scholarly journals T6SS secretes an LPS-binding effector to recruit OMVs for exploitative competition and horizontal gene transfer

2021 ◽  
Author(s):  
Changfu Li ◽  
Lingfang Zhu ◽  
Dandan Wang ◽  
Zhiyan Wei ◽  
Xinwei Hao ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Outer Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Membrane Receptors ◽  
Receptor Interaction ◽  
Bacterial Cells ◽  
Type Vi Secretion System ◽  
Lps Binding

AbstractOuter membrane vesicles (OMVs) can function as nanoscale vectors that mediate bacterial interactions in microbial communities. How bacteria recognize and recruit OMVs inter-specifically remains largely unknown, thus limiting our understanding of the complex physiological and ecological roles of OMVs. Here, we report a ligand-receptor interaction-based OMV recruitment mechanism, consisting of a type VI secretion system (T6SS)-secreted lipopolysaccharide (LPS)-binding effector TeoL and the outer membrane receptors CubA and CstR. We demonstrated that Cupriavidus necator T6SS1 secretes TeoL to preferentially associate with OMVs in the extracellular milieu through interactions with LPS, one of the most abundant components of OMVs. TeoL associated with OMVs can further bind outer membrane receptors CubA and CstR, which tethers OMVs to the recipient cells and allows cargo to be delivered. The LPS-mediated mechanism enables bacterial cells to recruit OMVs derived from different species, and confers advantages to bacterial cells in iron acquisition, interbacterial competition, and horizontal gene transfer (HGT). Moreover, our findings provide multiple new perspectives on T6SS functionality in the context of bacterial competition and HGT, through the recruitment of OMVs.

scholarly journals Incorporation of Plasmid DNA Into Bacterial Membrane Vesicles by Peptidoglycan Defects in Escherichia coli

2021 ◽  
Vol 12 ◽  
Author(s):  
Sharmin Aktar ◽  
Yuhi Okamoto ◽  
So Ueno ◽  
Yuhei O. Tahara ◽  
Masayoshi Imaizumi ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Outer Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Bacterial Membrane ◽  
Gram Negative Bacteria ◽  
Plasmid Copy ◽  
Gram Negative

Membrane vesicles (MVs) are released by various prokaryotes and play a role in the delivery of various cell-cell interaction factors. Recent studies have determined that these vesicles are capable of functioning as mediators of horizontal gene transfer. Outer membrane vesicles (OMVs) are a type of MV that is released by Gram-negative bacteria and primarily composed of outer membrane and periplasm components; however, it remains largely unknown why DNA is contained within OMVs. Our study aimed to understand the mechanism by which DNA that is localized in the cytoplasm is incorporated into OMVs in Gram-negative bacteria. We compared DNA associated with OMVs using Escherichia coli BW25113 cells harboring the non-conjugative, non-mobilized, and high-copy plasmid pUC19 and its hypervesiculating mutants that included ΔnlpI, ΔrseA, and ΔtolA. Plasmid copy per vesicle was increased in OMVs derived from ΔnlpI, in which peptidoglycan (PG) breakdown and synthesis are altered. When supplemented with 1% glycine to inhibit PG synthesis, both OMV formation and plasmid copy per vesicle were increased in the wild type. The bacterial membrane condition test indicated that membrane permeability was increased in the presence of glycine at the late exponential phase, in which cell lysis did not occur. Additionally, quick-freeze deep-etch and replica electron microscopy observations revealed that outer-inner membrane vesicles (O-IMVs) are formed in the presence of glycine. Thus, two proposed routes for DNA incorporation into OMVs under PG-damaged conditions are suggested. These routes include DNA leakage due to increased membrane permeation and O-IMV formation. Additionally, our findings contribute to a greater understanding of the vesicle-mediated horizontal gene transfer that occurs in nature and the utilization of MVs for DNA cargo.

scholarly journals Outer Membrane Vesicles Derived from Klebsiella pneumoniae Are a Driving Force for Horizontal Gene Transfer

2021 ◽  
Vol 22 (16) ◽  
pp. 8732
Author(s):  
Federica Dell’Annunziata ◽  
Carmela Dell’Aversana ◽  
Nunzianna Doti ◽  
Giuliana Donadio ◽  
Fabrizio Dal Piaz ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Klebsiella Pneumoniae ◽  
Outer Membrane ◽  
Resistance Genes ◽  
Copy Number ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Copy Number Plasmid

