ASO Flashcards
____________– common bacteria responsible for sore throat but most common cause
are the _____________.
Streptococci
Viruses
Identify characteristics/ complications of the following:
Scarlet fever –
Rheumatic fever –
Glomerulonephritis –
Scarlet fever – red rashes
Rheumatic fever – cardiac issues
Glomerulonephritis – worst kidney problem
No lysis of red blood cells
Gamma hemolysis
Incomplete lysis of red blood cells, results in a greenish halo
Alpha hemolysis
Complete lysis of red blood cells and a clear zone surrounding the colonies.
Beta hemolysis
Differentiate S. pneumoniae & S. viridans
- S. pneumoniae – optochin sensitive and bile soluble
- S. viridans – optochin resistant and bile insoluble
Gamma-hemolytic bacteria
Enterococcus group
Beta-hemolytic bacterias
- Group A – S. pyogenes
- Group B – S. agalactiae
Alpha-hemolytic bacteria
S. pneumoniae
S. viridans
differentiate the beta-hemolytic streptococcus group using Bacitracin test
- Group A – S. pyogenes : Sensitive
- Group B – S. agalactiae : Resistant
differentiate the beta-hemolytic streptococcus group using CAMP Test
- Group A – S. pyogenes : Negative
- Group B – S. agalactiae : Positive
Standard method for identifying the
group b streptococcus serotype methods.
Lancefield precipitation test
Tests to differentiate the beta-hemolytic streptococcus group:
Bacitracin test
CAMP (Christie–Atkins–Munch-Peterson) test
Lancefield precipitation test
hemolytic factor produced by most strains of Group A beta-hemolytic streptococci
STREPTOLYSIN O
streptolysin O, the O stands for _______
oxygen- labile
streptolysin S, the S stands for _______
oxygen-stable
Differentiate Streptolysin O & Streptolysin S
Streptolysin O – active only on reduced state. Is antigenic and give rise to ASO antibodies
Streptolysin S – active both on reduced and oxidized condition. Non-antigenic
enzyme that causes complete hemolysis on blood agar plate.
Streptokinase
enzyme that specifies the chromatin breakdown during apoptosis or necrosis.
DNAse
State the causes of a hemolyzed sample
Incorrect needle size
Excessive suction
Improper tube mixing
Prolonged tourniquet application
Improper tube filling
Difficulty in extraction
ASO appears in serum from ___________ after the onset of a streptococcal infection
1 week – 1 month
ASO Normal ranges:
Children:
Adult:
Normal ranges:
Children = <150 iu/ml
Adult = <200 iu/ml
Incubation period for Streptococcal Infections
2nd week – signs & symptoms appears
5th week – peak
T or F
Time collection is important to avoid false results
T
best way to confirm false results
Anti-DNAse test
use to determine the organisms ability to
hydrolyze the DNA and use it as carbon and energy for growth.
DNAse test
T or F
Incidence decreases as the time increases
T
antibody levels begin to rise after________
1 to 3 weeks
antibody levels begin to peak _____
3 to 5 weeks
antibody levels falls back to insignificant levels in _____
6 months
If the titer doesn’t decrease with time; this means that a ________
recurrent or chronic infection may exist.
Anti-streptolysin O can react specifically with _____ and inhibits the hemolytic activity
SLO
T or F
The amount of ASO can be estimated by dilution of patient’s serum in the
presence of constant amount of SLO to the point where there is no prevention of hemolysis.
F
there is still complete prevention of hemolysis.
COMMERCIALLY AVAILABLE TESTS
Used for screening a significant raise in ASO titer
ASO LATEX SLIDE TEST
COMMERCIALLY AVAILABLE TESTS
Used to determine the titer of ASO antibody
ASO TITRATION TEST
Principle of RAPID ASO LATEX AGGLUTINATION TEST
In the presence of ASO antibody, a visible agglutination reaction will be
exhibited when a serum specimen combine with latex particle coated with
streptolysin O antigen.
Specimen for RAPID ASO LATEX AGGLUTINATION TEST
serum that is clear and hemolysis free
REAGENT STORAGE AND STABILITY
Reagent are stable until stated expiration date.
Must be refrigerated (2-8C)
DO NOT FREEZE
ASO Latex reagent, once shaken must be uniform without visible clumping.
Do not use the latex reagent or controls if become contaminated.
If the test cannot be carried out on the same day, store the specimen for
7 days at _______. If it will not be used for 3 months or more, store at ______.
2-8 C
-20 C
T or F
we can use plasma in testing for ASO
F
Serum only
