ASO LATEX AGGLUTINATION TEST Flashcards
what bacteria is the one we test for ASO latex agglutination test
streptococcus pyogenes
in terms of lancefield group, what group do streptococcus pyogenes do belong?
group A
streptococci are divided into how many groups?
20
what is the hemolytic pattern of group A streptococcus
alpha - partial hemolysis and a greenish discoloration
what is the main virulence factor of streptococcus pyogenes?
m protein
the virulence factor of streptococcus pyogenes - M protein functions as
as inhibitor of phagocytosis
what are the exo enzymes of streptococcus
streptolysin O
streptokinase
hyaluronidase
DNAse B
NADase
among the exoenzyme of streptococcus pyogenes, which one is the most immunogenic(capable of inducing immune reactions) - can cause antibody reaction
streptolysin O
among the exoenzyme of streptococcus pyogenes, which one is the oxygen stable and not capable of inducing immune reactions) -
streptokinase
what is the general rule of ASO latex agglutination test?
always use 2 antibodies
the exo enzyme of streptococcus pyogenes that it lyses the rbc and also known as oxygen labile
streptolysin O
the exo enzyme of streptococcus pyogenes that inhibits clotting - mechanism to isolate infection
streptokinase
the exo enzyme of streptococcus pyogenes that is the spreading factor
hyaluronidase
the exo enzyme of streptococcus pyogenes that destroys dna
DNAse B
the exo enzyme of streptococcus pyogenes that destroys NAD
NADase
what are the ways of streptococcus pyogenes to counter attack
–avoid wbc
–inactivate complementary system
–inhibits phagocytosis - using protein and capsule to inactivate it
the presence of polysaccharide capsules are usually seen in __ they can inhibit phagocytosis using capsule that evolves from their cell body
Neisseria meningitidis, streptococcus pneumoniae, yersinia pestis, haemophilus influenzae
hall marks or the signs for streptococcus pyogenes
upper respiratory tract infection (pharyngitis and tonsilitis)
skin infections caused by streptococcus pyogenes
skin infection (skin impetigo)
streptococcal pyoderma
Erysipelas- form of skin infection
cellulitis - inflammation of folicles
toxic shock syndrome
inflammation of follicles
cellulitis
gastrointestinal tract infection
puerperal sepsis
___ - characterzied by rashes. Second disease causing rash
SCARLET FEVER
inflammation of the middle ear
otitis media
first disease causing rash
measles
cardinal signs of streptococcus pyogenes- caused by pyrogenic exotoxins of S. pyogenes
strawberry colored tongue
a further consequences of having strepto (aftermath)
damaging sequale
2 damaging sequale
- acute rheumatic fever
- post streptococcal glomerulonephritis
the antibodies will attach the antigens in the heart and kidney that is similar to the antigen for strepto
- called ___
cross reaction/reactivity
IN ORDER TO DETECT ANTIGENS WE USED THE what assay?
LATERAL FLOW IMMUNOCHROMATOGRAPHY ASSAY
what is the principle of aso slide method or the aso latex agglutination test
Passive/ Indirect Agglutination
bacterial screening for screening is the
BACITRACIN TEST - susceptible in bacitracin test
confirmatory test for S. pyogenes
positive in PYR - Pyrrolidonyl arylamidase
detection of antibodies is LONG terms as it can detect the PAST infection as well
true or false
true
ASO LATEX REAGENT
Suspension of
polystyrene particles sensitized with
Streptolysin O
Analytical Sensitivity
200 IU/mL
positive for aso latex agglutination test
if titer is > 200 IU/ml
3 reagents used for aso slide method
ASO LATEX REAGENTS
ASO POSITIVE CONTROL
ASO NEGATIVE CONTROL
all reagents contain ___ as a preservative
0.1% sodium azide
ASO SLIDE METHOD
- Allow each components of the test kit (reagents, controls) to reach room temperature.
- Gently shake the latex reagent to disperse the particles.
- Place a drop of undiluted serum into a circle of a test slide.
- Add one drop of ASO Latex reagent next to the drop of
serum. - Spread the reagent and serum sample over the entire area of
the test circle using a separate stirrer for each sample. - Gently tilt the test slide backwards and forwards for two minutes.
- Observe and interpret the results.
Diagnosis of
the probability for
sequelae
S. pyogenes infection
ASO TUBE TEST
type of dilution for aso tube test
Compound dilution
Principle for aso tube test
NEUTRALIZATION/Enzyme
inhibition test
Multi-Enzyme test to detect
Antibody to the multiple
exoenzymes of S. pyogenes
Streptozyme Test
PRINCIPLE of streptozyme test
Passive Hemagglutination
reagents used for streptozyme test
Formalinized/ Aldehyde fixed
sheep RBCs coated with exoenzymes of S.
pyogenes
how many tubes are used for aso tube test
14 tubes
what is the titer for aso tubes test
Titer: last tube with no hemolysis
