Deck 23: Microbial Diseases of the Digestive System

Question 1

All of the following are true statements concerning staphylococcal food poisoning EXCEPT:

A) Enterotoxins involved in the food poisoning are heat stable.
B) The number of cases is unknown.
C) Contaminated food can be detected by its unusual taste.
D) Outbreaks are usually associated with large social functions.
E) Antibiotics are not an effective means of treatment.

Answer 1

C

Question 2

Which of the following is NOT an accessory digestive organ?

A) the gallbladder
B) the esophagus
C) the pancreas
D) the liver
E) the tongue

Answer 2

B

Question 3

The most important virulence factor of Vibrio cholerae is

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

Answer 3

C

Question 4

The most common bacterial cause of diarrhea in the United States is

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

Question 5

Streptococcus mutans is associated with

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

Question 6

All of the following statements accurately characterize Salmonella EXCEPT:

A) It is not part of the normal microbiota in humans.
B) Virulent strains are resistant to stomach acid.
C) It is a motile, Gram- negative bacillus.
D) There are over 2000 species known.
E) S. enterica is thought to be the only species.

Question 7

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

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

Question 8

E. coli O157:H7 can be transmitted by which of the following?

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

Question 9

All of the following are normal microbiota of the colon EXCEPT:

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

Question 10

An outbreak of gastroenteritis on a cruise ship might be caused by all of the following EXCEPT:

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

Question 11

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

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

Question 12

All of the following are true statements concerning oral herpes EXCEPT:

A) Lesions can be triggered by emotional stress or menstruation.
B) Primary infections are usually asymptomatic.
C) The virus establishes a latent infection in the trigeminal nerve ganglion.
D) Lesions become more severe with each recurrence.
E) Ninety percent of all cases are caused by HSV- 1.

Question 13

Shigellosis can be differentiated from salmonellosis by the fact that Shigella

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

Question 14

Porphyromonas gingivalis is associated with

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

Question 15

All of the following are characteristics of coliforms EXCEPT:

A) they include bacteria such as E. coli.
B) they are all facultatively anaerobic.
C) they are found in the intestinal tracts of humans and animals.
D) they are Gram- negative bacilli.
E) they ferment lactose.

Question 16

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

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

Question 17

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

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

Question 18

Which of the following serotypes of Salmonella enterica causes most US cases of human salmonellosis?

A) enteritidis
B) paratyphi
C) Both A and C are correct.
D) typhimurium
E) A, B, and C are correct.

Question 19

The most common cause of traveler's diarrhea is

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

Question 20

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

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

Question 21

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

Question 22

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

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

Question 23

All of the following are true statements concerning the association of hepatitis B with liver cancer EXCEPT:

A) Chronic carriers of HBV are 200 times more likely to develop liver cancer.
B) HBV integration may activate oncogenes.
C) Liver cancer is common in geographic areas with a high prevalence of hepatitis B infection.
D) The HBV genome does not integrate into liver cancer cells.
E) Liver cancer cells express HBV antigens.

Question 24

What is the primary symptom of Enterobius infections?

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

Question 25

All of the following are true statements concerning Entamoeba histolytica EXCEPT:

A) It uses pseudopodia to attach to the intestinal lining.
B) It causes a potentially fatal disease.
C) It reproduces by binary fission.
D) It is diagnosed by the identification of microscopic cysts in the stool.
E) It is carried asymptomatically in 90% of the world's population.

Question 26

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

Question 27

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

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

Question 28

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

Question 29

Which of the following hepatitis viruses is spread by fecally contaminated drinking water?

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

Question 30

All tapeworms are intestinal parasites that completely lack digestive systems.

Question 31

Tapeworms are usually transmitted to humans through ingestion of

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

Question 32

Which of the following causes "beaver fever"?

A) Enterobius
B) Entamoeba
C) Campylobacter
D) Taenia
E) Giardia

Question 33

Which of the following is a common childhood parasite?

A) Giardia
B) Taenia
C) Enterobius
D) Entamoeba
E) Cryptosporidium

Question 34

Which of the following hepatitis viruses usually produces subclinical infections?

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

Question 35

Bile, a substance produced by the liver, helps to emulsify fats for digestion.

Question 36

A vaccine is available against which of the following?

A) hepatitis A
B) hepatitis B
C) hepatitis C
D) Both A and B are correct.
E) A, B, and C are correct.

Question 37

All of the following are symptoms associated with hepatitis EXCEPT:

A) dark urine.
B) jaundice.
C) nausea and vomiting.
D) a widespread rash.
E) weight loss.

Question 38

Which of the following is a notable symptom of giardiasis?

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

Question 39

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

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

Question 40

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

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

Question 41

Supportive care is the only treatment for staphylococcal food poisoning.

Question 42

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

Question 43

The internal surface of the folds into finger- like projections called villi in order to increase the surfa area for absorption.

Question 44

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

Question 45

_ streptococci are alpha- hemolytic Gram- positive cocci most often found in the oral cavity.

Question 46

E. coli O157:H7 produces _ toxin, which inhibits protein synthesis, kills cells, and can result in death of the infected individual.

Question 47

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

Question 48

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

Question 49

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

Question 50

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

Question 51

Beavers are a common zoonotic source of in the wild.

Question 52

are ulcers that pierce the stomach or intestines, and can be a severe consequence of H. pylori
infection.

Question 53

is a severe and painful type of bacterial gastroenteritis characterized primarily by bloody diarrhea.

Question 54

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

Question 55

O1 el Tor is a bacterial strain responsible for the pandemics of seen worldwide since 1817.

Question 56

Simultaneous infection, or , with hepatitis B and hepatitis D viruses can result in a severe acute disease.

Question 57

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

Question 58

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

Question 59

is inflammation of the liver that can be produced by a variety of causes, including viral infections.

Question 60

The causative agent of pinworm infections is an example of a long, thin, unsegmented helminthic worm called a(n) _ .

Question 61

Describe some of the evidence linking hepatitis B infections with liver cancer.

Question 62

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

Question 63

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

Question 64

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

Question 65

List and describe the three types of amebiasis.