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 Bacterial Quorum Sensing and Microbial Community Interactions

mBio ◽  
2018 ◽  
Vol 9 (3) ◽  
Author(s):  
Rhea G. Abisado ◽  
Saida Benomar ◽  
Jennifer R. Klaus ◽  
Ajai A. Dandekar ◽  
Josephine R. Chandler
Keyword(s):  
Quorum Sensing ◽  
Bacterial Infections ◽  
Molecular Mechanisms ◽  
Cell Communication ◽  
Microbial Interactions ◽  
Community Interactions ◽  
Bacterial Populations ◽  
Bacterial Quorum Sensing ◽  
A Cell ◽  
Bacterial Quorum

ABSTRACTMany bacteria use a cell-cell communication system called quorum sensing to coordinate population density-dependent changes in behavior. Quorum sensing involves production of and response to diffusible or secreted signals, which can vary substantially across different types of bacteria. In many species, quorum sensing modulates virulence functions and is important for pathogenesis. Over the past half-century, there has been a significant accumulation of knowledge of the molecular mechanisms, signal structures, gene regulons, and behavioral responses associated with quorum-sensing systems in diverse bacteria. More recent studies have focused on understanding quorum sensing in the context of bacterial sociality. Studies of the role of quorum sensing in cooperative and competitive microbial interactions have revealed how quorum sensing coordinates interactions both within a species and between species. Such studies of quorum sensing as a social behavior have relied on the development of “synthetic ecological” models that use nonclonal bacterial populations. In this review, we discuss some of these models and recent advances in understanding how microbes might interact with one another using quorum sensing. The knowledge gained from these lines of investigation has the potential to guide studies of microbial sociality in natural settings and the design of new medicines and therapies to treat bacterial infections.

scholarly journals Quorum Sensing Pseudomonas Quinolone Signal Forms Chiral Supramolecular Assemblies With the Host Defense Peptide LL-37

2021 ◽  
Vol 8 ◽  
Author(s):  
Ferenc Zsila ◽  
Maria Ricci ◽  
Imola Csilla Szigyártó ◽  
Priyanka Singh ◽  
Tamás Beke-Somfai
Keyword(s):  
Quorum Sensing ◽  
Host Defense ◽  
Bacterial Infections ◽  
Molecular Mechanisms ◽  
Cell Communication ◽  
Quorum Quenching ◽  
Bacterial Biofilms ◽  
Phenotypic Traits ◽  
Signal Molecules ◽  
Supramolecular Architectures

Host defense antimicrobial peptides (HDPs) constitute an integral component of the innate immune system having nonspecific activity against a broad spectrum of microorganisms. They also have diverse biological functions in wound healing, angiogenesis, and immunomodulation, where it has also been demonstrated that they have a high affinity to interact with human lipid signaling molecules. Within bacterial biofilms, quorum sensing (QS), the vital bacterial cell-to-cell communication system, is maintained by similar diffusible small molecules which control phenotypic traits, virulence factors, biofilm formation, and dispersion. Efficient eradication of bacterial biofilms is of particular importance as these colonies greatly help individual cells to tolerate antibiotics and develop antimicrobial resistance. Regarding the antibacterial function, for several HDPs, including the human cathelicidin LL-37, affinity to eradicate biofilms can exceed their activity to kill individual bacteria. However, related underlying molecular mechanisms have not been explored yet. Here, we employed circular dichroism (CD) and UV/VIS spectroscopic analysis, which revealed that LL-37 exhibits QS signal affinity. This archetypal representative of HDPs interacts with the Pseudomonas quinolone signal (PQS) molecules, producing co-assemblies with peculiar optical activity. The binding of PQS onto the asymmetric peptide chains results in chiral supramolecular architectures consisting of helically disposed, J-aggregated molecules. Besides the well-known bacterial membrane disruption activity, our data propose a novel action mechanism of LL-37. As a specific case of the so-called quorum quenching, QS signal molecules captured by the peptide are sequestered inside co-assemblies, which may interfere with the microbial QS network helping to prevent and eradicate bacterial infections.

