1. Foodborne Pathogen and Disease

2. Foodborne Pathogens
a biological infectious agent (Microorganism) that causes Foodborne illness to host (referred to as food poisoning) is any illness resulting from the consumption of contaminated food.

3. Foodborne Pathogens:
Foodborne pathogens are the leading causes of illness and death in less developed countries killing approximately 1.8 million people annually.
In developed countries foodborne pathogens are responsible for millions of cases of infectious gastrointestinal diseases each year, costing billions of dollars in medical care and lost productivity.

4. New foodborne pathogens and foodborne diseases are likely to emerge driven by factors such as pathogen evolution, changes in agricultural and food manufacturing practices, and changes to the human host status.
There are growing concerns that terrorists could use pathogens to contaminate food and water supplies in attempts to incapacitate thousands of people and disrupt economic growth.

5. Pathogenic microorganisms
1. Intoxication :
- Staphylococcus aureus
- Clostridium botulinum
- Bacillus cereus
2. Infection :
- Salmonella
- Clostridium perfringens
- Vibrio
- Phathogenic E.coli

6. Staphylococcus aureus
TAXONOMY
Gram positive coccus (producing an exotoxin)
Source of contamination of food
- nose and skin of humans and animals
- high level in people with
- skin infection
- heavily colonised skin disease

7. Contamination by food handler
Eliminated by pasteurization
Microwave decreases counts
Fat/ sugar/ salt protects the organism
Usually about 106 / g needed to produce sufficient toxin
Generally low numbers are allowed in food

8. GROWTH REQUIREMENTS * Temperature range 7 - 48 o C (optimum 37 oC)
* pH range
(optimum 6 - 7)
* Facultative anaerobe

9. REQUIREMENTS FOR TOXIN PRODUCTION
Range is more limited than growth range
optimum temperature 40 – 45 o C
Aw above 0.85

10. Staphylococcal Exotoxin (Enterotoxin / Neurotoxin)
* Resistant to proteolytic enzymes
e.g. trypsin in the gut
* Resistant to heat

11. Mechanism of Activity
Toxin (exotoxin) is performed and ingested in food
Stimulates neural receptors in the gastrointestinal tract
Vomiting within approx 4 hours (1-6 hours) after ingestion of toxin
The toxin can also induce diarrhea, nausea, headache

12. Examples of foods implicated in outbreaks
Salted meats
Cold cooked meats
Poultry
Custard
Cream filled bakery products
(whipped cream)
Mayonnaise
egg

13. MOST OUTBREAK ASSOCIATED WITH ONE OR MORE OF :
PREVENTION
MOST OUTBREAK ASSOCIATED WITH ONE OR MORE OF :
Inadequate in refrigeration
Food prepared in advance
Poor personal hygiene
Moderate cooking or heat processing
Holding food in warmer
SO…
* Control post-process contamination
* Control temperature abuse (cooking/ holding/ refrigeration)
* Handle food correctly
* Good quality raw material

14. Salmonella Enterobacteriaceae Gram Negative, Short Rod
TAXONOMY
Enterobacteriaceae
Gram Negative, Short Rod
Non spore forming
Peritrichous flagella
RESERVIOR
Intestinal of domestic and wild animal
Water, Sewage, Environment

15. GROWTH REQUIREMENTS * Temperature range optimum 37 oC
42 oC used for selective enrichment
* pH range
4 - 9
* Facultative anaerobe

16. Found in many foods :
Contamination directly or indirectly with animal or human feaces
- Raw/Undercooked eggs
- Uncooked meat
- Raw milk and milk products
- Poultry and poultry products
- Skim milk powder
- Ice-cream
- Mayonnaise
- Chocolate
- Cantaloupes

17. Clinical Diarrhoea Vomiting Antibiotics minimal effect
Organism may be excreted for weeks
Some outbrakes have shown very low infective dose causing death in infants, elderly and immunosuppressed.

18. PREVENTION
Correct food hygiene – direct or indirect feacal contamination
Correct food processing – heating / cooling / storing.
Correct personal hygiene to control secondary spread
Food handlers should have consecutive negative feacal cultures before returning to work with food.

19. Indicator Microorganisms

20. Coliform is the name of a test for the Enterobacteriaceae family.
commonly-used bacterial indicator of sanitary quality of foods and water.
They are defined as rod-shaped Gram-negative non-spore forming organisms.
Some genus can ferment lactose with the production of acid and gas when incubated at 35-37°C.
abundant in the feces of warm-blooded animals, but can also be found in the aquatic environment, in soil and on vegetation.
they are easy to culture and their presence is used to indicate that other pathogenic organisms of fecal origin may be present. Fecal pathogens include bacteria, viruses,or protozoa and many multicellular parasites

21. Escherichia coli Member of the coliform group
Gram Negative, rod and Non-sporulating
Facultative anaerobic
ferment lactose at 44°C in the fecal coliform test
When cultured on an EMB plate,
a positive result for E. coli is Metallic
sheen colonies on a dark purple media.

22. Reference
Adams, M.R. and Moss, M.O., Food Microbiology, 2008