Quiz 5 Content Flashcards
(79 cards)
1
Q
According to Health Canada, how many Canadian’s self-report a food allergy?
A
7%
2
Q
In westernized countries, how many young children and how many adults are estimated to have a food allergy?
A
5-6% of children
3-4% of adults
3
Q
What are food allergies commonly triggered by in children? [5]
A
- Eggs
- Milk
- Peanuts
- Tree nuts
- Wheat
4
Q
Where is labelling of the Big-8 mandatory? [5]
A
- EU
- Canada
- Japan
- Austalia
- New Zealand
5
Q
What are the big 8?
A
- Milk
- Eggs
- Fish
- Crustacean/shellfish
- Tree nuts
- Peanuts
- Wheat
- Soya
6
Q
Describe Food Allergen Recalls in Canada.
A
- Improved detection methods
- Centralized food processing
- The increase in recalls is not necessarily indicating that foods are becoming more unsafe.
7
Q
What does Class 1 recall mean?
A
Class I: a situation where serious adverse health
consequences or death may result if the product
is consumed.
HIGH RISK
There is high risk that consumption of the food may lead to serious health problems or death.
8
Q
What is a Class 2 recall?
A
Class II: a situation where a health hazard possibly exists but the probability is remote.
MODERATE RISK
There is a moderate risk that consuming the food may lead to short-term or non-life threatening health problems
9
Q
What is a class 3 recall?
A
Class III: a situation where the consumption of the product is not likely to cause any health problems (e.g., severe quality issues)
LOW RISK
There is a low risk that consuming the food may result in any undesirable health problems. This class also includes food that do not pose a health risk, but that do not comply with legislation.
10
Q
Describe food allergy in Asia.
A
- Overall prevalence is comparable, but types of food allergy differ in order of relevance.
- Shellfish is the most common food allergy
- Peanut allergy prevalence in Asia is extremely low compared to the West for reasons not yet understood
- Among young children and infants, eggs and milk are the two most common food allergies with prevalence data comparable to the West.
11
Q
What is the most common cause of anaphylaxis in Japan and Korea (and increasing in Thailand)?
A
Wheat allergy (though uncommon in most other Asian countries)
12
Q
Which country has the longest list of allergens to regulate?
A
- South Korea (not shown on this list) - they consider tomato an allergen
13
Q
Food allergy is one of the most common causes of anaphylaxis. In addition to gastrointestinal symptoms, individuals may experience [8], caused by […].
A
In addition to gastrointestinal symptoms, individuals may experience urticaria (i.e., hives), angioedema, asthma, rhinitis, conjunctivitis, hypotension, shock and cardiac arrhythmias, caused by the massive release of mediators from mast cells and basophils.
14
Q
What are the common food allergens in infants/young children? [5]
A
- Milk
- Chicken eggs
- Soy
- Peanuts
- Wheat
15
Q
What are the common food allergies in older children and adults? [8]
A
- Peanut
- Tree nuts
- Fish
- Shellfish
- Fruit
- Vegetables
- Seeds
- Spices
16
Q
What are the most common food allergies that cause anaphylaxis? [8]
A
- Milk
- Chicken eggs
- Peanuts
- Tree nuts
- Shellfish
- Fruit
- Vegetables
- Seeds
17
Q
Define food hypersensitivity.
A
The umbrella term for both food allergies and non-allergenic food sensitivities.
18
Q
Define food allergies.
A
Sensitivities caused by a reaction of the body’s immune system to specific proteins in a food.
19
Q
Define food intolerances.
A
Food sensitivities that do not involve the individual’s immune system.
20
Q
Compare the type of reaction between food allergies and food intolerances.
A
Allergy: immune response
Intolerance: chemical reaction
21
Q
Compare the trigger for food allergy to those for food intolerance.
A
Allergy: Can be triggered by a small amount of the food and occur every time the food is consumed.
Intolerance: Often are dose related
22
Q
Compare the symptoms of food allergies with those of food intolerances.
A
- Symptoms may be hard to differentiate: nausea, stomach pain, cramps, vomiting, headaches, etc.
Allergy: Involve multiple organs; affect the respiratory system, GI tract, skin or cardiovascular system; sometimes are fatal
Intolerance: Originate in the gastrointestinal system
23
Q
Compare the prevention of food allergies with that of food intolerance.
A
Allergy: At risk of a life-threatening allergic reaction; may need to carry an epinephrine shot for emergency self-treatment
Intolerance: May be recommended with steps to aid digestion of certain foods or to treat the underlying condition causing the reaction
24
Q
Describe the mechanisms of food allergy.
A
- Most food allergies are mediated by immunoglobulin E (IgE)
- Some non-IgE-mediated reactions appeared to be T-cell mediated
- In allergic individuals, a food protein is mistakenly identified by the immune system as being harmful
25
What is an immunoglobulin/antibody?
