Clostridium perfringensPotential Food Safety Hazard
Food poisoning caused by Clostridium perfringens may occur when foods such as meat or poultry are cooked and held without maintaining adequate heating or refrigeration before serving. The presence of small numbers of C. perfringens is not uncommon in raw meats, poultry, dehydrated soups and sauces, raw vegetables, and spices.Because the spores of some strains are resistant to temperatures as high as 100ºC for more than l h, their presence in foods may be unavoidable. Furthermore, the oxygen level may be sufficiently reduced during cooking to permit growth of the clostridia. Spores that survive cooking may germinate and grow rapidly in foods that are inadequately refrigerated after cooking. Thus, when clinical and epidemiological evidence suggests that C. perfringens is the cause of a food poisoning outbreak, the presence of hundreds of thousands or more of these organisms per gram of food substantiates the diagnosis.
Illness typically occurs 8-15 h after ingestion of the contaminated food. The symptoms, which include intense abdominal cramps, gas, and diarrhea (nausea and vomiting are rare), have been attributed to a protein enterotoxin produced during sporulation of the organism in the intestine. The enterotoxin can be detected in sporulating cultures, and a method for this purpose is included. A high correlation has been established between the ability of C. perfringens strains to produce enterotoxin and their ability to cause food poisoning. However, it is difficult to obtain consistent sporulation with some strains (Rhodehamel and Harmon, 1998).
Control Measures
Control measures emphasize proper food preparation and storage techniques, especially temperature control. Control measures include:1. Rapid, uniform cooling of cooked foods to <10ºC (50ºF) within 2-3 h;
2. Hot holding of cooked foods at or above 60ºC (140ºF);
3. Reheating cooled or chilled foods to a minimum internal temperature of 75ºC (167ºF) immediately before serving;
4. Not leaving foods at room temperature or thawing frozen foods at room temperature;
5. Preventing cross-contamination of cooked foods with bacteria from raw foods by using separate food-contact surfaces for preparing raw and cooked food items, or by thoroughly cleaning and sanitizing food-contact surfaces after being used for raw products;
6. Maintaining food preparation areas so that they are free of soil and dust;
7. Cleaning and sanitizing meat slicers, meat-cutting equipment, food-contact surfaces, and other equipment after use; and
8. Using good personal hygiene methods, and thoroughly washing hands frequently when handling food products, especially after handling raw products and before handling cooked products (Labbe, 1989; Reed, 1994).
Content Source: Seafood Network Information Center