Question 1

Shigella and cholera toxin both

Accepted Answer

A)  have an A-B arrangement. 
B)  work through ADP ribosylation. 
C)  increase cAMP levels. 
D)  prevent protein synthesis. 
E)  are endotoxins. 
A)  have an A-B arrangement. 
B)  work through ADP ribosylation. 
C)  increase cAMP levels. 
D)  prevent protein synthesis. 
E)  are endotoxins.

Question 2

Amebiasis

Accepted Answer

A)  is caused by Cryptosporidium parvum. 
B)  often causes a bloody diarrhea. 
C)  is an infection of the stomach. 
D)  is restricted to temperate climates. 
E)  is caused by Cryptosporidium parvum AND often causes a bloody diarrhea. 
A)  is caused by Cryptosporidium parvum. 
B)  often causes a bloody diarrhea. 
C)  is an infection of the stomach. 
D)  is restricted to temperate climates. 
E)  is caused by Cryptosporidium parvum AND often causes a bloody diarrhea.

Question 3

The diarrhea of cholera has been described as

Accepted Answer

A)  a viscous fluid. 
B)  a rice water stool. 
C)  small in volume. 
D)  somewhat watery. 
E)  dysentery. 
A)  a viscous fluid. 
B)  a rice water stool. 
C)  small in volume. 
D)  somewhat watery. 
E)  dysentery.

Question 4

Why don't medications such as acyclovir cure oral herpes simplex infections?

Accepted Answer

A)  Acyclovir is an antiviral medication, but oral herpes is caused by a bacterium. 
B)  Acyclovir is an antibacterial medication, but oral herpes is caused by a virus. 
C)  Herpes simplex virus DNA persists in a latent form that is not removed by acyclovir. 
D)  Herpes simplex virus RNA persists in a latent form that is not removed by acyclovir. 
E)  Herpes simplex virus forms endospores that are resistant to all medications. 
A)  Acyclovir is an antiviral medication, but oral herpes is caused by a bacterium. 
B)  Acyclovir is an antibacterial medication, but oral herpes is caused by a virus. 
C)  Herpes simplex virus DNA persists in a latent form that is not removed by acyclovir. 
D)  Herpes simplex virus RNA persists in a latent form that is not removed by acyclovir. 
E)  Herpes simplex virus forms endospores that are resistant to all medications.

Question 5

Most cases of Salmonella gastroenteritis have a(n)

Accepted Answer

A)  water source. 
B)  human source. 
C)  plant source. 
D)  animal source. 
E)  human source AND animal source. 
A)  water source. 
B)  human source. 
C)  plant source. 
D)  animal source. 
E)  human source AND animal source.

Question 6

You are a nurse on a post-surgical ward. One of your patients is an elderly woman who has just had her gallbaldder removed. When you go into her room to check on her, you find that she has significant diarrhea, as well as fever and abdominal pain. You suspect that she has Clostridium difficile infection (CDI), and send a sample of her feces down to the hospital lab for analysis. The test result indicates that your patient does indeed have CDI. You make your patient comfortable and answer her questions about her illness.
-Your patient asks what treatment she will be given for the CDI. You explain that initially, she will be taken off all antibiotics. This may cure her by

Accepted Answer

A)  allowing her own gut normal microbiota to recover and to outcompete the C. difficile. 
B)  strengthening her innate and adaptive immune responses against the Clostridium difficile. 
C)  destroying any endospores that the C. difficile may have produced. 
D)  destroying any endospores that the C. difficile may have produced AND strengthening her innate and adaptive immune responses against the Clostridium difficile. 
E)  increasing antibiotic sensitivity in the Clostridium difficile, thereby weakening the pathogen so that the person's own immune system gets effectively rid of it. 
A)  allowing her own gut normal microbiota to recover and to outcompete the C. difficile. 
B)  strengthening her innate and adaptive immune responses against the Clostridium difficile. 
C)  destroying any endospores that the C. difficile may have produced. 
D)  destroying any endospores that the C. difficile may have produced AND strengthening her innate and adaptive immune responses against the Clostridium difficile. 
E)  increasing antibiotic sensitivity in the Clostridium difficile, thereby weakening the pathogen so that the person's own immune system gets effectively rid of it.

