Question 1

MATCHING
Match the substance with the correct description.

-Hyaluronidase

Accepted Answer

A)  Is elaborated by scarlet fever-associated strains
B)  Also called "spreading factor"
C)  Dissolves clots by converting plasminogen to plasmin
D)  Four immunologically distinct forms B

Question 2

Streptolysin S is: *

Accepted Answer

A)   antigenic.
B)   an oxygen-stable enzyme.
C)   the most frequently used serologic indicator of an antibody response to a recent streptococcal infection.
D)   detected by DNA analysis. B

Question 3

Match each ASO titer situation to the appropriate description.

-Rising titer

Accepted Answer

A)  Current infection
B)  Past infection
C)  Trend toward recovery
D)  Rules out Streptococcus pyogenes infection A

Question 4

Serologic testing for S.pyogenes should compare acute and convalescent specimens collected ___________ apart.

Accepted Answer

A)   24 hours
B)   72 hours
C)   1 week
D)   3 weeks

Question 5

Streptolysin O is: *

Accepted Answer

A)   nonantigenic.
B)   an oxygen-stable enzyme.
C)   the most frequently used serologic indicator of an antibody response to a recent streptococcal infection.
D)   detected by DNA analysis.

Question 6

Members of the S.pyogenes species are almost always _____-hemolytic.

Accepted Answer

A)   alpha
B)   beta
C)   gamma
D)   alpha or beta

Question 7

The classic antistreptolysin O (ASO)procedure has been replaced by a(n):

Accepted Answer

A)   optical immunoassay procedure.
B)   direct immunofluorescence.
C)   radioimmunoassay (RI
A)  .
D)   both a and b

Question 8

Mortality following an outbreak of S.pyogenes that progresses to toxic shock can be as high as:

Accepted Answer

A)   25%.
B)   50%.
C)   70%.
D)   90%.

Question 9

Match each ASO titer situation to the appropriate description.

-Declining titer

Accepted Answer

A)  Current infection
B)  Past infection
C)  Trend toward recovery
D)  Rules out Streptococcus pyogenes infection

Question 10

MATCHING
Match the substance with the correct description.

-DNase

Accepted Answer

A)  Is elaborated by scarlet fever-associated strains
B)  Also called "spreading factor"
C)  Dissolves clots by converting plasminogen to plasmin
D)  Four immunologically distinct forms

Question 11

Streptococcus pyogenes is the most common causative agent of:

Accepted Answer

A)   pharyngitis.
B)   scarlet fever.
C)   impetigo.
D)   all of the above.

Question 12

Shocklike symptoms can be produced by high levels of:

Accepted Answer

A)   antibodies to S.pyogenes.
B)   S.pyogenes superantigens.
C)   cytokines.
D)   both b and c

Question 13

M protein contributes to S.pyogenes invasiveness because it:

Accepted Answer

A)   neutralizes complement.
B)   blocks antigen recognition.
C)   blocks an antibody response.
D)   impedes phagocytosis.

Question 14

The portal of entry of streptococci in streptococcal toxic shock syndrome (STSS)can be determined in approximately ________ of cases.

Accepted Answer

A)   25%
B)   50%
C)   75%
D)   100%

Question 15

Laboratory diagnosis of S.pyogenes can be made by:

Accepted Answer

A)   culturing of throat or nasal specimens.
B)   an ASO procedure.
C)   anti-DNase B (ADN-
B)  .
D)   all of the above.

Question 16

The R antigen found on the fimbriae of pyogens:

Accepted Answer

A)   is structurally similar to the M antigen.
B)   is immunologically distinct from the M antigen.
C)   has no known biologic role.
D)   all of the above.

Question 17

An elevated antistreptolysin O (ASO)titer indicates: *

Accepted Answer

A)   a chronic streptococcal infection.
B)   a relatively recent streptococcal infection.
C)   carditis of acute rheumatic fever within the past 24 hours.
D)   a response to a streptococcal infection within the past 48 hours.

Question 18

Match each ASO titer situation to the appropriate description.

-Constant (low)titer

Accepted Answer

A)  Current infection
B)  Past infection
C)  Trend toward recovery
D)  Rules out Streptococcus pyogenes infection

Question 19

MATCHING
Match the substance with the correct description.

-Streptokinase

Accepted Answer

A)  Is elaborated by scarlet fever-associated strains
B)  Also called "spreading factor"
C)  Dissolves clots by converting plasminogen to plasmin
D)  Four immunologically distinct forms

Question 20

A substance that could mediate the fever,shock,and tissue injury observed in patients with STSS is:

Accepted Answer

A)   antibody against antistreptolysin O (ASO) .
B)   M protein.
C)   TNF-a.
D)   lymphokine.

Exam 17: Streptococcal Infections

MATCHING Match the substance with the correct description. -Hyaluronidase

Streptolysin S is: *

Match each ASO titer situation to the appropriate description. -Rising titer

Serologic testing for S.pyogenes should compare acute and convalescent specimens collected ___________ apart.

Streptolysin O is: *

Members of the S.pyogenes species are almost always _____-hemolytic.

The classic antistreptolysin O (ASO) procedure has been replaced by a(n) :

Mortality following an outbreak of S.pyogenes that progresses to toxic shock can be as high as:

Match each ASO titer situation to the appropriate description. -Declining titer

MATCHING Match the substance with the correct description. -DNase

Streptococcus pyogenes is the most common causative agent of:

Shocklike symptoms can be produced by high levels of:

M protein contributes to S.pyogenes invasiveness because it:

The portal of entry of streptococci in streptococcal toxic shock syndrome (STSS) can be determined in approximately ________ of cases.

Laboratory diagnosis of S.pyogenes can be made by:

The R antigen found on the fimbriae of pyogens:

An elevated antistreptolysin O (ASO) titer indicates: *

Match each ASO titer situation to the appropriate description. -Constant (low) titer

MATCHING Match the substance with the correct description. -Streptokinase

A substance that could mediate the fever,shock,and tissue injury observed in patients with STSS is: