Deck 25: Microbial Diseases of the Digestive System

Question 1

Which of the following statements about salmonellosis is FALSE?

A) Severity of disease depends on number of organisms ingested.
B) A healthy carrier state exists.
C) It is a bacterial infection.
D) It is often associated with poultry products.
E) The mortality rate is high.

Answer 1

E

Question 2

Acute gastroenteritis that occurs after an incubation period of two to three days and commonly affects children is probably caused by

A) rotavirus.
B) Staphylococcus aureus.
C) Trichinella.
D) Salmonella.
E) Giardia.

Answer 2

A

Question 3

Which of the following statements about staphylococcal food poisoning is FALSE?

A) It can be prevented by adequate refrigeration of food.
B) It is treated by replacing water and electrolytes.
C) It is caused by ingesting an enterotoxin.
D) It can be prevented by heating foods to 50°C for 15 minutes.
E) It is characterized by rapid onset and short duration of symptoms.

Answer 3

D

Question 4

Thorough cooking of food will prevent all of the following EXCEPT

A) shigellosis.
B) salmonellosis.
C) staphylococcal food poisoning.
D) trichinellosis.
E) beef tapeworm.

Question 5

Which of the following organisms feeds on red blood cells?

A) Giardia lamblia
B) Taenia spp.
C) Escherichia coli
D) Entamoeba histolytica
E) Vibrio parahaemolyticus

Question 6

All of the following infections can result from drinking contaminated water EXCEPT

A) Cyclospora infection.
B) trichinellosis.
C) giardiasis.
D) cryptosporidiosis.
E) cholera.

Question 7

Typhoid fever differs from salmonellosis in that in typhoid fever

A) the incubation period is much longer.
B) the microorganisms multiply within macrophages.
C) the symptoms are due to infection of the gallbladder.
D) infection occurs due to ingestion of endospores.
E) infection is spread only in the feces of domesticated animals.

Question 8

In humans, beef tapeworm infestations are acquired by ingesting

A) segments of Taenia solium tapeworms.
B) the eggs of Taenia saginata.
C) cysticerci of Taenia solium in undercooked meat.
D) cysticerci of Taenia saginata in undercooked meat.
E) water contaminated with Diphyllobothrium latum eggs.

Question 9

Which of the following organisms is likely to be transmitted via contaminated shrimp?

A) Staphylococcus aureus
B) Clostridium perfringens
C) Vibrio parahaemolyticus
D) Trichinella spiralis
E) Giardia lamblia

Question 10

Poultry products are a likely source of infection by

A) Clostridium perfringens.
B) Salmonella enterica.
C) Vibrio cholerae.
D) Helicobacter pylori.
E) Shigella spp.

Question 11

Which of the following is directly involved in the initiation of dental caries?

A) dentin
B) crevicular fluid
C) lysozyme
D) sucrose
E) lactic acid

Question 12

The digestive tract is essentially one long tube. The order of the structures, beginning with the mouth, is

A) pharynx, stomach, esophagus, small intestine, large intestine.
B) esophagus, stomach, pharynx, small intestine, large intestine.
C) esophagus, pharynx, stomach, small intestine, large intestine.
D) pharynx, esophagus, stomach, large intestine, small intestine.
E) pharynx, esophagus, stomach, small intestine, large intestine.

Question 13

Gums bleeding while brushing oneʹs teeth is most commonly associated with

A) gingivitis.
B) cavities.
C) periodontitis.
D) trench mouth.
E) halitosis.

Question 14

Which of the following is mismatched?

A) pinworm infestation  humans ingest parasiteʹs eggs
B) hydatid disease  humans are the definitive host
C) trichinellosis  humans eat larva of parasite
D) Taenia infestation  humans are the definitive host
E) hookworm infestation  parasite bores through skin

Question 15

Which of the following helminthic diseases is a common infestation found in the southeastern United States?

A) Taenia saginata
B) Trichuris trichiura
C) Echinococcus granulosus
D) Ascaris lumbricoides
E) Enterobius vermicularis

Question 16

Which one of the following diseases of the gastrointestinal system is transmitted by the respiratory route?

A) travelerʹs diarrhea
B) mumps
C) bacillary dysentery
D) staphylococcal enterotoxicosis
E) Vibrio gastroenteritis

Question 17

Most of the normal microbiota of the digestive system are found in the

A) stomach and small intestine.
B) stomach.
C) small intestine and large intestine.
D) mouth.
E) accessory structures.

Question 18

Clostridium difficile-associated diarrhea is usually preceded by

A) travel to an underdeveloped country.
B) eating contaminated food.
C) extended use of antibiotics.
D) a blood transfusion.
E) improper food storage.

