Group A Streptoccocal Infection Flashcards
Onset of symptoms of Rheumatic fever or glomerulonephritis is associated with
Antibody response
During acute and convalascent phase of infection (group A infection) there should be
4 fold increase of Ab titer
Based on the neutralization hemolysin of Streptolysin O
Antistreptolysin O Titer
Antistreptolysin O Titer:
Titer is reported as:
Reciprocal of Highest Dilution showing NO HEMOLYSIS
Antistreptolysin O Titer:
Is expressed as
Todd Units
International Units
Antistreptolysin O Titer:
Normal Titer
< 166 Todd units
Antistreptolysin O Titer:
Moderately elevated (Adult)
> 240 Todd units
Antistreptolysin O Titer:
Moderately elevated (child)
> 320 Todd Units
Based on the Neutralization of depolymerizing activity of DNAse b
Anti DNAse B Test
Anti DNAse B Test
If there is no antibody present, the test will show
colorless
Anti DNAse B Test
Anti DNAse B is present, the test will show
green color remains
Stain used for Anti DNAse Test
Methyl green
Anti DNAse B test are graded:
4+
Intensity unchanged
Anti DNAse B Test
0
Loss of color
Slide agglutination screening test
Streptozyme Test
detection of antibodies to several streptococcal antigen
Streptozyme Test
In streptozyme test, what is being coated in antigens
Sheep’s RBC
Streptozyme Test:
Antigens used for coating the SHEEP’s RBC
Streptokinase
Streptolysin
Hyaluronidase
DNAse
NADase
Streptozyme Test:
Positive Reaction
Hemagglutination
Gold standard for detection of Rickettsial infection
Indirect Fluorescence Assay (IFA)
Microimmunofluorescence (micro-IF)
gram-positive cocci
Lancet shaped
appears in chains and pairs
Alpha, Gamma, Beta hemolysis
Streptococci
Primary reservoir of Group A streptococcus
Humans
Group A strep primarily affects
Upper Respiratory Tract
Skin
Group A strep common clinical manifestation
Pharyngitis
Streptococcal pyoderma
2 sequelae of Group A strep Infection
Acute Rheumatic Fever
Poststreptococcal glomerulonephritis
