What types of bacteria are there?

The following definitions of the different types of bacteria that can contaminate meat products are taken from The Problem of Foodborne Illness.


These bacteria produce toxin only in an environment of little acidity. They are found in canned goods e.g. liver pate and also in luncheon meats, ham, sausage etc.


These bacteria found on poultry, cattle and sheep and can contaminate meat of these animals. Chief raw food sources include:

  • raw poultry
  • meat
  • unpasteurised milk.

Clostridium perfingens

In most instances, this bacteria is present because of a failure to keep food hot. A few organisms are often present after cooking and multiply to toxic levels during cool down and storage of prepared foods. Meats and meat products are the foods most frequently implicated.


Found in and on raw meats, poultry, milk and other dairy products.

E.coli 0157 and other STECs

The principle source of this bacteria is the gut content of animals. Found in and on the raw meat, this bacteria has been associated with major outbreaks of food poisoning.

Shigella species

Food becomes contaminated when a human carrier does not wash their hands and then handles food that is not thoroughly cooked afterwards. Faecal organisms like E.coli multiply in food left at room temperature.

Staphylococcus aureus

The toxin produced when food contaminated with this bacteria is left too long at room temperature is a major cause of food poisoning. Meat is a good environment for these bacteria to produce toxin.

Entamoeba histolytica

These protozoa exist in the intestinal tract of humans and are expelled in faeces. Poor personal hygiene can transfer this protozoa on to meat.

Listeria species

Listeria is common throughout the environment and is found in man, animals, soil and water. This causes a very dangerous form of food poisoning and pregnant women are particularly at risk. It is transmitted by eating contaminated food products, usually dairy products, pâté or uncooked vegetables.

Giardia lamblia (water contamination)

Giardia lamblia may be transmitted by uncooked foods that become contaminated while growing or after cooking by infected food handlers. Cool, moist conditions favour the protozoa’s survival.