[STREP TEST] STREPTOCOCCAL DISEASE

Question 1

What is the primary pathogen responsible for streptococcal diseases?

Answer 1

Streptococcus pyogenes (Group A Streptococcus).

Question 2

What is the main serological test used for detecting streptococcal infections?

Answer 2

Anti-streptolysin O (ASO) test.

Question 3

What is the ASO test used for?

Answer 3

Detects anti-streptolysin O antibodies in a patient’s serum.

Question 4

What does ASO stand for?

Answer 4

Anti-streptolysin O.

Question 5

What is the principle of the ASO titer test?

Answer 5

Neutralization reaction detecting the inhibition of hemolysis by ASO antibodies.

Question 6

What is a normal ASO titer range?

Answer 6

0-125 IU/mL.

Question 7

What does a high ASO titer indicate?

Answer 7

Recent or past streptococcal infection.

Question 8

What type of antigen does the ASO test detect?

Answer 8

Streptolysin O, a toxin produced by Streptococcus pyogenes.

Question 9

What diseases are associated with high ASO titers?

Answer 9

Acute rheumatic fever and post-streptococcal glomerulonephritis.

Question 10

What is the specimen used for the ASO test?

Answer 10

Serum.

Question 11

What is the principle of the ASO slide test?

Answer 11

Passive agglutination.

Question 12

How does the ASO latex test work?

Answer 12

Latex particles coated with streptolysin O react with ASO antibodies causing agglutination.

Question 13

What is the Streptozyme test?

Answer 13

A rapid test that detects multiple streptococcal antibodies.

Question 14

What is the principle of the Streptozyme test?

Answer 14

Passive hemagglutination.

Question 15

What antibodies does the Streptozyme test detect?

Answer 15

Anti-streptolysin O, anti-deoxyribonuclease B (ADN-B), anti-streptokinase (ASK), and anti-hyaluronidase (AH).

Question 16

What are the advantages of the Streptozyme test?

Answer 16

Detects multiple streptococcal antibodies in a single test.

Question 17

What is DNase B and why is it significant?

Answer 17

A bacterial enzyme that degrades DNA and is associated with streptococcal virulence.

Question 18

How does the DNase B test help in streptococcal diagnosis?

Answer 18

Measures antibodies against DNase B to confirm streptococcal infections.

Question 19

What is the principle of the DNase B test?

Answer 19

Enzyme immunoassay detecting DNase B-specific antibodies.

Question 20

What are the common complications of Streptococcus pyogenes infections?

Answer 20

Acute rheumatic fever, post-streptococcal glomerulonephritis.

Question 21

What is acute rheumatic fever?

Answer 21

An inflammatory disease affecting the heart, joints, and skin following a streptococcal infection.

Question 22

How does streptococcal infection lead to acute glomerulonephritis?

Answer 22

Immune complex deposition in the kidneys following streptococcal pharyngitis or impetigo.

Question 23

What are the clinical symptoms of post-streptococcal glomerulonephritis?

Answer 23

Hematuria, hypertension, and proteinuria.

Question 24

What is the incubation period for streptococcal infections?

Answer 24

1-3 days.

Question 25

What is the significance of a rising ASO titer?

Answer 25

Indicates an ongoing or recent streptococcal infection.

Question 26

How does the ASO test differ from the Streptozyme test?

Answer 26

ASO detects anti-streptolysin O antibodies; Streptozyme detects multiple streptococcal antibodies.

Question 27

Why is serial testing important in streptococcal serology?

Answer 27

Monitors antibody response over time to confirm active infection.

Question 28

What is the role of C-reactive protein (CRP) in streptococcal infections?

Answer 28

A marker of inflammation elevated in streptococcal infections.

Question 29

What is the principle of the CRP slide test?

Answer 29

Latex agglutination.

Question 30

What specimen is used for CRP testing?

Answer 30

Serum.

Question 31

How is the CRP test interpreted?

Answer 31

Agglutination indicates elevated CRP levels due to inflammation.

Question 32

What is the function of streptolysin O?

Answer 32

Lyses red blood cells by forming pores in the membrane.

Question 33

What is the function of streptokinase?

Answer 33

Converts plasminogen to plasmin, aiding bacterial spread.

Question 34

What is the function of hyaluronidase in streptococcal infections?

Answer 34

Degrades hyaluronic acid, allowing bacterial invasion.

Question 35

What is the role of M protein in streptococcal pathogenicity?

Answer 35

A major virulence factor that prevents phagocytosis.

Question 36

What are the Lancefield groups of Streptococcus?

Answer 36

Groups A, B, C, D, F, G based on carbohydrate antigen classification.

Question 37

Which Lancefield group does Streptococcus pyogenes belong to?

Answer 37

Group A.

Question 38

What are the hemolytic patterns of streptococci?

Answer 38

Alpha, beta, and gamma hemolysis.

Question 39

What type of hemolysis does Streptococcus pyogenes exhibit?

Answer 39

Beta-hemolysis.

Question 40

What is the principle of the RF latex test?

Answer 40

Latex agglutination detecting rheumatoid factor.

Question 41

What does a positive RF test indicate?

Answer 41

Suggests rheumatoid arthritis or other autoimmune diseases.

Question 42

What is the function of rheumatoid factor (RF)?

Answer 42

An autoantibody directed against the Fc portion of IgG.

Question 43

What are the limitations of the ASO test?

Answer 43

Low sensitivity in early infections and cross-reactivity with other conditions.

Question 44

What are confirmatory tests for streptococcal infections?

Answer 44

DNA-based assays and culture confirmation.

Question 45

How does molecular testing complement serodiagnostic testing for Streptococcus?

Answer 45

Identifies genetic material of Streptococcus, increasing diagnostic accuracy.

Question 46

What are the advantages of serological tests over bacterial culture for streptococcal infections?

Answer 46

Faster diagnosis and detects past infections even when cultures are negative.

Question 47

Why is early diagnosis of streptococcal infections important?

Answer 47

Prevents complications like rheumatic fever and glomerulonephritis.

Question 48

What is the treatment for streptococcal infections?

Answer 48

Antibiotics, primarily penicillin or amoxicillin.

Question 49

What antibiotics are commonly used for streptococcal infections?

Answer 49

Penicillin, amoxicillin, and cephalosporins.

Question 50

How can streptococcal infections be prevented?

Answer 50

Hand hygiene, avoiding contact with infected individuals, and vaccination (if applicable).