scholarly journals Through the wall: extracellular vesicles in Gram-positive bacteria, mycobacteria and fungi

2015 ◽  
Vol 13 (10) ◽  
pp. 620-630 ◽  
Author(s):  
Lisa Brown ◽  
Julie M. Wolf ◽  
Rafael Prados-Rosales ◽  
Arturo Casadevall
Keyword(s):  
Extracellular Vesicles ◽  
Gram Positive ◽  
Gram Positive Bacteria

scholarly journals Answers to naysayers regarding microbial extracellular vesicles

2019 ◽  
Vol 47 (4) ◽  
pp. 1005-1012 ◽  
Author(s):  
Carolina Coelho ◽  
Arturo Casadevall
Keyword(s):  
Cell Wall ◽  
Extracellular Vesicles ◽  
Living Cell ◽  
Physiological Function ◽  
Biological Significance ◽  
Gram Negative Bacteria ◽  
Biological Processes ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Abstract It is now over 30 years since the discovery of extracellular vesicles (EVs) in Gram-negative bacteria. However, for cell-walled microbes such as fungi, mycobacteria and Gram-positive bacteria it was thought that EV release would be impossible, since such structures were not believed to cross the thick cell wall. This notion was disproven 10 years ago with the discovery of EVs in fungi, mycobacteria, and gram-positive bacteria. Today, EVs have been described in practically every species tested, ranging from Fungi through Bacteria and Archaea, suggesting that EVs are a feature of every living cell. However, there continues to be skepticism in some quarters regarding EV release and their biological significance. In this review, we list doubts that have been verbalized to us and provide answers to counter them. In our opinion, there is no doubt as to existence and physiological function of EVs and we take this opportunity to highlight the most pressing topics in our understanding of the biological processes underlying these structures.

Biogenesis and Function of Extracellular Vesicles in Gram-Positive Bacteria, Mycobacteria, and Fungi

2020 ◽  
pp. 47-74 ◽  
Author(s):  
Ainhoa Palacios ◽  
Carolina Coelho ◽  
Maria Maryam ◽  
Jose L. Luque-García ◽  
Arturo Casadevall ◽  
...  
Keyword(s):  
Extracellular Vesicles ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
And Function

scholarly journals Microbiota–host communications: Bacterial extracellular vesicles as a common language

2021 ◽  
Vol 17 (5) ◽  
pp. e1009508
Author(s):  
Rogers A. Ñahui Palomino ◽  
Christophe Vanpouille ◽  
Paolo E. Costantini ◽  
Leonid Margolis
Keyword(s):  
Nucleic Acids ◽  
Extracellular Vesicles ◽  
Bioactive Molecules ◽  
Common Language ◽  
Gram Positive ◽  
Gram Negative ◽  
Host Interactions ◽  
Gram Positive Bacteria ◽  
Current State ◽  
Mother Cells

Both gram-negative and gram-positive bacteria release extracellular vesicles (EVs) that contain components from their mother cells. Bacterial EVs are similar in size to mammalian-derived EVs and are thought to mediate bacteria–host communications by transporting diverse bioactive molecules including proteins, nucleic acids, lipids, and metabolites. Bacterial EVs have been implicated in bacteria–bacteria and bacteria–host interactions, promoting health or causing various pathologies. Although the science of bacterial EVs is less developed than that of eukaryotic EVs, the number of studies on bacterial EVs is continuously increasing. This review highlights the current state of knowledge in the rapidly evolving field of bacterial EV science, focusing on their discovery, isolation, biogenesis, and more specifically on their role in microbiota–host communications. Knowledge of these mechanisms may be translated into new therapeutics and diagnostics based on bacterial EVs.

scholarly journals Extracellular vesicles: An emerging platform in gram-positive bacteria

