scholarly journals Rapamycin Re-Directs Lysosome Network, Stimulates ER-Remodeling, Involving Membrane CD317 and Affecting Exocytosis, in Campylobacter Jejuni-Lysate-Infected U937 Cells

2020 ◽  
Vol 21 (6) ◽  
pp. 2207
Author(s):  
Barbara Canonico ◽  
Erica Cesarini ◽  
Mariele Montanari ◽  
Gianna Di Sario ◽  
Raffaella Campana ◽  
...  
Keyword(s):  
Campylobacter Jejuni ◽  
Symptom Severity ◽  
Membrane Microdomains ◽  
U937 Cells ◽  
Bacterial Lysate ◽  
Cytotoxic Effects ◽  
Lethal Effects ◽  
Gram Negative ◽  
Lysosomal Compartment ◽  
First Time

The Gram-negative Campylobacter jejuni is a major cause of foodborne gastroenteritis in humans worldwide. The cytotoxic effects of Campylobacter have been mainly ascribed to the actions of the cytolethal distending toxin (CDT): it is mandatory to put in evidence risk factors for sequela development, such as reactive arthritis (ReA) and Guillain–Barré syndrome (GBS). Several researches are directed to managing symptom severity and the possible onset of sequelae. We found for the first time that rapamycin (RM) is able to largely inhibit the action of C. jejuni lysate CDT in U937 cells, and to partially avoid the activation of specific sub-lethal effects. In fact, we observed that the ability of this drug to redirect lysosomal compartment, stimulate ER-remodeling (highlighted by ER–lysosome and ER–mitochondria contacts), protect mitochondria network, and downregulate CD317/tetherin, is an important component of membrane microdomains. In particular, lysosomes are involved in the process of the reduction of intoxication, until the final step of lysosome exocytosis. Our results indicate that rapamycin confers protection against C. jejuni bacterial lysate insults to myeloid cells.

Ultrastructure of periplasmic bodies in gram-negative bacteria

1990 ◽  
Vol 48 (3) ◽  
pp. 640-641
Author(s):  
Xie Nianming ◽  
Ding Shaoqing ◽  
Wang Luping ◽  
Yuan Zenglin ◽  
Zhan Guolai ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Campylobacter Jejuni ◽  
Proteus Mirabilis ◽  
Shigella Flexneri ◽  
Morphological Description ◽  
Gram Negative Bacteria ◽  
Periplasmic Space ◽  
Clostridium Tetani ◽  
Gram Negative ◽  
Brucella Canis

Perhaps the data about periplasmic enzymes are obtained through biochemical methods but lack of morphological description. We have proved the existence of periplasmic bodies by electron microscope and described their ultrastructures. We hope this report may draw the attention of biochemists and mrophologists to collaborate on researches in periplasmic enzymes or periplasmic bodies with each other.One or more independent bodies may be seen in the periplasmic space between outer and inner membranes of Gram-negative bacteria, which we called periplasmic bodies. The periplasmic bodies have been found in seven species of bacteria at least, including the Pseudomonas aeroginosa. Shigella flexneri, Echerichia coli. Yersinia pestis, Campylobacter jejuni, Proteus mirabilis, Clostridium tetani. Vibrio cholerae and Brucella canis.

scholarly journals The antimicrobial potential of cannabidiol

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Mark A. T. Blaskovich ◽  
Angela M. Kavanagh ◽  
Alysha G. Elliott ◽  
Bing Zhang ◽  
Soumya Ramu ◽  
...  
Keyword(s):  
Bacterial Infections ◽  
Modern Medicine ◽  
Gram Negative Bacteria ◽  
Gram Negative ◽  
New Class ◽  
Clostridioides Difficile ◽  
Excellent Activity ◽  
Induce Resistance ◽  
First Time

AbstractAntimicrobial resistance threatens the viability of modern medicine, which is largely dependent on the successful prevention and treatment of bacterial infections. Unfortunately, there are few new therapeutics in the clinical pipeline, particularly for Gram-negative bacteria. We now present a detailed evaluation of the antimicrobial activity of cannabidiol, the main non-psychoactive component of cannabis. We confirm previous reports of Gram-positive activity and expand the breadth of pathogens tested, including highly resistant Staphylococcus aureus, Streptococcus pneumoniae, and Clostridioides difficile. Our results demonstrate that cannabidiol has excellent activity against biofilms, little propensity to induce resistance, and topical in vivo efficacy. Multiple mode-of-action studies point to membrane disruption as cannabidiol’s primary mechanism. More importantly, we now report for the first time that cannabidiol can selectively kill a subset of Gram-negative bacteria that includes the ‘urgent threat’ pathogen Neisseria gonorrhoeae. Structure-activity relationship studies demonstrate the potential to advance cannabidiol analogs as a much-needed new class of antibiotics.