Question 7

Cryptosporidium parvum may infect

Accepted Answer

A)  dogs. 
B)  pigs. 
C)  cattle. 
D)  humans. 
E)  All of the choices are correct. 
A)  dogs. 
B)  pigs. 
C)  cattle. 
D)  humans. 
E)  All of the choices are correct.

Question 8

The animal(s) often associated with Salmonella strains is/are

Accepted Answer

A)  turtles. 
B)  iguanas. 
C)  baby chickens. 
D)  ducks. 
E)  All of the choices are correct. 
A)  turtles. 
B)  iguanas. 
C)  baby chickens. 
D)  ducks. 
E)  All of the choices are correct.

Question 9

Intestinal protozoan infections are typically spread by

Accepted Answer

A)  the respiratory route. 
B)  blood transfusion. 
C)  body fluids. 
D)  the fecal-oral route. 
E)  vectors. 
A)  the respiratory route. 
B)  blood transfusion. 
C)  body fluids. 
D)  the fecal-oral route. 
E)  vectors.

Question 10

Shigella moves from cell to cell using

Accepted Answer

A)  cilia. 
B)  actin tails. 
C)  pili. 
D)  flagella. 
E)  flagella AND pili. 
A)  cilia. 
B)  actin tails. 
C)  pili. 
D)  flagella. 
E)  flagella AND pili.

Question 11

The initial attachment required for establishment of an intestinal infection is by

Accepted Answer

A)  flagella. 
B)  pili. 
C)  cilia. 
D)  pseudopodia. 
E)  a capsule. 
A)  flagella. 
B)  pili. 
C)  cilia. 
D)  pseudopodia. 
E)  a capsule.

Question 12

Which of the following E. coli serovars produces a toxin somewhat similar to that produced by Shigella dysenteriae?

Accepted Answer

A)  Enterotoxigenic 
B)  Enteroinvasive 
C)  Enteropathogenic 
D)  Enterohemorrhagic 
E)  All of the choices are correct. 
A)  Enterotoxigenic 
B)  Enteroinvasive 
C)  Enteropathogenic 
D)  Enterohemorrhagic 
E)  All of the choices are correct.

Question 13

What are A/E lesions, produced by some strains of E. coli?

Accepted Answer

A)  Inflammatory patches caused by the attachment of the bacteria to the intestinal lining by small suction appendages. 
B)  Intestinal abscesses that form after the bacteria have entered M cells, destroying them and causing bloody diarrhea. 
C)  Intestinal damage characterized by pedestals that form under bacterial cells as a result of induced actin rearrangement in the intestinal cell. 
D)  Cytoplasmic extensions induced in intestinal epithelial cells by the injection of superantigens via type III secretion systems. 
E)  Appendages used by E. coli strains to avoid phagocytosis and enter M cells of the intestinal epithelium. 
A)  Inflammatory patches caused by the attachment of the bacteria to the intestinal lining by small suction appendages. 
B)  Intestinal abscesses that form after the bacteria have entered M cells, destroying them and causing bloody diarrhea. 
C)  Intestinal damage characterized by pedestals that form under bacterial cells as a result of induced actin rearrangement in the intestinal cell. 
D)  Cytoplasmic extensions induced in intestinal epithelial cells by the injection of superantigens via type III secretion systems. 
E)  Appendages used by E. coli strains to avoid phagocytosis and enter M cells of the intestinal epithelium.

Question 14

A common source of cholera infection is

Accepted Answer

A)  acid rain. 
B)  unpasteurized milk. 
C)  fecal contaminated water. 
D)  boiled water. 
E)  acid rain AND boiled water. 
A)  acid rain. 
B)  unpasteurized milk. 
C)  fecal contaminated water. 
D)  boiled water. 
E)  acid rain AND boiled water.

Question 15

Explain how Vibrio cholerae causes cholera without apparent damage to the intestinal epithelium.