2020 ◽  
Vol 7 (12) ◽  
pp. 312-322
Author(s):  
Swagata Bose ◽  
Shifu Aggarwal ◽  
Durg Vijai Singh ◽  
Narottam Acharya
Keyword(s):  
Extracellular Vesicles ◽  
Intercellular Communication ◽  
Pathogenic Bacteria ◽  
Membrane Vesicles ◽  
Gram Negative Bacteria ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
Functional Aspects ◽  
As Stress

Extracellular vesicles (EV), also known as membrane vesicles, are produced as an end product of secretion by both pathogenic and non-pathogenic bacteria. Several reports suggest that archaea, gram-negative bacteria, and eukaryotic cells secrete membrane vesicles as a means for cell-free intercellular communication. EVs influence intercellular communication by transferring a myriad of biomolecules including genetic information. Also, EVs have been implicated in many phenomena such as stress response, intercellular competition, lateral gene transfer, and pathogenicity. However, the cellular process of secreting EVs in gram-positive bacteria is less studied. A notion with the thick cell-walled microbes such as gram-positive bacteria is that the EV release is impossible among them. The role of gram-positive EVs in health and diseases is being studied gradually. Being nano-sized, the EVs from gram-positive bacteria carry a diversity of cargo compounds that have a role in bacterial competition, survival, invasion, host immune evasion, and infection. In this review, we summarise the current understanding of the EVs produced by gram-positive bacteria. Also, we discuss the functional aspects of these components while comparing them with gram-negative bacteria.

scholarly journals Listeria monocytogenes virulence factors are secreted in biologically active Extracellular Vesicles

2017 ◽  
Author(s):  
Carolina Coelho ◽  
Lisa Brown ◽  
Maria Maryam ◽  
Meagan C. Burnet ◽  
Jennifer E. Kyle ◽  
...  
Keyword(s):  
Listeria Monocytogenes ◽  
Extracellular Vesicles ◽  
Outer Membrane Vesicles ◽  
Biologically Active ◽  
Host Cells ◽  
Immunogold Electron Microscopy ◽  
Dependent Manner ◽  
Listeriolysin O ◽  
Gram Positive ◽  
Gram Positive Bacteria

ABSTRACTOuter membrane vesicles produced by Gram-negative bacteria have been studied for half a century but the possibility that Gram-positive bacteria secreted extracellular vesicles (EVs) was not pursued due to the assumption that the thick peptidoglycan cell wall would prevent their release to the environment. However, following discovery in fungi, which also have cell walls, EVs have now been described for a variety of Gram-positive bacteria. EVs purified from Gram-positive bacteriaare implicated in virulence, toxin release and transference to host cells, eliciting immune responses, and spread of antibiotic resistance. Listeria monocytogenes is a Gram-positive bacterium that is the etiological agent of listeriosis. Here we report that L. monocytogenes produces EVs with diameter ranging from 20-200 nm, containing the pore-forming toxin listeriolysin O(LLO) and phosphatidylinositol-specific phospholipase C (PI-PLC). Using simultaneous metabolite, protein, and lipid extraction (MPLEx) multi-omics we characterized protein, lipid and metabolite composition of bacterial cells and secreted EVs and found that EVs carry the majority of listerial virulence proteins. Cell-free EV preparations were toxic to the murine macrophage cell line J774.16, in a LLO-dependent manner, evidencing EV biological activity. The deletion of plcA increased EV toxicity, suggesting PI-PLC can restrain LLO activity. Using immunogold electron microscopy we detect LLO localization at several organelles within infected human epithelial cells and with high-resolution fluorescence imaging we show that dynamic lipid structures are released from L. monocytogenes that colocalize with LLO during infection. Our findings demonstrate that L. monocytogenes utilize EVs for toxin release and implicate these structures in mammalian cytotoxicity.

scholarly journals Staphylococcus aureus Extracellular Vesicles Carry Biologically Active β-Lactamase

