Question 1

Superantigens produce intense immune responses by stimulating lymphocytes to produce

Accepted Answer

A)   exotoxins.
B)   leukocidins.
C)   cytokines.
D)   endotoxins.
E)   interferons.F) A) and D)
G) None of the above

Question 2

The Limulus amoebocyte assay is used to detect minute amounts of endotoxin in drugs and medical devices.

Accepted Answer

A) True 
 B)False

Question 3

Polio is transmitted by ingestion of water contaminated with feces containing polio virus. What portal of entry does polio virus use?

Accepted Answer

A)   skin only
B)   parenteral only
C)   mucous membranes only
D)   skin and parenteral
E)   skin, parenteral, and mucous membranesF) A) and B)
G) B) and D)

Question 4

In general, the LD50 for exotoxins is much greater than the LD50 for endotoxins.

Accepted Answer

A) True 
 B)False

Question 5

Injectable drugs are tested for endotoxins by

Accepted Answer

A)   filtering out the cells.
B)   looking for turbidity.
C)   culturing bacteria.
D)   counting the viable bacteria.
E)   the Limulus amoebocyte lysate test.F) B) and C)
G) C) and D)

Question 6

Which of the following cytopathic effects is cytocidal?

Accepted Answer

A)   antigenic changes
B)   release of enzymes from lysosomes
C)   giant cells
D)   transformation
E)   inclusion bodiesF) A) and E)
G) B) and D)

Question 7

Which of the following is NOT a membrane- disrupting toxin?

Accepted Answer

A)   A- B toxin
B)   streptolysin O
C)   leukocidin
D)   hemolysin
E)   streptolysin SF) None of the above
G) All of the above

Question 8

All of the following bacteria release endotoxin EXCEPT

Accepted Answer

A)   Haemophilus influenzae.
B)   Clostridium botulinum.
C)   Proteus vulgaris.
D)   Salmonella typhi.
E)   Neisseria meningitidis.F) B) and E)
G) A) and B)

Question 9

Gram- negative septic shock results from the following events. What is the second step?

Accepted Answer

A)   LPS is released from gram- negative bacteria.
B)   Phagocytes ingest gram- negative bacteria.
C)   IL- 1 is released.
D)   Body temperature is reset in the hypothalamus.
E)   Fever occurs.F) B) and E)
G) A) and E)

Question 10

Symptoms of intense inflammation and shock occur in some gram- positive bacterial infections due to

Accepted Answer

A)   lipid A.
B)   membrane- disrupting toxins.
C)   A- B toxins.
D)   superantigens.
E)   erythrogenic toxin.F) A) and E)
G) A) and D)

Question 11

Antibiotics can lead to septic shock if used to treat

Accepted Answer

A)   helminth infestations.
B)   gram- negative bacterial infections.
C)   protozoan infections.
D)   viral infections.
E)   gram- positive bacterial infections.F) B) and E)
G) A) and E)

Question 12

All of the following are methods of avoiding host antibodies EXCEPT

Accepted Answer

A)   antigenic changes.
B)   membrane- disrupting toxins.
C)   IgA proteases.
D)   invasins.
E)   inducing endocytosis.F) A) and B)
G) All of the above

Question 13

In response to the presence of endotoxin, phagocytes secrete tumor necrosis factor. This causes

Accepted Answer

A)   a decrease in blood pressure.
B)   a aram- negative infection.
C)   an increase in red blood cells.
D)   the disease to subside.
E)   a fever.F) C) and E)
G) A) and B)

Question 14

Cytopathic effects, such as inclusion bodies and syncytium formation, are the visible signs of viral infections.

Accepted Answer

A) True 
 B)False

Question 15

Which of the following is NOT a cytopathic effect of viruses?