Question 19

The most common cause of travelerʹs diarrhea is

A) Escherichia coli.
B) Salmonella enterica.
C) Campylobacter jejuni.
D) Giardia lamblia.
E) Shigella spp.

Question 20

Disease-causing exotoxins are produced by all of the following organisms EXCEPT

A) Shigella dysenteriae.
B) Vibrio cholerae.
C) Clostridium botulinum.
D) Clostridium perfringens.
E) Staphylococcus aureus.

Question 21

ʺRice water stoolsʺ are characteristic of

A) cholera.
B) tapeworm infestation.
C) bacillary dysentery.
D) salmonellosis.
E) amebic dysentery.

Question 22

Microscopic examination of a patientʹs fecal culture shows spiral bacteria. The bacteria probably belong to the genus

A) Campylobacter jejuni.
B) Salmonella typhi.
C) Shigella spp.
D) Escherichia coli.
E) Vibrio cholerae.

Question 23

A 38-year-old man had onset of fever, chills, nausea, and myalgia while vacationing on the Gulf of Mexico. On April 29, he had eaten raw oysters and gone wading in the warm coastal waters. On May 2, he was admitted to a hospital because of a fever of 39°C and two circular necrotic lesions on the left leg. He had a history of alcoholic liver disease. He was transferred to the ICU; therapy with antibiotics was initiated. On May 4, he died. Which of the following is the most likely cause?

A) Vibrio vulnificus
B) Cyclospora cayetanensis
C) Salmonella typhi
D) hepatitis C virus
E) Bacillus cereus

Question 24

All of the following are eukaryotic organisms that cause diarrheal disease EXCEPT

A) Entamoeba.
B) Cryptosporidium.
C) Campylobacter.
D) Giardia.
E) Cyclospora.

Question 25

Which of the following causes inflammation of the liver?

A) hepatitis A virus
B) Salmonella enterica
C) Escherichia coli
D) Shigella spp.
E) Vibrio cholerae

Question 26

Many bacterial infections of the lower digestive tract are treated with

A) water and electrolytes.
B) antitoxin.
C) thorough cooking.
D) quinacrine.
E) penicillin.

Question 27

Epidemics related to bacterial infection of the digestive system are typically caused by

A) the respiratory route.
B) contaminated food and water.
C) unpasteurized milk.
D) exposure to contaminated soil.
E) biological vectors.

Question 28

All of the following are gram-negative rods that cause gastroenteritis EXCEPT

A) Clostridium perfringens.
B) Yersinia enterocolitica.
C) Escherichia coli.
D) Shigella spp.
E) Salmonella typhi.

Question 29

Which of the following is mismatched?

A) shiga toxin  tissue destruction
B) Vibrio enterotoxin  secretion of Cl-, K+, and H₂O
C) aflatoxin  liver cancer
D) ergot  gangrene
E) Salmonella endotoxin  lyses red blood cells

Question 30

All of the following pertain to pinworm infections EXCEPT

A) all family members living with the patient must also be treated.
B) it is a helminth disease.
C) diagnosis is by detecting eggs on transparent tape pressed to the perianal area.
D) transmission is typically by contact with fomites or inhalation of eggs.
E) it is most commonly transmitted by cysts in water.

Question 31

Which of the following correctly lists the stages of tooth decay?

A) plaque accumulation, destruction of enamel, advancement of decay through enamel, decay in dentin, decay in tooth pulp
B) destruction of enamel, advancement of decay through enamel, plaque accumulation, decay in dentin, decay in tooth pulp
C) decay in dentin, plaque accumulation, destruction of enamel, advancement of decay through enamel, decay in tooth pulp
D) plaque accumulation, destruction of enamel, decay in tooth pulp, advancement of decay through enamel, decay in dentin
E) destruction of enamel, plaque accumulation, advancement of decay through enamel, decay in dentin, decay in tooth pulp

Question 32

Which of the following pertains to typhoid fever?

A) It is caused by several different species of Salmonella.
B) It is also called bacillary dysentery.
C) It is acquired via ingestion of contaminated meat.
D) Causative microorganism multiplies in patient phagocytes.
E) Enterotoxin spreads via the blood.

Question 33

Which of the following is included in GALT?

A) liver
B) salivary glands
C) thymus
D) tonsils
E) Peyerʹs patches

Question 34

Helicobacter pylori can grow in the stomach because it

A) makes a capsule.
B) invades epithelial cells.
C) hides in macrophages.
D) makes HCl.
E) possesses an enzyme that neutralizes HCl.

Question 35

The most common mode of HAV transmission is

A) contamination of food before it reaches a food service establishment.
B) blood transfusion.
C) contamination of food during preparation.
D) contaminated hypodermic needles.
E) airborne.

