—Microbiology Chapter 25—

Which of the following NOT true for both hepatitis B and hepatitis C infection?
The virus can cause a chronic disease.
The infection is transmitted through blood and body fluids.
Diagnosis can be achieved through testing the blood for antibodies.

The disease is prevented by vaccination.

What do hepatitis A and hepatitis B have in common?

Both can be prevented by a vaccine.

What organ is most affected by hepatitis B virus?

liver

Choose the FALSE statement from those listed below.
Certain accessory digestive structures lie outside the gastrointestinal (GI) tract and convey their secretions via ducts.
The digestive system includes the mouth and pharynx.
Over the course of an average life span, approximately 25 tons of food pass through the gastrointestinal (GI) tract.

Intestinal gas includes microbially produced oxygen.

John went to a picnic. He took some leftover chicken and rice home, heated it on the stove, ate it, and got sick two hours later. John thought the heating made his food safe because it would have killed any bacteria present. He didn’t know that __________ produces a heat-stable toxin.

Staphylococcus aureus

A patient exhibits hemorrhagic colitis and is treated via intravenous rehydration. The pathogen is a gram-negative rod. It is isolated and differentiated from related organisms based on its inability to ferment sorbitol. Which of the following is a likely diagnosis?

Escherichia coli gastroenteritis

A patient presents with diarrhea that has lasted for weeks and is accompanied by malaise, flatulence, weight loss, and abdominal cramps. You detect the odor of sulfur on his breath. Based on the signs and symptoms, you suspect __________, a protozoan. It is not easily found in stool samples, so you do a string test.

giardiasis

Which of the following statements concerning mumps virus infection is FALSE?
The virus is present in urine approximately 10 days after the onset of symptoms.
The illness frequently begins with painful swelling of one or both parotid glands.
The virus is transmitted in saliva and respiratory secretions.

The testes can become inflamed about 2 to 3 weeks after the onset of symptoms.

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

lactic acid

Clostridium difficile-associated diarrhea is usually preceded by

extended use of antibiotics.

Which of the following statements about salmonellosis is FALSE?
A healthy carrier state exists.
It is a bacterial infection.
Severity of disease depends on number of organisms ingested.
It is often associated with poultry products.

The mortality rate is high.

Disease-causing exotoxins are produced by all of the following organisms EXCEPT
Staphylococcus aureus
Vibrio cholerae
Clostridium perfringens
Clostridium botulinum

Shigella dysenteriae

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

mumps

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

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

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

Ascaris lumbricoides

Poultry products are a likely source of infection by

Salmonella enterica.

All of the following infections can result form drinking contaminated water EXCEPT
cholera.
giardiasis.
cryptosporidiosis.
Cyclospora infection.

trichinellosis.

Which of the following organisms feeds on red blood cells?

Entamoeba histolytica

In humans, beef tapeworm infestations are acquired by ingesting

cystycerci of Taenia saginata in undercooked meat.

Which of the following statements about staphylococcal food poisoning is FALSE?
It is characterized by rapid onset and short duration of symptoms.
It is treated by replacing water and electrolytes.
It is caused by ingesting an enterotoxin.
It can be prevented by adequate refrigeration of food.

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

The most common cause of traveler’s diarrhea is

Escherichia coli.

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

rotavirus.

Which of the following is mismatched?
trichinellosis – humans eat larva of parasite
pinworm infestation – humans ingest parasite’s eggs
hookworm infestation – parasite bores through skin
Taenia infestation – humans are the definitive host

hydatid disease – humans are the definitive host

Thorough cooking of food will prevent all of the following EXCEPT
salmonellosis.
trichinellosis.
beef tapeworm.
shigellosis.

staphylococcal food poisoning.

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

small intestine and large intestine.

Gums bleeding while brushing ones teeth is most commonly associated with

gingivitis

Typhoid fever differs from salmonellosis in that in typhoid fever

the incubation period is much longer.

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

Vibrio parahaemolyticus

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

Trichinella spiralis

A vaccine to provide active immunity to HBV is prepared from

genetically modified yeast.

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

mycotoxin; peanuts

Which of the following causes inflammation of the liver?

hepatitis A virus

"Rice water stools" are characteristic of

cholera

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

contaminated food and water.

Many bacterial infections of the lower digestive tract are treated with

water and electrolytes.

Dental plaque is an example of

biofilm

Which of the following is mismatched?

Salmonella endotoxin – coagulates blood

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

have shorter incubation times.

The most common mode of HAV transmission is

contamination of food during preparation.

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

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

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?

Vibrio vulnificus

Which of the following is included in GALT?

Peyers patches

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

Campylobacter jejuni.

Which of the following pertains to typhoid fever?

Causative microorganism multiplies in patient phagocytes.

All of the following are gram-negative rods that cause gastroenteritis EXCEPT
Yersinia enterocolitica.
Escherichia coli.
Shigella spp.
Salmonella typhi.

Clostridium perfringens.

Helicobacter pylori can grow in the stomach because it

possesses an enzyme that neutralizes HCl.

All of the following are eukaryotic organisms that cause diarrheal disease EXCEPT
Cyclospora.
Giardia.
Cryptosporidium.
Entamoeba.

Campylobacter.

All of the following pertain to pinworm infections EXCEPT
it is a helminth disease.
diagnosis is by detecting eggs on transparent tape pressed to the perianal area.
transmission is typically by contact with fomites or inhalation of eggs.
all family members living with the patient must also be treated.

it is most commonly transmitted by cysts in water.

What is a Dane particle?

the infectious virion that causes HBV

Which of the following is mismatched?
chicken – Campylobacter jejuni
beef – E. coli O157:H7
oysters -Vibrio parahaemolyticus
custard and cream pies – Staphylococcus aureus

eggs – Trichinella spirlais

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 the situation, fecal samples should be cultured for all of the following EXCEPT
Shigella spp.
enteropathogenic Escherichia coli.
Salmonella enterica.
Campylobacter jejuni.

Giardia lamblia

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

microscopic examination of fecess for oocysts.

Food Relative Risk
Black beans 0.58
Corn soup 0.75
Jalapeño peppers 34.13
Roma tomatoes 5.40

The relative risks shown in the table were calculated for foods suspected of transmitting Salmonella. Which food is the most likely source of infection?

jalapeño peppers