Accepted Answer

A)   host cells fusing to form multinucleated syncytia
B)   increased cell growth
C)   inclusion bodies forming in the cytoplasm or nucleus
D)   toxin production
E)   cell deathF) A) and D)
G) None of the above

Question 16

The most frequently used portal of entry for pathogens is the

Accepted Answer

A)   skin.
B)   parenteral route.
C)   mucous membranes of the respiratory tract.
D)   mucous membranes of the gastrointestinal tract.
E)   All of these portals are used equally.F) C) and E)
G) C) and D)

Exam 15: Microbial Mechanisms of Pathogenicity

The most frequently used portal of entry for pathogens is the

Correct Answer
verified

The Limulus amoebocyte assay is used to detect minute amounts of endotoxin in drugs and medical devices.

Correct Answer
verified

All of the following bacteria release endotoxin EXCEPT

Correct Answer
verified

Symptoms of intense inflammation and shock occur in some gram- positive bacterial infections due to

Correct Answer
verified

Which of the following cytopathic effects is cytocidal?

Correct Answer
verified

In response to the presence of endotoxin, phagocytes secrete tumor necrosis factor. This causes

Correct Answer
verified

Which of the following is NOT a cytopathic effect of viruses?

Correct Answer
verified

Cytopathic effects, such as inclusion bodies and syncytium formation, are the visible signs of viral infections.

Correct Answer
verified

Antibiotics can lead to septic shock if used to treat

Correct Answer
verified

All of the following are methods of avoiding host antibodies EXCEPT

Correct Answer
verified

Injectable drugs are tested for endotoxins by

Correct Answer
verified

Superantigens produce intense immune responses by stimulating lymphocytes to produce

Correct Answer
verified

In general, the LD₅₀for exotoxins is much greater than the LD₅₀for endotoxins.

Correct Answer
verified

Polio is transmitted by ingestion of water contaminated with feces containing polio virus. What portal of entry does polio virus use?

Correct Answer
verified

Gram- negative septic shock results from the following events. What is the second step?

Correct Answer
verified

Which of the following is NOT a membrane- disrupting toxin?

Correct Answer
verified

Exam 15: Microbial Mechanisms of Pathogenicity

The most frequently used portal of entry for pathogens is the

Correct AnswerverifiedShow Answer

The Limulus amoebocyte assay is used to detect minute amounts of endotoxin in drugs and medical devices.

Correct AnswerverifiedShow Answer

All of the following bacteria release endotoxin EXCEPT

Correct AnswerverifiedShow Answer

Symptoms of intense inflammation and shock occur in some gram- positive bacterial infections due to

Correct AnswerverifiedShow Answer

Which of the following cytopathic effects is cytocidal?

Correct AnswerverifiedShow Answer

In response to the presence of endotoxin, phagocytes secrete tumor necrosis factor. This causes

Correct AnswerverifiedShow Answer

Which of the following is NOT a cytopathic effect of viruses?

Correct AnswerverifiedShow Answer

Cytopathic effects, such as inclusion bodies and syncytium formation, are the visible signs of viral infections.

Correct AnswerverifiedShow Answer

Antibiotics can lead to septic shock if used to treat

Correct AnswerverifiedShow Answer

All of the following are methods of avoiding host antibodies EXCEPT

Correct AnswerverifiedShow Answer

Injectable drugs are tested for endotoxins by

Correct AnswerverifiedShow Answer

Superantigens produce intense immune responses by stimulating lymphocytes to produce

Correct AnswerverifiedShow Answer

In general, the LD50 for exotoxins is much greater than the LD50 for endotoxins.

Correct AnswerverifiedShow Answer

Polio is transmitted by ingestion of water contaminated with feces containing polio virus. What portal of entry does polio virus use?

Correct AnswerverifiedShow Answer

Gram- negative septic shock results from the following events. What is the second step?

Correct AnswerverifiedShow Answer

Which of the following is NOT a membrane- disrupting toxin?

Correct AnswerverifiedShow Answer

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In general, the LD₅₀for exotoxins is much greater than the LD₅₀for endotoxins.

Correct Answer
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