Accepted Answer

A)  This microbe causes destruction of the cellular structures underneath the intestinal epithelium-this is what induces the watery rice-stool characteristic of the illness. This leaves the overlying intestinal epithelium intact. 
B)  This microbe directly invades the intestinal epithelial cells, but does not kill them. Instead, while multiplying inside them, it causes them to secrete large amounts of chloride ions. This induces water to follow by osmosis, resulting in the watery rice-stool characteristic of the illness. 
C)  This microbe attaches to the surface of intestinal epithelial cells, producing an exotoxin that causes the epithelium to secrete chloride ions. This induces large amounts of water to follow by osmosis, resulting in the watery rice-stool characteristic of the illness. 
D)  The inflammatory reaction to the presence of this microbe causes the watery rice-stool characteristic of the illness. Therefore, it's technically the immune response that initiates the disease, although this response is induced by the presence of the microbe on the intestinal epithelium. 
E)  This microbe attaches to the surface of intestinal epithelial cells, producing an endotoxin that causes the epithelium to secrete potassium ions. This induces small amounts of water to follow by osmosis, resulting in the watery rice-stool characteristic of the illness. 
A)  This microbe causes destruction of the cellular structures underneath the intestinal epithelium-this is what induces the watery rice-stool characteristic of the illness. This leaves the overlying intestinal epithelium intact. 
B)  This microbe directly invades the intestinal epithelial cells, but does not kill them. Instead, while multiplying inside them, it causes them to secrete large amounts of chloride ions. This induces water to follow by osmosis, resulting in the watery rice-stool characteristic of the illness. 
C)  This microbe attaches to the surface of intestinal epithelial cells, producing an exotoxin that causes the epithelium to secrete chloride ions. This induces large amounts of water to follow by osmosis, resulting in the watery rice-stool characteristic of the illness. 
D)  The inflammatory reaction to the presence of this microbe causes the watery rice-stool characteristic of the illness. Therefore, it's technically the immune response that initiates the disease, although this response is induced by the presence of the microbe on the intestinal epithelium. 
E)  This microbe attaches to the surface of intestinal epithelial cells, producing an endotoxin that causes the epithelium to secrete potassium ions. This induces small amounts of water to follow by osmosis, resulting in the watery rice-stool characteristic of the illness.

Question 16

Your brother is an enthusiatic hiker. He returns from a walking vacation and tells you that although he had a good time, he ran into a bit of trouble on one of the days he was away because he had got lost in the woods for several hours. Although he took enough food for the day, your brother ran out of water. Luckily, he came across a small stream and was able to fill up his water bottle and to finish his hike without any further problems. Your brother mentions as an aside that he must have eaten something bad while he was away, because he has had pretty bad diarrhea since he got back. He tells you he doesn't feel too bad, but that he has been having what he describes as "explosive diarrhea." He also complains of abdominal pain. You urge him to go to the doctor because you suspect that he may have something more than just food-related diarrhea. 
-You brother asks whether he will be given penicillin for his infection. What do you tell him?

Accepted Answer

A)  Yes-G. lamblia has a peptidoglycan cell wall. 
B)  Yes-G. lamblia has 70S ribosomes. 
C)  No-G. lamblia is a virus. 
D)  No-G. lamblia is a protozoan. 
E)  No-G. lamblia has a protective LPS layer. 
A)  Yes-G. lamblia has a peptidoglycan cell wall. 
B)  Yes-G. lamblia has 70S ribosomes. 
C)  No-G. lamblia is a virus. 
D)  No-G. lamblia is a protozoan. 
E)  No-G. lamblia has a protective LPS layer.

Question 17

This chemical compound, typically added to drinking water, makes enamel more resistant to dissolving in acid.

Accepted Answer

A)  Calcium 
B)  Chlorine 
C)  Chloramine 
D)  Fluoride 
E)  Phosphate 
A)  Calcium 
B)  Chlorine 
C)  Chloramine 
D)  Fluoride 
E)  Phosphate

Question 18

Where in the body does the latent, non-infectious, non-replicating form of the herpes simplex virus persist?

Accepted Answer

A)  Motor neurons 
B)  Sensory nerves 
C)  Red blood cells 
D)  Cranial nerves 
E)  Spinal cord 
A)  Motor neurons 
B)  Sensory nerves 
C)  Red blood cells 
D)  Cranial nerves 
E)  Spinal cord

Question 19

Please select the INCORRECT statement regarding mumps and oral herpes.

