Clostridium difficile is a gram-positive, anaerobic, spore-forming bacterium that produces TcdA and TcdB toxins causing severe tissue damage. It ia an opportunistic pathogen that is the major cause of antibiotic-associated diarrhoea and pseudomembranous colitis in humans. C. dificile infection can also result in abdominal pain, inflammation, and ulceration of the lining of the intestinal wall.