Single-molecule analysis of Pseudomonas fluorescens footprints

Area of Science:

• Microbiology
• Nanomedicine
• Biophysics

Background:

• Bacterial adhesion and biofilm formation are crucial in microbiology and nanomedicine.
• Extracellular polymeric substances strengthen bacterial adhesion but are difficult to study.
• Understanding cell-substrate interactions is key for developing antibacterial strategies.

Purpose of the Study:

• To functionally analyze the biophysical properties of bacterial footprints using single-molecule atomic force microscopy (AFM).
• To investigate the role of the LapA adhesin protein from Pseudomonas fluorescens in bacterial adhesion.
• To characterize the distribution, adhesion, and extension of adhesive macromolecules left on substrates.

Main Methods:

• Utilized single-molecule atomic force microscopy (AFM) to analyze bacterial footprints.
• Employed AFM tips functionalized with specific antibodies for targeted analysis.
• Studied the LapA protein from Pseudomonas fluorescens, a key adhesin.

Main Results:

• Bacterial adhesion to hydrophobic substrates actively accumulates LapA protein at the cell-substrate interface.
• Single LapA proteins form microscale domains and exhibit multiple adhesion peaks.
• The mechanical behavior of LapA footprints enables Pseudomonas fluorescens to attach to diverse surfaces.

Conclusions:

• Single-molecule AFM provides unprecedented insights into the biophysics and dynamics of the cell-substrate interface.
• LapA protein-based footprints act as versatile bridging polymers, crucial for bacterial surface attachment.
• This research offers new perspectives for antibacterial strategies in nanomedicine.