Ultrastructural studies of Chlamydia psittaci 6BC variant strains. I. Ultrastructure of the surface layers of egg-passaged 6BC strain

1973 ◽  
Vol 19 (8) ◽  
pp. 887-894
Author(s):  
Linda Poffenroth ◽  
J. W. Costerton ◽  
Nonna Kordová ◽  
John C. Wilt
Keyword(s):  
Chick Embryo ◽  
Microscopic Examination ◽  
Electron Microscopic Examination ◽  
Chlamydia Psittaci ◽  
Gram Negative Bacteria ◽  
Surface Layers ◽  
Electron Microscopic ◽  
Gram Negative ◽  
Ultrastructural Studies ◽  
First Time

Electron microscopic examination of a semipurified Chlamydia psittaci 6BC strain attenuated in chick embryo yolk sac revealed for the first time two morphologically distinct small elementary bodies which differ both in the ultrastructure of their surface layers and in their buoyant densities in sucrose gradients. Also, the morphology of the surface layers of the larger reticulate forms in cell-free systems is described for the first time. Many points of difference between the surface envelopes and internal structure of chlamydial particles and those of Gram-negative bacteria are discussed.

scholarly journals Shadowing the Actions of a Predator: Backlit Fluorescent Microscopy Reveals Synchronous Nonbinary Septation of Predatory Bdellovibrio inside Prey and Exit through Discrete Bdelloplast Pores

2010 ◽  
Vol 192 (24) ◽  
pp. 6329-6335 ◽  
Author(s):  
A. K. Fenton ◽  
M. Kanna ◽  
R. D. Woods ◽  
S.-I. Aizawa ◽  
R. E. Sockett
Keyword(s):  
Cell Division ◽  
Outer Membrane ◽  
Fluorescent Microscopy ◽  
Gram Negative Bacteria ◽  
Bacterial Cell Division ◽  
Prey Cell ◽  
Gram Negative ◽  
A Genome ◽  
Predatory Bacteria ◽  
First Time

ABSTRACT The Bdellovibrio are miniature “living antibiotic” predatory bacteria which invade, reseal, and digest other larger Gram-negative bacteria, including pathogens. Nutrients for the replication of Bdellovibrio bacteria come entirely from the digestion of the single invaded bacterium, now called a bdelloplast, which is bound by the original prey outer membrane. Bdellovibrio bacteria are efficient digesters of prey cells, yielding on average 4 to 6 progeny from digestion of a single prey cell of a genome size similar to that of the Bdellovibrio cell itself. The developmental intrabacterial cycle of Bdellovibrio is largely unknown and has never been visualized “live.” Using the latest motorized xy stage with a very defined z-axis control and engineered periplasmically fluorescent prey allows, for the first time, accurate return and visualization without prey bleaching of developing Bdellovibrio cells using solely the inner resources of a prey cell over several hours. We show that Bdellovibrio bacteria do not follow the familiar pattern of bacterial cell division by binary fission. Instead, they septate synchronously to produce both odd and even numbers of progeny, even when two separate Bdellovibrio cells have invaded and develop within a single prey bacterium, producing two different amounts of progeny. Evolution of this novel septation pattern, allowing odd progeny yields, allows optimal use of the finite prey cell resources to produce maximal replicated, predatory bacteria. When replication is complete, Bdellovibrio cells exit the exhausted prey and are seen leaving via discrete pores rather than by breakdown of the entire outer membrane of the prey.

scholarly journals Draft Genome Sequence of Pantoea sp. Strain A4, a Rafflesia-Associated Bacterium That ProducesN-Acylhomoserine Lactones as Quorum-Sensing Molecules

2012 ◽  
Vol 194 (23) ◽  
pp. 6610-6610 ◽  
Author(s):  
Kar-Wai Hong ◽  
Han Ming Gan ◽  
Siew-Moon Low ◽  
Patrick Kok Yuen Lee ◽  
Yee-Meng Chong ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Genome Sequence ◽  
Draft Genome ◽  
Draft Genome Sequence ◽  
Negative Bacterium ◽  
Gram Negative ◽  
Content Type ◽  
First Time

