Clostridium difficile colitis.

Clostridium difficile, the agent that causes pseudomembranous colitis associated with antibiotic therapy, has been identified in recent years as a common nosocomial pathogen. First described in 1935 by Hall and O'Toole, this gram-positive anaerobic bacillus was named “the difficult clostridium” because it resisted early attempts at isolation and grew very slowly in culture1. Although the organism released potent toxins in broth culture, the fact that it was found in stool specimens from healthy neonates led to its classification as a commensal. C. difficile subsequently passed into obscurity. In the 1960s and 1970s antibiotic-associated pseudomembranous colitis became a major clinical . . .