Researchers at Case Western Reserve University have uncovered a natural defense mechanism that could be key to fighting the stubborn and sometimes deadly "superbug" Clostridium difficile, know as "C. diff," without using conventional antibiotics. The new findings were published Sunday in the online issue of the journal Nature Medicine. C. diff, a bacterium resistant to many drugs, has become a major problem for hospital and nursing home patients in Ohio and nationwide killing more than 28,000 people each year, according to the Centers for Disease Control and Prevention. Researcher Jonathan Stamler, MD, said that he and his colleagues have uncovered a natural defense produced in a person's body to fight C. diff. C. diff often invades the colon after antibiotics have destroyed the healthy flora. The bacterium releases toxins in the gut that can cause diarrhea, more serious conditions such as colitis and sometimes death. In the study Stamler describes the mechanism that is capable of inactivating the toxins spread in the colon by C. diff. Stamler explained that the newly discovered mechanism involves a nitric oxide-based molecule called S-nitrosoglutathione or GSNO. This molecule binds to the toxins secreted by C. diff, deactivates them and prevents them from penetrating and damaging cells.