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Size Exclusion Chromatography to Analyze Bacterial Outer Membrane Vesicle Heterogeneity
Published on: March 31, 2021
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Outer-inner membrane vesicles naturally secreted by gram-negative pathogenic bacteria.
Carla Pérez-Cruz1, Lidia Delgado2, Carmen López-Iglesias2
1Laboratori de Microbiologia, Facultat de Farmàcia, Universitat de Barcelona, Barcelona, Spain.
Plos One
|January 13, 2015
Summary
Outer-inner membrane vesicles (O-IMVs) are now identified in pathogenic bacteria, not just Shewanella. These vesicles carry cytoplasmic components like DNA and ATP, expanding our understanding of bacterial communication.
Area of Science:
- Microbiology
- Cell Biology
- Bacterial Pathogenesis
Background:
- Outer-inner membrane vesicles (O-IMVs) were first identified in the Antarctic bacterium Shewanella vesiculosa M7T.
- Their formation involves the protrusion of both outer and plasma membranes, encapsulating cytoplasmic components.
Purpose of the Study:
- To investigate the presence and characteristics of O-IMVs in pathogenic Gram-negative bacteria.
- To determine if O-IMV secretion is a broader phenomenon beyond extremophiles.
Main Methods:
- Transmission Electron Microscopy (TEM) and Cryo-transmission electron microscopy (Cryo-TEM) for structural analysis.
- Gold DNA immunolabeling to detect double-stranded DNA within vesicles.
- Proteomic analysis of N. gonorrhoeae-derived membrane vesicles.
Main Results:
- O-IMVs were confirmed in pathogenic bacteria: Neisseria gonorrhoeae, Pseudomonas aeruginosa PAO1, and Acinetobacter baumannii AB41.
- These O-IMVs contained cytoplasmic components, including DNA and ATP, confirmed by specific labeling and proteomic analysis.
- O-IMVs constituted 0.23% to 1.2% of total vesicles produced by these pathogenic strains.
Conclusions:
- The definition of membrane vesicles in Gram-negative bacteria is expanded to include O-IMVs.
- The presence of cytoplasmic DNA, ATP, and proteins in O-IMVs offers new insights into bacterial mechanisms.
- O-IMV production by pathogens suggests potential roles in lateral gene transfer and intercellular communication.
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