Gram-negative bacteria release Outer Membrane Vesicles (OMVs) into the extracellular environment. Recent studies recognized these vesicles as vectors to horizontal gene transfer; however, the parameters that mediate OMVs transfer within bacterial communities remain unclear. The present study highlights for the first time the transfer of plasmids containing resistance genes via OMVs derived from Klebsiella pneumoniae (K. pneumoniae). This mechanism confers DNA protection, it is plasmid copy number dependent with a ratio of 3.6 times among high copy number plasmid (pGR) versus low copy number plasmid (PRM), and the transformation efficiency was 3.6 times greater. Therefore, the DNA amount in the vesicular lumen and the efficacy of horizontal gene transfer was strictly dependent on the identity of the plasmid. Moreover, the role of K. pneumoniae-OMVs in interspecies transfer was described. The transfer ability was not related to the phylogenetic characteristics between the donor and the recipient species. K. pneumoniae-OMVs transferred plasmid to Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa and Burkholderia cepacia. These findings address the pivotal role of K. pneumoniae-OMVs as vectors for antimicrobial resistance genes spread, contributing to the development of antibiotic resistance in the microbial communities.

scholarly journals Outer membrane vesicles derived from Klebsiella pneumoniae are a driving force for horizontal gene transfer

2021 ◽  
Author(s):  
Federica Dell'Annunziata ◽  
Carmela Dell’Aversana ◽  
Nunzianna Doti ◽  
Giuliana Donadio ◽  
Fabrizio Dal Piaz ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Klebsiella Pneumoniae ◽  
Outer Membrane ◽  
Resistance Genes ◽  
Copy Number ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Copy Number Plasmid

Gram-negative bacteria release outer membrane vesicles (OMVs) into the extracellular environment. Recent studies recognized these vesicles as vectors to horizontal gene transfer, however the parameters that mediate OMVs transfer within bacterial communities remain unclear. The present study highlights for the first time the transfer of plasmids containing resistance genes via OMVs derived from Klebsiella pneumoniae ( K. pneumoniae ). This mechanism confers DNA protection and it is plasmid copy number dependent with a ratio of 3.6 time among high copy-number plasmid (pGR) versus low copy number plasmid (PRM) and the transformation efficiency was 3.6 times greater. Therefore, the DNA amount in the vesicular lumen and the efficacy of horizontal gene transfer was strictly dependent on the identity of the plasmid. Moreover, the role of K. pneumoniae -OMVs in interspecies transfer was described. The transfer ability was not related to the phylogenetic characteristics between the donor and the recipient species. K. pneumoniae -OMVs transferred plasmid to Escherichia coli, Salmonella enterica, Pseudomonas aeruginosa and Burkholderia cepacia . These findings address the pivotal role of K. pneumoniae -OMVs as vectors for antimicrobial resistance genes spread, contributing to the development of antibiotic resistance in the microbial communities.

scholarly journals Gene Transfer Potential of Outer Membrane Vesicles of Gram-Negative Bacteria

2021 ◽  
Vol 22 (11) ◽  
pp. 5985
Author(s):  
Federica Dell’Annunziata ◽  
Veronica Folliero ◽  
Rosa Giugliano ◽  
Anna De Filippis ◽  
Cristina Santarcangelo ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Horizontal Gene Transfer ◽  
Outer Membrane ◽  
Pathogenic Bacteria ◽  
Membrane Vesicles ◽  
Multidrug Resistant ◽  
Outer Membrane Vesicles ◽  
Biologically Active ◽  
Gram Negative Bacteria ◽  
Gram Negative

The increasing spread of multidrug-resistant pathogenic bacteria is one of the major threats to public health worldwide. Bacteria can acquire antibiotic resistance and virulence genes through horizontal gene transfer (HGT). A novel horizontal gene transfer mechanism mediated by outer membrane vesicles (OMVs) has been recently identified. OMVs are rounded nanostructures released during their growth by Gram-negative bacteria. Biologically active toxins and virulence factors are often entrapped within these vesicles that behave as molecular carriers. Recently, OMVs have been reported to contain DNA molecules, but little is known about the vesicle packaging, release, and transfer mechanisms. The present review highlights the role of OMVs in HGT processes in Gram-negative bacteria.

scholarly journals Spheres of Hope, Packets of Doom: the Good and Bad of Outer Membrane Vesicles in Interspecies and Ecological Dynamics

