Deck 23: Microbial Diseases of the Digestive System

Question 1

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

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

Answer 1

C

Question 2

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

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

Answer 2

D

Question 3

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

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

Answer 3

E

Question 4

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

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

Question 5

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

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

Question 6

Which of the following is zoonotic?

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

Question 7

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

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

Question 8

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

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

Question 9

The most common cause of travelerʹs diarrhea is

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

Question 10

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

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

Question 11

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

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

Question 12

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

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

Question 13

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

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

Question 14

The is an accessory organ of the digestive system.

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

Question 15

Porphyromonas gingivalis contributes to the development of

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

Question 16

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) the bacteria release toxins when they are digested.
D) toxins produced by the bacteria growing in the food are ingested along with the food.
E) affected people appear drunk.

Question 17

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

Question 18

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

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

Question 19

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) multiplies in the host cellʹs cytosol.
D) causes severe diarrhea, abdominal cramps, and fever.
E) kills host cells.

Question 20

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

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

Question 21

Which of the following is a notable symptom of giardiasis?

A) ʺrice-waterʺ stools
B) jaundice
C) dysentery
D) irritability and sleep disturbance
E) foul-smelling ʺrotten eggʺ stools

Question 22

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

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

Question 23

Chronic infection with may progress to hepatic cancer.

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

Question 24

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

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

Question 25

Peritonitis may develop in severe cases of

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

Question 26

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

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

Question 27

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

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

Question 28

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. The man has a history of kidney transplant and recently returned from an overseas trip. The man may be infected with

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

Question 29

Accessory organ infections are caused by

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

Question 30

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

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

Question 31

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

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

Question 32

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

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

Question 33

The primary treatment for viral gastroenteritis is

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

Question 34

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

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

Question 35

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

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

Question 36

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

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

Question 37

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

Question 38

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

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

Question 39

Tapeworms are usually transmitted to humans through ingestion of

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

Question 40

Observation of the specimens in the figure is diagnostic for

A) Enterobius vermicularis.
B) Anisakis simplex.
C) Cryptosporidium parvum.
D) Giardia intestinalis.
E) Taenia solium.

Question 41

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

Question 42

A bacterial strain known as O1 El Tor is responsible for pandemics of (cholera/shigellosis/typhoid) seen worldwide since 1817.

Question 43

Helicobacter pylori produces (bicarbonate/carbohydrates/urease) to reduce the acidity of the stomach fluids.

Question 44

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

Question 45

Peptic ulcers are erosions of the lining of the small or large intestines.

Question 46

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

Question 47

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

Question 48

All tapeworms are intestinal parasites that completely lack digestive systems.

Question 49

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

Question 50

Vomiting is a common sign of viral gastroenteritis.

Question 51

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 52

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

Question 53

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

Question 54

Contamination of meat with tapeworm cysts can be detected by visual inspection.

Question 55

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

Question 56

The normal intermediate host for Taenia solium is (cows/humans/pigs).

Question 57

The causative agent of pinworm infections is an example of a long, cylindrical, unsegmented helminth called a (cestode/nematode/trematode).

Question 58

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

Question 59

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

Question 60

Supportive care is the only treatment for staphylococcal food poisoning.

Question 61

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

Question 62

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 63

AIDS patients sometimes suffer from pain and difficulty swallowing as a result of developing herpes (esophagitis/gingivostomatitis/pharyngitis) along with fever and chills.

Question 64

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

Question 65

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

Question 66

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

Question 67

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

Question 68

List and compare the three types of amebiasis.

Question 69

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

Question 70

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