Question 1

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

Accepted Answer

A) True 
 B)False

Question 2

Lysogenic bacteriophages contribute to bacterial virulence because bacteriophages

Accepted Answer

A)  produce toxins. 
B)  give new gene sequences to the host bacteria. 
C)  carry plasmids. 
D)  kill human cells. 
E)  kill the bacteria, causing release of endotoxins. 
A)  produce toxins. 
B)  give new gene sequences to the host bacteria. 
C)  carry plasmids. 
D)  kill human cells. 
E)  kill the bacteria, causing release of endotoxins.

Question 3

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

Accepted Answer

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

Question 4

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

Accepted Answer

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

Question 5

Botulism is caused by ingestion of a proteinaceous exotoxin; therefore, it can easily be prevented by

Accepted Answer

A)  filtering food. 
B)  preventing fecal contamination of food. 
C)  boiling food prior to consumption. 
D)  not eating canned food. 
E)  administering antibiotics to patients. 
A)  filtering food. 
B)  preventing fecal contamination of food. 
C)  boiling food prior to consumption. 
D)  not eating canned food. 
E)  administering antibiotics to patients.

Question 6

Most pathogens that gain access through the skin

Accepted Answer

A)  must be injected. 
B)  must adhere first while their invasive factors allow them to penetrate. 
C)  enter through hair follicles and sweat ducts. 
D)  can penetrate intact skin. 
E)  just infect the skin itself. 
A)  must be injected. 
B)  must adhere first while their invasive factors allow them to penetrate. 
C)  enter through hair follicles and sweat ducts. 
D)  can penetrate intact skin. 
E)  just infect the skin itself.

Question 7

All of the following are used by bacteria to attach to host cells EXCEPT

Accepted Answer

A)  A-B toxins. 
B)  M protein. 
C)  ligands. 
D)  capsules. 
E)  fimbriae. 
A)  A-B toxins. 
B)  M protein. 
C)  ligands. 
D)  capsules. 
E)  fimbriae.

Question 8

All of the following are examples of entry via the parenteral route EXCEPT

Accepted Answer

A)  injection. 
B)  surgery. 
C)  hair follicle. 
D)  bite. 
E)  skin cut. 
A)  injection. 
B)  surgery. 
C)  hair follicle. 
D)  bite. 
E)  skin cut.

Question 9

Cytopathic effects are changes in host cells due to

Accepted Answer

A)  viral infections. 
B)  helminthic infections. 
C)  protozoan infections. 
D)  fungal infections. 
E)  bacterial infections. 
A)  viral infections. 
B)  helminthic infections. 
C)  protozoan infections. 
D)  fungal infections. 
E)  bacterial infections.

Question 10

Which of the following is an example of direct damage due to bacterial infection?

Accepted Answer

A)  the invasion and lysis of intestinal cells by E. coli 
B)  the excessive secretion of fluids in a Vibrio cholera infection 
C)  the fever, nausea, and low blood pressure in a Salmonella infection 
D)  the hemolysis of red blood cells in a staphylococcal infection 
E)  the uncontrolled muscle contractions in Clostridium tetani infection 
A)  the invasion and lysis of intestinal cells by E. coli 
B)  the excessive secretion of fluids in a Vibrio cholera infection 
C)  the fever, nausea, and low blood pressure in a Salmonella infection 
D)  the hemolysis of red blood cells in a staphylococcal infection 
E)  the uncontrolled muscle contractions in Clostridium tetani infection

Question 11

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

Accepted Answer

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

Question 12

The ID50 is

Accepted Answer

A)  the dose that will cause an infection in some of the test population. 
B)  the dose that will cause an infection in 50 percent of the test population. 
C)  the dose that will kill some of the test population. 
D)  a measure of pathogenicity. 
E)  the dose that will kill 50 percent of the test population. 
A)  the dose that will cause an infection in some of the test population. 
B)  the dose that will cause an infection in 50 percent of the test population. 
C)  the dose that will kill some of the test population. 
D)  a measure of pathogenicity. 
E)  the dose that will kill 50 percent of the test population.

Question 13

Which of the following mechanisms is used by gram -negative bacteria to cross the blood-brain barrier?

Accepted Answer

A)  producing toxins 
B)  inducing endocytosis 
C)  producing fimbriae 
D)  antigenic variation 
E)  inducing TNF 
A)  producing toxins 
B)  inducing endocytosis 
C)  producing fimbriae 
D)  antigenic variation 
E)  inducing TNF

Question 14

Table 15.1 $$\begin{array} { | l | l | l | } 
\hline \text { Bacterium } & \text { P ortal of Entry } & \text { ID50 } \
\hline \text { Staphylococcus aureus } & \text { Wound } & < 10 \
\hline \text { Staphylococcus aureus } & \text { Wound + Ampicillin } & 300 \
\hline
\end{array}$$ Table 15.1 shows the ID50 for Staphylococcus aureus in wounds with and without the administration of ampicillin before surgery. Based on the data, the administration of ampicillin before surgery

Accepted Answer

A)  has no effect on risk of infection. 
B)  replaces tetracycline. 
C)  decreases the risk of staphylococcal infection. 
D)  increases the risk of staphylococcal infection. 
E)  The answer cannot be determined based on the information provided. 
A)  has no effect on risk of infection. 
B)  replaces tetracycline. 
C)  decreases the risk of staphylococcal infection. 
D)  increases the risk of staphylococcal infection. 
E)  The answer cannot be determined based on the information provided.

Question 15

Which of the following statements about staphylococcal enterotoxin is FALSE?

Accepted Answer

A)  It is a superantigen. 
B)  It is produced by Staphylococcus aureus growing in the hostʹs intestines. 
C)  It causes vomiting. 
D)  It causes diarrhea. 
E)  It is an exotoxin. 
A)  It is a superantigen. 
B)  It is produced by Staphylococcus aureus growing in the hostʹs intestines. 
C)  It causes vomiting. 
D)  It causes diarrhea. 
E)  It is an exotoxin.

Exam 15: Microbial Mechanisms of Pathogenicity

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

Lysogenic bacteriophages contribute to bacterial virulence because bacteriophages

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

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

Botulism is caused by ingestion of a proteinaceous exotoxin; therefore, it can easily be prevented by

Most pathogens that gain access through the skin

All of the following are used by bacteria to attach to host cells EXCEPT

All of the following are examples of entry via the parenteral route EXCEPT

Cytopathic effects are changes in host cells due to

Which of the following is an example of direct damage due to bacterial infection?

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

The ID50 is

Which of the following mechanisms is used by gram -negative bacteria to cross the blood-brain barrier?

Which of the following statements about staphylococcal enterotoxin is FALSE?

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 Dna Technology

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

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 Disease of the Urinary and Reproductive Systems

Environmental Microbiology

Applied and Industrial Microbiology

Innate Immunity: Nonspecific Defenses of the Host

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