BE ON GUARD
Botulism is food poisoning caused by the toxin produced by the bacterium Clostridium botulism. The toxin is extremely dangerous as it affects the nervous system and is often fatal. Botulism is usually found in low-acid, canned foods such as canned meat and seafood, smoked and processed fish. Botulism can be prevented by cooking to destroy the toxins, proper refrigeration and sanitation. Canned foods which show evidence of swelling should not be eaten. The illness causing toxin can be inactivated by cooking for 15 minutes at 185ºF.
Staphylococcal Food Poisoning
The bacteria Staphylococcus aureus produces enterotoxin which causes gastroenteritis (inflammation of the stomach and intestinal linings) and can also affect the nervous system. Although unpleasant, this type of food poisoning rarely results in death. Staphylococcal food poisoning is one of the most common foodborne illnesses in the United States. Foods most commonly affected by this type of bacteria are cream and custard filled pastries, potato salad, dairy products, and cooked meats (especially ham and poultry).
These bacteria can reproduce to very large numbers without changing the color, flavor, or smell of the food. Growth rate of Staphylococcus aureus is highest at temperatures above 68 ºF and in foods with little acidity. While the bacteria are easily destroyed by heat (151ºF for 12 minutes), the illness causing toxins produced by the bacteria are much more difficult to destroy (250 ºF for 30 minutes). This type of food poisoning can be prevented by pasteurization of susceptible foods, refrigeration, and sanitation.
Clostridium perfringens Food Infection
This type of food infection is caused by an anaerobic spore forming bacteria that produces toxins and large amounts of gas during growth. While the bacteria is found in many foods, large amounts of it must be eaten for this type of food infection to occur. At greatest risk for growth of this type of bacteria are meat products which are cooked, allowed to cool slowly, and held for an extended period before serving.
This type of food infection can be prevented by rapidly cooling cooked and heat processed foods, proper refrigeration of foods, and good sanitation. Temperatures of foods on steam tables should be held above 140 ºF. Leftovers should be thoroughly heated to destroy the bacteria and its toxins.
There is a large variety of Salmonellae organisms that can cause the food infection Salmonellosis. These bacteria grow inside the host and produce a toxin which causes illness by irritating the intestinal walls. One million or more organisms must be ingested in order to cause illness. Most cases of salmonellosis are a result of contact of prepared foods with raw meet or its juices. Eating raw or rare meat is also a danger. Other cases result from insufficiently cooked poultry, eggs, and dairy products especially when kept unrefrigerated for longer periods of time. Salmonellae bacteria can be prevented by cleanliness and sanitation of food handlers and equipment, pasteurization, and refrigeration.
One of the most well known parasites which causes food infection is Trichinella spiralis. These small, wormlike organisms can be found in insufficiently cooked meat of carnivorous animals such as pigs. Ingested larvae mature in the upper part of the intestinal walls within five to seven days. The mature worms then reproduce in the intestine where new larvae are hatched. The larvae then migrate to the circulatory system and are carried to the muscles of the host where they burrow and become encysted causing muscle pain in the host. The most common way to prevent this type of food infection is by cooking pork to internal temperatures of at least 138 ºF.
Poultry and other types of meats can be contaminated with Campylobacter jejuni and Campylobacter coli. Ingestion of as few as 500 bacteria can cause food infection with severe abdominal pain and diarrhea. Fortunately, these bacteria are easily controlled as they are killed at normal cooking temperatures and do not multiply at temperatures below 86 ºF