Question 1

The food products most commonly contaminated with Salmonella strains are

Accepted Answer

A)  meat and seafood. 
B)  eggs and poultry. 
C)  milk and cheese. 
D)  fruit and vegetables. 
E)  eggs and fruit. 
A)  meat and seafood. 
B)  eggs and poultry. 
C)  milk and cheese. 
D)  fruit and vegetables. 
E)  eggs and fruit.

Question 2

The mumps virus initially infects the respiratory tract.

Accepted Answer

A) True 
 B)False

Question 3

Which of the following is NOT a mechanism of spread of HBV?

Accepted Answer

A)  Blood 
B)  Blood products 
C)  Saliva 
D)  Semen 
E)  These are all mechanisms of spread for HBV. 
A)  Blood 
B)  Blood products 
C)  Saliva 
D)  Semen 
E)  These are all mechanisms of spread for HBV.

Question 4

Most North American outbreaks of Cyclospora cayetanensis have been associated with

Accepted Answer

A)  imported cattle. 
B)  iguanas. 
C)  imported vegetables. 
D)  chickens. 
E)  foreign mosquitoes. 
A)  imported cattle. 
B)  iguanas. 
C)  imported vegetables. 
D)  chickens. 
E)  foreign mosquitoes.

Question 5

Which of the following hepatitis viruses are transmitted by the fecal-oral route?

Accepted Answer

A)  HAV and HBV 
B)  HAV and HCV 
C)  HAV, HBV, and HCV 
D)  HAV and HEV 
E)  All hepatitis viruses 
A)  HAV and HBV 
B)  HAV and HCV 
C)  HAV, HBV, and HCV 
D)  HAV and HEV 
E)  All hepatitis viruses

Question 6

In which of these organs does a carrier of typhoid bacilli maintain the bacteria?

Accepted Answer

A)  Liver 
B)  Gallbladder 
C)  Peyer's patches 
D)  Colon 
E)  Liver AND Peyer's patches 
A)  Liver 
B)  Gallbladder 
C)  Peyer's patches 
D)  Colon 
E)  Liver AND Peyer's patches

Question 7

Which statement about rotavirus gastroenteritis is False?

Accepted Answer

A)  Rotaviruses are transmitted by the fecal-oral route. 
B)  Deaths related to the disease are usually caused by dehydration. 
C)  Most cases of the disease occur in infants and children. 
D)  Rotaviruses mainly infect the epithelial cells in the upper part of the small intestine. 
E)  There are no vaccines available for preventing rotavirus gastroenteritis. 
A)  Rotaviruses are transmitted by the fecal-oral route. 
B)  Deaths related to the disease are usually caused by dehydration. 
C)  Most cases of the disease occur in infants and children. 
D)  Rotaviruses mainly infect the epithelial cells in the upper part of the small intestine. 
E)  There are no vaccines available for preventing rotavirus gastroenteritis.

Question 8

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. 
-Giardiasis involves

Accepted Answer

A)  treatment with mitochondria-targeting medications. 
B)  aerosol droplet transmission. 
C)  a Gram-negative causative agent. 
D)  a protozoan that uses fimbriae for attachment. 
E)  production of resistant, infectious cysts. 
A)  treatment with mitochondria-targeting medications. 
B)  aerosol droplet transmission. 
C)  a Gram-negative causative agent. 
D)  a protozoan that uses fimbriae for attachment. 
E)  production of resistant, infectious cysts.

Question 9

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. 
-The signs and symptoms of giardiasis vary among people. Which of the following is your brother unlikely to experience with his infection?

Accepted Answer

A)  Bloody, frothy urine 
B)  Jaundice and malabsorption 
C)  Indigestion and gas 
D)  Nausea and vomiting 
E)  These all may be experienced with giardiasis. 
A)  Bloody, frothy urine 
B)  Jaundice and malabsorption 
C)  Indigestion and gas 
D)  Nausea and vomiting 
E)  These all may be experienced with giardiasis.

Question 10

The saliva of asymptomatic carriers of herpes simplex is not infectious.

Accepted Answer

A) True 
 B)False

Question 11

Mumps is a good candidate for elimination from the population due to

Accepted Answer

A)  the existence of an effective vaccine. 
B)  a human-only reservoir. 
C)  the absence of a latent state. 
D)  a single serotype. 
E)  All of the choices are correct. 
A)  the existence of an effective vaccine. 
B)  a human-only reservoir. 
C)  the absence of a latent state. 
D)  a single serotype. 
E)  All of the choices are correct.

