Question 1

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. 
A)  antigenic changes. 
B)  membrane- disrupting toxins. 
C)  IgA proteases. 
D)  invasins. 
E)  inducing endocytosis.

Question 2

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. 
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.

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

Question 4

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

Question 5

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

Question 6

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. 
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.

Question 7

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 death 
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 death

Question 8

Superantigens produce intense immune responses by stimulating lymphocytes to produce

Accepted Answer

A)  exotoxins. 
B)  leukocidins. 
C)  cytokines. 
D)  endotoxins. 
E)  interferons. 
A)  exotoxins. 
B)  leukocidins. 
C)  cytokines. 
D)  endotoxins. 
E)  interferons.

Question 9

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

Accepted Answer

A) True 
 B)False

Question 10

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

Question 11

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

Accepted Answer

A) True 
 B)False

Question 12

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 S 
A)  A- B toxin 
B)  streptolysin O 
C)  leukocidin 
D)  hemolysin 
E)  streptolysin S

Question 13

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

Accepted Answer

A) True 
 B)False

Question 14

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. 
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.

Question 15

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

Question 16

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

Exam 15: Microbial Mechanisms of Pathogenicity

All of the following are methods of avoiding host antibodies EXCEPT

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

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

Injectable drugs are tested for endotoxins by

Which of the following cytopathic effects is cytocidal?

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

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

Superantigens produce intense immune responses by stimulating lymphocytes to produce

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

Antibiotics can lead to septic shock if used to treat

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

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

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

The most frequently used portal of entry for pathogens is the

All of the following bacteria release endotoxin EXCEPT

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

The Microbial World and You

Chemical Principles

Observing Microorganisms Through a Microscope

Functional Anatomy of Prokaryotic and Eukaryotic Cells

Microbial Metabolism

Microbial Growth

The Control of Microbial Growth

Microbial Genetics

Biotechnology and Recombinant Dna

Classification of Microorganisms

The Prokaryotes: Domains Bacteria and Archaea

The Eukaryotes: Fungi, Algae, Protozoa, and Helminths

Viruses, Viroids, and Prions

Principles of Disease and Epidemiology

Innate Immunity: Nonspecific Defenses of the Host

Adaptive Immunity: Specific Defenses of the Host

Practical Applications of Immunology

Disorders Associated With the Immune System

Antimicrobial Drugs

Microbial Diseases of the Skin and Eyes

Microbial Diseases of the Nervous System

Microbial Diseases of the Cardiovascular and Lymphatic Systems

Microbial Diseases of the Respiratory System

Microbial Diseases of the Digestive System

Microbial Diseases of the Urinary and Reproductive Systems

Environmental Microbiology

Applied and Industrial Microbiology

Filters

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