ABSTRACTPantoeasp. strain A4 is a Gram-negative bacterium isolated from theRafflesiaflower. We present here, for the first time, the genome sequence ofRafflesia-associatedPantoeasp. strain A4, which exhibited quorum-sensing activity.

scholarly journals A New 3-Prenyl-2-flavene and Other Extractives from Baphia massaiensis and Their Antimicrobial Activities

2018 ◽  
Vol 13 (4) ◽  
pp. 1934578X1801300 ◽  
Author(s):  
Ngonye Keroletswe ◽  
Runner R. T. Majinda ◽  
Ishmael B. Masesane
Keyword(s):  
Escherichia Coli ◽  
2D Nmr ◽  
Antimicrobial Activities ◽  
Spectroscopic Techniques ◽  
Good Activity ◽  
Gram Negative ◽  
E Coli ◽  
Chromatographic Techniques ◽  
Inhibition Zones ◽  
First Time

One new 3-prenyl-2-flavene, named baphiflavene A, 1, and eleven known compounds, 2-12, were isolated and reported for the first time from Baphia massaiensis using several chromatographic techniques. Their structures were elucidated using different spectroscopic techniques; 1D and 2D-NMR, HRMS, GC-MS, UV/Vis, FTIR and by comparison with literature data. The isolates were tested against Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Escherichia coli and Candida albicans to establish their preliminary antimicrobial activities. The results revealed that compound 1 had moderate activities against both Gram positive ( B. subtilis and S. aureus) and Gram negative ( E. coli and P. aeruginosa) bacteria, and good activity against C. albicans with inhibition zones of 10–23 mm (compared to 19 mm for chloramphenicol and miconazole standards). To the best of our knowledge, this is the first phytochemical work reported on Baphia massaiensis.

Fusobacterium nucleatum, the first Gram-negative bacterium demonstrated to produce polyglutamate

2009 ◽  
Vol 55 (5) ◽  
pp. 627-632 ◽  
Author(s):  
Thomas Candela ◽  
Marie Moya ◽  
Michel Haustant ◽  
Agnès Fouet
Keyword(s):  
In Silico Analysis ◽  
Fusobacterium Nucleatum ◽  
Gram Negative Bacteria ◽  
Negative Bacterium ◽  
Gram Positive ◽  
Gram Negative ◽  
Gram Positive Bacteria ◽  
The Third ◽  
Gram Negative Organisms ◽  
First Time

Poly-γ-glutamate has been described in many Gram-positive organisms. When anchored to the surface, it is a capsule and as such a virulence factor. Based on sequence similarities, few Gram-negative organisms have been suggested to synthesize poly-γ-glutamate. For the first time, a Gram-negative bacterium, Fusobacterium nucleatum , is shown to produce and secrete poly-γ-glutamate. Putative poly-γ-glutamate-synthesizing genes from Gram-negative organisms have been compared with their Gram-positive homologs by in silico analysis, i.e., gene sequence and phylogenetic analysis. Clusters of three instead of four genes were highlighted by our screen. The products of the first two genes display similarity with their Gram-positive equivalents, yet the sequences from the Gram-negative organisms can be distinguished from those of the Gram-positives. Interestingly, the sequence of the predicted product of the third gene is conserved among Gram-negative bacteria but displays no similarity to that of either the third or fourth gene of the Gram-positive operons. It is suggested that, like for Gram-positive bacteria, poly-γ-glutamate has a role in virulence for pathogens and one in survival for other Gram-negative bacteria.

scholarly journals Cytotoxic Activity of Essential Oils of Aerial Parts and Ripe Fruits of Echinophora spinosa (Apiaceae)

2013 ◽  
Vol 8 (11) ◽  
pp. 1934578X1300801 ◽  
Author(s):  
Daniele Fraternale ◽  
Donata Ricci ◽  
Cinzia Calcabrini ◽  
Michele Guescini ◽  
Chiara Martinelli ◽  
...  
Keyword(s):  
Linear Regression ◽  
Essential Oils ◽  
Cytotoxic Activity ◽  
Central Italy ◽  
U937 Cells ◽  
Cytotoxic Effects ◽  
Regression Curves ◽  
Aerial Parts ◽  
Ic50 Values ◽  
Per Se

