Rapid Characterization of Quorum Sensing Inhibitory Molecules from Garcinia indica Choisy Seed Methanol Extract by GC-MS Analysis

2020 ◽  
Vol 16 (6) ◽  
pp. 887-891 ◽  
Author(s):  
Rajesh P. Shastry ◽  
Mohammed Aman
Keyword(s):  
Quorum Sensing ◽  
Methanol Extract ◽  
Cell Communication ◽  
Garcinia Indica ◽  
Biosensor Strain ◽  
Bioactive Fraction ◽  
Violacein Production ◽  
Rapid Characterization ◽  
Inhibitory Molecules

Background: Bacteria communicate by producing small signaling molecules to maintain threshold cell density. Quorum sensing inhibition is an effective and most potent approach for the prevention of cell to cell communication. Methods: In the present study, the methanol extract of Garcinia indica was tested for anti-quorum sensing activity using Chromobacterium violaceum as a biosensor. The extract inhibited violacein production in biosensor strain without affecting the growth of the bacteria and this was corroborated by bioautography assay. Results: The bioactive fraction was analysed by the aid of GC-MS revealed that, the presence of coumarin (7-hydroxy-3-(1,1-dimethylprop-2-enyl) coumarin) and eugenol (1,2-dimethoxy-4-(1-methoxy-1- propenyl) benzene) derivatives as anti-quorum sensing molecules. Conclusion: A detailed investigation is required to study the mechanism of action involved in control of quorum sensing signals and possible applications.

scholarly journals Coumarin’s Anti-Quorum Sensing Activity Can Be Enhanced When Combined with Other Plant-Derived Small Molecules

Molecules ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 208
Author(s):  
Dmitry Deryabin ◽  
Kseniya Inchagova ◽  
Elena Rusakova ◽  
Galimzhan Duskaev
Keyword(s):  
Quorum Sensing ◽  
Small Molecules ◽  
Bacterial Communities ◽  
Cell Communication ◽  
Small Plant ◽  
Eucalyptus Leaves ◽  
Eucalyptus Viminalis ◽  
Fold Reduction ◽  
Half Maximal Effective Concentration ◽  
Violacein Production

Coumarins are class of natural aromatic compounds based on benzopyrones (2H-1-benzopyran-2-ones). They are identified as secondary metabolites in about 150 different plant species. The ability of coumarins to inhibit cell-to-cell communication in bacterial communities (quorum sensing; QS) has been previously described. Coumarin and its derivatives in plant extracts are often found together with other small molecules that show anti-QS properties too. The aim of this study was to find the most effective combinations of coumarins and small plant-derived molecules identified in various plants extracts that inhibit QS in Chromobacterium violaceum ATCC 31532 violacein production bioassay. The coumarin and its derivatives: 7-hydroxycoumarin, 7.8-dihydroxy-4-methylcoumarin, were included in the study. Combinations of coumarins with gamma-octalactone, 4-hexyl-1.3-benzenediol, 3.4.5-trimethoxyphenol and vanillin, previously identified in oak bark (Quercus cortex), and eucalyptus leaves (Eucalyptus viminalis) extracts, were analyzed in a bioassay. When testing two-component compositions, it was shown that 7.8-dihydroxy-4-methylcoumarin, 4-hexyl-1.3-benzendiol, and gamma-octalactone showed a supra-additive anti-QS effect. Combinations of all three molecules resulted in a three- to five-fold reduction in the concentration of each compound needed to achieve EC50 (half maximal effective concentration) against QS in C. violaceum ATCC 31532.

Quorum Sensing – A Stratagem for Conquering Multi-Drug Resistant Pathogens

2020 ◽  
Vol 26 ◽  
Author(s):  
Madison Tonkin ◽  
Shama Khan ◽  
Mohmmad Younus Wani ◽  
Aijaz Ahmad
Keyword(s):  
Drug Resistance ◽  
Quorum Sensing ◽  
Virulence Factors ◽  
Biofilm Formation ◽  
Cell Communication ◽  
Natural Compounds ◽  
Quorum Sensing Inhibitors ◽  
Communication Technique ◽  
Multicellular Organisms ◽  
Chemical Strategies