Proteins produced by plasma cells in response to an antigen, capable of binding to the antigen that stimulated its production
26
Why are babies more likely to develop allergies?
* The GI tract neutralizes foreign antigens and blocks them from entering circulation. Many of the immunological and mechanical barriers involved in this process are immature at birth, leaving infants at risk.
* Immunologically intake food proteins penetrate the gut barrier and enter into circulation, but clinical tolerance prevents pathologic reactions. A failure to develop tolerance or a breakdown in tolerance results in excessive production of food-specific IgE antibodies.
| This is why babies are more likely to develop allergies.
27
Describe sensitization.
1. Allergen is consumed, sensitizing individual
2. Sensitization results in production of allergen-specific IgE antibodies which then attach to receptors on mast cells and basophils.
3. Upon subsequent exposure to the substance, the allergen cross-links two antibodies on the surface of the mast cell or basophil membrane, stimulating release into tissues and blood of chemical mediators, such as histamine, inducing an immediate hypersensitivity reaction.
## Footnote
Note that antihistimines are not an affective treatment to an allergenic reaction. The only effective treatment is epinephrine (which helps open up airways and blood vessels).
28
How can allergenicity be reduced in the food supply? [5]
* The best way is to **know and avoid** foods that cause signs and symptoms.
* **Traceability** throughout the food chain from primary production to the finished product
* **Analysis** of each step involved in the manufacturing process; identification of allergenic risks and the critical points at which those risks can be controlled
* **Quantification** of the allergens at each of those points, in which analytical methodologies play a critical role
* **Risk assessment** takes into account exposure and the characteristics of the allergens (how much has to be consumed to cause an allergic reaction)
29
Describe MS-based methods for detection of allergen peptide biomarkers in food products.
* Mass spectrometry based methods are mostly used for research and development because it's **very costly**.
30
Detection methods for food allergens were established after 1990, and evolved with increasing awareness and regulations. List them. [4]
1. ELISA
2. Lateral flow
3. PCR
4. Liquid Chromatography - Mass Spectroscopy (mostly for R&D)
31
What is the most commonly used method of allergen detection in the food industry?
ELISA
32
Describe ELISA for allergen detection. [5]
* Highly specific to the allergenic food
* Sensitive
* Compatible with different sample types (e.g., food ingredients, finished products, water, environmental samples)
* Kits are available
* Can be qualitative, semi-quantitative, or quantitative
* 30 mins to 6 hours total analysis time.
## Footnote
Laboratory & machines required
33
Describe lateral flow devices in allergen detection. [7]
* Antibody-based like ELISA, but less expensive
* Qualitative
* Available for many food allergens
* Rapid on-site analysis (< 5 mins)
* Sensitive (LOD ~5ppm)
* Some are designed for water only and not food
* Require confirmatory methods
34
What are LFD typically used for? [3]
* Environmental sampling
* Cleaning verification
* Screening of foods
35
Describe the advantages of PCR in allergen detection. [4]
* Available for many allergenic food sources
* Sensitive
* Rapid
* Allows for multiplexing (e.g., detection of several tree nuts)
36
Describe the limitations of PCR in allergen detection. [4]
* Expensive equipment
* Quantification is difficult
* Absence of DNA does not necessarily indicate absence of protein
* Cannot distinguish by-product proteins from tissue proteins (egg/chicken; milk/beef)
37
List the sources of chemical contaminants in foods. [7]
1. Pesticide residues (insecticides, fungicides, herbicides)
2. Veterinary drug residues
3. Environmental contaminants (e.g., heavy metals)
4. Food processing contaminants (e.g., acrylamide, nitrosamines)
5. Migrants from packaging materials
6. Toxins (e.g., mycotoxins)
7. Unapproved food additives and adulterants (e.g., melamine)
38
What are veterinary drug residues and what do they include [3]?
* Very small amounts of veterinary medicines that can remain in animal products and therefore make their way into the food chain
* Include:
* The parent compound (whatever has been administered to the animal)
* Their metabolities in any **edible portion** of the animal product
* Residues of associated impurities of the veterinary drug concerned.
39
What is the VDD?
* Health Canada - Veterinary Drug Directorate
* Health Products and Food Branch
* Evaluates and monitors the (1) safety, (2) quality, and (3) effectiveness
* Sets standards
* Promotes the prudent use of veterinary drugs administered to food-producing and companion animals
40
What is the Codex Alimentarious Commission?
* Established by FAO & WHO
* Develops harmonized **international food standards**, guidelines and codes of practice to (1) protect the health of consumers and (2) ensure fair practices in the food trade
41
What are the veterinary drug functional classes?
