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Size Matters: Measurement of Capsule Diameter in Cryptococcus neoformans
Published on: February 27, 2018
The elastic properties of the Cryptococcus neoformans capsule
Susana Frases1, Bruno Pontes, Leonardo Nimrichter
1Department of Microbiology and Immunology, Albert Einstein College of Medicine, The Bronx, New York, USA. scarvaja@aecom.yu.edu
Biophysical Journal
|August 19, 2009
Summary
We developed a new method using optical tweezers to measure the elastic properties of the Cryptococcus neoformans fungal capsule. This technique reveals how capsule size and calcium affect its mechanical characteristics.
Area of Science:
- Microbiology
- Biophysics
- Mycology
Background:
- Microbial capsules are crucial for virulence but their physical properties remain largely uncharacterized.
- The polysaccharide capsule of Cryptococcus neoformans is essential for its pathogenicity and a target for immune responses.
Purpose of the Study:
- To investigate the elastic properties of the Cryptococcus neoformans capsule.
- To develop a novel, non-destructive method for probing capsular biomechanics.
Main Methods:
- Utilized optical tweezers to manipulate polystyrene beads and apply force to the fungal capsule.
- Measured the Young's modulus of the capsule under varying conditions.
Main Results:
- Capsular Young's modulus decreases with increasing capsule size.
- Young's modulus increases with higher Ca(2+) concentration in the surrounding solution.
- Observed an unexpected affinity between capsular polysaccharide and polystyrene beads.
Conclusions:
- Optical tweezers provide a versatile tool for assessing fungal capsule biomechanics.
- Capsular properties are sensitive to environmental factors like size and ion concentration.
- The observed bead-polysaccharide interaction may have implications for fungal adhesion to host and environmental surfaces.
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