Comparative genomic analysis of 94 strains of clinical strains of C. difficile. The probes were arranged by their corresponding C. difficile 630 gene, with CD0001 at the top and CD3680 at the bottom, followed by CDS from the plasmid pCD630 (CDP01 to CDP11) and finally probes representing the genes unique to ribotype 027. Each column represents an isolate, and each row corresponds to a probe. The status of each probe is indicated by color as follows: red, present/conserved in the test strain; blue, absent in the test strain and yellow present in both the test and control strains. The strains are grouped by PCR-ribotype and this is indicated below. The writing on the left indicates regions of divergence from CD630 in all of the strains tested.