Faculty Opinions recommendation of Quorum-sensing inhibitory compounds from extremophilic microorganisms isolated from a hypersaline cyanobacterial mat.

2016 ◽  
Author(s):  
James Coker
Keyword(s):  
Quorum Sensing ◽  
Cyanobacterial Mat ◽  
Inhibitory Compounds ◽  
Extremophilic Microorganisms

scholarly journals Quorum-sensing inhibitory compounds from extremophilic microorganisms isolated from a hypersaline cyanobacterial mat

2013 ◽  
Vol 40 (7) ◽  
pp. 759-772 ◽  
Author(s):  
Raeid M. M. Abed ◽  
Sergey Dobretsov ◽  
Marwan Al-Fori ◽  
Sarath P. Gunasekera ◽  
Kumar Sudesh ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Cyanobacterial Mat ◽  
Inhibitory Compounds ◽  
Extremophilic Microorganisms

scholarly journals Co-existence of Quorum Sensing and Quorum Sensing Inhibitory Compounds in Marine Sponge Sarcotragus spinosulus

2019 ◽  
Author(s):  
Kumar Saurav ◽  
Nicola Borbone ◽  
Ilia Burgsdorf ◽  
Roberta Teta ◽  
Alessia Caso ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Acyl Chain ◽  
Genetic Regulation ◽  
Marine Sponges ◽  
Signal Molecules ◽  
E Coli ◽  
Inhibitory Compounds ◽  
Dependent Inhibition ◽  
Eukaryotic Organisms ◽  
And Function

Marine sponges, a well documented prolific source of natural products, harbors numerous microbial communities believed to possess N-acyl homoserine lactones (AHLs) mediated Quorum sensing (QS) as one of the mechanisms of interaction. Bacteria and eukaryotic organisms are known to produce molecules that can interfere with QS signaling, thus affecting microbial genetic regulation and function. In the present study, we established the potential for production of both QS signal molecules as well as QS interfering molecules (QSI) in the same sponge species Sarcotragus spinosulus. A total of eighteen saturated acyl chain AHLs were identified along with six putative unsaturated acyl chain AHLs. Bioassay guided purification led to the isolation of two brominated metabolites with QS-interfering activity. The structures of these compounds were elucidated by comparative spectral analysis of 1HNMR and HR-MS data and was identified as 3-Br-N-methyltyramine (1) and 5,6-dibromo-N,N-dimethyltryptamine (2). The QSI activity of compounds 1 and 2 were evaluated using reporter gene assays for long- and short-chain signals (E. coli pSB1075 and E. coli pSB401) and was confirmed by measuring dose dependent inhibition of proteolytic activity and pyocyanin production in P. aeruginosa PAO1. The obtained results showed the co-existence of QS and QSI in S. spinosulus, a complex network which may mediate the orchestrated function of the microbiome within the sponge holobiont.

scholarly journals Investigation of the quorum-sensing regulon of the biocontrol bacterium Pseudomonas chlororaphis strain PA23

2019 ◽  
Author(s):  
Nidhi Shah ◽  
April Gislason ◽  
Michael Becker ◽  
Mark F. Belmonte ◽  
W.G. Dilantha Fernando ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Differentially Expressed Genes ◽  
Differentially Expressed ◽  
Pseudomonas Chlororaphis ◽  
Phenotypic Analysis ◽  
Promoter Regions ◽  
Altered Expression ◽  
Inhibitory Compounds ◽  
General Metabolism ◽  
Rot Disease

AbstractPseudomonas chlororaphis strain PA23 is a biocontrol agent capable of protecting canola from stem rot disease caused by the fungal pathogen Sclerotinia sclerotiorum. PA23 produces several of inhibitory compounds that are under control of a complex regulatory network. Included in this cascade is the PhzRI quorum sensing (QS) system, which plays an essential role in PA23 biocontrol. The focus of the current study was to employ RNA sequencing to explore the spectrum of PA23 genes under QS control. Transcriptomic profiling revealed 545 differentially expressed genes (365 downregulated; 180 upregulated) in the phzR mutant and 534 genes (382 downregulated; 152 upregulated) in the AHL-deficient PA23-6863. In both strains, decreased expression of phenazine, pyrrolnitrin, and exoprotease biosynthetic genes was observed. We have previously reported that QS activates expression of these genes and their encoded products. In addition, elevated siderophore and decreased chitinase gene expression was observed in the QS-deficient stains, which was confirmed by phenotypic analysis. Inspection of the promoter regions revealed the presence of “phz-box” sequences in only 58 of the 807 differentially expressed genes, suggesting that much of the QS regulon is indirectly regulated. Consistent with this notion, 41 transcriptional regulators displayed altered expression in one or both of the QS-deficient strains. Collectively, our findings indicate that QS governs expression of approximately 13% of the PA23 genome affecting diverse functions ranging from secondary metabolite production to general metabolism. To the best of our knowledge, this represents the first global transcriptomic analysis of the QS regulon of a biocontrol pseudomonad.

