Week 9C2 : food safety

Question 1

Wha are the 6 main causes of unsafe food?

Answer 1

1. Presence of pathogen
2. Presence of natural toxins
3. Extraneous matter
4. Environmental contaminants
5. Harmful additives
6. Allergens

Question 2

What is the cause of the hamburger disease?

Answer 2

Emergence of E.coli O157:H7

Question 3

What is the percentage of the population affected by food poisoning in the US?

Answer 3

30%

Question 4

T or F: food microbiology adresses only the microbiological contamination to make the food safe

Answer 4

F it is also because food contamination is the leading cause of food loss/spoilage

Question 5

What are the microorganisms of concern in food microbiology?

Answer 5

1. Bacteria

2. Fungi (molds and yeasts)

Question 6

T or F : viruses can cause food spoilage

Answer 6

false, but they can cause minor foodborne illnesses because they don’t prolifate in food.

Question 7

What is the two main goals of food microbiology

Answer 7

1. reducing spoilage

2. making food more safe

Question 8

T or F : the microorganisms can be found equally in and on the tissues of the food

Answer 8

False, they are mostly found on the tissues

Question 9

bacteria reproduce by ___, resulting in an

exponential rate of growth: population can double every ___ min

Answer 9

Binary fission

20-30

Question 10

T or F : fungus and bacteria reproduce by binary fission

Answer 10

False, only bacteria does

Question 11

What is the standard for grade A raw milk prior to pasteurization

Answer 11

100 000 bacteria per milliliter

Question 12

What are the three shapes of bacteria?

Answer 12

spherical, rod shape and spiral

Question 13

What are the dimensions of bacteria?

Answer 13

1-4µm

Question 14

What are the dimension of yeast?

Answer 14

20µm

Question 15

What are the shapes of yeast?

Answer 15

spherical and ellipsoidal

Question 16

Which microorganism is mostly used in fermentation

Answer 16

yeast

Question 17

What is the multicellular form of molds ?

Answer 17

Hyphae

Question 18

Which of the microorganism is a common spoilage cause?

Answer 18

molds

Question 19

How does the microorganisms degrade food ?

Answer 19

by excreting enzymes

Question 20

___ are generally better at growing at lower moisture levels than other microorganisms

Answer 20

Molds

Question 21

Mesophilic organisms best over a temperature range of ___

Answer 21

20- 45°C

Question 22

Thermophilic (heat-loving) organisms grow best at temperatures above___ , some are able to grow at temperatures up to __

Answer 22

45°C

82˚C

Question 23

Psychrophilic (cold-loving) organisms grow best at ___

Answer 23

low temperatures (<10°C)

Question 24

Psychrotrophic organisms are able to grow at ___

Answer 24

refrigerator temperature (~4°C).

Question 25

____ grow in the absence of oxygen.

Answer 25

Anaerobes

Question 26

___ grow in the presence of oxygen.

Answer 26

Aerobes

Question 27

Microorganisms can be ____ (require aerobic or anaerobic conditions) or _____ (can adapt to either condition).

Answer 27

obligate | facultative

Question 28

What is the difference between food infection and food intoxication?

Answer 28

food infection : pathogenic microorganism establishes itself in the intestines and causes an infection. food intoxication : A toxin produced by the microorganism causes illness

Question 29

How is done the microorganisms taxonomy?

Answer 29

1. Genus (capital letter) : Escherichia 2. Specie (small letter) : coli 3. subspecies or serotype : O157:H7 ex E. coli O157:H7

Question 30

_____ is an infection caused by bacteria belonging to the genus Salmonella: severe gastrointestinal illness.

Answer 30

Salmonellosis

Question 31

What is the main vehicle of transmission of salmonella

Answer 31

poultry

Question 32

_____ is an infection caused by the bacterial species Listeria monocytogenes, often termed “refrigerator disease” because this species grows in chilled products.

Answer 32

Listeriosis

Question 33

What is the refigerator diseases?

Answer 33

Listeriosis

Question 34

What is the 3rd leading cause of death from food poisoning?

