SNPs between CD196 and 24 other hypervirulent C. difficile isolates. Outer circle: CDSs of C. difficile CD196 genome, shown on a pair of concentric rings representing both coding strands; two inner circles: G+C% content plot and GC deviation plot (>0% olive, <0% purple); in between: SNPs (blue and red) between CD196 and other isolates, from outer to inner: 2004013, 2004102, 2004118, 2004163, 2006439, 2007140, 2007218, 2007825, 2007833, 2007837, 2007855, BI-1, BI-2, BI-3, BI-4, BI-5, BI-6, BI-6p, BI-7, BI-10, BI-11, BI-13, BI-15, and R20291. The rings representing isolates with large homologous recombination blocks (BI–4 and BI–11) are shown in red.