Quorum-Sensing Inhibitory Compounds

2007 ◽  
pp. 51-77 ◽  
Author(s):  
Dacheng Ren ◽  
Michael Givskov ◽  
Thomas Bovbjerg Rasmussen ◽  
Naomi Balaban
Keyword(s):  
Quorum Sensing ◽  
Inhibitory Compounds

scholarly journals Quorum sensing inhibitors: a bargain of effects

Microbiology ◽  
2006 ◽  
Vol 152 (4) ◽  
pp. 895-904 ◽  
Author(s):  
Thomas B. Rasmussen ◽  
Michael Givskov
Keyword(s):  
Quorum Sensing ◽  
Pathogenic Bacteria ◽  
Plant Pathogens ◽  
Signal Molecules ◽  
Antimicrobial Drugs ◽  
Development Of Resistance ◽  
Inhibitory Compounds ◽  
Opportunistic Pathogenic ◽  
Regulated Gene Expression

Many opportunistic pathogenic bacteria rely on quorum sensing (QS) circuits as central regulators of virulence expression. In Pseudomonas aeruginosa, QS-regulated gene expression contributes to the formation and maintenance of biofilms and their tolerance to conventional antimicrobials and the host innate immune system. Therefore, QS is an obvious target for a novel class of antimicrobial drugs which would function to efficiently block reception of the cognate QS signals in vivo, and thereby be capable of inducing chemical attenuation of pathogens. As QS is not directly involved in processes essential for growth of the bacteria, inhibition of QS does not impose harsh selective pressure for development of resistance as with antibiotics. Numerous chemical libraries of both natural and synthetic origin have been screened and several QS-inhibitory compounds have been identified. In animal pulmonary infection models, such inhibitors have proven able to significantly improve clearing of the infecting bacteria and reduce mortality. In addition, several enzymes that are able to inactivate the bacterial QS signal molecules have been identified. This inactivation leads to blockage of QS-mediated virulence of plant pathogens in several models.

Early Platelet-Collagen Interactions in Whole Blood and Their Modifications by Aspirin and Dipyridamole Evaluated by a New Method (Basic Wave)

1985 ◽  
Vol 54 (04) ◽  
pp. 799-803 ◽  
Author(s):  
José Luís Pérez-Requejo ◽  
Justo Aznar ◽  
M Teresa Santos ◽  
Juana Vallés
Keyword(s):  
Whole Blood ◽  
Ex Vivo ◽  
Platelet Rich Plasma ◽  
White Blood Cells ◽  
Reversible Aggregation ◽  
Inhibitory Compounds ◽  
Rapid Generation ◽  
Stimulation Of ◽  
Collagen Stimulation

SummaryIt is shown that the supernatant of unstirred whole blood at 37° C, stimulated by 1 μg/ml of collagen for 10 sec, produces a rapid generation of pro and antiaggregatory compounds with a final proaggregatory activity which can be detected for more than 60 min on a platelet rich plasma (PRP) by turbidometric aggregometry. A reversible aggregation wave that we have called BASIC wave (for Blood Aggregation Stimulatory and Inhibitory Compounds) is recorded. The collagen stimulation of unstirred PRP produces a similar but smaller BASIC wave. BASIC’s intensity increases if erythrocytes are added to PRP but decreases if white blood cells are added instead. Aspirin abolishes “ex vivo” the ability of whole blood and PRP to generate BASIC waves and dipyridamole “in vitro” significantly reduces BASIC’s intensity in whole blood in every tested sample, but shows little effect in PRP.

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