Deck 22: Infectious Diseases Affecting the Gastrointestinal Tract

Question 1

Which of the following groups of microorganisms is not found among the normal gut microbiota?

A) Firmicutes (Streptococcus, Staphylococcus, Clostridium, Bacillus)
B) Protozoa (Entamoeba, Trichomonas)
C) Enterics (Escherichia, Enterobacter)
D) Spirilla (Leptospira, Borrelia)
E) Fungi (Candida)

Answer 1

D

Question 2

Cells of the immune system are not found in which of the following tissues in the gastrointestinal tract?

A) Tonsils and adenoids
B) Appendix
C) Peyer's patches
D) Tooth enamel

Answer 2

D

Question 3

Most of the bacteria involved in periodontal disease are obligate (strict)anaerobes.Explain why this is the case.

A) Mouthwashes and toothpaste destroy most of the strict aerobes that are found on teeth.
B) The oral cavity is a low oxygen environment.
C) The crevice between the gingiva and the tooth is low in oxygen.
D) Sugar and other carbohydrates used by the oral bacteria can be more easily consumed anaerobically.

Answer 3

C

Question 4

Defenses of the GI tract against pathogens include ______.

A) mucus, acid, and saliva
B) secretory IgA and lysozyme
C) peristalsis
D) GALT (gut-associated lymphoid tissue)
E) All of the choices are correct.

Question 5

GALT refers to

A) defenses of the GI tract: Gut microbes, Adenoids, Lysozyme, Tonsils.
B) Gut-Associated Lymphoid Tissue.
C) Gingival Adhesive Labile Toxin, a virulence factor for gingivitis.
D) sterile organs of the GI tract: Gingiva, Appendix, Large intestine, Tonsils.

Question 6

Salmonella are ______.

A) methane producers
B) motile
C) gram-positive bacilli
D) lactose fermenters
E) All of the choices are correct.

Question 7

Which of the following statements is incorrect about shigellosis?

A) Outbreaks have occurred in day care centers.
B) It frequently complicates to sepsis.
C) Human carriers cause fecal transmission.
D) It is also called dysentery.
E) Symptoms include watery diarrhea with bloody, mucoid stools and abdominal cramps.

Question 8

Which of the following statements regarding shiga toxin-producing E.coli is correct?

A)It synthesizes shiga exotoxin from a bacteriophage.
B)It synthesizes shiga exotoxin from the E.coli chromosome.
C)It synthesizes shiga endotoxin from a bacteriophage.
D)It synthesizes shiga endotoxin from the E.coli chromosome.

Question 9

E.coli O157:H7 secretes shiga exotoxin.

Question 10

Which of the following fluids within the gastrointestinal tract is correctly paired with its antimicrobial effect?

A) Stomach fluid; high pH
B) Bile; lactoferrin
C) Pancreatic fluid; IgE
D) Saliva; lysozyme

Question 11

Enterotoxin production is a characteristic of ______.

A) Clostridium perfringens
B) Clostridium difficile
C) Clostridium tetani
D) Clostridium botulinum

Question 12

Antibiotics are used to treat diarrhea caused by shiga toxin-producingE.coli.

Question 13

Oral bacteria on the tooth surface

A) develop a biofilm.
B) use fimbriae and slime layers to adhere.
C) metabolize sucrose, produce sticky glucans, and form plaque.
D) All of the above are correct.

Question 14

Enteropathogenic
E. coli (EPEC) causes gut effacement with shiga toxin.

Question 15

There are no infectious agents that can penetrate intact skin.

Question 16

Which organ of the gastrointestinal tract has a large commensal population of microorganisms?

A) Pancreas
B) Liver
C) Salivary glands
D) Small intestine
E) Large intestine

Question 17

The gastrointestinal tract has both a long tube that nutrients traverse from mouth to anus and accessory organs that aid in food digestion.From the following list of organs in the digestive system,identify the mismatch.

