Enterohemorrhagic Escherichia coli senses Oxygen to increase its virulence and colonization in the intestine

Pathogens adapt to the host gut ecosystem by precisely regulating the expression of their metabolism and virulence genes. Among the many regulatory factors, we identified ArcA as a key factor regulating the virulence repertoire of EHEC O157:H7. Central to our findings is the excellence of the ArcAB two-component system in sensing changes in oxygen levels and exerting tight control over the expression of virulence factors in EHEC. This process has not only been observed under controlled laboratory conditions, but has also been demonstrated in the complex environment of a living mouse model. Our study highlights the complexity of the pathogen in managing its energy resources to express virulence factors at the right time to ensure efficient colonization of the host.

病原菌通过精准调控自身代谢与毒力基因的表达，以适应宿主肠道微生态系统。在众多调控因子中，我们鉴定出ArcA作为调控肠出血性大肠杆菌（Enterohemorrhagic Escherichia coli, EHEC）O157:H7毒力谱的关键因子。本研究的核心发现在于，ArcAB双组分系统（two-component system）在感知氧水平变化以及严格调控该菌毒力因子表达方面展现出卓越性能。该调控过程不仅在可控实验室条件下被观测到，还在活体小鼠模型的复杂肠道环境中得到了验证。本研究凸显了病原菌通过精准调配能量资源，在恰当时机表达毒力因子以实现宿主高效定殖的复杂调控机制。