Reductions in bacterial viability stimulate the production of Extra-intestinal Pathogenic Escherichia coli (ExPEC) cytoplasm-carrying Extracellular Vesicles (EVs)
Fig 5
ExPEC EVs contain multiple types of vesicles.
(A) Green fluorescent protein (GFP) in ExPEC strains was visualized with fluorescence microscopy. Scale bars: 20 μm. (B) Illustration of experiment to detect cytoplasm-carrying membrane vesicles in ExPEC EVs. (C) Immunofluorescent images of EVs produced by ExPEC strains. The EVs were stained with TRITC-labeled primary mouse anti-EV antibody. The coexistence ratio of GFP-carrying vesicles (green fluorescence) among the total EVs (red fluorescence) represents the percentage of cytoplasm-carrying membrane vesicles, which is indicated on the right. Data were obtained from at least three independent experiments. Graphs show a representative image. Scale bars: 10 μm. (D) GFP and OmpA proteins in EVs were determined with western blotting. (E) The outer–inner-membrane vesicles (OIMVs) of ExPEC were observed with transmission electron microscopy (TEM). ExPEC EVs displayed a double bilayered structure (red square), or single bilayered structure (orange square). Scale bars: 200 nm. (F) The outer–inner-membrane vesicles (OIMVs) of ExPEC were observed with Cryo-TEM. ExPEC EVs displayed a double bilayered structure (red square), or single bilayered structure (orange square). Scale bars: 200 nm.