A) Rectum; part of the digestive tube
B) Liver; part of the digestive tube
C) Pharynx; part of the digestive tube
D) Appendix; accessory organ
E) Salivary glands; accessory organ

Question 18

The gastrointestinal microbiota has been implicated in the development of

A) non-infectious diseases like obesity.
B) appropriate immune responses to microbial antigens.
C) dental plaque.
D) All of the responses are correct.

Question 19

Because the gut microbiome is a tremendously diverse population,an infection can be viewed as

A) the presence of helminths instead of the normal bacteria in the gut.
B) an increase in the overall number of microbes in the gut.
C) a shift in the relative proportions of the microbes in this environment.
D) a change in a person's enterotype.

Question 20

Despite acidic conditions,some microorganisms have been found residing within the human stomach.

Question 21

All of the following are true of acute necrotizing ulcerative gingivitis (ANUG)except that it

A) is common in AIDS patients.
B) is associated with severe pain, bleeding, pseudomembranes, and necrosis.
C) involves Treponema vincentii, Prevotella intermedia, and Fusobacterium.
D) is due to poor oral hygiene, altered host defenses, or prior gum disease.
E) is highly contagious.

Question 22

Which of the following is not true of enterotoxigenic

A) It causes traveler's diarrhea.
B) It can be life-threatening in infants.
C) It causes a high fever.
D) Fluid replacement is vital to surviving an infection.
E) coli (ETEC)?

Question 23

The most common infectious disease in humans is ______.

A) dental caries
B) gastritis
C) the common cold
D) pharyngitis
E) diarrhea

Question 24

The most immediate and important treatment needed to prevent death in cholera victims is ______.

A) broad-spectrum antimicrobials
B) antitoxin
C) surgery
D) water and electrolyte replacement

Question 25

Gingivitis

A) involves the formation of calculus and plaque.
B) is primarily caused by normal anaerobic biota.
C) involves a crevice in the gum along the tooth.
D) may involve archaeal species.
E) All of the choices are correct.

Question 26

The causative organism for mumps is ______.

A) Vibrio cholerae
B) Corynebacterium diphtheriae
C) Morbillivirus
D) Paramyxovirus
E) Streptococcus pyogenes

Question 27

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

A) Campylobacter
B) Salmonella
C) E. coli
D) Shigella

Question 28

Which of the following statements is not true regarding Clostridium difficile?

A) Infection is precipitated by broad-spectrum antibiotic therapy.
B) It produces "rice-water" stools.
C) It is part of the normal intestinal biota.
D) It is also called pseudomembranous colitis.
E) It is a gram-positive, endospore-forming rod.

Question 29

Symptoms of cryptosporidiosis include

A) bloody, mucus-filled stools and fever.
B) headache, sweats, vomiting, severe abdominal cramps, and diarrhea.
C) chills, fever, and sweats.
D) a red skin papule that spreads to a large ulcer.

Question 30

A current news story describes a cruise ship in the Carribbean with an outbreak of diarrheal illness,affecting hundreds of people.With all of those people in a small area,opening and closing doors,using handrails,etc,you are trying to figure out what infectious agent may be the cause.Your most likely guess is that the pathogen is ______.

A)Clostridium difficile
B)hepatitis B
C)norovirus
D) cholera
E)shiga-toxin-producing E.coli

Question 31

Infection with which apicomplexan has been associated with fecal-contaminated drinking water?

A) Entamoeba histolytica
B) Ascaris lumbricoides
C) Cryptosporidium
D) Rotavirus

Question 32

The virulence of Vibrio cholerae is due to its ______.

A) neurotoxin
B) invasive enzymes
C) enterotoxin
D) capsule

Question 33

The primary viral cause of chronic diarrhea globally is ______.

A) rotavirus
B) Cryptosporidium
C) arbovirus
D) adenovirus
E) norovirus

Question 34

Which of the following statements regarding Clostridium difficile infection is incorrect?

