According to David McSwane, H.S.D., bacteria are the most important biological foodborne hazard and are responsible for more cases of foodborne illness than any other hazard. Bacteria that cause "food poisoning" can cause illness in one of the three ways. An infection is when the bacteria actually burrow in the digestive tract and multiply. In an intoxication, the bacteria actually multiply in the food and produce a toxin that a person can ingest. And lastly, in a toxin-mediated infection, the bacteria are consumed with the food and the toxin is then produced within the body.
Staphylococcus Aureus
Staphylococcus aureus is a bacterium that produces a toxin in food that can cause intoxication. The bacteria grow well in foods that contain high salt or high sugar, such as ham, egg and tuna salads, custards and ready-to-eat meats. Staphylococcus aureus food poisoning produces severe nausea, acute abdominal pain, vomiting and diarrhea. The onset of this intoxication is rapid, within one to six hours, and lasts approximately 24 hours. The toxin is "heat stable" and once produced cannot be destroyed by cooking.
Listeria Monocytogenes
Listeria monocytogenes is a bacterium that causes infection in people. Unlike most bacteria, listeria has the ability to grow at refrigerated temperatures. The most common foods contaminated with listeria are lunch meats, hot dogs and soft cheeses. Listeria produces flu-like disease in ordinarily healthy adults, with nausea, vomiting, fever and chills. However, severe complications can occur in certain "high-risk" individuals, such as pregnant women, the elderly and people with weakened immune systems.
Clostridium Botulinum
Botulism is a severe intoxication produced by the anaerobic bacterium Clostridium botulinum. The toxin produced is a neurotoxin that is considered one of the deadliest biological toxins known. The symptoms of botulism include headache, dizziness, an inability to swallow and respiratory paralysis. The foods most commonly implicated in botulism are improperly canned foods, such as green beans, meats and fish. Unlike the toxin associated with S. aureus above, the toxin produced by C. botulinum can be destroyed by boiling the food for 20 minutes.
Salmonella
The Salmonella species of bacteria produces an infection in an individual who ingests the contaminated foods. The foods most commonly associated with salmonella infection are raw meats and poultry, raw milk and dairy products and eggs. Salmonella is frequently transmitted to foods through cross-contamination, in which uncontaminated foods come into contact with surfaces or utensils used for contaminated foods. The onset of salmonella food poisoning ranges from six to 48 hours and produces nausea, fever, cramps and diarrhea.
E. Coli O157:H7
This type of food poisoning made national headlines in 1993 in the Jack-in-the-Box restaurant outbreak. E. coli O157:H7 can cause disease both as an infection and as toxin-mediated infection. Foods most commonly implicated include raw or undercooked meats (hamburger in particular), unpasteurized milk and juices, and contaminated vegetables. The disease in humans can cause severe abdominal pain, vomiting, bloody diarrhea, kidney failure (hemolytic uremic syndrome) and death.
References
- "Essentials of Food Safety and Sanitation"; David McSwane, H.S.D.; 2000
- FDA Bad Bug Book
