Deck 23: Microbial Diseases of the Digestive System

Question 1

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.

Answer 1

E

Question 2

Which of the following serotypes of Salmonella enterica causes most cases of human salmonellosis in the United States?

A) Enteritidis
B) Paratyphi
C) Typhimurium
D) Typhi
E) both Enteritidis and Typhimurium

Answer 2

E

Question 3

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.

Answer 3

C

Question 4

Streptococcus mutans is associated with

A) dental caries.
B) periodontitis.
C) food poisoning.
D) severe diarrhea.
E) typhoid fever.

Question 5

The most common cause of traveler's diarrhea is

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

Question 6

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 7

Which of the following is an organ of the gastrointestinal tract?

A) the salivary glands
B) the gallbladder
C) the esophagus
D) the pancreas
E) the liver

Question 8

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.

Question 9

Where in the digestive tract does the absorption of water take place?

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

Question 10

Which of the following is now known to be the cause of most peptic ulcers?

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

Question 11

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 12

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 13

The common source of contamination in the majority of cases of staphylococcal food poisoning (intoxication) is

A) dairy products.
B) eggs.
C) fecal contamination.
D) the skin of food preparers.
E) contaminated water.

Question 14

The most important virulence factor of Vibrio cholerae 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 15

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 16

Which of the following is a defining characteristic of coliforms?

A) They are Gram-positive bacilli.
B) They are found in the intestinal tracts of humans and animals.
C) They ferment lactose.
D) They are strictly anaerobic.
E) They are never pathogenic.

Question 17

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 18

Porphyromonas gingivalis is associated with

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

Question 19

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

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

Question 20

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 21

Which of the following hepatitis viruses usually produces subclinical infections?

A) HAV
B) HBV
C) HCV
D) HDV
E) HEV

Question 22

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 23

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

Question 24

Which of the following causes "beaver fever?"

A) Entamoeba histolytica
B) Taenia saginata
C) Giardia intestinalis
D) Enterobius vermicularis
E) Campylobacter jejuni

Question 25

What is the primary symptom of Enterobius infections?

A) bloody diarrhea
B) liver enlargement
C) perianal itching
D) intestinal blockage
E) vomiting and nausea

Question 26

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 27

Differentiation between Taenia saginata and Taenia solium is carried out via examination of the

A) scolex.
B) cysticerci.
C) proglottids.
D) eggs.
E) larvae.

Question 28

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 29

Peritonitis may develop in severe cases of

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

Question 30

The DNA virus known as "serum hepatitis" is

A) HAV.
B) HBV.
C) HCV.
D) HDV.
E) HEV.

Question 31

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 32

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

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

Question 33

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

A) It reproduces by schizogony.
B) It uses pseudopodia to attach to the intestinal lining.
C) It causes a form of hepatitis.
D) It is an intracellular parasite.
E) An effective vaccine against infection is available.

Question 34

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) cold sores

Question 35

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 36

Tapeworms are usually transmitted to humans through ingestion of

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

Question 37

Accessory organ infections are caused by

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

Question 38

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 39

A vaccine is available against which of the following?

A) hepatitis A
B) hepatitis B
C) hepatitis C
D) both hepatitis A and hepatitis B
E) hepatitis A, B, and C

Question 40

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 41

Beavers are a common zoonotic source of __________ in the wild.

Question 42

Isolation of Gram-positive cocci in clusters from food suspected of being the source of an outbreak of diarrhea indicates the disease is the result of __________ intoxication.

Question 43

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

Question 44

Commonly called trench mouth during World War I, acute necrotizing ulcerative __________ is an extreme and rare type of periodontal disease.

Question 45

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

Question 46

The causative agent of pinworm infections is an example of a long, thin, unsegmented helminth called a(n) __________.

Question 47

Hepatitis is inflammation of the __________ that can be caused by a variety of agents, including viral infections.

Question 48

Supportive care is the only treatment for staphylococcal food poisoning.

Question 49

The internal surface of the small intestine folds into finger-like projections called __________ to increase the surface area for absorption.

Question 50

All tapeworms are intestinal parasites that completely lack digestive systems.

Question 51

Vomiting is a common sign of viral gastroenteritis..

Question 52

Ulcers that pierce the stomach or intestines, and can be a sever consequence of Helicobacter pylori infection, are __________. (Be sure your answer is plural.)

Question 53

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

Question 54

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

Question 55

Pigs serve as a(n) __________, or secondary, host of Taenia solium.

Question 56

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

Question 57

O1 El Tor is a bacterial strain responsible for pandemics of __________ seen worldwide since 1817.

Question 58

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

Question 59

Viridans streptococci are alpha-hemolytic Gram-positive cocci most often found in the __________ cavity.

Question 60

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

Question 61

Topical creams containing __________ can be effective in the treatment of fever blisters.

Question 62

Young patients with fever blisters often have a severe infection called herpetic __________ in which lesions extend into the oral cavity.

Question 63

List and compare the three types of amebiasis.

Question 64

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

Question 65

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

Question 66

Escherichia coli O157:H7 produces __________-like toxin, which inhibits protein synthesis, kills cells, and can result in death of the infected individual. (Be sure to use capital letters appropriately.)

Question 67

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

Question 68

A severe and painful type of bacterial gastroenteritis, characterized primarily by bloody diarrhea, is __________.

Question 69

A biofilm commonly called dental __________ is associated with most cases of dental caries.

Question 70

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