anti-streptolysin o test
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ANTI-STREPTOLYSIN “O” LATEX TEST
GROUP 5
-Manuel
-Nuqui
-Olazo
-Ong
-Perez
-Puentespina
INTRODUCTION Group A Hemolytic Streptococci
Also known as Streptococcus pyogenes
1º INFECTION Impetigo Pharyngitis Sore throat Scarlet fever
Scarlet feverImpetigo
Strep throat
2º INFECTION (complication arising from 1º infection)
Acute Glomerulonephritis May follow either a throat or a skin infection. Results to impaired renal function
Rheumatic Fever Sequel to pharyngitis or tonsillitis, and damage to the
smooth muscle of the heart may result
Enlargement of the heart
ASO Test – can detect these nonsuppurative sequelae of streptococcal infection
Inflammation of the joints
Hemolysins:(Destroys both RBC and WBC)
Streptolysin O Discovered by Todd in 1932 Oxygen-labile Has direct action on heart and kidney Produces rheumatic fever & glomerulonephritis Antibodies formed (ASO)
Streptolysin S Stable Cause hemolysis on the blood agar No antibodies formed
Immunology-Serology by R. Rabor (2006)
STREPTOCOCCAL ANTIGENS
STREPTOCOCCAL DIAGNOSTIC MARKERS
Streptolysin OAnti-streptolysin O
antibody (ASO)Hyaluronidase Anti-hyaluronidase (AHL)
Streptokinase Anti-streptokinase (ASK)
Streptococcal deoxyribonucleases
Anti-streptococcal deoxyribonucleases (AND)
Streptococcal nicotinamide adenine dinucleotidase
Anti-streptococcal nicotinamide adenine dinucleotidase (ANAD)
ASO is the most commonly measured
antibody in the serum to diagnose streptococcal infection.
It increases within 1 to 2 weeks after infection and peak between 3 to 6 weeks ff. initial symptoms
Detectable ASO does not occur to all patients = 2 tests for different exotoxin is recommded
Varies with age, geographic location, season
DIAGNOSTIC TESTS FOR STREPTOCOCCAL INFECTION Anti-streptolysin O Titer (ASO Titer)
Anti-streptolysin O Latex (ASO Latex)
Anti-Dnase B Testing
Streptozyme Testing
PRINCIPLE INDIRECT AGGLUTINATION/ PASSIVE
AGGLUTINATION Antigen (Streptolysin O) is enlarged based on an immunologic reaction between
streptococcal exotoxins bound to biologically inert latex particles and streptococcal antibodies in the test sample. Visible agglutination occurs when increased Ab level, are present in the serum.
PROCEDUREPlace 1 drop of the positive control, negative control and test
serum on each of the oval in the glass card.
Add 1 drop of the reagent,Polystyrene latex coated with Streptolysin O, on each of the
oval.
Mix using the dispenstir then gently tilt the glass card
Observe agglutination after
2mins.
Record the results.
ANTIBODY & ANTIGEN
ANTIBODY ANTIGENAnti-streptolysin
“O” in patient serum
Polystyrene latex particles coated with
Streptolysin “O”
REAGENTS
ASO Latex Reagent A suspension of polystyrene particles coated
with streptococcal exotoxins. Must be mixed well before using.
ASO Positive Control A stabilized human serum containing at least
200 iU/ml of ASO reactive with the test reagent.
ASO Negative Control A stabilized human serum containing less than
200 iU/ml of ASO non-reactive with the test reagent. Need not to be diluted.
DESCRIPTION OF TEST: Anti-streptolysin “O” Latex test
Screening test The latex test is a rapid slide test using single dilution of the
patient serum and does not require RBC as an indicator system. Streptolysin O is added to the patient serum in a quantity
sufficient to bind 200 IU of ASO per mL.
Positive result (+): Presence of white agglutinates
Negative result (-): Smooth homogenous milky suspension
INTERPRETATION A positive result means that the Anti-
Streptolysin “O” titer in the serum is more than 200 IU/ML . The sample reaction must be compared to a positive control.
A negative result is not indicative of absence of a Streptococcal infection. The test specificity is high but the sensitivity is much lower.
MANNER OF REPORTING Write:
“POSITIVE (+)” when the presence of agglutination is observed.
“NEGATIVE (-)” when agglutination is not observed.