Figure 2.

Emergence of new emm1 lineage among non-invasive Streptococcus pyogenes isolates

Maximum likelihood phylogenetic tree constructed from core single-nucleotide polymorphisms (excluding prophage regions) of emm1 non-invasive isolates collected in northwest London in 2009–16 (n=135). Background shading in grey indicates the emergent lineage M1_UK. 52 (85%) of 61 strains within the emergent lineage were isolated in either 2015 or 2016. The scale bar indicates the nucleotide substitutions per site. The black star indicates the reference strain MGAS5005. See appendix (p 3) for rooted tree with available metadata.