Biofilm dispersal patterns revealed using far-red fluorogenic probes.

Area of Science:

• Microbiology
• Cell Biology
• Pathogen Dynamics

Background:

• Bacteria form biofilms, complex multicellular communities, to colonize environments.
• Dispersal, the active exit of cells from biofilms, is crucial for bacterial colonization and spread.
• Mechanisms of single-cell biofilm dispersal remain poorly understood, especially in pathogenic bacteria.

Purpose of the Study:

• To characterize the single-cell process of biofilm dispersal in the pathogen *Vibrio cholerae* at high resolution.
• To identify novel micro-scale physical patterns associated with biofilm dispersal.
• To investigate the genetic and mechanical factors influencing dispersal patterns.

Main Methods:

• Development of a novel far-red cell-labeling strategy to overcome limitations of fluorescent proteins.
• High-resolution imaging and analysis of *Vibrio cholerae* biofilm dispersal.
• Characterization of dispersal patterns in wild-type and mutant strains with altered dispersal properties.

Main Results:

• Biofilm dispersal initiates at the biofilm periphery, with approximately 25% of cells remaining within the biofilm.
• Novel micro-scale dispersal patterns were identified, including biofilm compression and the formation of dynamic channels.
• Mutations affecting overall dispersal or local mechanical properties altered these observed dispersal patterns.

Conclusions:

• The study provides fundamental insights into the mechanisms governing bacterial biofilm dispersal at the single-cell level.
• Identified micro-scale patterns and mechanical properties are critical for understanding how pathogens like *Vibrio cholerae* disseminate.
• The developed far-red labeling technique offers a valuable tool for future studies on bacterial community dynamics.