The evolving epidemic of Clostridium difficile 630.

Clostridium difficile is a major pathogen responsible for a range of diseases in humans and animals. The genetic tools used to explore C. difficile biology are a relatively recent development in comparison to those used to investigate some other pathogens. Consequently, a rapid and haphazard dispersal of strains throughout the scientific community has led to the evolution of different C. difficile lineages within strains in different geographical locations and these genotypic differences are likely to affect the phenotype of the organism. Here we review the history of C. difficile 630, the first genome-sequenced C. difficile isolate and the most widely distributed reference strain, and its derivatives. We also invite researchers to take part in a community wide genome sequencing study to trace the evolution of these strains as they have travelled between laboratories around the world.