链球菌A组的自然变异碳水化合物生物合成基因影响宿主-病原体相互作用
Kim Schipper1, Sara M Tamminga1, Nicholas Murner2
1Department of Medical Microbiology and Infection Prevention, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, Netherlands.
Microbial genomics
|July 17, 2025
概括
在Streptococcus pyogenes gacH基因中的罕见突变破坏了A组碳水化合物装饰,影响了病原性和诊断测试结果. 这项研究分析了 gac 基因变异和 gacH 突变的功能后果.
科学领域:
- 微生物学 微生物学
- 基因组学就是基因组学.
- 生物化学 生物化学
背景情况:
- 在全球范围内,Streptococcus pyogenes导致了显著的死亡率.
- 它的细胞壁具有A组碳水化合物 (GAC) 与N-乙葡萄糖胺 (GlcNAc) 和甘酸 (GroP) 装饰.
- gacA-L基因集群对于GAC生物合成至关重要, gacH-L介导了GlcNAc-GroP的装饰.
研究的目的:
- 为了研究S. pyogenes. gacA-L基因集群中的遗传变异.
- 为了确定 gacH.中无活化突变的功能后果.
- 了解GAC装饰对S. pyogenes致病性和宿主相互作用的影响.
主要方法:
- 对2021年S. pyogenes分离物的基因组分析,以确定 gacA-L集群中的变异.
- 在 gacH 缺乏的 S. pyogenes 菌株中, gacH 变体的基于等离子体的表达.
- 细胞壁分析以评估GAC GroP水平,对IIA组分泌的脂酶的耐药性,以及对毒性的敏感性.
主要成果:
- 只有1.3%的分离物在 gac 基因中具有过早停止编码子;其中46%在 gacH中.
- 突变的 gacH 变体的表达导致了 GAC GroP 的减少.
- 突变菌株对人类杀菌酶表现出完全的耐药性,对毒性的敏感性增加.
结论:
- 在全球S. pyogenes种群中的 gacA-L集群中存在遗传变异.
- 在 gacH 中罕见的失活突变显著损害了 GacH 功能.
- 这些GAC装饰的功能变化影响了S. pyogenes与宿主环境的相互作用.
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