* Growth promoters
* Production aids (e.g., hormones for increased milk production, improved growth performance)
* Insecticides
* Anthelmintic agents (eradicate intestinal worms)
* Antimicrobial agents (anti-bacterial, anti-protozoal)
* Others (tranquilizers, anti-inflammatory, etc.)
## Footnote
Potentially dangerous residues in food of animal origin, risk analysis required
42
What are the short term health implications associated with veterinary drug residues? [2]
* Drug residue allergy
* Toxicity
43
What are the long term health implications associated with veterinary drug residues? [4]
* Carcinogenicity
* Reproductive and developmental effects
* Teratogenicity (cause fetal abnormalities)
* Development of antimicrobial resistant microbes
44
What is beta-lactam?
* An antibiotic widely used in therapy of cattle
45
Describe the allergenicity of beta-lactam. [2]
* Anaphylactic shock (a severe, potentially fatal allergic reaction; rapid, weak pulse, skin rash, and nausea and vomiting)
* Beef cattle should be withheld from slaughter for food use for 30 days following last treatment.
46
What is Clenbuterol?
* The most effective **beta-agonist** non-steroidal metabolism accelerator
* A growth promoter: induces weight gain and a greater proportion of muscle to fat
47
What is the concern with Clenbuterol?
* 1992 outbreak in Spain: 113 cases associated with the consumption of tainted veal liver.
* The use of clenbuterol has been banned in Canada and the US in meat
48
Clenbuterol is permitted in Canada.
True or False?
False.
## Footnote
The use of clenbuterol has been banned in Canada in meat, but is approved for use in the management of horses.
49
Clenbuterol is not permitted in Canada.
True or False?
True.
## Footnote
The use of clenbuterol has been banned in Canada in meat, but is approved for use in the management of horses.
50
What is ractopamine?
* Beta-agonist used as a feed additive to promote growth and leanness in pigs that are raised for their meat
* Responsible for muscle growth
* Not as toxic to humans as compared to other agonists (e.g., Clenbuterol)
* Permitted in Canada, US, Australia, etc.
* Banned in Europe, China, etc.
51
Ractopamine is permitted in Canada.
True or False?
True.
52
Ractopamine is not permitted in Canada.
True or False?
False.
53
What are MRLs? [3]
* The maximum concentration of residue following administration of a veterinary medicine which is legally permitted or acceptable in food.
* Determined as not to pose a risk for human health.
* MRLs define how much of a residue can be in the food.
## Footnote
MRLs have a big impact on international trade.
54
What kind of animals is ractopamine intended to use in? What's JECFA's evaluation process of the drug and any important factors involved in the considerations?
* Intended for use in mature animals: cattle and swine (and heavy turkeys to a limited extent).
* JECFA reviewed available data and performed comprehensive risk assessment considering (1) toxicology, (2) residues in, and (3) intake from food animals in 1993, 2004, 2006, and in 2010.
* JECFA established acceptable daily intake based on an acute cardiac response from a human study, noting a wide safety margin.
55
Describe deaths attributable to antimicrobial resistance every year by 2050.
56
Describe the issue of antimicrobial resistance.
* A major issue of drug use in food animals as well as over-use of antibiotics in humans
57
How does AMR occur? [4]
1. Lots of germs. Few are germ resistant.
2. Antibiotics kill bacteria causing the illness, as well as good bacteria protecting the body from infection.
3. The drug-resistant bacteria are now allowed to grow and take over.
4. Some bacteria give their drug-resistance to other bacteria, causing more problems.
58
What is intrinsic resistance?
The existence of genes in the bacterial genome that could generate a resistance phenotype.
## Footnote
The list of mechanisms shown in the graphic are not exhaustive.
59
Describe resistance due to human activities. [4]
* Therapeutic use in humans accounts for <50% of all applications of antibiotics produced commercially
* Growth promotion/prophylactic use in animals
* Therapeutic/prophylactic use in aquaculture
* Others: pets, pest controlling, etc.
60
Describe intrinsic mechanisms of resistance.
1. Antibiotic A binds Penicillin binding protein which inactivates it.
2. Efflux pumps protect the bacteria against the effects of antibiotic B.
3. Antibiotic C doesn't work since it is unable to cross the membrane of the bacteria.
61
What are beta-lactamases?
* Enzyme which breaks a bond in the beta-lactam ring of penicillin to disable the molecule.
* Bacteria with this enzyme can resist the effects of penicillin and other beta-lactam antibiotics
62
How do non-resistant bacteria acquire resistance?
* **Horizontal gene transfer**: the process of swapping genetic material between neighbouring bacteria.
* Many of the AMR genes are carried on plasmids or transposons that can act as vectors that transfer these genes to other members of the same bacterial species, as well as to bacteria in another genus or species
63
What are the 3 types of horizontal gene transfer?