A) It is a colitis that is a superinfection.
B) It is associated with disruption of normal biota due to broad-spectrum antimicrobials.
C) It is due to ingestion of contaminated, improperly stored, cooked meats and gravies.
D) It is the major cause of diarrhea in hospitals.

Question 35

Escherichia coli infections

A) are often transmitted by fecal contaminated water and food.
B) include EIEC that destroys gut mucosa.
C) involve enterotoxin in traveler's diarrhea.
D) are self-limiting with the only treatment being rehydration.
E) All of the choices are correct.

Question 36

"Rice-water stools" are associated with disease caused by which organism?

A) Vibrio vulnificus
B) Helicobacter pylori
C) Vibrio cholerae
D) Campylobacter jejuni
E) Vibrio parahaemolyticus

Question 37

Which of the following statements is not true of enteroinvasive E.coli (EIEC)?

A)Blood and pus are found in the stool.
B)High fever is present.
C)It makes no heat-labile or heat-stable exotoxins.
D)Prompt treatment with a broad-spectrum antibiotic is essential to recover from an infection.
E)It invades the gut mucosa.

Question 38

Which of the following statements regarding Campylobacter infection is incorrect?

A) It can lead to Guillain-Barre syndrome.
B) It is caused by a shiga toxin.
C) Campylobacter burrows into the mucosa of the ileum and multiplies.
D) It can last over 2 weeks.
E) It can cause acute temporary paralysis.

Question 39

All of the following diseases can be transmitted by drinking contaminated water except ______.

A) trichinosis
B) campylobacter
C) cyclosporiasis
D) giardiasis
E) cryptosporidiosis

Question 40

Cholera symptoms are

A) copious watery diarrhea.
B) loss of blood volume.
C) acidosis, sunken eyes, and thirst.
D) hypotension, tachycardia, and shock.
E) All of the choices are correct.

Question 41

Giardiasis involves

A) a protozoan that does not form cysts.
B) infection of the large intestine.
C) symptoms of abdominal pain, flatulence, and diarrhea.
D) vector transmission.
E) All of the choices are correct.

Question 42

Mumps causes permanent sterility in young male adults.

Question 43

Which of the following is not a normal causative agent of acute diarrhea with vomiting (food poisoning)?

A) Clostridium perfringens
B) Staphylococcus aureus
C) Bacillus cereus
D) Clostridium difficile

Question 44

It is now past the normal dinner time,but you do not even want to think about food.Only diarrhea,abdominal cramps,and vomiting are on your mind.This all started a few hours ago after having a ham sandwich for lunch purchased from a street vendor.With your microbiology knowledge,you surmise that it is a Staphylococcus aureus-related disorder.Why do you think this?

A) Staphylococcus aureus is the most common cause of gastrointestinal disease.
B) The toxin produced by Staphylococcus aureus was already in the ham, so the symptoms can occur quickly.
C) Ham is notorious for being contaminated with Staphylococcus aureus bacteria.
D) Only Staphylococcus aureus infection causes vomiting, along with cramps and diarrhea.

Question 45

Research does not indicate a link between the numbers and types of bacteria causing periodontitis and thicker carotid arteries in an individual.

Question 46

Which of the following statements is incorrect about Staphylococcus aureus food intoxication?

A) Food left unrefrigerated for several hours is at risk for contamination.
B) Symptoms come on quickly and include nausea, vomiting, and diarrhea.
C) Food becomes contaminated by a human carrier.
D) Common affected foods include custards, ham, cream pastries, and processed meats.
E) Ingestion of the pathogen allows it to multiply and damage the GI tract lining.

Question 47

Your son has not had the MMR vaccine (measles,mumps,rubella)because you are apprehensive about vaccines and their side effects.Your sister says that you are setting him up for a potentially damaging scenario.Which argument has the great scientific validity and why?

