Figure 2.

(A) Inferred genetic relationships among strains based on 1443 concatenated SNP loci identified by whole-genome sequencing. Newly sequenced strains all cluster within the epidemic clonal complex, with the exception of a Canadian emm59 GAS strain isolated in 1993. This strain is also genetically distant from invasive strains from Spain, Japan and the United States. Scale bar represents genetic distance. (B) Magnification of the epidemic complex part of the tree, showing the geographical area of isolation (Canadian province or US state). Strains recovered during years 2010–2011 are highlighted. In general, these more recent strains are found in the outermost part of every tree branch.