Single-cell force spectroscopy of pili-mediated adhesion

Area of Science:

• Microbiology
• Biophysics
• Nanotechnology

Background:

• Bacterial pili mediate cell adhesion, but molecular mechanisms remain unclear.
• Understanding these interactions is crucial for probiotics and pathogens.

Purpose of the Study:

• To directly measure forces of pili-mediated adhesion using single-cell force spectroscopy (SCFS).
• To investigate adhesion mechanisms of Lactobacillus rhamnosus GG (LGG) on various surfaces.

Main Methods:

• Employed non-invasive single-cell force spectroscopy (SCFS).
• Quantified adhesion forces between individual bacteria and biotic (mucin, intestinal cells) or abiotic (hydrophobic monolayers) surfaces.

Main Results:

• Pili exhibit nanospring properties on hydrophobic surfaces, enhancing adhesion and resisting shear forces.
• Increased nanospring frequency and adhesion forces observed on mucin, indicating specific pili-mucin interactions.
• Adhesion on Caco-2 cells showed constant force plateaus and nanotether rupture, differing from other surfaces.

Conclusions:

• Pili utilize nanosprings and nanotethers for surface colonization, with distinct mechanisms on different substrates.
• Findings offer insights into microbial adhesion for nanomedicine applications, including probiotic and pathogen control.