Deck 32: Waterborne and Foodborne Bacterial and Viral Diseases

Question 1

The principle behind salt or sugar preservation is to

A) introduce a mechanical barrier to microbial invasion.
B) reduce water activity (aw).
C) introduce a microbicide in anticipation of contaminating bacteria or fungi.
D) accomplish all of the described functions depending on the food being preserved.

Answer 1

B

Question 2

Pickling is a type of food preservation utilizing

A) weak acids.
B) basic substances.
C) lyophilization.
D) irradiation.

Answer 2

A

Question 3

Verotoxin can cause

A) hemorrhagic diarrhea.
B) liver failure.
C) brain damage.
D) hemorrhagic diarrhea, liver failure, and brain damage.

Answer 3

A

Question 4

The most important potential common source of infectious disease is

A) industrial waste.
B) arthropod reservoirs found near surface water supplies.
C) water.
D) human and animal wastes.

Question 5

Clostridium botulinum is a gram-________ rod that produces an ________.

A) negative / endotoxin
B) negative / exotoxin
C) positive endospore-forming / exotoxin
D) positive endospore-forming / endotoxin

Question 6

Listeria monocytogenes is

A) acid-tolerant.
B) cold-tolerant.
C) salt-tolerant.
D) acid-, cold-, and salt-tolerant.

Question 7

Staphylococcus aureus is a common causative agent of foodborne disease because it

A) grows on common foods.
B) is present in some humans that work in food processing.
C) produces several heat-stable enterotoxins.
D) grows on many foods, is present in some humans that work in food processing, and produces several heat-stable enterotoxins.

Question 8

The degree of susceptibility a food has to microbial activity is determined by its

A) chemical characteristics.
B) physical characteristics.
C) water content.
D) chemical characteristics, physical characteristics, and water content.

Question 9

Listeriosis is diagnosed from ________ cultures and treated with ________.

A) sputum / intravenous antibiotics
B) blood or spinal fluid / hydration therapy
C) sputum / hydration therapy
D) blood or spinal fluid / intravenous antibiotics

Question 10

The Staphylococcus aureus toxins are

A) neurotoxins.
B) endotoxins.
C) superantigen ectotoxins.
D) superantigen enterotoxins.

Question 11

Psychrotolerant microorganisms can survive and grow at

A) refrigeration temperatures.
B) boiling temperatures.
C) extreme fluctuations in water availability.
D) high salt or sugar concentrations.

Question 12

Severe cases of Staphylococcus aureus food poisoning may require treatment

A) with powerful antibiotics.
B) for dehydration.
C) with cleansing enemas.
D) for dehydration, along with powerful antibiotics and cleansing enemas.

Question 13

Flour and sugar are classified as ________ foods.

A) highly perishable
B) semiperishable
C) nonperishable
D) selectively perishable

Question 14

At approximately what temperature are most household freezers kept?

A) 4°C
B) 0°C
C) -20°C
D) -80°C

Question 15

ETEC strains produce one of two heat-________ diarrhea-producing ________.

A) stable / endotoxins
B) labile / endotoxins
C) stable / enterotoxins
D) labile / enterotoxins

Question 16

Clostridium perfringens food poisoning leads to diarrhea, because the

A) toxin causes the shedding of the intestinal lining.
B) permeability of the intestinal epithelium is altered by the toxin it produces.
C) disease causes such extreme thirst that the patient drinks more water than can be absorbed.
D) organism multiplies more rapidly than the immune system can handle.

Question 17

The pH of most foods is

A) basic.
B) neutral or basic.
C) acidic.
D) neutral or acidic.

Question 18

Salmonellosis is most frequently caused by

A) Salmonella enterica serovar Typhi.
B) Salmonella enterica serovar Typhimurium.
C) Salmonella enterica serovar Enteriditis.
D) Salmonella enterica serovars Typhimurium and Enteriditis.

Question 19

The rate of contaminant microbial growth during the exponential phase in food depends on

A) temperature.
B) the nutrient value of the food.
C) water content.
D) temperature, nutrient value, and water content.

