Fig. 1.

Maximum-likelihood phylogenetic tree with MIC information of four drugs. Circular presentation of the recombination-free ML phylogeny (midpoint rooted in order to display the structure clearly, five isolates were removed as outliers by Gubbins). MLST clades are labeled on the outer circle; predominant (top 1 for clade 3, 4, 5; top 3 for clade 2; top 5 for clade 1) ribotypes are highlighted in the inner circle. The MICs of MOX, RIF, MET, and VAN for each isolate are presented as heatmaps plotted on the phylogenic tree. The color key for the four outer circles indicates the drug sensitivity of isolates as per EUCAST guidelines: red, resistant or reduced susceptibility; green, sensitive. Branch lengths are indicative of the estimated substitution rate per variable site. CDI C. difficile infection, EUCAST European Committee on Antimicrobial Susceptibility Testing, MET metronidazole, MIC minimum inhibitory concentration, ML maximum-likelihood, MLST multi-locus sequence typing, MOX moxifloxacin, RIF rifaximin, VAN vancomycin