2017 ◽  
Vol 199 (15) ◽  
Author(s):  
Jonathan B. Lynch ◽  
Rosanna A. Alegado
Keyword(s):  
Antimicrobial Activity ◽  
Horizontal Gene Transfer ◽  
Outer Membrane ◽  
Recent Progress ◽  
Membrane Vesicles ◽  
Stress Relief ◽  
Outer Membrane Vesicles ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
By Products

ABSTRACT Outer membrane vesicles (OMVs) are proteoliposome nanoparticles ubiquitously produced by Gram-negative bacteria. Typically bearing a composition similar to those of the outer membrane and periplasm of the cells from which they are derived, OMVs package an array of proteins, lipids, and nucleic acids. Once considered inconsequential by-products of bacterial growth, OMVs have since been demonstrated to mediate cellular stress relief, promote horizontal gene transfer and antimicrobial activity, and elicit metazoan inflammation. Recently, OMVs have gained appreciation as critical moderators of interorganismal dynamics. In this review, we focus on recent progress toward understanding the functions of OMVs with regard to symbiosis and ecological contexts, and we propose potential avenues for future OMV studies.

Effect of toluene onPseudomonas stutzeriST-9 morphology — plasmolysis, cell size, and formation of outer membrane vesicles

2016 ◽  
Vol 62 (8) ◽  
pp. 682-691 ◽  
Author(s):  
Esti Michael ◽  
Yeshayahu Nitzan ◽  
Yakov Langzam ◽  
Galia Luboshits ◽  
Rivka Cahan
Keyword(s):  
Outer Membrane ◽  
Cell Size ◽  
Membrane Integrity ◽  
Membrane Vesicles ◽  
Fold Increase ◽  
Outer Membrane Vesicles ◽  
Bacterial Cells ◽  
Facs Analysis ◽  
Sem Images ◽  
Additional Material

Isolated toluene-degrading Pseudomonas stutzeri ST-9 bacteria were grown in a minimal medium containing toluene (100 mg·L−1) (MMT) or glucose (MMG) as the sole carbon source, with specific growth rates of 0.019 h−1and 0.042 h−1, respectively. Scanning (SEM) as well as transmission (TEM) electron microscope analyses showed that the bacterial cells grown to mid-log phase in the presence of toluene possess a plasmolysis space. TEM analysis revealed that bacterial cells that were grown in MMT were surrounded by an additional “material” with small vesicles in between. Membrane integrity was analyzed by leakage of 260 nm absorbing material and demonstrated only 7% and 8% leakage from cultures grown in MMT compared with MMG. X-ray microanalysis showed a 4.3-fold increase in Mg and a 3-fold increase in P in cells grown in MMT compared with cells grown in MMG. Fluorescence-activated cell sorting (FACS) analysis indicated that the permeability of the membrane to propidium iodide was 12.6% and 19.6% when the cultures were grown in MMG and MMT, respectively. The bacterial cell length increased by 8.5% ± 0.1% and 17% ± 2%, as measured using SEM images and FACS analysis, respectively. The results obtained in this research show that the presence of toluene led to morphology changes, such as plasmolysis, cell size, and formation of outer membrane vesicles. However, it does not cause significant damage to membrane integrity.

scholarly journals Gene Transfer Potential of Outer Membrane Vesicles of Acinetobacter baylyi and Effects of Stress on Vesiculation

2014 ◽  
Vol 80 (11) ◽  
pp. 3469-3483 ◽  
Author(s):  
Shweta Fulsundar ◽  
Klaus Harms ◽  
Gøril E. Flaten ◽  
Pål J. Johnsen ◽  
Balu Ananda Chopade ◽  
...  
Keyword(s):  
Gene Transfer ◽  
Zeta Potential ◽  
Outer Membrane ◽  
Bacterial Species ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Hydrodynamic Diameter ◽  
Acinetobacter Baylyi ◽  
Content Type ◽  
Dsdna Antibodies

