High-Resolution Large-Area Image Analysis Deciphers the Distribution of Salmonella Cells and ECM Components in...

Area of Science:

• Microbiology
• Materials Science
• Electrochemistry

Background:

• Bacterial biofilms, crucial for colonization and pathogenesis, consist of cells within an extracellular matrix (ECM).
• Current antibacterial surface evaluations primarily focus on cell reduction, neglecting the ECM's role.
• Electroactive polymers offer potential for novel antibiofilm strategies, but their impact on biofilm composition remains underexplored.

Purpose of the Study:

• To develop and apply a method for separately quantifying bacterial cells and ECM in biofilms.
• To investigate the effect of electrochemical addressing on biofilm formation and composition on poly(3,4-ethylenedioxythiophene):polystyrenesulfonate (PEDOT:PSS).
• To identify key targets for developing effective antibiofilm strategies.

Main Methods:

• Utilized a custom biofilm reactor with electroactive PEDOT:PSS surfaces subjected to electrical bias.
• Employed fluorescence-based spectroscopic mapping and confocal microscopy for analyzing cell and ECM distribution.
• Integrated advanced image processing techniques for quantitative biofilm analysis.
• Validated findings using bacterial mutants deficient in ECM production.

Main Results:

• Electrochemical addressing of PEDOT:PSS surfaces upregulated bacterial ECM production.
• Cell counts remained largely unaffected by the applied electrical bias.
• Biofilm texture was altered, forming either small foci or more continuous structures.
• Demonstrated a direct link between conductive polymer material properties and bacterial metabolism.

Conclusions:

• Bacterial ECM is a critical target for developing novel antibiofilm strategies.
• Surface charge and electrical stimulation significantly influence biofilm matrix formation.
• Biofilm distribution patterns play a key role in antimicrobial susceptibility.
• This study provides novel insights into the interaction between electroactive polymers and bacterial biofilms, highlighting electrochemical control over ECM production.