C. difficile colonies on a blood agar plate. Scientific classification Kingdom: Bacteria Phylum: Firmicutes Class: Clostridia Order: Clostridiales Family: Clostridiaceae Genus: Clostridium Species: C. difficile Binomial name Clostridium difficile Hall & O'Toole, 1935 Clostridium difficile (pronounced /kl?s'tr?di?m d?'f?s?li/, also known as CDF/cdf', or 'C. diff') is a species of bacteria of the genus Clostridium which are Gram-positive, anaerobic, spore-forming rods (bacillus).[1] C. difficile is the most significant cause of pseudomembranous colitis,[2] a severe infection of the colon, often after normal gut flora is eradicated by the use of antibiotics. Treatment is performed by stopping any antibiotics and commencing specific anticlostridial antibiotics, e.g. metronidazole.

Individual drumstick shaped C. diff bacilli seen through electronmicroscopy