8.1 Serologic Test for Streptococcal Disease Flashcards
Main etiologic Agent for Strep disease?
S. pyogenes
Diseases: Strep throat; Scarlet fever; Impetigo; Erysipelas
What are the sequelae?
Glomerulonephritis (kidneys); Rheumatic Heart Disease (heart)
Important pathogenic determinant of Strep for Serologic testing?
Streptolysin O
Exoenzymes
Streptolysin O: Non immunogenic
Streptolysin S: Immunogenic
T or F
F
Baligtad
Streptolysin O is a responsible for Sub surface hemolysis
T or F
T
Streptolysin O: Oxygen labile
Streptolysin S: Oxygen Stable
T or F
T
ASO Tube method Principle?
a. Passive Agglutination
b. Neutralization
b
ASO tube method reagents includes:
- SLO Reagent
- PBS (Diluent)
- 5% _____
- NSS
- Distilled water
RCS
Specimen for ASO Tube method?
Serum
How many tube to set up ASO tube method?
12
Tube 11: Red Cell control
Tube 12: SLO Control
T or F
T
Tube 11: Positive Result
- No hemolysis
Tube 12: Negative result:
- Hemolysis
T or F
T
1-10 tubes: Test
11-12: Control
T or F
T
Tube dilution:
Tube 1: ______
Tube 2-6:______
Tube 7-10:______
1:10
1:100
1:500
Checking of hemolysis is by adding red cells and SLO Reagents then incubate
T or F
T
ASO Titer:
Reciprocal of highest dilution showing WITH Hemolysis
T or F
F
No
Normal Values for Tube method:
Children: <______
Adults:<______
125 Todd units
166 Todd units
Multienzyme test to detect antibodies against the different exoenzyme
Streptozyme test
Streptozyme test is a Semi-quantitative, confirmatory test
T or F
F
Screening
Specimen for Streptozyme
Serum
Detection limit for Streptozyme test?
166 Todd units
Components of Streptozyme Reagent?
Sheep RBC coated with enzyme
Is it possible that the patient would be positive with streptozyme but negative for ASO?
Yes, because the streptozyme detects not only ASO but also other antibodies
Streptozyme detects many antibodies related to Strep
T or F
T
if Streptozyme is positive, ASO may be negative
T or F
T
It can be negative since not only SO can be detected but other enzymes
however if ASO is positive, expect Streptozyme to be positive
ASO Slide method Principle?
a. Passive Agglutination
b. Neutralization
a
Specimen for ASO Slide test?
Serum 40uL
Detection limit for ASO Slide test?
200 IU/mL
ASO slide test is a Sensitivity test
T or F
T
Reagent for ASO sLide test?
Latex particle coated with SLO
Analyte of Interest for ASO Slide test?
Ab
Positive result for ASO Slide test?
Agglutination