: Quorum sensing is defined as cell to cell communication between microorganisms, which enables microorganisms to behave as multicellular organisms. Quorum sensing enables many collaborative benefits such as synchronisation of virulence factors and biofilm formation. Both quorum sensing as well as biofilm formation encourage the development of drug resistance in microorganisms. Biofilm formation and quorum sensing are causally linked to each other and play role in the pathogenesis of microorganisms. With the increasing drug resistance against the available antibiotics and antifungal medications, scientists are combining different options to develop new strategies. Such strategies rely on the inhibition of the communication and virulence factors rather than on killing or inhibiting the growth of the microorganisms. This review encompasses the communication technique used by microorganisms, how microorganism resistance is linked to quorum sensing and various chemical strategies to combat quorum sensing and thereby drug resistance. Several compounds have been identified as quorum sensing inhibitors and are known to be effective in reducing resistance as they do not kill the pathogens but rather disrupt their communication. Natural compounds have been identified as anti-quorum sensing agents. However, natural compounds present several related disadvantages. Therefore, the need for the development of synthetic or semi-synthetic compounds has arisen. This review argues that anti-quorum sensing compounds are effective in disrupting quorum sensing and could therefore be effective in reducing microorganism drug resistance.

scholarly journals An evaluation of the InDevR FluChip-8G insight microarray assay in characterizing influenza a viruses

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Emily S. Bailey ◽  
Xinye Wang ◽  
Mai-juan Ma ◽  
Guo-lin Wang ◽  
Gregory C. Gray
Keyword(s):  
Influenza A ◽  
Influenza Viruses ◽  
Time Range ◽  
Influenza B ◽  
Influenza A Viruses ◽  
Laboratory Methods ◽  
Duke University ◽  
Multiple Viral Strains ◽  
Rapid Characterization

AbstractInfluenza viruses are an important cause of disease in both humans and animals, and their detection and characterization can take weeks. In this study, we sought to compare classical virology techniques with a new rapid microarray method for the detection and characterization of a very diverse, panel of animal, environmental, and human clinical or field specimens that were molecularly positive for influenza A alone (n = 111), influenza B alone (n = 3), both viruses (n = 13), or influenza negative (n = 2) viruses. All influenza virus positive samples in this study were first subtyped by traditional laboratory methods, and later evaluated using the FluChip-8G Insight Assay (InDevR Inc. Boulder, CO) in laboratories at Duke University (USA) or at Duke Kunshan University (China). The FluChip-8G Insight multiplexed assay agreed with classical virologic techniques 59 (54.1%) of 109 influenza A-positive, 3 (100%) of the 3 influenza B-positive, 0 (0%) of 10 both influenza A- and B-positive samples, 75% of 24 environmental samples including those positive for H1, H3, H7, H9, N1, and N9 strains, and 80% of 22 avian influenza samples. It had difficulty with avian N6 types and swine H3 and N2 influenza specimens. The FluChip-8G Insight assay performed well with most human, environmental, and animal samples, but had some difficulty with samples containing multiple viral strains and with specific animal influenza strains. As classical virology methods are often iterative and can take weeks, the FluChip-8G Insight Assay rapid results (time range 8 to 12 h) offers considerable time savings. As the FluChip-8G analysis algorithm is expected to improve over time with addition of new subtypes and sample matrices, the FluChip-8G Insight Assay has considerable promise for rapid characterization of novel influenza viruses affecting humans or animals.

scholarly journals Cross-kingdom inhibition of bacterial virulence and communication by probiotic yeast metabolites

Microbiome ◽  
2021 ◽  
Vol 9 (1) ◽  
Author(s):  
Orit Malka ◽  
Dorin Kalson ◽  
Karin Yaniv ◽  
Reut Shafir ◽  
Manikandan Rajendran ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Gut Microbiome ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Molecular Mechanisms ◽  
Human Microbiome ◽  
Cell Communication ◽  
Probiotic Yeast ◽  
Gut Pathogen ◽  
Cell Cell

Abstract Background Probiotic milk-fermented microorganism mixtures (e.g., yogurt, kefir) are perceived as contributing to human health, and possibly capable of protecting against bacterial infections. Co-existence of probiotic microorganisms are likely maintained via complex biomolecular mechanisms, secreted metabolites mediating cell-cell communication, and other yet-unknown biochemical pathways. In particular, deciphering molecular mechanisms by which probiotic microorganisms inhibit proliferation of pathogenic bacteria would be highly important for understanding both the potential benefits of probiotic foods as well as maintenance of healthy gut microbiome. Results The microbiome of a unique milk-fermented microorganism mixture was determined, revealing a predominance of the fungus Kluyveromyces marxianus. We further identified a new fungus-secreted metabolite—tryptophol acetate—which inhibits bacterial communication and virulence. We discovered that tryptophol acetate blocks quorum sensing (QS) of several Gram-negative bacteria, particularly Vibrio cholerae, a prominent gut pathogen. Notably, this is the first report of tryptophol acetate production by a yeast and role of the molecule as a signaling agent. Furthermore, mechanisms underscoring the anti-QS and anti-virulence activities of tryptophol acetate were elucidated, specifically down- or upregulation of distinct genes associated with V. cholerae QS and virulence pathways. Conclusions This study illuminates a yet-unrecognized mechanism for cross-kingdom inhibition of pathogenic bacteria cell-cell communication in a probiotic microorganism mixture. A newly identified fungus-secreted molecule—tryptophol acetate—was shown to disrupt quorum sensing pathways of the human gut pathogen V. cholerae. Cross-kingdom interference in quorum sensing may play important roles in enabling microorganism co-existence in multi-population environments, such as probiotic foods and the gut microbiome. This discovery may account for anti-virulence properties of the human microbiome and could aid elucidating health benefits of probiotic products against bacterially associated diseases.

