microbiology chapter 25 and 26

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

A) sucrose

B) lysozyme

C) lactic acid

D) crevicular fluid

E) dentin

C

Clostridium difficile-associated diarrhea is usually preceded by

A) eating contaminated food.

B) a blood transfusion.

C) extended use of antibiotics.

D) improper food storage.

E) travel to an underdeveloped country.

C

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.

E) It is often associated with poultry products.

D

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

A) Clostridium perfringens.

B) Vibrio cholerae.

C) Shigella dysenteriae.

D) Staphylococcus aureus.

E) Clostridium botulinum.

C

Which one of the following diseases of the gastrointestinal system is transmitted by

the respiratory route?

A) staphylococcal enterotoxicosis

B) mumps

C) Vibrio gastroenteritis

D) bacillary dysentery

E) traveler's diarrhea

B

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.

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

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

A

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

D) Trichuris trichiura

E) Echinococcus granulosus

B

Poultry products are a likely source of infection by

A) Helicobacter pylori.

B) Salmonella enterica.

C) Vibrio cholerae.

D) Shigella spp.

E) Clostridium perfringens.

B

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

A) Cyclospora infection.

B) giardiasis.

C) trichinellosis.

D) cholera.

E) cryptosporidiosis.

C

Which of the following organisms is shed in the feces of humans and animals,

including beavers, and can contaminate water?

A) Giardia lamblia

B) Escherichia coli

C) Taenia spp.

D) Vibrio parahaemolyticus

E) Entamoeba histolytica

A

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.

E) cysticerci of Taenia solium in undercooked meat.

D

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.

D) It is treated by replacing water and electrolytes.

E) It is characterized by rapid onset and short duration of symptoms.

C

The most common cause of traveler's diarrhea is

A) Shigella spp.

B) Salmonella enterica.

C) Giardia lamblia.

D) Escherichia coli.

E) Campylobacter jejuni.

D

Acute gastroenteritis that occurs after an incubation period of two to three days,

persists for about a week, and commonly affects children is probably caused by

A) Giardia.

B) rotavirus.

C) Salmonella.

D) Staphylococcus aureus.

E) Trichinella.

B

Which of the following is mismatched?

A) Echinococcus granulosus – most benign of human tapeworm infections

B) Taenia solium – cysticerosis

C) trichinellosis – humans eat larva of parasite in undercooked meat

D) pinworm infestation – humans ingest parasite's eggs

E) hookworm infestation – heavy infections may cause pica

A

Thorough cooking of food will prevent all of the following EXCEPT

A) trichinellosis.

B) beef tapeworm.

C) staphylococcal food poisoning.

D) salmonellosis.

E) shigellosis.

C

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.

E) accessory structures.

D

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

A) halitosis.

B) cavities.

C) gingivitis.

D) periodontitis.

E) trench mouth.

C

Typhoid fever differs from salmonellosis in that in typhoid fever

A) the microorganisms multiply within macrophages.

B) the organism is only spread in the feces of humans.

C) the incubation period is much shorter.

D) the organism first invades the intestinal mucosa.

E) infection occurs due to ingestion of endospores.

B

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

shrimp?

A) Trichinella spiralis

B) Vibrio parahaemolyticus

C) Giardia lamblia

D) Clostridium perfringens

E) Staphylococcus aureus

B

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

and horse?

A) Salmonella enterica

B) Staphylococcus aureus

C) Trichinella spiralis

D) Entamoeba histolytica

E) Shigella spp.

C

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.

D) viruses grown in embryonated eggs.

E) viral particles in patients.

B

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

A) mycotoxin; peanuts

B) mycotoxin; rye or other cereal grains

C) enterotoxin; peanuts

D) enterotoxin; rye or other cereal grains

E) endotoxin; peanuts

A

Which of the following causes inflammation of the liver?

A) Salmonella enterica

B) Shigella spp.

C) hepatitis A virus

D) Vibrio cholerae

E) Escherichia coli

C

"Rice water stools" are characteristic of

A) salmonellosis.

B) cholera.

C) bacillary dysentery.

D) amebic dysentery.

E) tapeworm infestation.

B

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

by

A) biological vectors.

B) contaminated food and water.

C) unpasteurized milk.

D) the respiratory route.

E) exposure to contaminated soil.

B

Many bacterial infections of the lower digestive tract are treated with

A) antitoxin.

B) penicillin.

