Lesson 10: Food Safety Flashcards
What do we call a measure of probability that a substance or activity will cause harm under defined conditions of exposure?
Risk
What is chronic sequelae?
Chronic (secondary) complications following an acute illness
What are microbes?
Microorganisms too small too small to be seen with the naked eye
What families do microbes include?
Bacteria
Protists
Fungi
What are pathogens?
Microbes capable of causing disease
Which people are more susceptible to pathogens than others?
The very old The very young Pregnant women The malnourished Those with compromised immune systems
How are foodborne illnesses transmitted to human beings?
Through food and water
What are foodborne illnesses caused by?
either an infectious agent (foodborne infection) or a poisonous substance (food Intoxication); commonly known as food poisoning
How are foodborne infections caused?
by eating foods contaminated with live pathogens
What are the symptoms of foodborne infections?
Abdominal cramps
Fever
Vomiting
Diarrhea
What are food intoxications caused by?
eating foods containing natural toxins produced by pathogens
Do pathogens need to be present for intoxication to occur?
No, toxin-producing bacteria need only have infused the food with their toxin
What are the two types of toxins?
Enterotoxins that affect intestines
Neurotoxins that affect nervous system
Once contaminated food is consumed, how long before you get sick?
Ranges from 1 day to several weeks
What is the onset of symptoms for food intoxication?
Usually within a few hours
How can we reduce the risk of foodborne illnesses?
You need to be aware of pathogens & what makes them special. This information allows you to spot potential hazards.
What are the most common foodborne bacterial pathogens in Canada?
Campylobacter jejuni
Salmonella
Escherichia coli
Listeria
What can foodborne viral pathogens cause?
gastroenteritis (gastro is a foodborne illness, transmitted easily through person to person contact)
What is an example of a foodborne viral pathogen?
Norwalk virus
What are examples of bacterial toxin producers?
Staphylococcus aureus
Clostridium Botulinum
What are some other microorganism producing toxins?
Aflatoxin (fungal toxin) Marine toxins (algae)
What is something that makes all bacteria more pathogenic?
They can have sex (uncoupled sexual reproduction)
Bacteria produce pili. What are pili?
Extension of the bacteria’s cell membrane
True or False: Bacteria in cells are constantly exchanging genes - even genes for antibiotic resistance.
True
What does salmonella and campylobacter jejuni bacteria stem from?
Contamination from eating undercooked meat (especially chicken) and improperly handled poultry
What are related diseases to salmonella and CJB?
GBS (Guillain-Barre Syndrome)
Reactive arthritis
Irritable bowel syndrome
What is Guillain Barre syndrome?
a disease that causes impairment of neurons leading to neuro-muscular paralysis that can be triggered following campylobacter infection.
How does E.coli (escherichia coli) bacteria arise?
Infection occurs from improperly handling raw ground meat and by eating ground meat that is undercooked.
What is the difference between a beef patty and minced meat in relevance to e.coli?
Interior portion of any intact piece of beef is relatively free of bacteria since pathogens are on the surface where oxygen is present and when you sear the meat, the pathogens are destroyed
When having minced eat, pathogens are mixed throughout in the grinding process, which increases the surface area of protein-rich tissue and supplies oxygen for microbes to grow and multiply
What is MTB?
Mechanically tenderized beef in which we make incisions on the surface of an intact meat to break apart the muscle fibers in an effort to tenderize the meat.
Is there more or less of a risk for e.coli with MTB?
5 fold increase in risk
Where is listeria found?
in soil and water
What are the 2 adaptations that increase listeria’s pathogenicity?
Forms biofilm on surfaces (Can find it’s way into packaged food and proliferate)
Can grow and multiply in the refrigerator
How is listeria killed?
pasteurization and cooking
Where can listeria grow?
On vegetation, lunch meats
Why can buying precut lettuce increase your risk of listeria?
Cutting liberates nutrients previously confined to the inside of plant cells, and these released nutrients become food for pathogens to grow and multiply
What does Staphylococcus aureus produce? What is it?
a toxin that can make you sick. It is a bacterium that is commonly found on the surface of the skin, especially the hand and nose.
Does reheating leftover food destroy bacteria?
Yes but it does not destroy the toxin.
After how long do nausea, vomiting and stomach pain occur after Staphylococcus aureus bacteria infection?
After 1-6 hours
What does Clostridium Botulinum produce?
Botulinum, the most poisonous substance known to man`
How does Clostridium Botulinum grow?
It grows and multiplies in the absence of oxygen. In presence of oxygen, it forms a resistant spore that remains dormant.
What does to botulinum toxin cause?
neuromuscular paralysis in small doses
What is botox?
diluted solution of botulinum toxin injected under surface of skin to cause localized neuromuscular paralysis to make wrinkles disappear
What is the most common cause of intoxication of botulinum toxin?
Home canned foods and homemade garlic and oils stored at room temperature
What happens to the spores of botulinum toxin when there is an absence of oxygen and high pH?
The spores resume growth and the toxin is produced.
What is the Norwalk virus?
highly contagious pathogenic virus that also goes by name of stomach flu, winter vomiting disease
Why is the stomach flu a foodborne illness?
It can be transmitted through contaminated food, water and human-to-human contact
What do fungi produce?
mycotoxins
What is aflotoxin produced by?
moldy crops
What has aflotoxin been known to cause?
liver cancer
What do microorganisms in aquatic ecosystems produce?
Metabolic byproducts that are released in the water.
What are the most known metabolic byproducts of microorganisms?
Algae that produce toxic red tides
Where can marine toxins accumulate?
In shellfish
What can marine toxins cause?
paralytic shellfish poisoning
How can climate change worsen this problem?
Favoring the growing conditions of harmful algal blooms and increase the frequency & severity of this type of intoxication
What is a pesticide?
any chemical used to control unwanted insects, weeds, or fungi
What are the 3 modes of entry of a pesticide?/
Inhalation
Dermal Contact
Ingestion
What do we call the reference dose for a pesticide that is calculated as a function of the dose at which no effects are observed??
NOAEL (no observable adverse effects level)
What is pasteurization?
heat processing of food that inactivates some, but not all, microorganisms in the food; not a sterilization process
Are bacteria that cause spoilage still present after pasteurization?
Yes
How to refrigeration and freezing help with pathogens?
They retard the growth of pathogens
What is irradiation?
Involve the use of low-dose radiation to kill pathogens on food
Health Canada regulates the allowed dose of irradiation to be used for only 3 categories of food. What are these 3 foods?
Spices
Onions and potatoes
Wheat Flour
What do all foods that have been irradiated must contain?
The international symbol RADURA
Is irradiation linked to cancer?
No
What are nitrites?
food additive to preserve lunch meats and cold cuts
Are nitrites carcinogenic?
Yes but they are still used since they inhibit growth of clostridium botulinum spores
What are the canadian agencies that are responsible for ensuring our food is safe?
Health Canada
Canadian Food Inspection Agency
Agriculture and Agri-Food Canada
Environmental Bureau of Agriculture and Agri-Food Canada
Environment Canada World Health Organization (WHO)
What do these Canadian agencies do?
- Ensure nutritional quality of our foods
- Establish regulations to prevent contamination of our food by pathogens or their toxins
- Test safety of food additives
- Ensure proper use of industrial preservation techniques like pasteurization and irradiation
- Enable research and technology to promote sustainable agricultural practices