scholarly journals Electrochemical Approaches for Rapid Characterization of Oxidizable Compounds in Different Oak Alternatives

Beverages ◽  
2020 ◽  
Vol 7 (1) ◽  
pp. 1
Author(s):  
Jéremie Wirth ◽  
Davide Slaghenaufi ◽  
Stéphane Vidal ◽  
Maurizio Ugliano
Keyword(s):  
Linear Sweep Voltammetry ◽  
Wine Industry ◽  
Wine Aroma ◽  
Total Current ◽  
Strong Correlations ◽  
Tannin Content ◽  
Linear Sweep ◽  
Antioxidant Characteristics ◽  
Rapid Characterization

Oak alternatives (OAs) such as chips, granulates or staves, are becoming increasingly used in the wine industry. Although they are mostly considered for their contribution to wine aroma, they are also a source of phenolic compounds to be released in the wine, in particular ellagitannins contributing to wine mouthfeel and antioxidant characteristics. In the present study, we explore the potential for a rapid analytical method based on linear sweep voltammetry (LSV) combined with disposable sensors to provide a rapid measure of the oxidizable compounds present in different OAs, as well as their characterization. Strong correlations were found between the tannin content of different OAs and the total current measures during LSV analysis, allowing a rapid quantification of the oxidizable compounds present, mostly ellagitannin. Application of derivatization to raw voltammograms allowed extraction of a number of features that can be used for classification purposes, in particular with respect to OAs types (chips or staves) and degree of toasting.

scholarly journals N-3-Hydroxy Dodecanoyl-DL-homoserine Lactone (OH-dDHL) Triggers Apoptosis of Bone Marrow-Derived Macrophages through the ER- and Mitochondria-Mediated Pathways

2021 ◽  
Vol 22 (14) ◽  
pp. 7565
Author(s):  
Kyungho Woo ◽  
Dong Ho Kim ◽  
Man Hwan Oh ◽  
Ho Sung Park ◽  
Chul Hee Choi
Keyword(s):  
Bone Marrow ◽  
Quorum Sensing ◽  
Deletion Mutant ◽  
Transmembrane Protein ◽  
Cell Communication ◽  
Homoserine Lactone ◽  
Host Responses ◽  
Wild Type ◽  
Mutant Strains

Quorum sensing of Acinetobacter nosocomialis for cell-to-cell communication produces N-3-hydroxy dodecanoyl-DL-homoserine lactone (OH-dDHL) by an AnoR/I two-component system. However, OH-dDHL-driven apoptotic mechanisms in hosts have not been clearly defined. Here, we investigated the induction of apoptosis signaling pathways in bone marrow-derived macrophages treated with synthetic OH-dDHL. Moreover, the quorum-sensing system for virulence regulation was evaluated in vivo using wild-type and anoI-deletion mutant strains. OH-dDHL decreased the viability of macrophage and epithelial cells in dose- and time-dependent manners. OH-dDHL induced Ca2+ efflux and caspase-12 activation by ER stress transmembrane protein (IRE1 and ATF6a p50) aggregation and induced mitochondrial dysfunction through reactive oxygen species (ROS) production, which caused cytochrome c to leak. Pretreatment with a pan-caspase inhibitor reduced caspase-3, -8, and -9, which were activated by OH-dDHL. Pro-inflammatory cytokine and paraoxonase-2 (PON2) gene expression were increased by OH-dDHL. We showed that the anoI-deletion mutant strains have less intracellular invasion compared to the wild-type strain, and their virulence, such as colonization and dissemination, was decreased in vivo. Consequently, these findings revealed that OH-dDHL, as a virulence factor, contributes to bacterial infection and survival as well as the modification of host responses in the early stages of infection.

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