Deck 23: Microbial Diseases of the Digestive System

Question 1

Shigellosis can be differentiated from salmonellosis by the fact that Shigella

A) stimulates intestinal epithelial cells to phagocytize it.
B) multiplies in phagocytic vesicles.
C) kills host cells.
D) multiplies in the host cell's cytosol.
E) causes severe diarrhea, abdominal cramps, and fever.

Answer 1

D

Question 2

The most common cause of traveler's diarrhea is

A) Salmonella enterica.
B) Giardia intestinalis.
C) Cryptosporidium parvum.
D) Escherichia coli.
E) Shigella flexneri.

Answer 2

D

Question 3

The ________ is an accessory organ of the digestive system.

A) esophagus
B) stomach
C) tongue
D) duodenum
E) anus

Answer 3

C

Question 4

Most peptic ulcers are the result of colonization of the stomach by

A) Vibrio cholerae.
B) Escherichia coli O157:H7.
C) Shigella dysenteriae.
D) Salmonella enterica.
E) Helicobacter pylori.

Question 5

Escherichia coli O157:H7 is primarily associated with which of the following foods?

A) ground beef
B) dairy products
C) eggs
D) fomites
E) pork

Question 6

Urease is an important virulence factor of which of the following?

A) Porphyromonas gingivalis
B) Vibrio cholerae
C) Escherichia coli O157:H7
D) Helicobacter pylori
E) Shigella dysenteriae

Question 7

Where in the digestive tract does most of the absorption of nutrients take place?

A) the large intestine
B) the small intestine
C) the rectum
D) the stomach
E) the esophagus

Question 8

The major symptoms of cholera are attributable to which of the following?

A) production of urease
B) activity of a type III secretion system
C) cessation of protein synthesis in host cells
D) death of cells lining the intestinal tract
E) activation of adenylate cyclase

Question 9

The viruses responsible for the majority of infant deaths resulting from diarrhea in the world are the

A) noroviruses.
B) rotaviruses.
C) caliciviruses.
D) astroviruses.
E) hepaciviruses.

Question 10

A young woman being treated for serious burns develops severe diarrhea accompanied by intense abdominal pain. She passes several watery, foul-smelling, bloody stools a day. A colonoscopy reveals patches of yellowish lesions in the large intestine. The probable causative agent is

A) Giardia intestinalis.
B) Clostridium difficile.
C) Campylobacter.
D) Salmonella enterica serotype Typhi.
E) Vibrio cholerae.

Question 11

Which of the following is a fungus that commonly lives in the large intestine?

A) Bacteroides
B) Escherichia
C) Campylobacter
D) Candida
E) Lactobacillus

Question 12

Which of the following is the major sign or symptom of mumps?

A) diarrhea
B) nausea and vomiting
C) deafness
D) parotitis
E) difficulty in breathing

Question 13

The bacterium ________ adheres to and grows on teeth, contributing to dental plaque formation.

A) Streptococcus mutans
B) Streptococcus agalactiae
C) viridians streptococci
D) Porphyromonas gingivalis
E) Enterobacter

Question 14

Which of the following produce the type III secretion system virulence factor?

A) E. coli O157:H7
B) Shigella
C) Salmonella
D) both E. coli O157:H7 and Salmonella
E) E. coli O157:H7, Shigella and Salmonella

Question 15

The most common bacterial cause of diarrhea that sends people to doctors in the United States is

A) Salmonella.
B) Staphylococcus.
C) Vibrio.
D) Escherichia.
E) Campylobacter.

Question 16

The virulence factor of Vibrio cholera, which is primarily responsible for the signs and symptoms of cholera, is

A) the presence of polar flagella.
B) its ability to survive in freshwater.
C) its ability to form biofilms in saltwater.
D) its activation of certain genes within the human body.
E) its ability to produce a potent exotoxin.

Question 17

Which of the following statements is TRUE with regard to oral herpes?

A) Lesions become more severe with each recurrence.
B) Ninety percent of all cases are caused by human herpesvirus 2 (HHV-2).
C) Lesions can be triggered by emotional stress or physiologic changes.
D) Primary infections are usually characterized by severe lesions.
E) There is an effective cure for oral herpes.

Question 18

Porphyromonas gingivalis contributes to the development of

A) gastroenteritis.
B) typhoid fever.
C) periodontitis.
D) food poisoning.
E) hepatitis.

