Micro Ch 25

Which one of the following is NOT required for tooth decay?

A) Sucrose  
B) Glucose  
C) Capsule-forming bacteria  
D) Acid-producing bacteria 

E) All of the above are required for tooth decay

Clostridium difficile-associated diarrhea is usually preceded by

A) Eating contaminated food.  
B) A blood transfusion.  
C) Use of broad-spectrum antibiotics.
D) Improper food storage.  
E) Travel to an underdeveloped country.

Which of the following statements about salmonellosis is false?

A) It is a bacterial infection.  
B) It requires a large infective dose.  
C) A healthy carrier state exists.
D) The mortality rate is high.  
E) It is often associated with poultry
products

Which 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

Which of the following does NOT produce a gastrointestinal disease due to an
exotoxin?

A) Clostridium perfringens  
B) Vibrio cholera  
C) Shigella dysenteriae  
D) Staphylococcus aureus

E)
Clostridium botulinum

Amoebic dysentery and bacillary dysentery differ in the

A) Mode of transmission.  
B) Appearance of the patient's stools.  
C) Etiologic agent.  
D) Presence of diarrhea.
E) Abscess formation

The symptoms of trichinellosis are due to the

A) Growth of larval Trichinella in the large intestine.  
B) Growth of adult Trichinella in the
large intestine.
C) Formation of cysticerci.  
D) Encystment of adult Trichinella in muscles.
E) Encystment of larval Trichinella in
muscles

Poultry products are a likely source of infection by

A) Staphylococcus aureus.  
B) Salmonella enterica. 
C) Vibrio cholerae.  
D) Shigella spp.  
E) Clostridium perfringens

Which of the following is diagnosed by the presence of flagellated protozoa in the
patient's feces?

A) Cyclospora infection  
B) Giardiasis  
C) Trichinellosis  
D) Cholera  
E) Cryptosporidiosis

Which of the following feeds on red blood cells?

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

In humans, beef tapeworm infestations are acquired by

A) Ingesting the eggs of Taenia saginata.  
B) Ingesting segments of adult tapeworms.
C) Ingesting contaminated water.  
D) Ingesting cysticerci in the intermediate host.  
E) Ingesting contaminated definitive hosts

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

A) Suspect foods are those not cooked before eating.  
B) It can be prevented by refrigeration.
C) It can be prevented by boiling foods for 5 minutes before eating.
D) It is treated by replacing water and electrolytes.  
E) It is characterized by rapid onset and short duration of symptoms

The most common cause of traveler's diarrhea is probably

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

Acute astroenteritis that occurs after an incubation period of 2 to 3 days is
probably caused by

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

Which of the following pairs 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  
D) Pinworm infestation – humans ingest parasite's eggs
E) Hookworm infestation – parasite bores through skin

Thorough cooking of food will prevent all of the following EXCEPT

A) Trichinellosis.  
B) Beef tapeworm.  
C) Staphylococcal food poisoning.  
D) Salmonellosis.  
E) Shigellosis.

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

A) Mouth.  
B) Stomach.  
C) Small intestine.  
D) Large intestine.  
E) C and D.

Which of the following organisms is most likely to be responsible for periodontal
disease?

A) Gram-positive cocci  
B) Gram-positive rods  
C) Gram-negative cocci  
D) Gram-negative

Typhoid fever differs from salmonellosis in that in typhoid fever

A) The microorganisms become invasive.  
B) The symptoms are due to an exotoxin.  
C) The symptoms are due to infection of the gallbladder.  
D) The classic symptom is diarrhea.
E) Chemotherapy is highly effective.

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

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

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

A) Salmonella  
B) Staphylococcus  
C) Trichinella  
D) Entamoeba  
E) Shigella

A vaccine to provide active immunity to serum hepatitis 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.

Which one of the following is NOT transmitted by water?

A) Salmonella  
B) Cyclospora  
C) Trichinella  
D) Cryptosporidium  
E) Hepatitis A virus

"Rice water stools" are characteristic of

A) Salmonellosis.  
B) Cholera.  
C) Bacillary dysentery.  
D) Amebic dysentery.  
E) Tapeworm infestation.

