3 - Sources of Bacterial Pathogens

Question 1

Opportunities for contamination along the food distribution continuum include:

Answer 1

• Production
• Processing
• Distribution
• Retail/Restaurant
• Home prep
• Restaurant prep / consumers

Question 2

Internal tissues of “________” and “______” plants and animals are essentially sterile
(which is why you can eat rare steak or beef tartare)

Answer 2

healthy, fresh

Question 3

Processed food may contain ______, ______, _______, and ______ from processing environment

Answer 3

mold, yeast, bacteria and viruses

Question 4

Contamination occurs from ________ and _______ sources

Answer 4

natural and external

Question 5

give a few examples of natural sources of contamination:

Answer 5

• GI tract
• Skin
• Feathers
• Surface of cut fruit
• Damaged tissues

Question 6

give a few examples of external sources of contamination:

Answer 6

• Air
• Sewage
• Water
• Feed
• Human
• Ingredients
• Equipment
• Packages
• Insects

Question 7

_________ is a great example of animal infection

Answer 7

Bacillus anthracis

Question 8

Anthrax is a zoonotic disease caused by the spore-forming bacterium

Answer 8

B. anthracis.

Question 9

Gastrointestinal anthrax in humans occurs 1–7 days after eating raw __________________________

Answer 9

raw or undercooked meat from infected animals

Question 10

Why was the listeria in caramel coated apples outbreak was unanticipated?

Answer 10

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.

Question 11

How did the listeria caramel coated apples outbreak happened?

Answer 11

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.

Question 12

Plants (Fruits and Vegetables) harbour microbes on their _______

Answer 12

surface

Question 13

Pathogens (particularly enterics) in fruits and vegetables can be present if the soil was contaminated with _______

Answer 13

raw sewage (mexican harvester policy)

Question 14

What can you due to reduce bacterial load on fruits and vegetables?

Answer 14

• Proper methods like using treated sewage
• Quick washing with clean water
• Storage at low temperature
• Workers must also follow good hygiene practices

Question 15

There have been several outbreaks of __________ and _________ in Canada/ USA from imported frozen fruits and berries

Answer 15

Hepatitis A

Norovirus

Question 16

Lab analysis shows that viruses can survive >_______ in frozen berries

Answer 16

2 years

The virus can come from ill workers, contaminated irrigation water or surfaces, or harvesting baskets

Question 17

Food producing animals normally carry _________________ in their digestive, respiratory, urogenital tracts, teats, skin, hooves, hair, and feathers

Answer 17

indigenous microorganisms

Question 18

TRUE OR FALSE: Many food producing animals carry human pathogens without showing symptoms (i.e. Chickens and Salmonella)

Answer 18

TRUE

Question 19

Shellfish may carry human pathogens (i.e. __________) as part of the natural microbiota again with no symptoms

Answer 19

Vibrio

Question 20

Contamination in milk can occur due to fecal material on the ________, eggs can come into contact with fecal material during _________, meat can _________ during slaughter

Answer 20

udder surface
laying
GI tract

Question 21

How can you avoid bacterial contamination in animal, birds, fish, shellfish?

Answer 21

• 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

Question 22

TRUE OR FALSE: Microbes are present in dust and moisture droplets in the air

Answer 22

TRUE

Question 23

Mostly “air” microbes are _______________________

Answer 23

bacterial or mold spores, yeast, or some select gram-positive bacteria

Question 24

How can air contamination be reduced?

Answer 24

• remove potential sources of contamination
• control dust particles in the air (using filtered air)
• using positive air pressure
• reducing humidity
• installing UV lights

Question 25

Especially when used as a fertilizer in crops can contaminate food with microbes, particularly enteropathogenic bacteria and viruses:

Answer 25

sewage (it is better not to use sewage as a fertilizer)

Question 26

Aqua culture operations can be contaminated by _________ if the harvest sites are near cities or waste water treatment plants

Answer 26

effluent

Question 27

How can humans be a source of contamination?

Answer 27

By carrying environmental contamination into processing plants, and sick workers can contaminate food products

Question 28

TRUE OR FALSE: Contaminated water can be a source of pathogens

Answer 28

TRUE

Question 29

What type of water should be used for washing and storage?

Answer 29

fresh potable water

Question 30

How did the Japanese reduce their V. parahaemolyticus problem by intervening in possible contamination routes and limiting the chances for bacterial growth?

Answer 30

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

Question 31

T OR F: Equipment can be contaminated by any of the previously mentioned sources and spread contamination to future batches

Answer 31

T (chocolate milk outbreak)