A) Your sister is correct. Even if your son does not get the mumps now when he is young, but gets the infection later in life, there is a possibility of severe side effects.
B) Your sister is correct in her warnings. If your son gets a severe case of mumps, he will likely develop a fatal secondary infection.
C) You are correct in protecting your son. If you can keep him from getting mumps when young, it is no longer a problem. It is simply a childhood disease.
D) You are correct to be apprehensive because vaccines have been the cause of autism in children.

Question 48

As recently as the 1980s,the medical establishment believed ulcers to be caused by stress and an increase in gastric acidity.How has the current understanding of ulcer development changed patient treatment?

A) There is no treatment for ulcers, then or now.
B) Antibiotics are now used to treat ulcers.
C) Different foods are now suggested for patients having ulcers.
D) Doctors now give their patients sedatives to calm patients with ulcers.

Question 49

Only feces from humans that contaminates food and water can be involved in transmission of amoebiasis.

Question 50

Which of the following statements regarding Campylobacter jejuni is incorrect?

A) It causes fever and a watery to bloody diarrhea.
B) It produces an enterotoxin that stimulates diarrhea.
C) It infects the stomach.
D) It is transmitted through ingestion of contaminated chicken, meat, milk, or water.
E) The cells are gram-negative, curved rods with darting motility.

Question 51

Boiling will not inactivate Giardia lamblia cysts in contaminated water.

Question 52

Shiga toxin-producing E.coli characteristics include all of the following except that it

A)has a reservoir inside of cattle intestines.
B)causes a bloody diarrhea.
C) in some cases,leads to the development of hemolytic uremic syndrome (HUS)with possible kidney failure
D)is transmitted by ingestion of contaminated,undercooked food,especially hamburger.
E)only causes occupational illness in people who work with animals.

Question 53

Which of the following antigen types found in gram-negative enterics is mismatched?

A) H antigen - flagellar
B) K antigen - capsule
C) O antigen - cell wall
D) All of the choices are correct matches.

Question 54

Outbreaks of which protozoan disease have been associated with fecal-contaminated imported raspberries,fresh greens,and drinking water?

A) Toxoplasmosis
B) Cyclosporiasis
C) Trichinosis
D) Cryptosporidiosis

Question 55

In the absence of dietary carbohydrates,bacteria do not cause tooth decay.

Question 56

The best treatment for acute diarrhea is oral replacement of electrolytes and water.

Question 57

Helicobacter pylori causes ______.

A) gastritis
B) duodenal ulcers
C) stomach ulcers
D) increased risk for stomach cancer
E) All of the choices are correct.

Question 58

Orchitis and epididymitis are seen in young,adult males as a complication of ______.

A) hepatitis
B) tapeworm infestation
C) mumps
D) gingivitis

Question 59

Which is not a characteristic of Helicobacter pylori?

A) Produces urease to buffer stomach acidity
B) Curved rods
C) Lives in the stomach
D) Produces enteroxin that causes diarrhea
E) Gram-negative

Question 60

A common food intoxication is caused by enterotoxin-producing strains of ______.

A) Streptococcus pyogenes
B) Staphylococcus saprophyticus
C) Streptococcus agalactiae
D) Staphylococcus aureus
E) Staphylococcus epidermidis

Question 61

The most definitive test to diagnose a helminth infection is

A) a blood cell count to look for elevated levels of eosinophils.
B) a good medical history of the patient, including recent foreign travel.
C) an ova and parasite smear for microscopy.
D) a serological test for the presence of anti-helminthic antibodies.

Question 62

Most antihelminthic medications act only against the pathogens,not the human host.

Question 63

Hepatitis B infection

A) has an incubation of 2 to 3 weeks.
B) increases risk for hepatocellular cancer.
C) can be transmitted by the fecal-oral route.
D) is responsible for most cases of post-transfusion hepatitis.

Question 64

Which of the following symptoms of trichinosis is most indicative of this disease?

