3 - Sources of Bacterial Pathogens Flashcards
Opportunities for contamination along the food distribution continuum include:
- Production
- Processing
- Distribution
- Retail/Restaurant
- Home prep
- Restaurant prep / consumers
Internal tissues of “________” and “______” plants and animals are essentially sterile
(which is why you can eat rare steak or beef tartare)
healthy, fresh
Processed food may contain ______, ______, _______, and ______ from processing environment
mold, yeast, bacteria and viruses
Contamination occurs from ________ and _______ sources
natural and external
give a few examples of natural sources of contamination:
- GI tract
- Skin
- Feathers
- Surface of cut fruit
- Damaged tissues
give a few examples of external sources of contamination:
- Air
- Sewage
- Water
- Feed
- Human
- Ingredients
- Equipment
- Packages
- Insects
_________ is a great example of animal infection
Bacillus anthracis
Anthrax is a zoonotic disease caused by the spore-forming bacterium
B. anthracis.
Gastrointestinal anthrax in humans occurs 1–7 days after eating raw __________________________
raw or undercooked meat from infected animals
Why was the listeria in caramel coated apples outbreak was unanticipated?
Because both the pH of apples (less than 4.0) and the water activity of the caramel coating (less than 0.80) are too low to support Listeria growth.
How did the listeria caramel coated apples outbreak happened?
when apples were poked with stick listeria that was present on the outside of the apples received enough moisture from the inside of the apple to grow at the apple caramel interface. The low pH of the apple juice appeared to be buffered by the higher pH of the caramel coating. Leading to the proliferation of the bacteria and the resultant outbreak.
Plants (Fruits and Vegetables) harbour microbes on their _______
surface
Pathogens (particularly enterics) in fruits and vegetables can be present if the soil was contaminated with _______
raw sewage (mexican harvester policy)
What can you due to reduce bacterial load on fruits and vegetables?
- Proper methods like using treated sewage
- Quick washing with clean water
- Storage at low temperature
- Workers must also follow good hygiene practices
There have been several outbreaks of __________ and _________ in Canada/ USA from imported frozen fruits and berries
Hepatitis A
Norovirus
Lab analysis shows that viruses can survive >_______ in frozen berries
2 years
The virus can come from ill workers, contaminated irrigation water or surfaces, or harvesting baskets
Food producing animals normally carry _________________ in their digestive, respiratory, urogenital tracts, teats, skin, hooves, hair, and feathers
indigenous microorganisms
TRUE OR FALSE: Many food producing animals carry human pathogens without showing symptoms (i.e. Chickens and Salmonella)
TRUE
Shellfish may carry human pathogens (i.e. __________) as part of the natural microbiota again with no symptoms
Vibrio
Contamination in milk can occur due to fecal material on the ________, eggs can come into contact with fecal material during _________, meat can _________ during slaughter
udder surface
laying
GI tract
How can you avoid bacterial contamination in animal, birds, fish, shellfish?
- using effective husbandry
- avoid overcrowding, use clean food and water
- test flocks for the presence of pathogens prior to slaughter
- careful removal of the GI tract
- harvest fish/shellfish from clean water, and store in clean water
TRUE OR FALSE: Microbes are present in dust and moisture droplets in the air
TRUE
Mostly “air” microbes are _______________________
bacterial or mold spores, yeast, or some select gram-positive bacteria
How can air contamination be reduced?
- remove potential sources of contamination
- control dust particles in the air (using filtered air)
- using positive air pressure
- reducing humidity
- installing UV lights
Especially when used as a fertilizer in crops can contaminate food with microbes, particularly enteropathogenic bacteria and viruses:
sewage (it is better not to use sewage as a fertilizer)
Aqua culture operations can be contaminated by _________ if the harvest sites are near cities or waste water treatment plants
effluent
How can humans be a source of contamination?
By carrying environmental contamination into processing plants, and sick workers can contaminate food products
TRUE OR FALSE: Contaminated water can be a source of pathogens
TRUE
What type of water should be used for washing and storage?
fresh potable water
How did the Japanese reduce their V. parahaemolyticus problem by intervening in possible contamination routes and limiting the chances for bacterial growth?
Regulation 1: use hygienic seawater to wash and process shellfish and finfish
Regulation 2: Temperature control below 10C for seafood distribution and storage
Regulation 3: V.parahaemolyticus levels in seafood, set microbiological standards at below 100 MPN/g for raw consumption
Regulation 4: Rapid consumption, consume seafood within 2h after removal form the refrigerator
T OR F: Equipment can be contaminated by any of the previously mentioned sources and spread contamination to future batches
T (chocolate milk outbreak)
