Clostridium perfringens bacterium, illustration. These are Gram-positive, endospore-forming, rod-shaped bacteria. This bacterium frequently occurs in the intestines of humans and many domestic and feral animals. Food poisoning occurs when foods such as beef, gravy and poultry are cooled and/or reheated improperly and large numbers of vegetative cells are ingested. Toxin production in the digestive tract is associated with sporulation. C. perfringens is also a major pathogen of wound infections, producing a variety of toxins that act both locally and systemically. One toxin it produces, the alpha toxin, damages cell membranes and is responsible for gas gangrene.