2. • food poisoning or food intoxication can be
result of either chemical poisoning or the
ingestion of toxicant ( which is produced by
microorganism , plant and animals).
3. Types of intoxication
• a. Bacterial intoxications
• b. Fungal intoxications
• c. Chemical intoxication
• d. Plant toxicants
• e. Poisonous animals
4. Bacterial intoxication
• There are four chief bacteria which caused
the food intoxication.
• 1. Staphylococcus aureus
• 2. Bacillus cereus
• 3. Clostridium perfringens
• 4. Clostridium botulinum
5. Staphylococcal food intoxication
• This is a type of food borne intoxication is
caused by consumption of food
contaminated with staphylococcal
enterotoxins produced by certain strains of
Staphylococcus aureus while growing in
food.
6. • The organism produces the following five
serologically different enterotoxins that are
involved in food borne intoxication.
1. Staphylococcal enterotoxin A(SEA),
2. Staphylococcal enterotoxin B (SEB),
3. Staphylococcal enterotoxin C (SEC),
4. Staphylococcal enterotoxin D (SED),
5. Staphylococcal enterotoxin E (SEE)
• -Individual strains of S. aureus may produce
one or more of enterotoxin types while
growing in food.
7. Food involved
• Growth of staphylococcus and their toxin
production required a food sources.
• E.g Milk and milk products (including
pasteurized milk, yoghurt, chocolate milk,
fermented milk, cream filled pastries),
poultry, fish, shellfish, meat and meat
products, non meat salads, egg and egg
products, vegetables and cereal products
have been involved.
8. Toxin production
• Toxin production occurs at growth
temperature 12-44°C, pH 4.2 and salt
concentration of ≤10%.
• No toxin production occurs at temperatures
below 12°C, pH < 4.2 and > 10 % salt
• 75% of all staphylococcal food poisoning
outbreaks occurs because of inadequate
cooling of foods.
9. Prevention
The means of prevention of out breaks of
staphylococcus food poisoning include:-
1. Prevention of contamination of food with
staphylococci.
2. Prevention of growth of the staphylococcus.
3. Killing staphylococci in foods.
10. Control
• Contamination of food can be reduced by
general method such as
1. By pasteurization of raw milk
2. By adequate refrigeration of food
3. By addition of bacteriostatic substance such
as serine , antibiotic.
11. Clostridium botulinum foodborne
Intoxication
• Botulism :- botulism is caused by the ingestion of food
containing the neurotoxin produced by clostridium
botulinum.
• The intoxication is caused by botulinal toxins A, B, E, F
and G, produced by C. botulinum type A, B, E, F and G,
while the organism grows in food.
• C. botulinum types C and D produce toxins C and D
that cause disease in animals
• Type E strains are non-proteolytic while the rest are
proteolytic.
• Spores of C. botulinum type A can survive temperatures
of 120°C.
12. • The strains are divided into proteolytic and non-
proteolytic types according to whether they
hydrolyze proteins or not.
• Growth characteristics
• Proteolytic strains grow at temperature range
between 10-50°C, while non-proteolytic grow at
3.3- 45°C (optimum 35-37°C).
• Toxin production occurs at temperature range
between 25-30°C.
• Botulinus toxin is one of the most lethal poisons
known. The calculated lethal dose for an adult
person is 10 μg.
13. Food involved
• Canned food-string beans , corn , beets, peas
, figs etc.
• Preserved meat and fish
14. Preventive measures
• proper manufacturing practices e.g. ensure
proper sterilization and preservation of
canned meat.
• Preserved foods possessing rancid or other
odors should be rejected.
15. Clostridium perfringens intoxication
• Clostridium perfringens intoxication caused by
Clostridium perfringens enterotoxin (CPE)
produced in the gastrointestinal tract.
• The organism is found in the soil, dust, water,
sewage marine sediments, decaying materials,
intestinal tracts of humans and other animals
• If the spores are present as contaminants on raw
meat they may resist boiling or steaming for 4 or
more hours, and on slow cooling the spores will
germinate into rapidly multiplying bacterial
cells,which produce large amounts of toxin..
16. Vehicle foods
• The food involved are those that are prepared
one day and served the next day.
• Foods that have been involved include red
meats, chickens, fish, pork, fruits, vegetables,
etc.
• Foods poisoning occurs when the level
reaches 107-108 cells/g of food.
• Growth is enhanced by anaerobic conditions
achieved after removal of oxygen by cooking.
17. Prevention
• 1. Proper cooking of food and eating freshly
prepared foods.
• 2. Fast cooling of cooked food. Storing food in
small quantities will enhance cooling.
• 3. Storage of leftovers or unused foods in
freezers.
18. Fungal intoxications
• These are caused by consumption of
metabolites produced by fungi, when growing
in food.
• These metabolites are called mycotoxins.
• Grains, oilseeds, fruits and vegetables are
mostly involved if they are stored at high
humidity or if they are not properly dried
before storage.
19. Types of fungal toxin
• Aflatoxin
• Patulin
• Ochratoxin ……..and many more.
20. Prevention of mycotoxin
• Proper drying and storage of grains and other
affected foods.
• Quality control of potentially hazardous foods
by use of appropriate analytical tests.
• Use of fungicides as seed dressings to protect
stored cereals and other foods like pulses and
potatoes against fungal invasion.
21. Chemical intoxication
• Poisoning by consumption of chemicals is
rather uncommon and usually is characteristic
by appearance of the symptoms with in short
time after the poisonous food is eaten.
• E.g antimony, arsenic, cadmium ,chlorinated
hydrocarbons, copper ,cyanide, fluoride,
nicotinic acid, lead and zinc.
22. Animals toxicant
• Seafood toxins include ciguatera toxin(reef fish),
scombroid toxin(decayed fish), shellfish toxins.
• Shellfish poisoning:- many shellfish become toxic
to humans as a result of feeding on toxic
algae,particularly dinoflagellates , including
Gonyaulax catenella and G.tamareusis.
• After consumption of this type of shell , it causes
respirational paralysis and death can result with
in 2-12 hour.
23. Plant toxin
• Food contains natural chemicals that are essential for growth
and health, including carbohydrates, sugars, proteins and
vitamins. But some foods contain potentially harmful natural
toxins.
• The reason for the presence of natural toxins is not always
known. In some foods, a toxin is present as a naturally
occurring pesticide to ward off insect attack.
• Fruit seeds and pits
• Apple and pear seeds and the inner stony pit (kernel) of
apricots and peaches contain a naturally occurring substance
called amygdalin. Amygdalin can release hydrogen cyanide
in the gut causing discomfort or illness. It can be fatal if too
much is consumed in a short period of time