Question 20

The Campylobacter spp. are

A) aerobes.
B) anaerobes.
C) microaerophiles.
D) facultative anaerobes.

Question 21

Legionella pneumophila is generally transmitted by

A) contaminated food.
B) contaminated drinking water.
C) contaminated water in coolers, pools, and domestic water systems.
D) person-to-person contact.

Question 22

The most common route of transmission of Salmonella enterica typhi worldwide is through

A) contaminated food.
B) contaminated water.
C) direct contact.
D) insect vectors.

Question 23

Vibrio cholerae primarily infects the

A) stomach.
B) small intestine.
C) large intestine.
D) rectum.

Question 24

The water activity of food can be reduced by all of the following EXCEPT

A) physically removing water.
B) adding salt.
C) adding nitrites.
D) adding sugar.

Question 25

The presence of specific ________ signals that a given water source might be contaminated with pathogens.

A) exotoxins
B) chemical compounds
C) endotoxins
D) indicator microorganisms

Question 26

Coliforms in a water sample indicate ________ contamination.

A) fecal
B) industrial or chemical
C) arthropod
D) All of the answers are correct.

Question 27

Which of the following bacterial pathogens is found in aquatic environments and is commonly present in air conditioning systems?

A) Enterobacter aerogenes
B) Klebsiella pneumoniae
C) Legionella pneumophila
D) Vibrio cholerae

Question 28

The type of Escherichia coli that produces a verotoxin similar to the one produced by Shigella dysenteriae is ________ E. coli.

A) enterohemorrhagic
B) enterotoxigenic
C) enteropathogenic
D) enteroimmunogenic

Question 29

Irradiation of food uses

A) ionizing radiation.
B) a variety of chemical treatments.
C) desiccation.
D) non-ionizing radiation.

Question 30

What is the medium used in the membrane filter (MF) procedure to differentiate fecal coliforms and Escherichia coli?

A) mannitol salt agar (MSA)
B) eosin-methylene blue agar (EMB)
C) triple sugar iron agar
D) blood agar

Question 31

Which of the following is NOT characteristic of a coliform?

A) facultatively aerobic
B) gram-negative
C) rod shaped
D) resistant to chlorination

Question 32

Which U.S. government agency monitors water utility reports?

A) Environmental Protection Agency
B) Food and Drug Administration
C) Water Safety Board
D) Natural Resources Conservancy Commission

Question 33

In the United States, individuals become infected with Vibrio cholerae most commonly by

A) consuming contaminated shellfish.
B) drinking contaminated water.
C) eating contaminated vegetables.
D) person-to-person contact.

Question 34

Raw food and food-handling equipment can be decontaminated with ________ to reduce the risk of listeriosis.

A) heat, but not radiation
B) radiation, but not heat
C) radiation and heat
D) neither radiation nor heat

Question 35

The most common source of individual foodborne botulism outbreaks are due to consumption of

A) honey.
B) dairy products.
C) nonacid, home-canned vegetables.
D) egg and meat salads.

Question 36

What organisms are the most likely pathogens to grow in food that has low water activity or solute-loaded?

A) gram-positive cocci
B) fungi
C) gram-negative bacilli
D) gram-positive bacilli

Question 37

Which organisms are NOT involved in food fermentations?

A) lactic acid bacteria
B) sulfuric acid bacteria
C) acetic acid bacteria
D) propionic acid bacteria

Question 38

When solute is added to food products, the water activity (aw)

A) increases.
B) decreases.
C) remains the same.
D) initially increases and then decreases.

Question 39

In the developed countries of the world, most intestinal infections are transmitted via

A) water.
B) person-to-person contact.
C) food.
D) hospital contamination.

Question 40

The most common source of Escherichia spp. food poisoning is contaminated

A) meat.
B) fruits.
C) grains.
D) milk and milk products.

Question 41

The most important coliform for water quality testing is Escherichia coli because it is only found in the intestine.

Question 42

Many food infection agents also cause waterborne diseases.

Question 43

The critical step in making water safe to drink is chlorination.

Question 44

Food poisoning generally results from the ingestion of food containing microbial toxins.

