Whole-genome analysis was applied to investigate atypical point-source transmission of 2 invasive group A streptococcal (GAS) infections. Isolates were serotype M4, ST39, and genetically indistinguishable. Comparison with MGAS10750 revealed nonsynonymous polymorphisms in ropB and increased speB transcription. This study demonstrates the usefulness of whole-genome analyses for GAS outbreaks.
Keywords: Streptococcuspyogenes; group A Streptococcus; invasive disease; speB; whole-genome sequencing.