Single-molecule imaging of DNA repair and cytoplasmic rigidification in intracellular bacteria
Year: 2026
Type: preprint
Abstract: DNA damage is an important component of the antibacterial response of phagocytes, but which DNA repair mechanisms are active in intracellular bacteria remains unclear. We developed a live-cell single-molecule tracking approach to directly measure DNA repair activity in Escherichia coli within macrophages. Phagocytosis activates bacterial base excision and nucleotide excision repair pathways and increases DNA mismatch repair foci indicative of DNA replication errors. Phagocyte-generated stresses also cause a general slowdown in protein diffusion within bacteria, consistent with a transition of the cytoplasm towards a glass-like state, which is associated with reduced metabolic activity. At the single-cell level, DNA repair activity is highly heterogeneous, with metabolically inactive bacteria showing the greatest engagement of repair proteins. Together, these findings reveal how distinct DNA repair pathways are deployed during macrophage infection and link repair activity to the metabolic and biophysical states of individual intracellular bacteria.
Authors: Fiona Anne Sargison, Nicolas Chérif Ducrot, Clara Kummerer, Claire Qu, Treasa B O’Hagan, Elliott Haywood, Anju Kudhail, Amy Moores, Lindsay Baker, Stephan Uphoff
Institution: University of Oxford
Language: English
Topic: DNA Repair Mechanisms
Subfield: Molecular Biology
Domain: Life Sciences
Open Access status: green
OpenAlex ID: W7213471295