Question 36

Bacterial intoxications differ from bacterial infections of the digestive system in that intoxications

A) are accompanied by high fever.
B) are more severe.
C) are transmitted via contaminated water.
D) are treated with antibiotics.
E) have shorter incubation times.

Question 37

Which of the following organisms is likely to be transmitted via undercooked pork and horse?

A) Shigella spp.
B) Staphylococcus aureus
C) Salmonella enterica
D) Trichinella spiralis
E) Entamoeba histolytica

Question 38

Dental plaque is an example of

A) a pellicle.
B) tooth enamel.
C) dentin.
D) gingivitis.
E) a biofilm.

Question 39

Aflatoxin is a(n) associated with ingestion of contaminated .

A) mycotoxin; rye or other cereal grains
B) mycotoxin; peanuts
C) enterotoxin; rye or other cereal grains
D) endotoxin; peanuts
E) enterotoxin; peanuts

Question 40

A vaccine to provide active immunity to HBV is prepared from

A) viruses grown in embryonated eggs.
B) pooled gamma globulin.
C) viruses grown in tissue culture.
D) viral particles in patients.
E) genetically modified yeast.

Question 41

Approximately 30 percent of the bodyʹs immune system is located in the intestinal tract.

Question 42

Discuss why cholera epidemics are often associated with floods.

Question 43

Mary made her familyʹs favorite cream of broccoli soup for lunch. Lunch was forgotten when her son suddenly remembered he had a soccer game at noon. The family finally returned several hours later and sat down to eat. Although Mary reheated the soup (which had been left out at room temperature while they were gone), why is this no guarantee that Mary and her family will not become sick due to food poisoning?

Question 44

Dental caries can also be referred to as periodontal disease.

Question 45

Gastroenteritis due to ingestion of food contaminated with Staphylococcus aureus is due to intoxication by enterotoxins.

Question 46

Aflatoxin poisoning is associated with liver cancer.

Question 47

Lactic acid, an end product of fructose fermentation, causes breakdown of tooth enamel and, eventually, cavities.

Question 48

EHEC is a major cause of diarrhea in developing countries and may result in the death of small children.

Question 49

Multiple pathovars of E. coli are well characterized. Identify four different pathogenic strains and discuss the mechanism of disease for each.

Question 50

Compare the modes of transmission for hepatitis A, B, and C.

Question 51

Campylobacter gastroenteritis is the leading cause of foodborne illness in the United States.

Question 52

H. pylori is able to survive the acidic environment of the stomach as a result of adaptations that allow it to increase the pH of the immediate environment.

Question 53

Which of the following is mismatched?

A) chicken  Campylobacter jejuni
B) oysters  Vibrio parahaemolyticus
C) eggs  Trichinella spiralis
D) beef  E. coli O157:H7
E) custard and cream pies  Staphylococcus aureus

Question 54

An outbreak of viral gastroenteritis occurs in a pediatrics ward. Rotavirus is the most likely causative agent.

Question 55

Table 25.1 $$\begin{array} { | l | l | } \hline { \text { Food } } & \text { Relative Risk } \\\hline \text { Black beans } & 0.58 \\\hline \text { Corn soup } & 0.75 \\\hline \text { Talapeño peppers } & 34.13 \\\hline \text { Roma tomatoes } & 5.40 \\\hline\end{array}$$ The relative risks shown in Table 25.1 were calculated for foods suspected of transmitting Salmonella. Which food is the most likely source of infection?

A) jalapeño peppers
B) black beans
C) corn soup
D) roma tomatoes
E) The answer cannot be determined based on the information provided.

Question 56

In Situation 25.1, fecal samples were found to be negative when cultured. The next step in diagnosing the cause of illness would be

A) to begin antibiotic therapy.
B) blood cultures.
C) muscle biopsy.
D) microscopic examination of feces for viruses.
E) microscopic examination of feces for oocysts.

Question 57

In Situation 25.1, fecal samples should be cultured for all of the following EXCEPT

A) Campylobacter jejuni.
B) Giardia lamblia.
C) Salmonella enterica.
D) enteropathogenic Escherichia coli.
E) Shigella spp.

Question 58

Describe the process of periodontal disease.

Question 59

What is a Dane particle?

A) the chlorine-resistant virus that causes HAV
B) the infectious virion that causes HBV
C) the filamentous particles that cause HAV
D) another name for an HBV surface antigen
E) the spherical particles found in serum of patients with HBV

Question 60

Bacterial infections, but not intoxications, can cause diarrhea.

Question 61

Thinking of a mumps infection, how do the symptoms involve the GI tract, yet lead to airborne transmission of the disease? Why isnʹt the disease transmitted by fecal -oral contamination instead?