The clostridium genus of bacteria are made up of over 100 known species, including a few clinically important pathogens. C. botulinum infections from contaminated food or wounds causes botulism from exposure to the botulinum neurotoxin. C. difficile infection of the human colon can lead to symptoms ranging from mild diarrhea to life threatening colitis. C. perfringens contamination of food is a common cause of foodborne illness. C. tetani produces the deadly toxin, tetanospasmin, which causes tetanus. Clostridium bacteria are generally anaerobic, gram positive and spore-forming.