Role of C. difficile in disease:
Clostridium difficiles are anaerobic, spore-forming, and Gram-positive bacteria that produce two exo-toxins: toxin A and B. This is a very common symptoms of Antibiotic-Associated Diarrhea (AAD).
Patients with C. difficiles feces spores, without strict precautions, the spores accidentally fall into the hands, kitchen utensils and food.
Then, these are swallowed by another person. The spores live in the second person's human digestive tract, but in normal conditions bacteria control C. difficiles and the disease does not develop.
But if "good" GI bacteria are eliminated with antibiotics, C. difficiles reproduction and growth produce toxins that damage the intestinal mucosa. It causes diarrhea, inflammation, and sometimes loss in appetite.