Question 19

Infection with some Salmonella enterica serotypes can progress to typhoid fever when the bacteria

A) attach to cells of the small intestine.
B) induce endocytosis by intestinal cells.
C) reproduce within cells of the small intestine.
D) produce type III secretion system proteins.
E) enter the blood and are engulfed by phagocytes.

Question 20

Staphylococcal food poisoning is called an intoxication disorder because

A) toxic bacteria are ingested in the food.
B) the bacteria produce type III secretion system toxins.
C) affected people appear drunk.
D) toxins produced by the bacteria growing in the food are ingested along with the food.
E) the bacteria release toxins when they are digested.

Question 21

What member of the human intestinal microbiota occasionally causes life-threatening disease?

A) Escherichia coli O157:H7
B) Clostridium difficile
C) Salmonella enterica
D) Giardia intestinalis
E) Lactobacillus

Question 22

Peritonitis may develop in severe cases of

A) giardiasis.
B) hepatitis.
C) pinworm infestation.
D) typhoid.
E) peptic ulcer disease.

Question 23

The primary treatment for viral gastroenteritis is

A) fever reducers.
B) antiviral medications.
C) antitoxins.
D) rehydration therapy.
E) antidiarrheal medication.

Question 24

Of the following, who is most likely to develop a chronic infection with hepatitis B virus?

A) children between the ages of 2 and 12
B) newborns
C) females at puberty
D) young adults
E) the elderly

Question 25

Which of the following is a common childhood parasite in the United States?

A) Taenia solium
B) Enterobius vermicularis
C) Entamoeba histolytica
D) Cryptosporidium parvum
E) Giardia intestinalis

Question 26

Diagnosis of hepatitis B infection is made by the observation of which of the following in the patient's body fluids?

A) O antigens
B) enterotoxins
C) endospores
D) oocysts
E) Dane particles

Question 27

Which of the following is a notable symptom of giardiasis?

A) "rice-water" stools
B) irritability and sleep disturbance
C) jaundice
D) foul-smelling "rotten egg" stools
E) dysentery

Question 28

Eating sashimi (uncooked fish) is a risk factor for infection with

A) Entamoeba histolytica.
B) Taenia saginata.
C) Giardia intestinalis.
D) Enterobius vermicularis.
E) Anisakis simplex.

Question 29

The intracellular parasite usually acquired in contaminated drinking water that causes a persistent watery diarrhea is

A) hepatitis A virus.
B) Cryptosporidium parvum.
C) Entamoeba histolytica.
D) Vibrio cholerae.
E) norovirus.

Question 30

A man reports to his doctor that he is tired all the time and his urine has become darker in color. He has not experienced fever or vomiting recently. The physician notes that his eyes are yellowish and his abdomen is swollen and tender. The man has a history of kidney transplant. The man may be infected with

A) hepatitis A virus.
B) hepatitis C virus.
C) norovirus.
D) Shigella.
E) Entamoeba histolytica.

Question 31

Accessory organ infections are caused by

A) human herpesvirus 1.
B) norovirus.
C) mumps virus.
D) rotavirus.
E) enterovirus.

Question 32

Which of the following conditions usually results in severe acute liver damage?

A) co-infection with hepatitis A and hepatitis B viruses
B) superinfection with hepatitis B and hepatitis delta viruses
C) co-infection with hepatitis B and hepatitis delta viruses
D) superinfection with hepatitis A and hepatitis E viruses
E) co-infection with hepatitis B and hepatitis C viruses

Question 33

Observation of the specimens in the figure is diagnostic for

A) anisakiasis.
B) amebiasis.
C) pinworms.
D) giardiasis.
E) tapeworms.

Question 34

Which of the following statements is TRUE with regard to Entamoeba histolytica?

A) It reproduces by schizogony.
B) It may invade the peritoneal cavity, causing serious disease.
C) It causes a form of hepatitis.
D) It is an intracellular parasite.
E) An effective vaccine against infection is available.

Question 35

Human infestation with Taenia saginata results from ingesting ________ in undercooked intermediate host.

A) scolex
B) cysticerci
C) proglottids
D) eggs
E) cysts

Question 36

Care in the handling and disposal of diapers in day care centers may prevent the spread of which of the following?

