Foodborne Zoonoses

Question 1

What are the 6 INTRINSIC parameters affecting bacterial growth?

Answer 1

pH: changes affect functioning and uptake of nutrients
MOISTURE: increases length of lag phage
OXIDATION-REDUCTION: ease with which substance loses or gains electrons
NUTRIENT COMPOSITION: energy, proteins
ANTIMICROBIAL CONSTITUENTS: lactoferrin in milk
BIOLOGICAL STRUCTURES: natural covering on foods can protect against microbial invasion

Question 2

What are the 4 EXTRINSIC parameters affecting bacterial growth?

Answer 2

TEMPERATURE
HUMIDITY
GASEUS ATMOSPHERE: aerobic vs anaerobic
OTHER MICROORGANISMS

Question 3

What are some sources of meat contamination?

Answer 3

• animal hides
• sticking knife
• GI tract
• hands/tools
• cutting/mincing operations
• lymph nodes
• packaging material

Question 4

What is the shelf-life of beef?

Answer 4

3-4 weeks/vacuum = 6-8 w

Question 5

What is the shelf-life of chicken?

Answer 5

2 weeks

Question 6

What is the shelf-life of pork?

Answer 6

2 weeks

Question 7

What is the shelf-life of lamb?

Answer 7

2 weeks

Question 8

What is Campylobacter?

Answer 8

A bacteria that commonly effects raw poultry (also found in rest)
Inactive below 30 degrees and are readily inactivated by heat and cooking procedures. Causes abdominal pain and diarrhoea in humans

Question 9

How is Camplylobacter prevented?

Answer 9

Proper hygiene from farm to fork:
F: clean water + biosecurity
S+P: freezing and irradiation
C: proper cooking meat

Question 10

What is Listeriosis?

Answer 10

• an infection in humans (meningitis, premature birth etc.)

- caused by L. monocytogenes a facultative bacteria (resistant to most environmental conditions)

Question 11

How is L. monocytogenes controlled?

Answer 11

• reformulation of product to eliminate growth
• strict temp controls (2-4 degrees)
• shortened shelf life
• good hygiene practices

Question 12

What is E.coli?

Answer 12

a facultative anaerobic bacteria found in intestinal tract of mammals and birds
can cause death in humans

Question 13

How is E.coli spread?

Answer 13

ANIMAL to ANIMAL: through contaminated hide, wild animal, birds, food and water
ANIMAL to HUMAN: hide/intestine to carcass and/or fecal contamination of other foods (veggies/fruits)

Question 14

How is E.coli controlled?

Answer 14

Proper management of animals: good biosecurity, exclusion, monitoring immune status

Question 15

What is a foodborne virus?

Answer 15

Viruses can enter at any stage of food production line, food is only a vehicle of transfer therefore HUMAN to HUMAN

Question 16

What is the Process Hygiene Criteria?

Answer 16

• AEROBIC COLONY COUNT + Enterobacteriaceae on cattle,
sheep, goats, horses and pig carcases
• SALMONELLA on cattle, sheep, goats, horses, pig, broiler and
turkey carcases;
• AEROBIC COLONY COUNT and E. COLI in minced meat and
mechanically separated meat;
• E. COLI in meat preparations

Question 17

What is the Food Safety Criteria?

Answer 17

absence of SALMONELLA in poultry meat

absence of L. MONOCYTOGENES in Ready to Eat foods

Question 18

What is the Testing of Working Surfaces?

Answer 18

Microbiological testing of working surfaces.

Question 19

When is the Testing of Working Surfaces not necessary?

Answer 19

1. Food Business Operator can verify their cleaning procedures
2. If they do not produce Ready-to-Eat products