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Electron Microscopy to Study the Fine Structure of the Pneumococcal Cell
Sven Hammerschmidt1, Manfred Rohde2
1Department of Molecular Genetics and Infection Biology, Interfaculty Institute for Genetics and Functional Genomics, University of Greifswald, Greifswald, Germany. sven.hammerschmidt@uni-greifswald.de.
Methods in Molecular Biology (Clifton, N.J.)
|April 1, 2019
Summary
A new fixation method preserves bacterial capsules for electron microscopy. This technique allows detailed study of bacterial surface structures and their interaction with host cells, aiding in understanding virulence factors.
Area of Science:
- Microbiology
- Microscopy
- Cell Biology
Background:
- Electron microscopy is crucial for high-resolution bacterial ultrastructure analysis.
- Transmission electron microscopy (TEM) reveals inner structures and attached elements.
- Scanning electron microscopy (SEM) visualizes cell surfaces and host-bacterial interactions.
Purpose of the Study:
- To recommend methodologies for detailed pneumococcal ultrastructure examination.
- To focus on preserving the pneumococcal capsular polysaccharide, a key virulence factor.
Main Methods:
- Utilizing transmission and scanning electron microscopy for bacterial imaging.
- Introducing a novel fixation protocol using lysine acetate, ruthenium red, and osmium (LRR fixation).
- Comparing LRR fixation with traditional methods, including serotype-specific antibodies.
Main Results:
- LRR fixation effectively preserves highly hydrated capsular polysaccharides.
- This method allows quantitative comparison of capsular material across different pneumococcal serotypes.
- The fixation protocol enables visualization of capsule presence/absence during host cell interactions.
Conclusions:
- LRR fixation offers a superior method for preserving pneumococcal capsule ultrastructure.
- This technique facilitates detailed studies of bacterial virulence factors and host-pathogen interactions.
- The method eliminates the need for serotype-specific antibodies for capsule preservation.
Keywords:
Critical point dryingCryo-FESEMField emission scanning electron microscopyInfectionLRR embeddingLRWhite resinPneumococcal capsulePneumococciTransmission electron microscopyMore Related Videos
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