Download Food Fact Sheet 6

Food Fact Sheet No. 6
BACTERIA
Bacteria are microscopic organisms that naturally occur in the environment. Some bacteria
however, when they are not in their natural environment can cause illness or death. Bacteria
can make you ill by:
 Consuming an infective dose*

Consuming the toxins created by the bacteria
* The infective dose is the number of bacteria required to cause food poisoning. A smaller number of bacteria
would be needed to poison the young, sick or elderly compared to healthy people.
How Bacteria Grows
Bacteria need the following conditions in which to optimize their growth:

Moisture

Food source (usually high protein foods)

Time to multiply (double in number every 20 minutes under ideal conditions)

Neutral acidity (pH 7)

Oxygen

Non saline environment

Temperature (bacteria die above 60°C and become inactive below 5°C)
Common Food Poisoning Bacteria
Some common pathogenic (food poisoning) bacteria and where they can be found include:

Staphylococcus aureus (found on the skin, hair etc as well as on meat and in dairy products)

Escherichia coli (found in the intestinal tract of animals and humans)

Salmonella spp. (found in meat, poultry and egg)

Clostridium perfringens (found in the soil)

Listeria monocytogenes (found in raw meats, unpasteurised dairy products and fermented meats)

Bacillus cereus (found in rice)

Vibrio parahaemalyticus (found in seafood)
ood Fact Sheet No. 7
Main Points - Bacteria



Bacteria can make you ill by consuming an infective dose* or by consuming the toxins formed by the
bacteria.
Bacteria need the following conditions to optimise growth - moisture, food source, non acidic environment,
oxygen, non saline environment as well as the correct temperature and the time required for them to
multiply to the number that can make you ill.
Some common food poisoning bacteria include - Staphylococcus aureus, Escherichia coli, Salmonella spp.,
Clostridium perfringens, Listeria monocytogenes, Bacillus cereus and Vibrio parahaemalyticus.