Barbecue cooks must know about perfringens

By JOE O'CONNELL, cbbqa past President
Updated Dec 28, 2003

Barbecue cooks should be familiar with food poisoning and its major causes, including perfringens, food poisoning caused by the bacterium Clostridium perfringens.

Perfringens

Perfringens ranks as the third most-common cause of food poisoning.  Like Staphylococcus and Salmonella, perfringens is present throughout the environment, including in the soil, the intestines of animals and humans, and in sewage.  Perfringens thrives at temperatures between 80° F and 120° F.

Perfringens differs from Staphylococcus and salmonella in two major ways.  First, it's anaerobic, which means that it thrives only in places where there is little or no oxygen.  Second, it produces two kinds of cells:  the poisonous living cell and the spore cell.  The poisonous living cell is a normal perfringens cell, but it causes poisoning in humans.  However, it is the spore cell which is particularly dangerous, because it can survive under conditions that kill the poisonous normal cells, and then, when they are exposed to temperatures between 70° F and 120° F, the spores transform into normal cells and begin to multiply quickly to disease-causing levels.

Symptoms of perfringens poisoning are usually mild diarrhea and gas pains, which begin from 8 to 24 hours after consumption.  The symptoms usually end within a day (thus, this is often mistaken for the "24 hour flu"), although people with certain medical conditions may be seriously affected.

This is the so-called "cafeteria germ", because it is often found in food which is served in quantity and is left for long periods at room temperature or even on a steam table.  Perfringens is often found in cooked beef, turkey, gravy, dressing, stews and casseroles.

To prevent perfringens poisoning, cooks must keep their food refrigerated at temperatures below 40° F or maintained at an internal temperature over 140° F.  In addition, because perfringens is anaerobic and so does not thrive in the air, cooks reduce the risk of poisoning by dividing large portions into small dishes for serving and even by stirring frequently.  Dividing buffet type foods into several small dishes exposes more of the food to the air, thus reducing the anaerobic conditions in which perfringens thrive.
 

Related information

• See the related Bibliography of Barbecue Health and Safety