来自Streptococcus equi亚种的Streptococcus equi的渐进进化. 动物流行病 (zooepidemicus) 和适应马匹宿主
Hayley J Wilson1,2, Jiangbao Dong3, Andries J van Tonder2
1PHG Foundation, linked exempt charity of University of Cambridge, Cambridge, UK.
Microbial genomics
|March 28, 2025
概括
基因组分析显示,Streptococcus equi是从Streptococcus zooepidemicus进化而来的,并获得了像 equibactin locus 这样的毒性因素. 一个新的驴子血统和最近的英国扫描显示了这种杀病原体的持续适应.
科学领域:
- 基因组学就是基因组学.
- 进化生物学 进化生物学
- 兽医微生物学 兽医微生物学
背景情况:
- 窒息,是由Streptococcus equi亚种引起的. 马肺部疾病 (equine respiratory disease) 是一种重要的马匹呼吸系统疾病.
- S. equi是从Streptococcus equi亚种中产生的. 动物流行病 (zooepidemicus),早期遗传事件被20世纪初全球人口替代所掩盖.
研究的目的:
- 确定导致S. equi.成功扩张的进化事件.
- 了解S. equi作为马匹独有的病原体出现的遗传基础.
主要方法:
- 对1201个S. equi和74个S. zooepidemicus的全基因组序列进行了大规模的基因组分析.
- 构建一个有日期的贝叶斯族系和祖先状态的重建.
- 使用新的框架对血统适应性的研究.
主要成果:
- 鉴定了一种来自中国驴的新型S. equi血统,距离300年前差异较大.
- 菌体编码的毒性因子 (slaA,seeL,seeM) 是全球S. equi在驴子血统分歧后获得的.
- 在S. equi中鉴定出了 equibactin locus,但在S. zooepidemicus中没有,这表明它在最初的出现中发挥了作用.
- 从2000年代初开始,英国出现了二次人口横扫的证据,新的亚系通过第五个prophage获得了额外的毒素基因.
结论:
- 获得 equibactin 位点对于 S. equi 成为马匹专有的病原体至关重要.
- 20世纪的人口扫描固定关键毒性因素,而最近的扫描表明正在进行的适应.
- 持续的S. equi适应对马产业构成潜在的未来风险.
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