FIGURE 1.

Phylogenetic tree of Escherichia coli and Shigella spp. The tree is based on the nucleotide alignment of universal single-copy orthologs. Clusters and corresponding phylogroups are shown in different colours; the number of genomes of each pathovar is indicated to the right of the pathovar’s name. Pathogenic E. coli strains are marked with coloured bands on the outer circle. The location of the unclassified Shigella strain is shown with an asterisk. The bars indicate the number of ISs found by ISsaga in bacterial chromosomes. The tree is unrooted.