Fig. 2.

Bayesian maximum credibility phylogeny shows expansion of discrete sub-lineages within SS14-lineage, with independent evolution of macrolide resistance. a Time-scaled phylogeny of all recently clinically derived genomes. Coloured tracks indicate lineage, sub-lineage, and presence of macrolide resistance conferring 23S rRNA SNPs (black = present, white = absent, grey = uncertain—alleles in some samples could not be definitively classified either because they appeared mixed or because of low numbers of reads at each site). Node points are shaded according to posterior support (black ≥ 96%, dark grey > 91%, light grey > 80%). *Sporadic (non-lineage associated) gain of resistance is highlighted in sub-lineage 3 (samples UW133B and UW262B). b Expanded view of sub-lineages, showing independent acquisition and fixation of macrolide resistance alleles