Answer 34

Listeriosis

Question 35

Listeriosis is often associated with _____ and ____

Answer 35

raw milk cheess and ready to eat meats

Question 36

What are the three bacterial foodborn infections seen in class

Answer 36

1. salmonellosis 2. Listeriosis 3. Campylobacteriosis

Question 37

What was the cause of the maple leaf outbreak

Answer 37

Listeria monocytogenes

Question 38

What is the bacteria causing campylobacteriosis?

Answer 38

Campylobacter C. jejuni

Question 39

What is the leading bacterial foodborne infection in the world

Answer 39

Campylobacteriosis

Question 40

What is the illness associated with cases of guillain-Barré Syndrome?

Answer 40

Campylobacteriosis

Question 41

If your symptoms appear rapidly after ingesting food, you most probably have a food ____

Answer 41

intoxication

Question 42

Clostridium botulinum is an ____anaerobe

Answer 42

obligate

Question 43

____ are toxins produced by bacteria belonging to the genus Staphylococcus.

Answer 43

Staphylococcal enterotoxins

Question 44

What is the toxin that is present on hands and one of the major reason why individuals in industries wear gloves

Answer 44

Staphylococcal enterotoxins

Question 45

What is the main vehicle of transmission for Staphylococcal enterotoxins

Answer 45

food handlers

Question 46

T or F : Staphylococcal enterotoxins are not destroyed by cooking

Answer 46

T

Question 47

T or F : Staphylococcal enterotoxins can form an enteroxins that is seirous

Answer 47

False

Question 48

____ are toxins produced by molds

Answer 48

mycotoxins

Question 49

For example, the mold ____ in moldy grain/cereals/peanuts produces aflatoxin (a hepatotoxin)

Answer 49

Aspergillus flavus

Question 50

What does STEC stands for?

Answer 50

Shiga-toxin–producing E. coli

Question 51

____ (such as Norwalk virus) are considered to be responsible for ~50% of all outbreaks of foodborne illness in North America: they are very easily transmissible through food and water, as well as from person to person.

Answer 51

Noroviruses

Question 52

T or F : Hepatitis A and polio plus a variety of other viral infections can also be transmitted via food and water.

Answer 52

T

Question 53

What is a norovirus?

Answer 53

A group of viruses that are a common cause of food poisoning and acute gastroenteritis ("stomach flu"

Question 54

What is the second leading cause of death from foodborne illness?

Answer 54

toxoplasmosis

Question 55

What is the first leading cause of death by foodborne illnes

Answer 55

Salmonellosis

Question 56

what is the protozoan parasite associated with toxoplasmosis?

Answer 56

Toxoplasma gondii

Question 57

What is the main vehicle of toxoplasmosis

Answer 57

undercooked meat

Question 58

____ are worms of the genus Trichinella that cause the disease trichinosis. Their larvae may be ingested in undercooked meat, primarily pork, and develop into worms (<3 mm long) in the intestines.

Answer 58

Trichinosis nematodes

Question 59

anisakiasis is the illness related to ____

Answer 59

Anisakis

Question 60

What is the macrobiological parasite often found in marine food

Answer 60

anisakis

Question 61

Anisakiasis is very effectively prevented by ____ of marine products

Answer 61

freezing

Question 62

T or F: within traditional food microbiology, the term microorganisms refers to bacteria and fungi.

Answer 62

True

Question 63

T or F: the microbial contamination often happens during the processing

Answer 63

true

Question 64

What is the standard analytical method to determine the bacterial load of a food

Answer 64

the standard plate count with an upper limit of the total microbial load that depends on the organism and the food

Question 65

T or F : if a vegetative cell causing a food infection is killed during the processing, you can still get food infection from the toxins of that vegetatitve cell

Answer 65

false, that is not food infection, that would be food intoxication

Question 66

Name one complication of the intoxication by the Shiga-toxin-producing E.coli (STEC) strain of E.coli

Answer 66

hemolytic uremic sundrome which can lead to death because of kidney failure, permanent kidney damage or death.