A) hepatitis A virus
B) Giardia intestinalis
C) Salmonella enterica
D) Cryptosporidium parvum
E) norovirus

Question 37

Chronic infection with ________ may progress to hepatic cancer.

A) HAV
B) HBV
C) HCV
D) HEV
E) both HBV and HCV

Question 38

Intermediate hosts become infested with tapeworms through ingestion of

A) cysticerci.
B) gravid proglottids.
C) tapeworm eggs.
D) mature tapeworms.
E) tapeworm larvae.

Question 39

Where in a tapeworm would you expect to find fertilized eggs?

A) the neck region of the strobila
B) at the end of the strobila
C) inside the scolex
D) outside the cuticle
E) in all proglottids

Question 40

A large number of people in a community experience diarrhea with fever. Public health authorities investigate and find that the people are passing dark urine, and some have yellowish skin. Furthermore, all of the affected individuals recently ate at a new restaurant in town known for its wide variety of fresh imported vegetables. Which of the following is the most likely causative agent?

A) Escherichia coli O157:H7
B) Salmonella enterica
C) hepatitis A virus
D) hepatitis E virus
E) norovirus

Question 41

The portion of the gastrointestinal tract indicated by the arrow is the (ascending/descending/sigmoid/transverse) colon.

Question 42

Staphylococcus aureus produces (endotoxin/enterotoxin/toxin B) to cause intoxication.

Question 43

All regions of the digestive system have extensive microbiota.

Question 44

Production of (acid/dextran/glycocalyces) allows Streptococcus mutans to colonize the mouth.

Question 45

The form of infection with Entamoeba histolytica that is frequently asymptomatic is known as (extraintestinal/dysentery/luminal) amebiasis.

Question 46

The small intestine is the site of the majority of nutrient digestion and absorption.

Question 47

Jaundice is a frequent sign of inflammation of the (colon/liver/pancreas).

Question 48

Marine mammals are the normal host for Anisakis simplex adults.

Question 49

Supportive care is the only treatment for staphylococcal food poisoning.

Question 50

The larval stage of pinworms is found in (cows/fish/humans).

Question 51

Cholera toxin is composed of five A subunits and one B subunit.

Question 52

Invasive extraintestinal amebiasis is the most severe type of Entamoeba histolytica infection.

Question 53

Vomiting is a common sign of viral gastroenteritis.

Question 54

Plaque and tartar provide an environment for the growth of (Lactobacillus/Porphyromonas/Streptococcus) leading to periodontitis.

Question 55

Salmonella is part of the normal microbiota of virtually all vertebrates except humans.

Question 56

Complete recovery from hepatitis A infection occurs 99% of the time.

Question 57

Dysentery is a severe type of gastroenteritis in which stools contain mucus and blood.

Question 58

Isolation of Gram-positive (bacilli/cocci/vibrios) from food suspected of being the source of an outbreak of diarrhea indicates the disease is the result of bacterial intoxication.

Question 59

A diarrhea called "rice-water" stools is diagnostic of (campylobacteriosis/cholera/shigellosis/typhoid).

Question 60

The (liver/pancreas/villus) is the accessory organ responsible for producing digestive enzymes active in the small intestine.

Question 61

Escherichia coli O157:H7 produces (cholera/Shiga/Staphylococcal)-like toxin, which inhibits protein synthesis, kills cells, and can result in death of the infected individual.

Question 62

Explain how Helicobacter pylori is able to resist the unfavorable environment of the stomach in order to cause disease.

Question 63

Infection with (hepatitis/norovirus/rotavirus) is a common cause of viral gastroenteritis in adults.

Question 64

The accumulation of plaque can lead to the development of (abscesses/caries/ulcers) in the mouth.

Question 65

List and describe three virulence factors associated with bacteria that cause gastroenteritis.

Question 66

There are vaccines to prevent infectious hepatitis and serum hepatitis, but none to prevent chronic hepatitis. Discuss why this is so.

Question 67

A painful creeping ulcerating lesion on or near the lips is the result of infection with (corona/herpes/mumps) virus.

Question 68

Helicobacter pylori colonizes the (mouth/liver/stomach/intestine) and can cause severe inflammation and tissue erosion.

Question 69

Explain the role of the intestinal microbiota in the maintenance of health.

Question 70

List and compare the three types of amebiasis.