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

A) sucrose

B) lysozyme

C) lactic acid

C

2) Clostridium difficile-associated diarrhea is usually preceded by

A) eating contaminated food.

B) a blood transfusion.

C) extended use of antibiotics.

C

3) Which of the following statements about salmonellosis is FALSE?

A) It is a bacterial infection.

B) Severity of disease depends on number of organisms ingested.

C) A healthy carrier state exists.

D) The mortality rate is high.

D

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

A) Clostridium perfringens.

B) Vibrio cholerae.

C) Shigella dysenteriae.

C

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

A) staphylococcal enterotoxicosis

B) mumps

C) Vibrio gastroenteritis

B

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

A) pharynx, esophagus, stomach, small intestine, large intestine.

B) esophagus, pharynx, stomach, small intestine, large intestine.

C) pharynx, esophagus, stomach, large intestine, small intestine.

A

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

A) Enterobius vermicularis

B) Ascaris lumbricoides

C) Taenia saginata

B

8) Poultry products are a likely source of infection by

A) Helicobacter pylori.

B) Salmonella enterica.

C) Vibrio cholerae.

B

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

A) Cyclospora infection.

B) giardiasis.

C) trichinellosis.

C

10) Which of the following organisms feeds on red blood cells?

A) Giardia lamblia

B) Escherichia coli

C) Taenia spp.

D) Vibrio parahaemolyticus

E) Entamoeba histolytica

E

11) In humans, beef tapeworm infestations are acquired by ingesting

A) the eggs of Taenia saginata.

B) segments of Taenia solium tapeworms.

C) water contaminated with Diphyllobothrium latum eggs.

D) cysticerci of Taenia saginata in undercooked meat.

D

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

A) It is caused by ingesting an enterotoxin.

B) It can be prevented by adequate refrigeration of food.

C) It can be prevented by heating foods to 50°C for 15 minutes.

C

13) The most common cause of traveler's diarrhea is

A) Shigella spp.

B) Salmonella enterica.

C) Giardia lamblia.

D) Escherichia coli.

D

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

A) Giardia.

B) rotavirus.

C) Salmonella.

B

15) Which of the following is mismatched?

A) hydatid disease — humans are the definitive host

B) Taenia infestation — humans are the definitive host

C) trichinellosis — humans eat larva of parasite

A

16) Thorough cooking of food will prevent all of the following EXCEPT

A) trichinellosis.

B) beef tapeworm.

C) staphylococcal food poisoning.

C

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

A) mouth.

B) stomach.

C) stomach and small intestine.

D) small intestine and large intestine.

D

18) Gums bleeding while brushing one's teeth is most commonly associated with

A) halitosis.

B) cavities.

C) gingivitis.

C

19) Typhoid fever differs from salmonellosis in that in typhoid fever

A) the microorganisms multiply within macrophages.

B) the incubation period is much longer.

C) the symptoms are due to infection of the gallbladder.

B

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

A) Trichinella spiralis

B) Vibrio parahaemolyticus

C) Giardia lamblia

B

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

A) Salmonella enterica

B) Staphylococcus aureus

C) Trichinella spiralis

C

22) A vaccine to provide active immunity to HBV is prepared from

A) viruses grown in tissue culture.

B) genetically modified yeast.

C) pooled gamma globulin.

B

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

A) mycotoxin; peanuts

B) mycotoxin; rye or other cereal grains

C) enterotoxin; peanuts

A

24) Which of the following causes inflammation of the liver?

A) Salmonella enterica

B) Shigella spp.

C) hepatitis A virus

C

25) "Rice water stools" are characteristic of

A) salmonellosis.

B) cholera.

C) bacillary dysentery.

B

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

A) biological vectors.

B) contaminated food and water.

C) unpasteurized milk.

B

27) Many bacterial infections of the lower digestive tract are treated with

A) antitoxin.

B) penicillin.

C) water and electrolytes.

C

28) Dental plaque is an example of

A) a pellicle.

B) a biofilm.

C) gingivitis.

B

29) Which of the following is mismatched?

A) ergot — gangrene

B) Salmonella endotoxin — lyses red blood cells

C) Vibrio enterotoxin — secretion of Cl-, K+, and H2O

B

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

A) are transmitted via contaminated water.

B) are more severe.

C) have shorter incubation times.

C

31) The most common mode of HAV transmission is

A) contamination of food during preparation.

B) contamination of food before it reaches a food service establishment.

C) blood transfusion.

A

32) 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) decay in dentin, plaque accumulation, destruction of enamel, advancement of decay through enamel, decay in tooth pulp

C) plaque accumulation, destruction of enamel, decay in tooth pulp, advancement of decay through enamel, decay in dentin

A

33) 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) Bacillus cereus

B) Cyclospora cayetanensis

C) Salmonella typhi

D) Vibrio vulnificus

D

34) Which of the following is included in GALT?

A) thymus

B) Peyer's patches

C) tonsils

B

35) Microscopic examination of a patient's fecal culture shows spiral bacteria. The bacteria probably belong to the genus

A) Campylobacter jejuni.

B) Escherichia coli.

C) Salmonella typhi.

A

36) Which of the following pertains to typhoid fever?

A) It is acquired via ingestion of contaminated meat.

B) Enterotoxin spreads via the blood.

C) It is caused by several different species of Salmonella.

D) Causative microorganism multiplies in patient phagocytes.

D

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

A) Clostridium perfringens.

B) Escherichia coli.

C) Salmonella typhi.

A

38) Helicobacter pylori can grow in the stomach because it

A) hides in macrophages.

B) makes a capsule.

C) possesses an enzyme that neutralizes HCl.

C

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

A) Cryptosporidium.

B) Cyclospora.

C) Entamoeba.

D) Giardia.

E) Campylobacter.

E

40) All of the following pertain to pinworm infections EXCEPT

A) transmission is typically by contact with fomites or inhalation of eggs.

B) diagnosis is by detecting eggs on transparent tape pressed to the perianal area.

C) all family members living with the patient must also be treated.

D) it is most commonly transmitted by cysts in water.

D

41) What is a Dane particle?

A) the chlorine-resistant virus that causes HAV

B) the infectious virion that causes HBV

C) the spherical particles found in serum of patients with HBV

B

42) Which of the following is mismatched?

A) beef — E. coli O157:H7

B) custard and cream pies — Staphylococcus aureus

C) eggs — Trichinella spiralis

C

Following a county fair, 160 persons complained of gastrointestinal symptoms. Symptoms included diarrhea (84 percent), abdominal cramps (96 percent), nausea (84 percent), vomiting (82 percent), body aches (50 percent), fever (60 percent; median body temperature = 38.3°C); median duration of illness 6 days (range 10 hr to 13 days).

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

A) Salmonella enterica.

B) Shigella spp.

C) Campylobacter jejuni.

D) enteropathogenic Escherichia coli.

E) Giardia lamblia.

E

44) 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) microscopic examination of feces for oocysts.

C

45) 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) black beans

B) corn soup

C) jalapeño peppers

C

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

TRUE

2) Dental caries can also be referred to as periodontal disease.

FALSE

3) Bacterial infections, but not intoxications, can cause diarrhea.

FALSE

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

TRUE

5) Aflatoxin poisoning is associated with liver cancer.

TRUE

6) Approximately 30 percent of the body's immune system is located in the intestinal tract.

FALSE

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

TRUE

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

TRUE

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

FALSE

10) 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.

TRUE