1. Transformation
2. Transduction
3. Conjugation
64
What is bacterial transformation?
* Occurs when naked DNA is released on lysis of an organism and is taken up by another organism.
* The antibiotic-resistance gene can be integrated into the chromosome or plasmid of the recipient cell.
65
What is bacterial transduction?
Antibiotic-resistance genes are transferred from one bacterium to another by means of **bacteriophages** and can be integrated into the chromosome of the recipient cell.
66
What is bacterial conjugation?
* Occurs by direct contact between two bacteria: plasmids form a **mating bridge** across bacteria and DNA is exchanged, which can result in acquisition of antibiotic-resistance genes by the recipient cell.
* Transposons can also carry antibiotic-resistance genes.
67
How does antimicrobial resistance spread (macroscale)?
* Animals get antibiotics and develop resistance in their guts
* Drug-resistant bacteria can remain on meat from animals. When not handled or cooked properly, the bacteria can spread to humans.
* Fertilizer or water containing animal feces and drug-resistant bacteria is used on food crops.
* Drug resistant bacteria in the animal feces can remain on crops and be eaten. These bacteria can remain in the human gut.
* George gets antibiotics and develops resistant bacteria in his gut
* George gets care at a hospital, or some other in-patient facility
* Resistant germs spread directly to the other patients or indirectly on unclean hands of healthcare providers.
* Resistant bacteria spread to other patients from surfaces within the facility.
* Patients go home
* George stays at home and in the general community and spreads resistant bacteria.
68
What are 6 antibiotic alternatives in food-producing animals and what is their function?
* **Vaccines** - induction of immune response
* **Immune modulators** - stimulation and enhancement of immune system
* **Phytochemicals** - bacterial growth inhibition and animal growth promotion
* **Antimicrobial peptides (AMPs)** - inhibition of bacterial growth
* **Probiotics** - improvement of host health
* **Bacteriophages** - inhibition of bacterial growth.
69
What are the pros [4] and cons [4] of vaccines as an antibiotic alternative in food-producing animals?
* **PROS**: (1) Prevention of pathogens; (2) improvement of production; (3) cost-effectiveness; (4) stimulation of host immune response
* **CONS**: (1) Adverse effects; (2) narrow range of inhibitory effect on bacterial growth; (3) host immune response-dependent activity; (4) difficulty in new vaccine development
70
What are the pros [3] and cons [3] of immune modulators as an antibiotic alternative in food-producing animals?
* **PROS**: (1) Broad range of inhibitory effect; (2) less harmful immune response; (3) enhancement of host immune system.
* **CONS**: (1) Adverse side effects; (2) host immune response-dependent activity; (3) few clinical evidences to oral administration
71
What are the pros [4] and cons [1] of phytochemicals as an antibiotic alternative in food-producing animals?
* **PROS**: (1) Animal growth production; (2) antioxidative activity; (3) antimicrobial activity; (4) improvement of gut health
* **CONS**: (1) Uncertainty of toxicity and interaction with other additives
72
What are the pros [4] and cons [4] of AMPs as an antibiotic alternative in food-producing animals?
* **PROS**: (1) High specificity; (2) high stability; (3) good bactericidal effects; (4) less adverse effect.
* **CONS**: (1) High production cost; (2) narrow range of inhibitory effect; (3) resistance to AMPs; (4) degradation by protease.
73
What are the pros [4] and cons [2] of probiotics as an antibiotic alternative in food-producing animals?
* **PROS**: (1) Inhibition of bacterial growth; (2) animal growth promotion; (3) production of antimicrobial compounds; (4) improvement of host gastrointestinal microbial balance.
* **CONS**: (1) Harmful health effect in the immunodeficient host; (2) risk of antibiotic resistance gene transfer.
74
What are the pros [4] and cons [4] of bacteriophages as an antibiotic alternative in food-producing animals?
* **PROS**: (1) High specificity; (2) low inherent toxicity; (3) **degradation of biofilm**; (4) low cost.
* **CONS**: (1) Narrow range of inhibitory effect; (2) removal by host immune system; (3) risk of antibiotic resistance gene transfer; (4) phage resistance.
75
How are veterinary drug residues tested for? [2]
* ELISA
* Lateral flow tests (liquid chromatography; gas chromatography)
76
How are antibiotic residues tested for? [3]
* Microbiological assays
* Analytical methods (HPLC, GC, etc.)
* Immunoassays
77
Describe the newest antibiotic residue test developed for use in Dairy.
* Cuts out incubation step; faster and simpler than original tests.
78
Which countries permit ractopamine?
* Permitted in Canada, US, Australia, etc.
## Footnote
* Banned in Europe, China, etc.
79
Which countries have banned ractopamine?
* Banned in Europe, China, etc.
## Footnote
* Permitted in Canada, US, Australia, etc.
