POST LAB EXPERIMENT 10 Flashcards
TST:
Direct Microscopic: Darkfield Microscopy, Fluorescent antibody testing, MHA-TP or Serodia TP- PA, DNA probe
NTT:
VDRL, RPR, TRUST
• Detects antibody to cardiolipin
Non-treponemal tests (NTT)
• Determine the presence of reagin
Non-treponemal tests (NTT)
• False positive results are common
Non-treponemal tests (NTT)
Non-treponemal tests (NTT)
• Antigen: (?)-used to detect the nontreponemal reaginic antibodies:
IgG or IgM class
cholesterol, lecithin, cardiolipin
• Based on flocculation reactions
Non-treponemal tests (NTT)
• NTTs are positive within (?) after the appearance of primary chancre.
1 to 4 weeks
Non-treponemal tests (NTT)
• Secondary stage-
False negative
• Titers decline in later stages
Non-treponemal tests (NTT)
• Both a qualitative and quantitative slide flocculation test for serum, and CSF
VDRL (Venereal Disease Research Laboratory)
• Serum: heated at (?) to inactivate complement and (?) is pipetted into ceramic ring of a glass slide.
56C for 30 minutes
0.05 mL
• Sera and patient samples are spread out to fill the entire ring
VDRL (Venereal Disease Research Laboratory)
• (?) of the VDRL antigen is then added to each ring.
One drop
VDRL (Venereal Disease Research Laboratory)
• Rotated for (?) on a rotator at (?)
4 minutes
180 rpm
Qualitative Serum VDRL:
18-gauge needle without bevel that will deliver 60 drops of antigen suspension per mL; Ring: 14mm
Quantitative Serum VDRL:
19-gauge needle without bevel that will deliver
75 drops of antigen suspension per mL
23-gauge needle that with or without bevel will deliver
100 drops of saline per mL
Ring: 14mm
• CSF VDRL:
21- or 22-gauge needle that will deliver
100 drops per mL
Ring: 16 mm
Read microscopically to determine the presence of flocculation or small clumps
VDRL
: the antigen volume used is less than the serum test and is at a different concentration
CSF
MAIN REACTING COMPONENT
CARDIOLOIPIN
•-ENHANCES THE REACTING SURFACE OF CARDIOLOIPIN
CHOLESTEROL
•-REMOVES THE ANTIC’ ACTIVITY OF CARDIOLOIPIN
LECITHIN
VDRL
• THE ANTIGEN IS CONSISTS OF
CARDIOLIPIN
CHOLESTEROL
LECITHIN
0.03%
0.9%
0.21%
-involves macroscopic agglutination
• Modified VDRL
RPR
• Cardiolipin containing antigen suspension is bound to charcoal particles
RPR
• The antigen is similar to the VDRL antigen with the addition of EDTA, thimerosal and choline chloride
RPR
•-makes the test easier to read
Charcoal
•: preservative
Thimerosal
•: inactivate the complement
Choline chloride
• Antigen Delivery Needle:
20-gauge disposable needle without bevel
60 drops are obtained in 1 mL
Ring: 18 mm
RPR • Rotation:
100 RPM for 8 minutes
• It is a macroscopic Non Treponemal flocculation test
TRUST (Toluidine Red Unheated Serum Test)
• Particles of toluidine red are used in place of the charcoal particles of the RPR as the visualizing agents.
TRUST (Toluidine Red Unheated Serum Test)
• Quantitative, microscopic, non-treponemal.
• USR (Unheated Serum Reagin Test)
• Flocculation test similar to VDRL
• USR (Unheated Serum Reagin Test)
• The VDRL antigen is enhanced by the addition of
choline chloride and EDTA.
• USR (Unheated Serum Reagin Test)
• Detects antibody directed against the T. pallidum organism or against specific treponemal antigens
• Treponemal Serological Tests
• Treponemal Serological Tests Two main types:
Fluorescent treponemal antibody absorbed test and agglutination tests
• Confirmation rather than screening
• Treponemal Serological Tests
• A dilution of heat-inactivated patient serum is incubated with a sorbent consisting of an extract of nonpathogenic treponemes (Reiter strain)
Fluorescent Treponemal Antibody Absorption Test (FTA-Abs)
• Slides used for this test have the Nichols strain of T. pallidum fixed to them
Fluorescent Treponemal Antibody Absorption Test (FTA-Abs)
- removes cross-reactivity with treponemes other than T. pallidum
• Reiter strain
- extracted from rabbit testicular tissue, as a substrate (antigen)
• Nichols strain
• Presence of fluorescence -?
Reactive
• Absence of fluorescence -?
Negative
• It is highly sensitive and specific
Fluorescent Treponemal Antibody Absorption Test (FTA-Abs)
• Secondary and latent syphilis-?
100% reactive
• Colored gelatin particles coated with treponemal antigens
Agglutination tests: Treponema pallidum Particle agglutination Tests, Hemagglutination Treponemal Test for Syphilis (TPPA)
• Sensitive in detecting primary syphilis
Agglutination tests: Treponema pallidum Particle agglutination Tests, Hemagglutination Treponemal Test for Syphilis (TPPA)
• Presence of T. pallidum antibodies are indicated by agglutination of sensitized gel particles
Agglutination tests:
Treponema pallidum Particle agglutination Tests
Hemagglutination Treponemal Test for Syphilis (TPPA)
- Antigen prepared from T. phagedenis
REITER’s ANTIGEN COMPLEMENT FIXATION TEST
- High proportion of false positive reactions
REITER’s ANTIGEN COMPLEMENT FIXATION TEST
- Gel particles or sheep red blood cells
Microhemagglutination Assay for Antibodies to Treponema pallidum (MHA-TP)
- Less sensitive than FTA-ABS
Microhemagglutination Assay for Antibodies to Treponema pallidum (MHA-TP)
Non Treponemal
SCREENING TESTS
Reagin
SCREENING TESTS
Rapid Plasma Reagin
SCREENING TESTS
Qualitative RPR
SCREENING TESTS
Quantitative RPR
SCREENING TESTS
Venereal Disease Research Laboratory
SCREENING TESTS
• Treponemal tests
CONFIRMATORY TESTS
• Darkfield Microscopy
CONFIRMATORY TESTS
• FTA-ABS
CONFIRMATORY TESTS
• TPPA
CONFIRMATORY TESTS
coated carrier particles of T. pallidum cell walls disrupted by high-frequency sound waves
Microhemagglutination Assay for Antibodies to Treponema pallidum (MHA-TP)