ABSTRACTOuter membrane vesicles (OMVs) are continually released from a range of bacterial species. Numerous functions of OMVs, including the facilitation of horizontal gene transfer (HGT) processes, have been proposed. In this study, we investigated whether OMVs contribute to the transfer of plasmids between bacterial cells and species using Gram-negativeAcinetobacter baylyias a model system. OMVs were extracted from bacterial cultures and tested for the ability to vector gene transfer into populations ofEscherichia coliandA. baylyi, including naturally transformation-deficient mutants ofA. baylyi. Anti-double-stranded DNA (anti-dsDNA) antibodies were used to determine the movement of DNA into OMVs. We also determined how stress affected the level of vesiculation and the amount of DNA in vesicles. OMVs were further characterized by measuring particle size distribution (PSD) and zeta potential. Transmission electron microscopy (TEM) and immunogold labeling were performed using anti-fluorescein isothiocyanate (anti-FITC)-conjugated antibodies and anti-dsDNA antibodies to track the movement of FITC-labeled and DNA-containing OMVs. Exposure to OMVs isolated from plasmid-containing donor cells resulted in HGT toA. baylyiandE. coliat transfer frequencies ranging from 10−6to 10−8, with transfer efficiencies of approximately 103and 102per μg of vesicular DNA, respectively. Antibiotic stress was shown to affect the DNA content of OMVs as well as their hydrodynamic diameter and zeta potential. Morphological observations suggest that OMVs fromA. baylyiinteract with recipient cells in different ways, depending on the recipient species. Interestingly, the PSD measurements suggest that distinct size ranges of OMVs are released fromA. baylyi.

scholarly journals The Attenuated Protective Effect of Outer Membrane Vesicles Produced by a mcr-1 Positive Strain on Colistin Sensitive Escherichia coli

2021 ◽  
Vol 11 ◽  
Author(s):  
Xue Li ◽  
Lang Sun ◽  
Congran Li ◽  
Xinyi Yang ◽  
Xiukun Wang ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Protective Effect ◽  
Outer Membrane ◽  
Lipid A ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Bacterial Cells ◽  
Colistin Resistance ◽  
E Coli ◽  
Positive Strain

Resistance to colistin, especially mobilized colistin resistance (mcr), is a serious threat to public health since it may catalyze a return of the “pre-antibiotic era”. Outer membrane vesicles (OMVs) play a role in antibiotic resistance in various ways. Currently, how OMVs participate in mcr-1-mediated colistin resistance has not been established. In this study, we showed that both OMVs from the mcr-1 negative and positive Escherichia coli (E. coli) strains conferred dose-dependent protection from colistin. However, OMVs from the mcr-1 positive strain conferred attenuated protection when compared to the OMVs of a mcr-1 negative strain at the same concentration. The attenuated protective effect of OMVs was related to the reduced ability to absorb colistin from the environment, thus promoting the killing of colistin sensitive E. coli strains. Lipid A modified with phosphoethanolamine was presented in the OMVs of the mcr-1 positive E. coli strain and resulted in decreased affinity to colistin and less protection. Meanwhile, E. coli strain carrying the mcr-1 gene packed more unmodified lipid A in OMVs and kept more phosphoethanolamine modified lipid A in the bacterial cells. Our study provides a first glimpse of the role of OMVs in mcr-1 -mediated colistin resistance.

scholarly journals Salmonella Paratyphi A outer membrane vesicles displaying Vi polysaccharide as multivalent vaccine against enteric fever

2020 ◽  
pp. IAI.00699-20
Author(s):  
G. Gasperini ◽  
R. Alfini ◽  
V. Arato ◽  
F. Mancini ◽  
M. G. Aruta ◽  
...  
Keyword(s):  
Outer Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Bacterial Cells ◽  
Middle Income ◽  
Bacterial Surface ◽  
Protective Antigens ◽  
Low Middle Income Countries ◽  
Membrane Antigens ◽  
Genetically Manipulated

Typhoid and paratyphoid fever have a high incidence worldwide and coexist in many geographical areas, especially in Low-Middle Income Countries (LMIC) in South and South East Asia. There is extensive consensus on the urgent need for better and affordable vaccines against systemic Salmonella infections. Generalized Modules for Membrane Antigens (GMMA), outer membrane exosomes shed by Salmonella bacteria genetically manipulated to increase blebbing, resemble the bacterial surface where protective antigens are displayed in their native environment.Here we engineered S. Paratyphi A using the pDC5-viaB plasmid to generate GMMA displaying the heterologous S. Typhi Vi antigen together with the homologous O:2 O-Antigen. The presence of both Vi and O:2 was confirmed by flow cytometry on bacterial cells and their amount was quantified on the resulting vesicles through a panel of analytical methods. When tested in mice, such GMMA induced a strong antibody response against both Vi and O:2 and these antibodies were functional in a serum bactericidal assay. Our approach yielded a bivalent vaccine candidate able to induce immune responses against different Salmonella serovars which could benefit LMIC residents and travellers.

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