scholarly journals Outer Membrane Vesicles Protect Gram-Negative Bacteria against Host Defense Peptides

mSphere ◽  
2021 ◽  
Author(s):  
Melanie D. Balhuizen ◽  
Albert van Dijk ◽  
Jeroen W. A. Jansen ◽  
Chris H. A. van de Lest ◽  
Edwin J. A. Veldhuizen ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Antibiotic Resistance ◽  
Host Defense ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Gram Negative Bacteria ◽  
Host Defense Peptides ◽  
Resistance Development ◽  
Gram Negative ◽  
Defense Peptides

Antibiotic resistance is a pressing problem and estimated to be a leading cause of mortality by 2050. Antimicrobial peptides, also known as host defense peptides (HDPs), and HDP-derived antimicrobials have potent antimicrobial activity and high potential as alternatives to antibiotics due to low resistance development.

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.

scholarly journals Thrombin-Derived Host-Defense Peptides Modulate Monocyte/Macrophage Inflammatory Responses to Gram-Negative Bacteria

2017 ◽  
Vol 8 ◽  
Author(s):  
Finja C. Hansen ◽  
Ann-Charlotte Strömdahl ◽  
Matthias Mörgelin ◽  
Artur Schmidtchen ◽  
Mariena J. A. van der Plas
Keyword(s):  
Host Defense ◽  
Inflammatory Responses ◽  
Gram Negative Bacteria ◽  
Host Defense Peptides ◽  
Gram Negative ◽  
Defense Peptides

Electrophysiological Characterization of Transport Across Outer Membrane Channels from Gram-Negative Bacteria in Their Native Environment

2019 ◽  
Author(s):  
Jiajun Wang ◽  
Rémi Terrasse ◽  
Jayesh Arun Bafna ◽  
Lorraine Benier ◽  
Mathias Winterhalter
Keyword(s):  
Outer Membrane ◽  
Lipid Membrane ◽  
Membrane Vesicles ◽  
Outer Membrane Vesicles ◽  
Multi Drug Resistance ◽  
Gram Negative Bacteria ◽  
Membrane Channels ◽  
Gram Negative ◽  
Electrophysiological Characterization

Multi-drug resistance in Gram-negative bacteria is often associated with low permeability of the outer membrane. To investigate the role of membrane channels in the uptake of antibiotics, we extract, purify and reconstitute them into artificial planar membranes. To avoid this time-consuming procedure, here we show a robust approach using fusion of native outer membrane vesicles (OMV) into planar lipid bilayer which moreover allows also to some extend the characterization of membrane protein channels in their native environment. Two major membrane channels from <i>Escherichia coli</i>, OmpF and OmpC, were overexpressed from the host and the corresponding OMVs were collected. Each OMV fusion revealed surprisingly single or only few channel activities. The asymmetry of the OMV´s translates after fusion into the lipid membrane with the LPS dominantly present at the side of OMV addition. Compared to conventional reconstitution methods, the channels fused from OMVs containing LPS have similar conductance but a much broader distribution. The addition of Enrofloxacin on the LPS side yields somewhat higher association (<i>k<sub>on</sub></i>) and lower dissociation (<i>k<sub>off</sub></i>) rates compared to LPS-free reconstitution. We conclude that using outer membrane vesicles is a fast and easy approach for functional and structural studies of membrane channels in the native membrane.

scholarly journals How Oxygen Availability Affects the Antimicrobial Efficacy of Host Defense Peptides: Lessons Learned from Studying the Copper-Binding Peptides Piscidins 1 and 3

2019 ◽  
Vol 20 (21) ◽  
pp. 5289 ◽  
Author(s):  
Adenrele Oludiran ◽  
David S. Courson ◽  
Malia D. Stuart ◽  
Anwar R. Radwan ◽  
John C. Poutsma ◽  
...  
Keyword(s):  
Antimicrobial Activity ◽  
Host Defense ◽  
Bacterial Species ◽  
Membrane Curvature ◽  
Lessons Learned ◽  
Health Concern ◽  
Copper Binding ◽  
Bacterial Killing ◽  
Host Defense Peptides ◽  
Defense Peptides

The development of new therapeutic options against Clostridioides difficile (C. difficile) infection is a critical public health concern, as the causative bacterium is highly resistant to multiple classes of antibiotics. Antimicrobial host-defense peptides (HDPs) are highly effective at simultaneously modulating the immune system function and directly killing bacteria through membrane disruption and oxidative damage. The copper-binding HDPs piscidin 1 and piscidin 3 have previously shown potent antimicrobial activity against a number of Gram-negative and Gram-positive bacterial species but have never been investigated in an anaerobic environment. Synergy between piscidins and metal ions increases bacterial killing aerobically. Here, we performed growth inhibition and time-kill assays against C. difficile showing that both piscidins suppress proliferation of C. difficile by killing bacterial cells. Microscopy experiments show that the peptides accumulate at sites of membrane curvature. We find that both piscidins are effective against epidemic C. difficile strains that are highly resistant to other stresses. Notably, copper does not enhance piscidin activity against C. difficile. Thus, while antimicrobial activity of piscidin peptides is conserved in aerobic and anaerobic settings, the peptide–copper interaction depends on environmental oxygen to achieve its maximum potency. The development of pharmaceuticals from HDPs such as piscidin will necessitate consideration of oxygen levels in the targeted tissue.

Structural determinants of host defense peptides for antimicrobial activity and target cell selectivity

Biochimie ◽  
2010 ◽  
Vol 92 (9) ◽  
pp. 1236-1241 ◽  
Author(s):  
Daisuke Takahashi ◽  
Sanjeev K. Shukla ◽  
Om Prakash ◽  
Guolong Zhang
Keyword(s):  
Antimicrobial Activity ◽  
Host Defense ◽  
Target Cell ◽  
Structural Determinants ◽  
Host Defense Peptides ◽  
Cell Selectivity ◽  
Defense Peptides
Sign in / Sign up

Export Citation Format

Share Document