Isolation method and characterization of outer membranes vesicles of Helicobacter pylori grown in a chemically defined medium

ABSTRACT: Outer membrane vesicles (OMVs) are small vesicles constitutively shed by all Gram-negative bacterium, which have been proposed to play a role in Helicobacter pylori persistence and pathogenesis. The methods currently available for the isolation of H. pylori OMVs are diverse and time-consuming, raising the need for a protocol standardization, which was the main aim of this study. Here, we showed that the chemically defined F12 medium, supplemented with cholesterol, nutritionally supports bacterial growth and maintains H. pylori viability for at least 72 h. Additionally, we developed an abridged protocol for isolation of OMVs from these bacterial cultures, which comprises a low-speed centrifugation, supernatant filtration through a 0.45 µm pore, and two ultracentrifugations for OMVs’ recovery and washing. Using this approach, a good yield of highly pure bona fide OMVs was recovered from cultures of different H. pylori strains and in different periods of bacterial growth. Analysis of the proteome of OMVs isolated from H. pylori F12-cholesterol cultures validated the efficacy of our isolation protocol in attaining a higher sample purity with low representation of flagella proteins. The comparison with the proteomes of H. pylori OMVs available in the literature demonstrated that OMVs carry a selective protein cargo, suggesting their importance for H. pylori survival and pathogenesis. In conclusion, this work proposes a time- and cost-efficient protocol for the isolation of H. pylori OMVs from a chemically defined culture medium that is suitable for implementation in research and in the biopharmaceutical field.

INSTRUMENT(S): Q Exactive

ORGANISM(S): Helicobacter Pylori 26695

TISSUE(S): Extracellular Vesicle

SUBMITTER: Hugo Osorio  

LAB HEAD: Ceu Figueiredo

PROVIDER: PXD025393 | Pride | 2021-05-31

REPOSITORIES: Pride