Question 1

Which of the following describes a case of food poisoning?

Accepted Answer

A)   After ingestion, a pathogen establishes infection in the host.
B)   Symptoms begin 1- 5 days after exposure.
C)   Recovery time can take anywhere from days to weeks.
D)   Signs and symptoms include fever, headache, muscle aches, nausea, diarrhea, and abdominal pain.
E)   Toxins from Staphylococcus aureus, Bacillus cereus, and Clostridium perfringens are responsible.F) A) and D)
G) D) and E)

Question 2

How does Helicobacter pylori cause stomach ulcers?

Accepted Answer

A)   Fimbriae enable to bacteria to penetrate the mucosa and bind to the epithelial lining of the stomach where toxins are released that bind and destroy epithelial cells.
B)   Peritrichous flagella help the bacteria squeeze through the mucosal lining to avoid stomach acid, where cytokine imposters are released which attract B cells and cause the immune response to destroy the epithelial lining of the stomach.
C)   The glycocalyx protects the bacteria from stomach acid as the bacteria enters a susceptible host and binds to an area of epithelial cells in the stomach with thin mucosa where toxins cause further damage and allow entry.
D)   Polar flagella help bacteria burrow into mucosal lining to escape stomach acid, where enzymes decrease the acidity around them, and they release a toxin to kill host cells.
E)   Bacterial capsules allow the bacteria to survive in the acidic lumen of the stomach as it releases toxins that bind to and destroy the epithelial lining of the stomach.F) C) and E)
G) A) and E) D

Question 3

After infection with a norovirus, the patient will be immune from all future norovirus infections.

Accepted Answer

A) True 
 B)False  False

Question 4

Why should antibiotics not be given to a patient with Escherichia coli O157:H7?

Accepted Answer

A)   This pathotype is part of the normal digestive tract of humans.
B)   Antibiotics tend to act as a hapten with this infection and are likely to cause an allergic response.
C)   This is not a bacterium, and therefore antibiotics would be ineffective.
D)   This pathotype is only found in cattle and does not infect humans.
E)   Antibiotics do not reduce disease and may precipitate HUS.F) A) and C)
G) A) and E)

Question 5

Which two hepatitis viruses primarily use the fecal- oral route for infection?

Accepted Answer

A)   hepatitis C and hepatitis D
B)   hepatitis B and hepatitis D
C)   hepatitis A and hepatitis E
D)   hepatitis D and hepatitis E
E)   hepatitis B and hepatitis CF) C) and E)
G) None of the above C

Question 6

Although four of the following options describe both rotavirus and norovirus, which one specifically describes norovirus?

Accepted Answer

A)   symptoms include vomiting, diarrhea, and nausea
B)   common in long- term care facilities
C)   definitive diagnosis requires detecting the RNA virus in the patient stool sample
D)   spreads via the fecal- oral route
E)   RNA virusF) B) and C)
G) C) and E)

Question 7

Limiting dietary sugars reduces lactic acid production by the bacteria in dental plaque and decreases the risk for dental caries.

Accepted Answer

A) True 
 B)False

Question 8

Which of the following features have not helped Giardia become the most common intestinal parasite?

Accepted Answer

A)   It can be transmitted via fecal- oral route, via contaminated fomites, or from direct contact with an infected patient.
B)   It lives in animals other than humans.
C)   No drugs are currently available for treatment.
D)   Ingesting as few as 10 cysts is sufficient to establish infection.
E)   A tough cyst form that resists chlorine disinfection used for municipal water treatment, UV light, and freezing.F) A) and D)
G) A) and B)

Question 9

Which of the following would not result from a C. difficile infection?

Accepted Answer

A)   severe abdominal pain, fever, nausea, and abundant watery diarrhea that may progress to dysentery
B)   pseudomembranous colitis
C)   toxic megacolon
D)   mild diarrhea
E)   hemolytic uremic syndromeF) C) and D)
G) A) and C)

Question 10

Tonsils at the back of the throat, the appendix, and Peyer's patches of the small intestine are all examples of mucosa- associated lymphoid tissue (MALT) found along the GI tract.

Accepted Answer

A) True 
 B)False

Question 11

Which hosts does the tapeworm Diphyllobothrium latum require to complete its lifecycle?

Accepted Answer

A)   crustaceans, fish, and mammals
B)   ants, sheep, and mammals
C)   snails, chickens, and mammals
D)   cows and humans
E)   pigs and mammalsF) B) and E)
G) C) and D)

Question 12

Which hepatitis virus has a genome made up of double- stranded DNA?

Accepted Answer

A)   hepatitis A
B)   hepatitis B
C)   hepatitis C
D)   hepatitis D
E)   hepatitis EF) B) and D)
G) A) and C)

Question 13

Trichinellosis, also known as trichinosis, occurs when

Accepted Answer

A)   inhaled cysts perforate the lungs as they make their way to the intestines.
B)   ingested cysts mature into worms in the intestines and the larvae migrate into blood and embed in muscles.
C)   ingested cysts mature into adult roundworms and release thousands of eggs as the adult releases toxins to promote severe diarrhea.
D)   ingested cysts mature into adult worms and cause the host to suffer from malnutrition.
E)   ingested cysts mature into adult tapeworms and release proglottids that force their way out of the anus.F) B) and E)
G) C) and D)

Question 14

Which of the following is not a virulence factor of Shigella species?