The cytotoxic effects of the essential oils obtained from the flowering aerial parts (APO) and ripe fruits (RFO) of Echinophora spinosa L. (Apiaceae) from central Italy toward human U937 promonocytoid cells were studied; the contribution of each of the major constituents to the whole cytotoxic activity of either APO or RFO was also characterized. The major components of APO were β-phellandrene (34.7%), myristicin (16.5%), p-cymene (16.3%), δ3-carene (12.6%), α-pinene (6.7%) and α-phellandrene (6.2%); those of RFO p-cymene (50.2%), myristicin (15.3%), α-pinene (15.1%) and α-phellandrene (8.1%). Both oils tested were toxic to U937 cells, but RFO was much more cytotoxic: indeed, the IC50 values calculated from the linear regression curves of RFO and APO were 14.5 ± 0.85 and 43.4 ± 2.81 μg/mL, respectively. α-Pinene and α-phellandrene were identified as the most toxically relevant constituents: however, they did not completely account for the toxic effects of genuine APO and RFO. Interestingly, we found that p-cymene, although per se devoid of toxicity within the tested range of concentrations, was capable of significantly sensitizing U937 cells to the cytotoxic activity of α-pinene and α-phellandrene, and that specific mixtures of these three terpenes were as toxic as genuine APO and RFO.

scholarly journals Resveratrol Targets Sphingolipid Metabolism to Induce Growth Inhibition in FLT3 ITD Acute Myeloid Leukemia

Proceedings ◽  
2019 ◽  
Vol 40 (1) ◽  
pp. 4
Author(s):  
Ersöz ◽  
Adan
Keyword(s):  
Growth Inhibition ◽  
Cell Fate ◽  
De Novo ◽  
Therapeutic Potential ◽  
Annexin V ◽  
Sphingolipid Metabolism ◽  
Ceramide Synthase ◽  
Cytotoxic Effects ◽  
Sphingosine 1 Phosphate ◽  
First Time

Sphingolipids are important signaling lipids which play crucial roles to determine the cell fate. Ceramide, apoptotic central molecule of sphingolipid metabolism, which is produced through de novo pathway by serine palmitoyl transferase (SPT) and can be converted to antiapoptotic sphingosine-1-phosphate (S1P) and glucosyl ceramide (GC) by sphingosine kinase (SK) and glucosyl ceramide synthase (GCS), respectively. It is aimed to investigate therapeutic potential of resveratrol on FLT3-ITD (Internal Tandem Duplication) AML cells and to identify potential mechanism behind resveratrol-mediated growth inhibition by targeting of ceramide metabolism. The cytotoxic effects of resveratrol, SPT inhibitor (myricoin), SK-1 inhibitor (SKI II), GCS inhibitor (PDMP), resveratrol: SPT inhibitor, resveratrol: SK-1 inhibitor and resveratrol: GCS inhibitor combinations on MOLM-13 and MV4-11 FLT3 ITD AML cells were investigated by cell proliferation assay. Apoptosis was evaluated by annexin V/PI double staining. There were synergistic cytotoxic effects of resveratrol with co-administration of SPT inhibitor, SK-1 inhibitor and GCS inhibitor and apoptosis was synergistically induced for resveratrol and its combinations. This preliminary data showed for the first time that resveratrol might inhibit the growth of FLT3 ITD AML cells through targeting ceramide metabolism.

scholarly journals Nimesulide Based Novel Glycolamide Esters: Their Design, Synthesis, and Pharmacological Evaluation

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Kavitha Kankanala ◽  
Vangala Ranga Reddy ◽  
Yumnam Priyadarshini Devi ◽  
Lakshmi Narasu Mangamoori ◽  
Khagga Mukkanti ◽  
...  
Keyword(s):  
Cancer Cell Line ◽  
Human Colon ◽  
Colon Cancer Cell Line ◽  
Cytotoxic Activities ◽  
Step Method ◽  
Human Colon Cancer ◽  
Cytotoxic Effects ◽  
Design Synthesis ◽  
First Time

The nimesulide based novel glycolamide esters were designed and synthesized for the first timeviaa three-step method starting from nimesulide. Structures of the synthesized compounds were confirmed by spectroscopic analysis. All the synthesized compounds were examined for their cytotoxic effectsin vitro,some of which showed significant cytotoxic activities against HCT-15 human colon cancer cell line.

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