2013 ◽  
Vol 57 (6) ◽  
pp. 2589-2595 ◽  
Author(s):  
Jaewook Lee ◽  
Eun-Young Lee ◽  
Si-Hyun Kim ◽  
Dae-Kyum Kim ◽  
Kyong-Su Park ◽  
...  
Keyword(s):  
Staphylococcus Aureus ◽  
Extracellular Vesicles ◽  
Extracellular Vesicle ◽  
Biologically Active ◽  
Gram Positive ◽  
Content Type ◽  
Gram Positive Bacteria ◽  
Heat Treated ◽  
Protease Digestion

ABSTRACTGram-positive bacteria naturally produce extracellular vesicles. However, little is known regarding the functions of Gram-positive bacterial extracellular vesicles, especially in the bacterial community. Here, we investigated the role ofStaphylococcus aureusextracellular vesicles in interbacterial communication to cope with antibiotic stress. We found thatS. aureusliberated BlaZ, a β-lactamase protein, via extracellular vesicles. These extracellular vesicles enabled other ampicillin-susceptible Gram-negative and Gram-positive bacteria to survive in the presence of ampicillin. However,S. aureusextracellular vesicles did not mediate the survival of tetracycline-, chloramphenicol-, or kanamycin-susceptible bacteria. Moreover,S. aureusextracellular vesicles did not contain theblaZgene. In addition, the heat-treatedS. aureusextracellular vesicles did not mediate the survival of ampicillin-susceptible bacteria. The β-lactamase activities ofS. aureussoluble and extracellular vesicle-associated BlaZ were similar, but only the extracellular vesicle-associated BlaZ was resistant to protease digestion, which suggests that the enzymatic activity of BlaZ in extracellular vesicles is largely protected by the vesicle structure. Our observations provide evidence of the important role ofS. aureusextracellular vesicles in antibiotic resistance, which allows the polymicrobial community to continue to evolve and prosper against antibiotics.

scholarly journals The biogenesis of extracellular vesicles fromStaphylococcus aureusand their application as a novel vaccine platform

2018 ◽  
Author(s):  
Xiaogang Wang ◽  
Christopher Weidenmaier ◽  
Jean C. Lee
Keyword(s):  
Extracellular Vesicles ◽  
Neutralizing Antibodies ◽  
Cytoplasmic Membrane ◽  
Bacterial Pathogenesis ◽  
Vaccine Platform ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Sepsis Model ◽  
Alpha Type

AbstractGram-positive bacteria secrete extracellular vesicles (EVs) that package diverse bacterial antigens and play key roles in bacterial pathogenesis. However, the mechanisms underlying EV production in Gram-positive bacteria are poorly understood. We purified and characterized EVs from a community-associated methicillin-resistantStaphylococcus aureusisolate (USA300) and investigated mechanisms underlying EV production. Native EVs contained 165 proteins, including cytosolic, surface, and secreted proteins, autolysins, and numerous cytolysins. Staphylococcal alpha-type phenol-soluble modulins (surfactant-like peptides) promoted EV biogenesis, presumably by acting at the cytoplasmic membrane, whereas peptidoglycan crosslinking and autolysin activity were found to increase EV production by altering the permeability of the staphylococcal cell wall. To address the immunogenicity of EVs, we created engineered EVs (eng-EVs) by expressing detoxified proteins HlaH35Land LukE in EVs generated from a nontoxicS. aureus ΔagrΔspamutant. Eng-EVs exhibited no cytotoxicity in vitro, and mice immunized with the eng-EVs produced toxin-neutralizing antibodies and showed reduced lethality in a mouse sepsis model. Our study reveals novel mechanisms underlyingS. aureusEV production and highlights the usefulness of EVs as a novelS. aureusvaccine platform.