Question 12

Please select the definition regarding aspects of the digestive system that is INCORRECT.

Accepted Answer

A)  Cariogenic-causing dental caries. 
B)  Dysentery-diarrhea characterized by fecal pus and blood. 
C)  Cirrhosis-liver scarring that interferes with function. 
D)  Gingivitis-inflammation of the teeth and gums. 
E)  Dysbiosis-imbalance of the intestinal normal microbiota. 
A)  Cariogenic-causing dental caries. 
B)  Dysentery-diarrhea characterized by fecal pus and blood. 
C)  Cirrhosis-liver scarring that interferes with function. 
D)  Gingivitis-inflammation of the teeth and gums. 
E)  Dysbiosis-imbalance of the intestinal normal microbiota.

Question 13

Both Giardia lamblia and Cryptosporidium parvum are resistant to chlorine.

Accepted Answer

A) True 
 B)False

Question 14

Why is it that the tongue and cheek epithelium doesn't provide a sufficient anaerobic environment for plaque anaerobes to grow, but the surface of teeth might?

Accepted Answer

A)  The epithelium is supplied with oxygen by capillary beds. This makes it a relatively aerobic environment and hostile to anaerobes. 
B)  The tooth enamel is supplied with oxygen by capillary beds. This makes it a relatively anaerobic environment and hostile to aerobes. 
C)  The surface of the tongue and cheek are constantly scraped by the action of consuming food. Layers of bacterial growth that might help to supply an anaerobic environment are scraped away, exposing lower levels to oxygen-rich air. 
D)  The surface of teeth like molars have many pits and crevices in which bacteria can grow. The bottoms of these pits are anaerobic. This isn't possible on the very smooth surface of the tongue and cheek epithelium. 
E)  The epithelium is supplied with carbon dioxide by capillary beds. This makes it a relatively anaerobic environment, friendly to obligate anaerobes. 
A)  The epithelium is supplied with oxygen by capillary beds. This makes it a relatively aerobic environment and hostile to anaerobes. 
B)  The tooth enamel is supplied with oxygen by capillary beds. This makes it a relatively anaerobic environment and hostile to aerobes. 
C)  The surface of the tongue and cheek are constantly scraped by the action of consuming food. Layers of bacterial growth that might help to supply an anaerobic environment are scraped away, exposing lower levels to oxygen-rich air. 
D)  The surface of teeth like molars have many pits and crevices in which bacteria can grow. The bottoms of these pits are anaerobic. This isn't possible on the very smooth surface of the tongue and cheek epithelium. 
E)  The epithelium is supplied with carbon dioxide by capillary beds. This makes it a relatively anaerobic environment, friendly to obligate anaerobes.

Question 15

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. 
-There are several stages in the life cycle of G. lamblia. Which is the correct sequence?
1) Trophozoites multiply in the intestine.
2) Mature cysts or trophozoites are released in feces.
3) Cysts pass through the stomach to the lower small intestine.
4) Dehydration in the large intestine stimulates formation of cysts.
5) Cysts enter the mouth by ingestion of contaminated food or water.
6) Trophozoites are released from the cysts.

Accepted Answer

A)  1, 2, 3, 4, 5, 6 
B)  2, 3, 1, 5, 4, 6 
C)  5, 2, 3, 1, 6, 4 
D)  5, 3, 6, 1, 4, 2 
E)  2, 5, 6, 1, 3, 4 
A)  1, 2, 3, 4, 5, 6 
B)  2, 3, 1, 5, 4, 6 
C)  5, 2, 3, 1, 6, 4 
D)  5, 3, 6, 1, 4, 2 
E)  2, 5, 6, 1, 3, 4

Question 16

How does H. pylori survive the acidic conditions of the stomach?

