Clostridium perfringens

Clostridium perfringens is a bacteria that is found just about everywhere in nature, including decaying vegetation, marine sediment and even the human intestines. However, it is one of the most common causes of food poisoning and, when it infects the bloodstream, commonly causes necrosis and gas gangrene.
C. perfringens thrives in the absence of oxygen and can form spores which are difficult to destroy, but can be restored into living bacteria when conditions improve.
C. perfringens is difficult to diagnose as it presents with many of the symptoms of similar diseases. However, it almost always responds to penicillin and antibiotics should be started any time the bacteria is suspected. Unlike botulism, which is a toxin produced by a closely related bacteria, C. perfringens itself does the damage to cells.
Clostridium perfringens at Wikipedia