Accepted Answer

A)  Herpes simplex virus is an enveloped double-stranded DNA virus while mumps virus is an enveloped single-stranded RNA virus. 
B)  Both herpes simplex virus and mumps virus are extremely resistant to detergents and disinfectants. 
C)  Cells infected with HSV exhibit an intranuclear inclusion body; cells infected with mumps virus do not exhibit this body. 
D)  Herpes simplex virus and mumps virus are both transmitted in the saliva of infected people. 
E)  A person with HSV infection may experience recurrences while a person who has recovered from mumps has lifelong immunity. 
A)  Herpes simplex virus is an enveloped double-stranded DNA virus while mumps virus is an enveloped single-stranded RNA virus. 
B)  Both herpes simplex virus and mumps virus are extremely resistant to detergents and disinfectants. 
C)  Cells infected with HSV exhibit an intranuclear inclusion body; cells infected with mumps virus do not exhibit this body. 
D)  Herpes simplex virus and mumps virus are both transmitted in the saliva of infected people. 
E)  A person with HSV infection may experience recurrences while a person who has recovered from mumps has lifelong immunity.

Question 20

Only one serotype of mumps virus is known. Why is this important?

Accepted Answer

A)  It has been possible to create an effective vaccine that protects against this virus. 
B)  When only one serotype of a virus exists, there is a great risk of mutation in that agent. 
C)  Herd immunity is not possible in a population if there is only one serotype of a virus. 
D)  It is not possible to create a vaccine for an infectious agent if there is only one serotype of the agent. 
E)  B cells and cytotoxic T cells are unable to respond to a virus if there is only a single serotype of that virus. 
A)  It has been possible to create an effective vaccine that protects against this virus. 
B)  When only one serotype of a virus exists, there is a great risk of mutation in that agent. 
C)  Herd immunity is not possible in a population if there is only one serotype of a virus. 
D)  It is not possible to create a vaccine for an infectious agent if there is only one serotype of the agent. 
E)  B cells and cytotoxic T cells are unable to respond to a virus if there is only a single serotype of that virus.

Exam 24: Digestive System Infections

Shigella and cholera toxin both

Amebiasis

The diarrhea of cholera has been described as

Why don't medications such as acyclovir cure oral herpes simplex infections?

Most cases of Salmonella gastroenteritis have a(n)

Cryptosporidium parvum may infect

The animal(s) often associated with Salmonella strains is/are

Intestinal protozoan infections are typically spread by

Shigella moves from cell to cell using

The initial attachment required for establishment of an intestinal infection is by

Which of the following E. coli serovars produces a toxin somewhat similar to that produced by Shigella dysenteriae?

What are A/E lesions, produced by some strains of E. coli?

A common source of cholera infection is

Explain how Vibrio cholerae causes cholera without apparent damage to the intestinal epithelium.

This chemical compound, typically added to drinking water, makes enamel more resistant to dissolving in acid.

Where in the body does the latent, non-infectious, non-replicating form of the herpes simplex virus persist?

Please select the INCORRECT statement regarding mumps and oral herpes.

Only one serotype of mumps virus is known. Why is this important?

Humans and the Microbial World

The Molecules of Life

Microscopy and Cell Structure

Dynamics of Microbial Growth

Control of Microbial Growth

Microbial Metabolism: Fueling Cell Growth

The Blueprint of Life, from DNA to Protein

Bacterial Genetics

Biotechnology

Identifying and Classifying Microorganisms

The Diversity of Bacteria and Archaea

The Eukaryotic Members of the Microbial World

Viruses, Viroids, and Prions

The Innate Immune Response

The Adaptive Immune Response

Host-Microbe Interactions

Immunological Disorders

Applications of Immune Responses

Epidemiology

Antimicrobial Medications

Respiratory System Infections

Skin Infections

Wound Infections

Blood and Lymphatic Infections

Nervous System Infections

Genitourinary Tract Infections

Microbial Ecology

Environmental Microbiology: Treatment of Water, Wastes, and Polluted Habitats

Food Microbiology

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