A) Puffiness around the eyes
B) Shortness of breath
C) Abdominal pain
D) Eosinophilia

Question 65

Which of the following statements is incorrect about hepatitis A?

A) It is transmitted by the oral-fecal route.
B) Havrix is an inactivated vaccine for prevention.
C) An infection predisposes a person for liver cancer.
D) Immune globulin therapy helps decrease the severity.
E) The virus produces flu-like symptoms with discomfort near the liver and darkened urine.

Question 66

The most common cause of liver cancer in the United States is hepatitis ______ virus.

A) A
B) B
C) C
D) D

Question 67

There are vaccines for immunity to the Hepatitis B virus.

Question 68

Enterobius vermicularis is

A) a whipworm.
B) common only to the tropics and subtropics.
C) an intestinal helminth that easily contaminates fingers and fomites.
D) often fatal in heavy infestations.
E) All of the choices are correct.

Question 69

Which of the following attributes is not common to the life and transmission cycles of Opisthorchis sinensis,Clonorchis sinensis,and Fasciola hepatica?

A) Infection causes obstruction of the bile duct.
B) Eggs are released in the feces.
C) They are transmitted by consuming inadequately cooked fish.
D) Fresh water snails are an intermediate host.

Question 70

Just back from a trip to South America,you now have a severe diarrheal illness.Your symptoms,other than diarrhea,are pain,cramps,some fecal blood,and fever.These are symptoms of many of the gastrointestinal diseases,so that information does not help you or the doctors identify the infectious agent.Your doctor wants to send a fecal sample to the microbiology lab for them to look at it under the light microscope.Based upon this protocol selection,the physician believes that you have ______.

A) salmonellosis
B) hepatitis A
C) rotavirus
D) cholera
E) amoebiasis

Question 71

Which of the following statements about parasitic helminths is incorrect?

A) They include roundworms and tapeworms.
B) They have larval forms that do not affect humans.
C) They have a definitive host in which the adult form lives.
D) They are multicellular animals.

Question 72

Which of the following is not a virulence factor associated with helminths?

A) Degradative enzymes to damage host tissue
B) Specialized structures for attachment to host tissues
C) Secretion of toxins
D) Thick cuticle to escape detection from the host immune system

Question 73

General symptoms of helminth infection includes all of the following except

A) eggs, larvae, or adult worms found in feces.
B) intense abdominal pain.
C) increased eosinophil count.
D) vague nausea.
E) increased sensitivity to helminth antigens.

Question 74

The transmission cycle of Fasciola hepatica differs from the cycles of Opisthorchis sinensis and Clonorchis sinensis in that

A) freshwater snails release cercariae.
B) eggs are released from an infected human via the urine.
C) encystment occurs on a freshwater plant.
D) helminth development occurs in the liver.

Question 75

Which of the following is not a helminth that causes primarily intestinal symptoms?

A) Taenia solium
B) Diphyllobothrium latum
C) Trichuris trichiura
D) Enterobius vermicularis

Question 76

Carriers of Hepatitis B virus are not common.

Question 77

Inflammation of the liver with necrosis of the hepatocytes and swelling due to a mononuclear response is a disease called ______.

A) jaundice
B) cirrhosis
C) mononucleosis
D) hepatitis

Question 78

Which of the following hepatitis viruses is mismatched with its description?

A) Hepatitis A virus - nonenveloped, single-stranded RNA enterovirus
B) Hepatitis B virus - enveloped DNA virus
C) Hepatitis C virus - RNA virus
D) Hepatitis D virus - defective RNA virus that coinfects with hepatitis A virus

Question 79

The only body fluid that can transmit Hepatitis B virus is blood.

Question 80

Hepatitis B virus

A) is principally transmitted by blood.
B) transmission risks include shared needles, anal intercourse, and heterosexual intercourse.
C) is transmitted to newborns from chronic carrier mothers.
D) has many chronic carriers.
E) All of the choices are correct.