Streptococcal infections Flashcards
S. pyogenes is the most common causative agent of all the
following disorders and complications except:
a. Pharyngitis
b. Gastroenteritis
c. Scarlet fever
d. Impetigo
b. Gastroenteritis
All the following characteristics are descriptive of M
protein except:
a. No known biological role
b. Found in association with the hyaluronic capsule
c. Inhibits phagocytosis
d. Antibody against M protein provides type-specific
immunity
a. No known biological role
Substances produced by S. pyogenes include all the
following except:
a. Hyaluronidase
b. DNAses (A, B, C, D)
c. Erythrogenic toxin
d. Interferon
d. Interferon
Laboratory diagnosis of S. pyogenes can be made by all the
following except:
a. Culturing of throat or nasal specimens
b. Febrile agglutinins
c. ASO procedure
d. Anti–DNase B
b. Febrile agglutinins
False ASO results may be caused by all the following
except:
a. Room temperature reagents and specimens at the
time of testing
b. The presence of beta-lipoprotein
c. Bacterial contamination of the serum specimen
d. Oxidation of ASO reagent caused by shaking or
aeration of the reagent vial
a. Room temperature reagents and specimens at the
time of testing
Members of the S. pyogenes species are almost always
_____ hemolytic.
a. Alpha-
b. Beta-
c. gamma-
d. Alpha- or beta-
b. Beta-
Long-term complications of S. pyogenes infection can
include:
a. Acute rheumatic fever
b. Poststreptococcal glomerulonephritis
c. Rheumatoid arthritis
d. Both a and b
d. Both a and b
Particularly virulent serotypes of S. pyogenes produce
proteolytic enzymes that cause __________________ in
a wound or lesion on an extremity.
a. Necrotizing fasciitis
b. Bone degeneration
c. Burning and itching
d. Severe inflammation
b. Bone degeneration
Match the substances produced by group A streptococci
with the appropriate description.
9. _____ Hyaluronidase
10. _____ Streptokinase
11. _____ Erythrogenic toxin
a. Degrades DNA
b. Also called spreading factor
c. Responsible for characteristic scarlet fever rash
d. Dissolves clots by converting plasminogen to plasmin
- b
- d
- c
All the following characteristics of S. pyogenes are correct
except:
a. It is an uncommon pathogen.
b. It occurs most frequently in school-age children.
c. It is spread by contact with large droplets produced
in the upper respiratory tract.
d. It has been known to cause foodborne and
milkborne epidemics.
a. It is an uncommon pathogen.
The clinical manifestations of S. pyogenes–associated
upper respiratory infection are:
a. Mild and usually unnoticeable
b. Age dependent
c. Associated with cold sores
d. Difficult to detect
b. Age dependent
The most reliable immunologic test for recent S. pyogenes
skin infection is:
a. ASO
b. Anti–DNAse B
c. Anti-NADase
d. Antibody to erythrogenic toxin
b. Anti–DNAse B
Match each ASO titer situation to the appropriate
description. (An answer may be used twice.)
15. _____ Rising titer
16. _____ Declining titer
17. _____ Constant (low) titer
a. Increase in severity of infection
b. Not a current infection, but indicates a past infection
c. Trend toward recovery
d. No clinical significance
- a
- c
- b
If a streptococcal infection is suspected, but the ASO
titer does not exceed the reference range, a(n)
_________________ should be performed.
a. Repeat titer
b. Anti–DNAse B test
c. Anti-NADase test
d. Throat culture
b. Anti–DNAse B test
The classic tests to demonstrate the presence of strepto-
coccal infection are:
a. ASO and anti-NADase
b. ASO and anti–DNAse B
c. Anti-NADase and anti-DNAse
d. Both a and b
b. ASO and anti–DNAse B
