Progressive evolution of Streptococcus equi from Streptococcus equi subsp. zooepidemicus and adaption to equine hosts

作者：Hayley J. Wilson, Jianbao Dong, Andries J. van Tonder, Christopher Ruis, Noémie Lefrancq, Abigail A. McGlennon, Carla Bustos, Sara Frosth, Albertine Léon, Adam Mark Blanchard, Matthew T. G. Holden, Andrew S. Waller, Julian Parkhill · 发表于：Microbial Genomics · 年份：2025 · DOI：10.1099/mgen.0.001366 · 被引用次数：7 · 研究领域：Streptococcal Infections and Treatments、Microbial infections and disease research、Plant Pathogenic Bacteria Studies

Streptococcus equi subsp. equi causes the equine respiratory disease ‘strangles’, which is highly contagious, debilitating and costly to the equine industry. S. equi emerged from the ancestral Streptococcus equi subsp. zooepidemicus and continues to evolve and disseminate globally. Previous work has shown that there was a global population replacement around the beginning of the twentieth century, obscuring the early genetic events in this emergence. Here, we have used large-scale genomic analysis of S. equi and its ancestor S. zooepidemicus to identify evolutionary events, leading to the successful expansion of S. equi. One thousand two hundred one whole-genome sequences of S. equi were recovered from clinical samples or from data available in public databases. Seventy-four whole-genome sequences representative of the diversity of S. zooepidemicus were used to compare the gene content and examine the evolutionary emergence of S. equi. A dated Bayesian phylogeny was constructed, and ancestral state reconstruction was used to determine the order and timing of gene gain and loss events between the different species and between different S. equi lineages. Additionally, a newly developed framework was used to investigate the fitness of different S. equi lineages. We identified a novel S. equi lineage, comprising isolates from donkeys in Chinese farms, which diverged nearly 300 years ago, after the emergence of S. equi from S. zooepidemicus, but before the global sweep. Ancestral ...