Clostridium perfringens toxins involved in food poisoning

Clostridium perfringens is a Gram-posit ive spore-forming, anaerobic and nonmotile rod. It is a normal soil inhabitant, and plays an important part in the putrification process. C. perfringens is also readily isolated from dust, raw meat and the intestinal tract of man and animals. It is divided into five types based on the production of four major lethal toxins, as shown in Table I. Table I also shows the different types of diseases caused by C. perfringens. The enterotoxin has been shown to be produced by types A, C and D (Table I), but is not used for typing C. perfringens. C. perfringens is responsible for two very different types of food poisoning (Table I). Type A causes the mild classic form of food poisoning, while the severe type of food poisoning known as necrotic enteritis is caused by type C. The symptoms of the C. perfringens type A food poisoning are: acute abdominal pain and diarrhoea with nausea and fever, with vomiting being rare. The symptoms usually appear 8-12 h (6-24 h) after ingestion of contaminated food (106-107 cells/g) and can last between 12-24 h (Hobbs, 1969). The poisoning is seldom fatal, although a few deaths have been reported in elderly and infirm (Parry, 1963; Sutton and Hobbs, 1965). The true incidence of C. perfringens food poisoning is not known, because of the relative mildness of the syndrome. Nevertheless, in several countries C. perfringens has been reported as the most important cause of food poisoning, only exceeded in incidence by food infections caused by Salmonella (Cliver, 1987; Reynolds, 1987). Necrotic enteritis is a rare and often fatal illness. The symptoms are: acute sudden onset of severe abdominal pain and diarrhoea (often bloody), sometimes with vomiting, and necrotic inflammation of the small intestine.