Related Experiment Video
Updated: May 7, 2026

Detection of Enterohemorrhagic Escherichia Coli Colonization in Murine Host by Non-invasive In Vivo Bioluminescence System
Published on: April 9, 2018
Enterohemorrhagic Escherichia coli senses colonic oxygen availability to modulate its virulence and colonization
Fang Fang1,2, Yunhe Li1, Ying Zhong1
1State Key Laboratory of Vaccines for Infectious Diseases, Xiang an Biomedical Laboratory, National Innovation Platform for Industry-Education Integration in Vaccine Research, School of Public Health, Xiamen University, Xiamen, China.
Abstract:
Intestinal oxygen gradients influence both gut homeostasis and pathogen colonization. Although oxygen release can promote infections like those caused by Citrobacter rodentium, it was unknown whether oxygen directly controls bacterial virulence systems. In this study, we demonstrate that enterohemorrhagic Escherichia coli (EHEC) senses oxygen via the metabolic two-component system ArcAB to regulate its type 3 secretion system (T3SS). Under low oxygen, phosphorylated ArcA binds the promoter of ler, which encodes the T3SS master regulator, to repress its expression. When oxygen increases, ArcB kinase activity is inhibited, leading to ArcA dephosphorylation and T3SS derepression. This oxygen-responsive ArcAB pathway is absent in C. rodentium, reflecting evolutionary adaptation. Additionally, ArcA suppresses Shiga toxin production. Our work reveals the ArcAB two-component system as a pivotal oxygen-sensing pathway that directly orchestrates locus of enterocyte effacement (LEE) gene expression and positions it as a promising target for antivirulence or metabolic interference strategies.
Related Concept Videos
Bacterial Gastroenteritis
Stringent Response in E. coli
Regulation of Bacterial Virulence
Cholera
Bacterial Toxins
Gene Regulation in Microbial Communities: Quorum Sensing

