两个组件的CpxAR系统有助于Cronobacter sakazakiii的毒性特性
Tong Jin1, Xiangjun Zhan1, Liuxin Pang1
1College of Food Science and Engineering, Northwest A&F University, Yangling, Shaanxi, 712100, China.
Food microbiology
|November 2, 2023
概括
这种CpxA/CpxR双组件系统 (TSC) 对Cronobacter sakazakii的毒性至关重要. 删除这个系统会削弱细菌的入侵,生存,并在小鼠中引起较轻的疾病.
科学领域:
- 微生物学 微生物学
- 食品安全 食品安全
- 病原体的毒性 病原体的毒性
背景情况:
- 克罗诺巴克特 (Cronobacter sakazakii) 是一种通过食物传播的病原体,对婴儿构成风险.
- 众所周知,CpxA/CpxR双组分系统 (TSC) 影响了格拉姆阴性细菌的应激反应和毒性.
- 在C. sakazakii的致病性中CpxA/CpxR的特定作用在很大程度上仍未被描述.
研究的目的:
- 研究CpxA/CpxR两组系统在Cronobacter sakazakii的毒性中的作用.
- 阐明CpxA/CpxR对细菌粘附,入侵,细胞内生存和宿主细胞损伤的贡献.
主要方法:
- 对C. sakazakii. 的CpxA,CpxR和CpxAR删除和补充菌株的构建和表征.
- 使用人类肠道细胞系 (HBMEC,Caco-2) 评估细菌粘附,入侵和转移.
- 在巨细胞中细胞内生存和复制的评估 (RAW264.7).
- 在Caco-2细胞单层中分析紧结蛋白破坏,亡和细胞毒性.
- 在新生小鼠体内毒性评估,包括细菌负载,肠道屏障功能和组织损伤.
- 使用qRT-PCR进行基因表达分析,以识别CpxAR调节的毒性基因.
主要成果:
- 缺乏CpxA/CpxR的C. sakazakii突变体显著减少了对肠道上皮细胞的粘附和侵入.
- 突变者在巨细胞内细胞内存活率下降,细胞单层中转移受损.
- 删除CpxAR导致Caco-2细胞中紧密结节的破坏减少,较低的亡和细胞毒性.
- 在体内研究表明,CpxAR删除突变体的毒性减弱,细菌负载较低,小鼠肠道损伤减少.
- 补充菌株恢复了野生类型的表型,证实了CpxAR的作用.
- qRT-PCR发现,CpxAR调节了与细菌毒性和细胞入侵相关的基因.
结论:
- 这种CpxA/CpxR两组系统是克罗诺巴克特 (Cronobacter sakazakii) 毒性的关键调节器.
- CpxAR TCS对于细菌的粘附,入侵,细胞内生存和宿主细胞损伤至关重要.
- 这项研究提高了对C. sakazakii致病性有助于遗传因素的理解.
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