Whole genome transcriptome analysis of Group A Streptococcus (Streptococcus pyogenes) isolates from the three distinct genetic clades of M89 population. Streptococcus pyogenes

The goal was to perform global transcriptome analysis on genetically representaive pre-epidemic and epidemic M89 strains to investigate how the genetic differnces may have altered gene expression potentially contributing to epidemic emergence and persistence. Overall design: The transcriptomes of 6 GAS emm89/M89 strains (one strain representative of each of clades 1, 2 and 3, and 3 strains from subclade3D) were compared at two phases of growth, mid-exponential and early-stationary, using 3 biological replicates, to identify differences in gene expression potentially contributing to the evolution and emergence of epidemic clade 3 and subclade 3D strains.