What are the difficulties in staining Treponema pallidum?
Gram - anaerobe
But too thin for a microscope to see
Can be made visible through special techniques (listed next)
What special techniqes can make staining for Treponema pallidum possible?
“Darkfield” microscopy (stain slide, not bacteria. Bacteria glow)
Immunofluorescence
Deposition of silver salts on bacterial surface
Electron microscopy
Describe the difficulties with creating live cultures of Treponema pallidum.
What is the benefit of this quality with regard to blood donation?
Cannot be grown in culture
Can be kept motile for several days in anaerobic albumin serum
If blood stores are maintained for more than a week, all Treponema die
Can be stored at -80 degrees Celsius
Injected and cultured in Rabbit testicles.
How are Treponema killed?
Killed easily by heat, drying, soap, and water.
How can Treponema be perpetuated for study?
Can be stored at -80 degrees Celsius
Injected and cultured in Rabbit testicles.
Say what?
What are the modes of transmission of Treponema pallidum?
Transmisible within 4 years of initial infection
Transmitted via genitalia and mucous membranes
Mother to fetus
Blood transfusion of very fresh blood (< 1 week)
Very rarely to healthcare providers with cuts and needles
What is the pathogenic steps of illness with Treponema pallidum?
Note: Don’t know the time periods. They vary too much.
Incubation Primary Lesion (Chancre) Secondary Lesions (desseminated) Tertiary Lesions (nervous system and heart)
What is the incubation period for Treponema pallidum?
What are symptoms?
2-6 weeks
Assymptomatic
Bacterial replication at site of entry and elsewhere
When and where does Primary Lesion aka Chancre sore develop from Treponema?
How does the Chancre sore heal?
1-4 weeks after infection
Genitalia and focal lymphadenopathy
Heals spontaneously in 1-5 weeks after appearance (so some people don’t get treated. Bad idea.)
What’s the difference between chancre and chancroid?
syphilus - CHANCRE
H. ducreyi - CHANCROID
See slide 15.
When and where do Secondary Lesions from Treponema develop?
Skin rash or mucosal lesions (these are infectious)
Secondary lesions are now on upper body, flanks, face, palms, soles (primary was on the mouth or genitalia)
2-20 weeks after primary lesion appears
What are accompanying symptoms to the secondary lesions from Treponema?
Arthritis
Renal dysfunction
Mucosal lesions are highly infectious
When and where do tertiary lesions from Treponema develop?
What do the lesions look like?
What is the damage do to?
Many years after initial infection. Devastating illness at this stage.
CNS and Aortic Valve
Have “rubbery” consistency and is called a “gumma”
Type 4 Hypersensitivity
Affects personality and aggression.
These occur years later.
What is Dx of Treponema pallidum?
Hx of exposure
Demonstrate organisms in open lesion via darkfield examination of exudate
Serology (positive in later primary stage) via Wassermann Antibody test or modern “specific and non-specific” tests (discussed next)
What is Wassermann Antibody test?
Wassermann antibody reacts with specific syphilis lipid: diphosphatidylglycerol aka cardiolipin to which is added lecithin and cholesterol
Complement fixed in reaction and degree of fixation is measured.
What is Wassermann Antibody Test (wiki answer)?
A sample of blood or cerebrospinal fluid is taken and introduced to the antigen - cardiolipin extracted from bovine muscle or heart. Syphilis non-specific antibodies (reagin, see RPR) react with the lipid - the Wassermann reaction of antiphospholipid antibodies (APAs). The intensity of the reaction (1, 2, 3, or 4) indicates the severity of the condition.
To execute the test we need to prepare two different test tubes; in the first tube:
1) we put the serum of the patient, and we heat it to 56°C for 20 minutes (this to eliminate the complement of our patient)
2) we insert the cardiolipin, our antigen
3) we insert fresh rabbit serum (that contain a determined quantity of complement; in this way we can measure exactly the quantity of complement in the test tube)
4) we insert a detector system, composed of mutton blood cells and anti-blood cells antibodies.
What are “non-specific” tests used for Trepomena pallidum (2)?
These tests are done 1st.
SEE SLIDE 33 FOR Dx TEST FLOW CHART.
1) VDRL Veneral Disease Research Laboratory test
- —-Flocculation test (clumping on a side) with Cardiolipin
2) Rapid Plasma Reagin
- —-Antigen is absorbed to carbon particles making clumping easier to see
What are “specific tests” used for Treponema pallidum (4)?
These tests are done 2nd.
Both specific and non-specific tests are done. Difficult to Dx. Important to get correct.
FTA-ABS (Flourescent Treponemal Antibody Absorption)
Micro-hemagglutination
ELISA
TPI (Treponema Pallidum Immobilization)