Nitric oxide promotes rapid development of motility to accelerate biofilm dispersal in Vibrio cholerae.

Bacterial biofilms are resilient multicellular communities that underlie persistent infections and environmental survival. Dispersal from biofilms is a pivotal event for transmission and pathogenesis, yet the host signals and bacterial mechanisms orchestrating this transition remain poorly understood. Here, we show that nitric oxide (NO), a ubiquitous host-derived signaling molecule, acts as a rapid trigger for biofilm dispersal in Vibrio cholerae, a highly motile gram-negative bacterium and the etiologic agent of cholera, by promoting the development of motility. NO exposure induces broad upregulation of flagellar biosynthesis genes, increases flagellin production, and reduces intracellular cyclic-di-GMP levels, thereby priming aflagellated biofilm-associated cells for active swimming and dispersion. Using single-cell imaging in custom microfluidic devices, we directly visualize NO-stimulated biofilm detachment and development of robust swimming motility within minutes. In vivo, biofilm-derived V. cholerae colonize more efficiently in NO-rich environments, and NO produced by epithelial cells enhances bacterial detachment from epithelial surfaces. Our findings reveal a host-pathogen interface in which NO serves as a morphogenetic cue, orchestrating the rapid transition from sessility to motility.