Accepted Answer

A)   the manufacture of several toxins that damage intestinal cells and induce fluid efflux
B)   the capability to cause stomach ulcers
C)   the capacity to pass between infected cells using an actin propulsion system
D)   a system that induces host cells to endocytose the bacteria
E)   the ability to escape from phagocytesF) A) and B)
G) C) and E)

Question 15

Besides diagnosing giardiasis via microscopic evaluation of feces for cysts or trophozoites, it can also be diagnosed

Accepted Answer

A)   by a urine sample.
B)   by a spinal fluid sample.
C)   by a blood sample.
D)   using PCR.
E)   by detecting Giardia antigens.F) A) and B)
G) All of the above

Question 16

How are Cryptosporidium sporozoites able to evade the immune system?

Accepted Answer

A)   They escape from phagocytes.
B)   They reside inside the host cells.
C)   They evade phagocytosis by using a capsule.
D)   They attach to host cells and build a protective membrane from modified host cell membrane materials.
E)   Special proteins bind and inhibit antibodies from adhering to them.F) A) and B)
G) C) and E)

Question 17

Oral rehydration is usually sufficient for most patients to fully recover from Vibrio cholerae.

Accepted Answer

A) True 
 B)False

Question 18

Which of the following is false of Campylobacter jejuni infections?

Accepted Answer

A)   It is a Gram- negative, flagellated, spiral- shaped bacterium that grows best in microaerophilic conditions.
B)   Although symptoms usually resolve within a week, in immune- compromised patients the bacteria may cause bacteremia, which could lead to sepsis and possibly septic shock.
C)   After ingestion, the bacteria burrow through the mucosal layer of the intestine and migrate through intestinal epithelial cells to multiply just beneath the epithelial layer.
D)   Infections are primarily associated with eating undercooked beef or cross- contaminating foods with raw beef juices.
E)   Antibodies that recognize C. jejuni's lipopolysaccharides can cross- react with sugars on neurons that trigger an autoimmune response against the nervous system called Guillain- Barré syndrome.F) A) and E)
G) D) and E)

Question 19

Giardiasis and cryptosporidiosis are both caused by helminth infections.

Accepted Answer

A) True 
 B)False

Question 20

Even though 90 percent of infections are asymptomatic, why should you always treat amebiasis?

Accepted Answer

A)   Pseudomembranous plaques form along the colon lining as toxins cause tissue damage in 10 percent of hosts.
B)   The immune system of the host can quickly become compromised.
C)   The protozoan can cause invasive disease that affects the liver, lungs, and brain.
D)   Exotoxin production can promote a vigorous inflammatory response in certain patients and also damage the cytoskeleton of the colon's epithelial cells.
E)   Asymptomatic patients can continue to spread the disease for years before dying themselves.F) A) and E)
G) A) and D)

Exam 19: Digestive System Infections

Which of the following describes a case of food poisoning?

Correct AnswerverifiedShow Answer

How does Helicobacter pylori cause stomach ulcers?

Correct AnswerverifiedD

After infection with a norovirus, the patient will be immune from all future norovirus infections.

Correct AnswerverifiedFalse

Why should antibiotics not be given to a patient with Escherichia coli O157:H7?

Correct AnswerverifiedShow Answer

Which two hepatitis viruses primarily use the fecal- oral route for infection?

Correct AnswerverifiedC

Although four of the following options describe both rotavirus and norovirus, which one specifically describes norovirus?

Correct AnswerverifiedShow Answer

Limiting dietary sugars reduces lactic acid production by the bacteria in dental plaque and decreases the risk for dental caries.

Correct AnswerverifiedShow Answer

Which of the following features have not helped Giardia become the most common intestinal parasite?

Correct AnswerverifiedShow Answer

Which of the following would not result from a C. difficile infection?

Correct AnswerverifiedShow Answer

Tonsils at the back of the throat, the appendix, and Peyer's patches of the small intestine are all examples of mucosa- associated lymphoid tissue (MALT) found along the GI tract.

Correct AnswerverifiedShow Answer

Which hosts does the tapeworm Diphyllobothrium latum require to complete its lifecycle?

Correct AnswerverifiedShow Answer

Which hepatitis virus has a genome made up of double- stranded DNA?

Correct AnswerverifiedShow Answer

Trichinellosis, also known as trichinosis, occurs when

Correct AnswerverifiedShow Answer

Which of the following is not a virulence factor of Shigella species?

Correct AnswerverifiedShow Answer

Besides diagnosing giardiasis via microscopic evaluation of feces for cysts or trophozoites, it can also be diagnosed

Correct AnswerverifiedShow Answer

How are Cryptosporidium sporozoites able to evade the immune system?

Correct AnswerverifiedShow Answer

Oral rehydration is usually sufficient for most patients to fully recover from Vibrio cholerae.

Correct AnswerverifiedShow Answer

Which of the following is false of Campylobacter jejuni infections?

Correct AnswerverifiedShow Answer

Giardiasis and cryptosporidiosis are both caused by helminth infections.

Correct AnswerverifiedShow Answer

Even though 90 percent of infections are asymptomatic, why should you always treat amebiasis?

Correct AnswerverifiedShow Answer

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