Influence of Cell Wall Composition on the Fossilisation of Bacteria and the Implications for the Search for Early Life Forms

1997 ◽  
Vol 161 ◽  
pp. 491-504 ◽  
Author(s):  
Frances Westall
Keyword(s):  
Cell Wall ◽  
Life Forms ◽  
Cation Binding ◽  
Positive Bacterium ◽  
Gram Positive ◽  
Gram Positive Bacteria ◽  
Transmission Electron ◽  
Hydrothermal Sediments ◽  
Identification Of Bacteria ◽  
The Difference

AbstractThe oldest cell-like structures on Earth are preserved in silicified lagoonal, shallow sea or hydrothermal sediments, such as some Archean formations in Western Australia and South Africa. Previous studies concentrated on the search for organic fossils in Archean rocks. Observations of silicified bacteria (as silica minerals) are scarce for both the Precambrian and the Phanerozoic, but reports of mineral bacteria finds, in general, are increasing. The problems associated with the identification of authentic fossil bacteria and, if possible, closer identification of bacteria type can, in part, be overcome by experimental fossilisation studies. These have shown that not all bacteria fossilise in the same way and, indeed, some seem to be very resistent to fossilisation. This paper deals with a transmission electron microscope investigation of the silicification of four species of bacteria commonly found in the environment. The Gram positiveBacillus laterosporusand its spore produced a robust, durable crust upon silicification, whereas the Gram negativePseudomonas fluorescens, Ps. vesicularis, andPs. acidovoranspresented delicately preserved walls. The greater amount of peptidoglycan, containing abundant metal cation binding sites, in the cell wall of the Gram positive bacterium, probably accounts for the difference in the mode of fossilisation. The Gram positive bacteria are, therefore, probably most likely to be preserved in the terrestrial and extraterrestrial rock record.

Microanatomy of the Periplasm of Bacillus Licheniformis

1971 ◽  
Vol 29 ◽  
pp. 262-263
Author(s):  
B.K. Ghosh
Keyword(s):  
Cell Wall ◽  
Plasma Membrane ◽  
Bacillus Licheniformis ◽  
External Environment ◽  
Permeability Barrier ◽  
Periplasmic Space ◽  
Modified Technique ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Periplasm of bacteria is the space outside the permeability barrier of plasma membrane but enclosed by the cell wall. The contents of this special milieu exterior could be regulated by the plasma membrane from the internal, and by the cell wall from the external environment of the cell. Unlike the gram-negative organism, the presence of this space in gram-positive bacteria is still controversial because it cannot be clearly demonstrated. We have shown the importance of some periplasmic bodies in the secretion of penicillinase from Bacillus licheniformis.In negatively stained specimens prepared by a modified technique (Figs. 1 and 2), periplasmic space (PS) contained two kinds of structures: (i) fibrils (F, 100 Å) running perpendicular to the cell wall from the protoplast and (ii) an array of vesicles of various sizes (V), which seem to have evaginated from the protoplast.

Rapid demonstration of septic or infectious arthritis due to Gram-negative bacteria

1992 ◽  
Vol 50 (1) ◽  
pp. 686-687
Author(s):  
Jacob S. Hanker ◽  
Paul R. Gross ◽  
Beverly L. Giammara
Keyword(s):  
Chronic Arthritis ◽  
Blood Cultures ◽  
Gram Negative Bacteria ◽  
Infectious Arthritis ◽  
Bacterial Arthritis ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria

Blood cultures are positive in approximately only 50 per cent of the patients with nongonococcal bacterial infectious arthritis and about 20 per cent of those with gonococcal arthritis. But the concept that gram-negative bacteria could be involved even in chronic arthritis is well-supported. Gram stains are more definitive in staphylococcal arthritis caused by gram-positive bacteria than in bacterial arthritis due to gram-negative bacteria. In the latter situation where gram-negative bacilli are the problem, Gram stains are helpful for 50% of the patients; they are only helpful for 25% of the patients, however, where gram-negative gonococci are the problem. In arthritis due to gram-positive Staphylococci. Gramstained smears are positive for 75% of the patients.

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