Texas Streptococcus equi subsp. equi and Streptococcus equi subsp. zooepidemicus strains

Streptococcus equi subsp. equi (SEE) is a host-restricted pathogen of horses considered to have evolved from Streptococcus equi subsp. zooepidemicus (SEZ). SEZ is promiscuous in its host range, and is commonly recovered from horses as a commensal. Comparison of a single strain of SEE with a single strain of SEZ using whole genome sequencing, supplemented by quantitative PCR for additional screening of SEE and SEZ strains of select genes these techniques were used to define characteristics that shaped the evolution of SEE. Because of the known genetic variability of SEZ, comparisons of the whole genomes of multiple SEE and SEZ is warranted. To fill this knowledge-gap, we utilized whole genome sequencing to characterize the accessory genome elements and methylomes of 50 SEE and 50 SEZ isolates from Texas.

马链球菌马亚种（Streptococcus equi subsp. equi, SEE）是一类宿主限制性马源致病菌，被认为由马链球菌兽疫亚种（Streptococcus equi subsp. zooepidemicus, SEZ）演化而来。SEZ宿主范围宽泛，常可从马体内作为共生菌群被分离获得。既往研究仅通过全基因组测序（whole genome sequencing）对比单株SEE与单株SEZ，并辅以定量PCR（quantitative PCR）对更多SEE和SEZ菌株的候选基因开展筛选，以此明确驱动SEE演化的关键特征。鉴于SEZ存在已知的遗传多样性，对多株SEE与SEZ进行全基因组对比分析具有必要性。为填补这一研究空白，本研究利用全基因组测序技术，对采自得克萨斯州的50株SEE和50株SEZ分离株的附属基因组（accessory genome）元件及甲基化组（methylomes）进行了系统性特征解析。