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Updated: Jul 10, 2026
Scalable Isolation and Purification of Extracellular Vesicles from Escherichia coli and Other Bacteria
Published on: October 13, 2021
Proteomics characterization of outer membrane vesicles from the extraintestinal pathogenic Escherichia coli DeltatolR
Francesco Berlanda Scorza1, Francesco Doro, Manuel José Rodríguez-Ortega
1Biochemistry and Molecular Biology Unit, Novartis Vaccines and Diagnostics, 53100 Siena, Italy.
Abstract:
Extraintestinal pathogenic Escherichia coli are the cause of a diverse spectrum of invasive infections in humans and animals, leading to urinary tract infections, meningitis, or septicemia. In this study, we focused our attention on the identification of the outer membrane proteins of the pathogen in consideration of their important biological role and of their use as potential targets for prophylactic and therapeutic interventions. To this aim, we generated a DeltatolR mutant of the pathogenic IHE3034 strain that spontaneously released a large quantity of outer membrane vesicles in the culture supernatant. The vesicles were analyzed by two-dimensional electrophoresis coupled to mass spectrometry. The analysis led to the identification of 100 proteins, most of which are localized to the outer membrane and periplasmic compartments. Interestingly based on the genome sequences available in the current public database, seven of the identified proteins appear to be specific for pathogenic E. coli and enteric bacteria and therefore are potential targets for vaccine and drug development. Finally we demonstrated that the cytolethal distending toxin, a toxin exclusively produced by pathogenic bacteria, is released in association with the vesicles, supporting the recently proposed role of bacterial vesicles in toxin delivery to host cells. Overall, our data demonstrated that outer membrane vesicles represent an ideal tool to study Gram-negative periplasm and outer membrane compartments and to shed light on new mechanisms of bacterial pathogenesis.
Insights
Researchers identified 100 outer membrane proteins from pathogenic Escherichia coli, including seven specific to pathogenic strains, offering new targets for vaccines and therapies against bacterial infections.
Area of Science:
- Microbiology
- Bacterial Pathogenesis
- Proteomics
Background:
- Extraintestinal pathogenic Escherichia coli cause severe human and animal infections.
- Outer membrane proteins are crucial for bacterial function and potential therapeutic targets.
Purpose of the Study:
- To identify outer membrane proteins of pathogenic E. coli.
- To explore their potential as targets for vaccines and therapeutics.
Main Methods:
- Generated a DeltatolR mutant of E. coli IHE3034 to enhance outer membrane vesicle (OMV) release.
- Analyzed OMVs using 2D electrophoresis and mass spectrometry.
Main Results:
- Identified 100 proteins in OMVs, primarily from outer membrane and periplasmic compartments.
- Discovered seven OMV proteins specific to pathogenic E. coli and enteric bacteria.
- Confirmed the association of cytolethal distending toxin with OMVs, suggesting a role in toxin delivery.
Conclusions:
- OMVs are valuable tools for studying Gram-negative bacterial outer membrane and periplasm.
- Identified pathogenic E. coli-specific proteins represent promising targets for novel vaccines and drugs.
- Bacterial vesicles play a role in delivering toxins to host cells, advancing understanding of pathogenesis.
