Deck 22: Infectious Diseases Affecting the Gastrointestinal Tract

Question 1

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

Answer 1

False

Question 2

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

A) The oral cavity is a low oxygen environment.
B) Mouthwashes and toothpaste destroy most of the strict aerobes that are found on teeth.
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 2

The crevice between the gingiva and the tooth is low in oxygen.

Question 3

There are no infectious agents that can penetrate intact skin.

Answer 3

False

Question 4

Salmonella are ______.

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

Question 5

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 choices are correct.

Question 6

E. coli O157:H7 secretes shiga exotoxin.

Question 7

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 8

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

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

Question 9

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

Question 10

Which of the following statements is incorrect about shigellosis?

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

Question 11

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

Question 12

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

Question 13

Enterotoxin production is a characteristic of ______.

A) Clostridium botulinum
B) Clostridium perfringens
C) Clostridium tetani
D) Clostridium di?cile

Question 14

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 15

GALT refers to _______.

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

Question 16

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

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

Question 17

Oral bacteria on the tooth surface _______.

A) develop a bio?lm
B) use ?mbriae and slime layers to adhere
C) metabolize sucrose, produce sticky glucans, and form plaque
D) All of the choices are correct.

Question 18

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

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

Question 19

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

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

Question 20

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) Spirilla (Leptospira, Borrelia)
D) Fungi (Candida)
E) Enterics (Escherichia, Enterobacter)

Question 21

Gingivitis _______.

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

Question 22

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

A) Campylobacter jejuni
B) Vibrio parahaemolyticus
C) Vibrio cholerae
D) Helicobacter pylori
E) Vibrio vulni?cus

Question 23

Which of the following is not true of enterotoxigenic

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

Question 24

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

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

Question 25

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

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

Question 26

Symptoms of cryptosporidiosis include _______.

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

Question 27

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

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

Question 28

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 29

The causative organism for mumps is ______.

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

Question 30

The most common infectious disease in humans is ______.

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

Question 31

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

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

Question 32

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

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

Question 33

A current news story describes a cruise ship in the Caribbean 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 ?gure out what infectious agent may be the cause. Your most likely guess is that the pathogen is ______.

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

Question 34

Which of the following statements regarding Clostridium di?cile infection is incorrect?

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

Question 35

Which of the following statements is not true regarding Clostridium di?cile?

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

Question 36

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

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

Question 37

Which of the following statements regarding Campylobacter infection is incorrect?

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

Question 38

The virulence of Vibrio cholerae is due to its ______.

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

Question 39

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 40

The primary viral cause of chronic diarrhea globally is ______.

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

Question 41

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 42

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

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

Question 43

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

Question 44

Giardiasis involves _______.

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

Question 45

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

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

Question 46

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

Question 47

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) Common affected foods include custards, ham, cream pastries, and processed meats.
C) Ingestion of the pathogen allows it to multiply and damage the GI tract lining.
D) Food becomes contaminated by a human carrier.
E) Symptoms come on quickly and include nausea, vomiting, and diarrhea.

Question 48

Which of the following statements regarding Campylobacter jejuni is incorrect?

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

Question 49

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

A) Clostridium perfringens
B) Clostridium di?cile
C) Bacillus cereus
D) Staphylococcus aureus

Question 50

Boiling will not inactivate Giardia lamblia cysts in contaminated water.

Question 51

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

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

Question 52

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

Question 53

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

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

Question 54

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 scienti?c validity and why?

A) Your sister is correct in her warnings. If your son gets a severe case of mumps, he will likely develop a fatal secondary infection.
B) 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.
C) 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.
D) You are correct to be apprehensive because vaccines have been the cause of autism in children.

Question 55

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

Question 56

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

Question 57

Mumps causes permanent sterility in young male adults.

Question 58

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

Question 59

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

Question 60

Which is not a characteristic of Helicobacter pylori?

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

Question 61

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

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

Question 62

There are vaccines for immunity to the Hepatitis B virus.

Question 63

Which of the following statements is incorrect about hepatitis A?

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

Question 64

Hepatitis B infection _______.

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

Question 65

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.

Question 66

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

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

Question 67

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 de?nitive host in which the adult form lives.
D) They are multicellular animals.

Question 68

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

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

Question 69

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

A) Pu?ness around the eyes
B) Eosinophilia
C) Shortness of breath
D) Abdominal pain

Question 70

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

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

Question 71

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

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

Question 72

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 73

Enterobius vermicularis is _______.

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

Question 74

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

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

Question 75

Carriers of Hepatitis B virus are not common.

Question 76

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

Question 77

Which of the following statements comparing Enterobius vermicularis and Diphyllobothrium latum is incorrect?

A) Symptoms of both infections are mild.
B)E. vermicularis is best treated with mebendazole, whereas D. latum is susceptible to praziquantel.
C) D. latum has ?sh as an intermediate host, whereas E. vermicularis has no intermediate host.
D) Both helminths affect primarily children.

Question 78

General symptoms of helminth infection includes all of the following except _______.

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

Question 79

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

Question 80

The most de?nitive test to diagnose a helminth infection is _______.

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