Which of the following causes an infection of the liver?

A) Salmonella  
B) Shigella  
C) Hepatitis A virus  
D) Vibrio  
E) Escherichia

Epidemics of bacterial infections of the digestive system are transmitted by

A) Food.  
B) Water.  
C) Milk.  
D) The respiratory route.  
E) All of the above

Most gastrointestinal infections are treated with

A) Antitoxin.  
B) Penicillin.  
C) Water and electrolytes.  
D) Quinacrine. 
E) Thorough cooking.

Which of the following is treated with tetracycline?

A) Staphylococcal food poisoning  
B) Vibrio parahaemolyticus gastroenteritis   C) Infectious hepatitis
D) Escherichia coli gastroenteritis  
E) Trichinellosis

Which of the following pairs is mismatched?

A) Ergot – gangrene  
B) Salmonella endotoxin – coagulates blood
C) Vibrio enterotoxin – secretion of Cl-, K+, and H2O  
D) Aflatoxin – liver cancer
E) Shiga toxin – tissue destruction

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

A) Are transmitted via water.  
B) Are more severe.  
C) Have shorter incubation times.
D) Are treated with antibiotics.  
E) Are accompanied by fever.

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.  
D) Contaminated hypodermic needles.  
E) Airborne

With which of the following substrates can Streptococcus mutans make a
capsule?

A) Xylitol  
B) Glucose  
C) Mannitol  
D) Sucrose  
E) All of the above

A 38-year-old man had onset of fever, chills, nausea, and myalgia. On April 29,
he had eaten raw oysters. 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
alcoholic liver disease. He was transferred to the ICU; therapy with ciprofloxacin was initiated. On May 4, he died. Which of the following is the most likely etiology?

A) Bacillus cereus  
B) Cyclospora  
C) Salmonella  
D) Vibrio vulnificus  
E) Yersinia enterocolitica

he easiest way to prevent outbreaks of gram-negative gastroenteritis is to

A) Cook foods thoroughly.  
B) Salt foods.  
C) Add vinegar and spices to foods.  
D) Refrigerate foods.
E) Avoid eating meat

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

A) Campylobacter.  
B) Escherichia.  
C) Salmonella.  
D) Shigella.  
E) Vibrio.

Feces from a patient with diarrhea lasting for weeks with frequent, watery stools
should be examined for

A) Bacillus cereus.  
B) Cyclospora.  
C) Salmonella.  
D) Vibrio vulnificus.  
E) Yersinia enterocolitica

Which of the following is NOT a gram-negative rod that causes gastroenteritis?

A) Clostridium  
B) Escherichia  
C) Salmonella  
D) Shigella  
E) Yersinia

Helicobacter can grow in the stomach because it

A) Hides in macrophages.  
B) Makes a capsule.  
C) Makes NH3.  
D) Makes HCl.  
E) Invades epithelial cells.

Which of the following is NOT a eukaryote that causes gastroenteritis?

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

Acute gastroenteritis that occurs after an incubation period of 4 to 24 hours is
probably caused by

A) Giardia  
B) Rotavirus  
C) Salmonella  
D) Staphylococcus aureus  
E) Trichinella

Which of the viruses listed meets these criteria?  diagnosed by PCR; incubation of 4 to 22 weeks; transmitted by the
parenteral route; is a flavivirus.

A) Hepatitis A virus  
B) Hepatitis B virus  
C) Hepatitis C virus  
D) Hepatitis D virus  
E) Hepatitis E virus

Which of the following pairs is mismatched?

A) Beef – E. coli O157:H7  
B) Delicatessen meats – Listeria  
C) Eggs – Trichinella  
D) Milk – Campylobacter
E) Oysters – Vibrio

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

A) Salmonella.  
B) Shigella.  
C) Campylobacter.  
D) Enteropathogenic Escherichia coli.  
E) Giardia.

In Situation 25.1, assume the samples were culture-negative. The next step is

A) To begin antibiotic therapy.  
B) Blood cultures.  
C) Microscopic examination for oocysts.  
D) Microscopic examination for viruses.  
E) Muscle biopsy

Use Table 25.1 to answer this question. The relative risks shown 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