Minimum spanning tree for the five VNTRs of 125 A. phagocytophilum samples, strain and genome. Each circle represents a unique genotype. The diameter of each circle corresponds to the number of field samples with the same genotype. Genotypes connected by a shaded background and tick lines differ by a maximum of one of the five VNTR markers, and could be considered as a "clonal complex". Regular connecting lines represent two loci differences; thin interrupted lines represent four or more differences. The length of each branch is proportional to the number of differences. Each host is represented by a specific color in the circle.