C) water and electrolytes.

D) quinacrine.

E) thorough cooking.

C

Dental plaque is an example of

A) a pellicle.

B) a biofilm.

C) gingivitis.

D) dentin.

E) tooth enamel.

B

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

D) aflatoxin – liver cancer

E) shiga toxin – tissue destruction

B

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.

D) are treated with antibiotics.

E) are accompanied by high fever.

C

The most common mode of HAV transmission is

A) contamination of food during preparation.

B) respiratory route.

C) blood transfusion.

D) contaminated hypodermic needles.

E) airborne.

A

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

D) destruction of enamel, advancement of decay through enamel, plaque accumulation,

decay in dentin, decay in tooth pulp

E) destruction of enamel, plaque accumulation, advancement of decay through enamel,

decay in dentin, decay in tooth pulp

A

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

E) hepatitis C virus

D

Which of the following is included in GALT?

A) thymus

B) Peyer's patches

C) tonsils

D) liver

E) salivary glands

B

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.

D) Shigella spp.

E) Vibrio cholerae.

A

Which of the following pertains to typhoid fever?

A) It is typically acquired via ingestion of contaminated eggs.

B) Enterotoxin spreads via the blood.

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

D) Causative microorganism multiplies in patient phagocytes.

E) It is also called bacillary dysentery.

D

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

A) Clostridium perfringens.

B) Escherichia coli.

C) Salmonella Typhi.

D) Shigella spp.

E) Yersinia enterocolitica.

A

Helicobacter pylori can grow in the stomach because it

A) hides in macrophages.

B) makes a capsule.

C) possesses an enzyme that neutralizes HCl.

D) makes HCl.

E) invades epithelial cells.

C

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

A) Cryptosporidium.

B) Cyclospora.

C) Entamoeba.

D) Giardia.

E) Campylobacter.

E

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.

E) it is a helminth disease.

D

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

D) the filamentous particles that cause HAV

E) another name for an HBV surface antigen

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

D) chicken – Campylobacter jejuni

E) oysters – Vibrio parahaemolyticus

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).

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

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).

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.

D) microscopic examination of feces for viruses.

E) muscle biopsy.

C

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

D) roma tomatoes

E) The answer cannot be determined based on the information provided.

C

Which structure or component of the small intestine is important to antimicrobial

defense?

A) salivary glands

B) stomach acid

C) Paneth cells

D) gall bladder

E) crevicular fluid

C

A rushed homemaker prepared a stew from a large cut of beef but the family only consumed a small portion for dinner. The still-hot large pot was placed in the refrigerator overnight. The next day the stew was warmed for lunch. By the evening the entire family was suffering from varying degrees of diarrhea, abdominal cramping and nausea. You most likely suspect the culprit of this event is

A) Salmonella.

B) H. pylori.

C) Shigella.

D) C. perfringes.

E) B. cereus.

D

Which is true of the Mumps virus?

A) It is transmitted by the fecal-oral route.

B) It typically begins with symptoms of gastroenteritis.

C) The portal of entry is the respiratory route.

D) A component vaccine is part of the MMR.

E) Male sterility occurs in 40% of infections.

C

Which is NOT true of HBV?

A) 1/3 of the world population shows serological evidence of past infection.

B) 5% of acute HBV infections progress to chronic infection.

C) Filamentous particles are not infectious.

D) Acute HBV infection may be subclinical.

E) Individuals infected as adults are the most likely to become carriers of the virus.

E

A young child received a red-eared slider turtle as a birthday gift. Within a week the child was suffering from a severe gastroenteritis that required a visit to urgent care. What is the child likely suffering from?

A) salmonellosis

B) Campylobacter infection

C) shigellosis

D) hepatitis A infection

E) cholera

A

TRUE OR FALSE

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

TRUE

TRUE OR FALSE

Clostridium perfringens typically causes a self-limiting gastroenteritis.

TRUE

TRUE OR FALSE

Bacterial infections, but not intoxications, can cause diarrhea.

FALSE

TRUE OR FALSE

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

TRUE

true or false

Aflatoxin poisoning is associated with liver cancer.

true

true or false

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

false

TRUE OR FALSE

Humans infected with Enterobius vermicularis may have hydatid cysts within their lungs or other organs.

TRUE

TRUE OR FALSE

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

TRUE

TRUE OR FALSE

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

FALSE

TRUE OR FALSE

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