Bacteria and food poisoning
Bacteria are single celled micro-organism, invisible to human eye and living all around the natural world. There are helpful bacteria, spoilage bacteria and photogenic bacteria.
Helpful bacteria help us to digest food, to make food such as yogurt and cheese and make crops.
Spoilage bacteria make food perish.
Pathogenic bacteria cause illness and responsible for food poisoning and food borne diseases. They can be found in raw food, pests and pets, people, air and dust, dirt and food waste.
Cooking usually destroys them, but when they form spores, that is a protective coating, bacteria can survive even harsh conditions.
Bacteria can move, but they cannot travel on their own. They need vehicles of contamination for example: people, animals, equipment and utensils.
To multiply to dangerous levels bacteria need particular conditions such as food, moisture, warmth and time.
Contaminants can be: physical, chemical and microbial.
Examples of physical contaminants are: stones, fruit leaves, shell fragments, fish scales, poultry bone fragments, jewellery, hair, fingernails, insects, dust, dirt.
Examples of chemical contaminants are: clearing chemicals, agricultural chemicals, pesticides and pest bait.
Example of microbial contaminants are: cuts, boils of the skin, poor personal hygiene on hands, ears, hair, insects, mice, dogs, cats, fur feathers, untreated sources of drinking water, unwashed fruit and vegetables.
Contamination can be:
DIRECT, when a raw food touches a high risk food;
INDIRECT, when a liquid or juice from a raw food drip onto high risk food;
CROSS, when bacteria are carried, for instance by hands or utensils, from a raw food to a high risk food.