Accepted Answer

A)  Producing urease, an enzyme that converts urea to ammonia, thereby creating an alkaline microenvironment. 
B)  Burrowing within the layer of mucus that coats the stomach lining. 
C)  Producing urease, an enzyme that converts ammonia to urea, thereby creating an alkaline microenvironment. 
D)  Producing urease, an enzyme that converts urea to ammonia, thereby creating an alkaline microenvironment AND burrowing within the stomach mucus layer. 
E)  Producing urease, an enzyme that converts ammonia to urea, thereby creating an alkaline microenvironment AND covering its flagella with protective sheaths. 
A)  Producing urease, an enzyme that converts urea to ammonia, thereby creating an alkaline microenvironment. 
B)  Burrowing within the layer of mucus that coats the stomach lining. 
C)  Producing urease, an enzyme that converts ammonia to urea, thereby creating an alkaline microenvironment. 
D)  Producing urease, an enzyme that converts urea to ammonia, thereby creating an alkaline microenvironment AND burrowing within the stomach mucus layer. 
E)  Producing urease, an enzyme that converts ammonia to urea, thereby creating an alkaline microenvironment AND covering its flagella with protective sheaths.

Question 17

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.
-You tell your patient that her CDI is caused by a bacterium belonging to the genus Clostridium. Which of the following is True of all Clostridia?

Accepted Answer

A)  They are Gram-positive, rod-shaped, endospore-forming obligate anaerobes. 
B)  They are encapsulated, flagellated, toxin-producing aerobes. 
C)  They are Gram-negative, rod-shaped, endospore-forming obligate aerobes. 
D)  They are flagellated and always cause significant inflammation. 
E)  Clostridial infections only occur if a state of dysbiosis exists in the host. 
A)  They are Gram-positive, rod-shaped, endospore-forming obligate anaerobes. 
B)  They are encapsulated, flagellated, toxin-producing aerobes. 
C)  They are Gram-negative, rod-shaped, endospore-forming obligate aerobes. 
D)  They are flagellated and always cause significant inflammation. 
E)  Clostridial infections only occur if a state of dysbiosis exists in the host.

Question 18

Why is it difficult to determine the causative agents of periodontal disease?

Accepted Answer

A)  The agents are fastidious bacteria that cannot be cultured in the laboratory. 
B)  Identification requires 16S rDNA sequencing and not all bacteria have this gene. 
C)  The infections are polymicrobial, so multiple species of interacting bacteria are involved. 
D)  The causative agents are typically viruses, which are difficult to identify. 
E)  The causative agents are encased in biofilm polysaccharides that cannot be removed. 
A)  The agents are fastidious bacteria that cannot be cultured in the laboratory. 
B)  Identification requires 16S rDNA sequencing and not all bacteria have this gene. 
C)  The infections are polymicrobial, so multiple species of interacting bacteria are involved. 
D)  The causative agents are typically viruses, which are difficult to identify. 
E)  The causative agents are encased in biofilm polysaccharides that cannot be removed.

Question 19

Who determined that the cholera outbreak in 1850s London was due to contaminated water and approached the problem by removing the pump handle at the contaminated site?

Accepted Answer

A)  Pasteur 
B)  Snow 
C)  Koch 
D)  Smith 
E)  Semmelweis 
A)  Pasteur 
B)  Snow 
C)  Koch 
D)  Smith 
E)  Semmelweis

Question 20

Cyclospora cayetanensis has, so far, not been identified with an animal source.

Accepted Answer

A) True 
 B)False

Exam 24: Digestive System Infections

The food products most commonly contaminated with Salmonella strains are

The mumps virus initially infects the respiratory tract.

Which of the following is NOT a mechanism of spread of HBV?

Most North American outbreaks of Cyclospora cayetanensis have been associated with

Which of the following hepatitis viruses are transmitted by the fecal-oral route?

In which of these organs does a carrier of typhoid bacilli maintain the bacteria?

Which statement about rotavirus gastroenteritis is False?

The saliva of asymptomatic carriers of herpes simplex is not infectious.

Mumps is a good candidate for elimination from the population due to

Please select the definition regarding aspects of the digestive system that is INCORRECT.

Both Giardia lamblia and Cryptosporidium parvum are resistant to chlorine.

Why is it that the tongue and cheek epithelium doesn't provide a sufficient anaerobic environment for plaque anaerobes to grow, but the surface of teeth might?

How does H. pylori survive the acidic conditions of the stomach?

Why is it difficult to determine the causative agents of periodontal disease?

Who determined that the cholera outbreak in 1850s London was due to contaminated water and approached the problem by removing the pump handle at the contaminated site?

Cyclospora cayetanensis has, so far, not been identified with an animal source.

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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