Question 45

Properly canned foods typically do not contain living vegetative cells.

Question 46

Cholera can be transmitted by water or food.

Question 47

BOTH physical and chemical methods are used to treat and purify water.

Question 48

Legionellosis, caused by the bacterial respiratory pathogen Legionella pneumophila, has decreased in recent years due to advances in wastewater treatment procedures.

Question 49

The U.S. Environmental Protection Agency (EPA) regulates the concentration of Escherichia coli in public recreational waters as well as private swimming pools, spas, and hot tubs to minimize waterborne disease outbreaks.

Question 50

Ideally, microbes should be eliminated from all foods.

Question 51

most wastewater treatment facilities employ methods designed to detect each pathogenic organism that may be present in a given sample.

Question 52

Typhoid fever has been virtually (although not completely) eliminated from developed countries.

Question 53

We are technically in the midst of a cholera pandemic.

Question 54

Acidic foods generally need a higher canning temperature than do nonacidic foods.

Question 55

Waterborne illness only occurs from exposure to contaminated drinking water, not from recreational use of contaminated water.

Question 56

For much of the period of microbial growth in food, there is no visible or easily detectable change in food quality.

Question 57

Not all coliforms are pathogenic.

Question 58

Norovirus is commonly transmitted by the fecal-oral route.

Question 59

Infection with Legionella pneumophila is usually treated with intravenous erythromycin.

Question 60

Local and state authorities can set standards for recreational water that are above or below the guidelines set by the United States government.

Question 61

Escherichia coli is found naturally in the intestines of birds, humans, and animals.

Question 62

Identify and define the categories of food perishability. Compare the perishability of sugar, milk, and hard cheeses (such as parmesan).

Question 63

How does Clostridium perfringens cause food poisoning? How is this process related to the metabolism and special structures of C. perfringens?

Question 64

What makes Listeria monocytogenes an especially difficult-to-prevent foodborne pathogen? Once in the human body, how does it evade the immune system?

Question 65

Why are enteric bacteria such as Escherichia coli common meat contaminants?

Question 66

Invasive listeriosis is often treated with antibiotics such as penicillin.

Question 67

Mass-processed ground meat is a particularly common source of infection with EHEC.

Question 68

To be certain the botulinum toxin is inactivated, the source must be heated for at least 2 minutes at 80°C.

Question 69

Salmonellosis can be caused by contaminated food or contaminated water.

Question 70

Antibiotic therapy is not very useful for treating typhoid fever.

Question 71

Campylobacter infections are the most common foodborne infections in the United States.

Question 72

Explain why coliforms are used to detect water contamination rather than directly quantifying individual pathogens such as Vibrio cholerae or Salmonella spp.

Question 73

There were numerous cases throughout the United States of patients having bloody diarrhea all within a week of each other, many of which were hospitalized with severe cases. Although the people spanned from California to New York, they all had attended a high school graduation party. Epidemiologists determined the common food factor was cheese curds homemade by a farmer. The home where the cheese curds were made was searched, and the cheese curds and milk used to produce them were taken to the local government lab. Among other microbes, Campylobacter jejuni was isolated from many of the cheese curds as well as the farmerʹs bulk tank milk. What should be done for those infected? What can be done to prevent this from happening again?

Question 74

Gram-negative bacteria are responsible for causing over 60% of foodborne illness.

Question 75

Explain how the membrane filter (MF) procedure is used.

Question 76

Treatment of all pathogenic E. coli infections involves supportive therapy and, in some cases, may also include antimicrobial drugs.

Question 77

Why is Staphylococcus aureus often described as an international picnic pest?

Question 78

What is the difference between food poisoning and food infection? Are antibiotics useful in either of them?

Question 79

As a visitor to a country in which cholera is an endemic disease, what specific steps would you take to reduce your risk of cholera exposure? Will these precautions also prevent you from contracting other waterborne diseases? If so, which ones? Identify waterborne diseases for which your precautions may not prevent infection.

Question 80

With Clostridium perfringens, the enterotoxin is present in the endospores that germinate under anoxic conditions.