Genomic epidemiology of invasive Group A Streptococcus infections in Argentina, 2023: high prevalence of 1-global and detection of 1 hypervirulent lineages.

The aim of this study is to describe the genomic epidemiology of invasive Group A Streptococcus (iGAS) in Argentina during 2023. A total of 476 invasive GAS isolates were subtyped and analyzed by whole-genome sequencing. A high prevalence of the 1-type strain was observed. Among the 1 strains, two highly virulent international variants, 1-UK and 1-DK, were identified. Additionally, a local variant, called 1-ST1319, was detected. This seminal study provides initial insights into the genomic landscape of iGAS, contributing to active surveillance to monitor emerging virulent 1 lineages and cross-border transmission in South America.IMPORTANCEAmid the increase in invasive infections in Argentina in 2023, the implementation of genomic analysis of isolates allowed us to detect at the national level the prevalence of the 1 type and within the M1 type, emerging national and international hypervirulent lineages. These findings from our report shed light on the distribution of invasive Group A Streptococcus, laying the foundation for genomic surveillance of this pathogen.