Seeing and Touching the Mycomembrane at the Nanoscale

Area of Science:

• Microbiology
• Biophysics

Background:

• Mycobacteria possess unique cell envelopes, surface characteristics, and growth patterns.
• These features contribute to their ability to infect, evade immune responses, spread, and resist antibiotics.

Purpose of the Study:

• To investigate the nanometer-scale ultrastructural, adhesive, and mechanical properties of mycobacteria.
• To understand the molecular interactions and surface dynamics of these pathogens.

Main Methods:

• Atomic force microscopy (AFM) was employed to study mycobacteria.
• AFM force spectroscopy unraveled molecular binding forces and surface hydrophobicity.
• Correlative AFM and fluorescence imaging provided real-time insights into cell envelope dynamics.

Main Results:

• AFM revealed nanometer-scale ultrastructural details of mycobacterial cell envelopes.
• Molecular forces of adhesin-host factor interactions (e.g., heparin, fibronectin) were quantified.
• The hydrophobic nature of the mycomembrane was characterized.
• Interplay between surface structure, cell envelope stress, and division was observed.

Conclusions:

• AFM provides critical insights into mycobacterial surface properties and mechanics.
• Understanding these properties is key to addressing challenges posed by mycobacterial pathogens.
• AFM has significant potential for future research on mycobacterial molecular interactions and growth.