Gut Feeling

2016 ◽  
Vol 33 (S1) ◽  
pp. S504-S505
Author(s):  
C. Cotta ◽  
G. Jesus ◽  
V. Vila Nova ◽  
C. Moreira
Keyword(s):  
Mental Disorders ◽  
Gut Microbiota ◽  
Gut Microbiome ◽  
Bacterial Infections ◽  
Human Microbiome ◽  
Dietary Interventions ◽  
Scientific Databases ◽  
Antibiotic Drugs ◽  
Microbiome Research ◽  
Competing Interest

IntroductionThere is growing evidence of the importance of nutrition in mental disorders. Gut microbiota, influenced by environmental factors such as diet and stress, has been proposed as one of the players on a dynamic called gut-brain axis, which is thought to have an influence on behaviour and mental health.Objectives and aimsTo summarize recent evidence on the topic, and its potential role in psychiatric interventions.MethodsThe authors review updated literature collected from online scientific databases.ResultsThe development of the brain itself has been shown to be influenced by the gut microbiome. Research demonstrates that the composition of the microbiota has influence on behaviour through neuroendocrine and other neuroactive messengers production by the bacteria within the gut lumen. Studies in germ-free animals, animals exposed to bacterial infections, probiotic suplements or antibiotic drugs suggest a role for the gut microbiota in the regulation of anxiety, mood, cognition and pain. The gut microbiome has been implicated in brain disorders including anxiety and depression, multiple sclerosis, Alzheimer's disease, Parkinson's disease, and autism.ConclusionsThe treatment of mental disorders is usually based on pharmacological and psychotherapeutic interventions, and little attention is given to dietary interventions. The emerging field of research focused on the human microbiome suggests an important role for the gut microbiota in influencing brain development, behaviour and mood in humans, and points new strategies for developing novel therapeutics for mental disorders.Disclosure of interestThe authors have not supplied their declaration of competing interest.

The cis -2-dodecenoic acid (BDSF) quorum sensing system in Burkholderia cenocepacia

2022 ◽  
Author(s):  
Mingfang Wang ◽  
Xia Li ◽  
Shihao Song ◽  
Chaoyu Cui ◽  
Lian-Hui Zhang ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Bacterial Infections ◽  
Xanthomonas Campestris ◽  
Cell Communication ◽  
Burkholderia Cenocepacia ◽  
Bacterial Cells ◽  
Communication Signals ◽  
Signal Perception ◽  
Sensing System ◽  
Diffusible Signal Factor

It has been demonstrated that quorum sensing (QS) is widely employed by bacterial cells to coordinately regulate various group behaviors. Diffusible signal factor (DSF)-type signals have emerged as a growing family of conserved cell-cell communication signals. In addition to the DSF signal initially identified in Xanthomonas campestris pv. campestris, B urkholderia d iffusible s ignal f actor (BDSF, cis -2-dodecenoic acid) has been recognized as a conserved DSF-type signal with specific characteristics in both signal perception and transduction from DSF signals. Here, we review the history and current progress of the research of this type of signal, especially focusing on its biosynthesis, signaling pathways, and biological functions. We also discuss and explore the huge potential of targeting this kind of QS system as a new therapeutic strategy to control bacterial infections and diseases.

scholarly journals TGF-β1 facilitates cell–cell communication in osteocytes via connexin43- and pannexin1-dependent gap junctions

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Wenjing Liu ◽  
Demao Zhang ◽  
Xin Li ◽  
Liwei Zheng ◽  
Chen Cui ◽  
...  
Keyword(s):  
Gap Junctions ◽  
Molecular Mechanisms ◽  
Ex Vivo ◽  
Lucifer Yellow ◽  
Cell Communication ◽  
Deep Understanding ◽  
Gap Junctional Intercellular Communication ◽  
Tgf Β1 ◽  
Cell Cell

Abstract Connexins and pannexins are two families of channel forming proteins that are able to pass small molecules to achieve communication between cells. While connexins have been recognized to mediate gap junctional intercellular communication (GJIC), pannexins are far less known. Our previous study reported the potential role of TGF-β1 in mediating of connexins in osteocytes in vitro. Herein, we aimed to elucidate the influence of TGF-β1 on cell–cell communication based on gap junctions assembled by connexins and pannexins in vitro and ex vivo. We first showed that TGF-β1 positively affected the elongation of dendritic processes of osteocytes. Our data indicated that TGF-β1 increased expressions of connexin43 (Cx43) and pannexin1 (panx1), which are indispensable for hemichannel formation in gap junctions, in osteocytes in vitro and ex vivo. TGF-β1 enhanced gap junction formation and impacted cell–cell communication in living osteocytes, as indicated by the scrape loading and Lucifer yellow transfer assays. TGF-β1 enhanced the expressions of Cx43 and panx1 via activation of ERK1/2 and Smad3/4 signalling. The TGF-β1-restored expressions of Cx43 and panx1 in osteocytes in the presence of an ERK inhibitor, U0126, further demonstrated the direct participation of Smad3/4 signalling. TGF-β1 increased the accumulation of Smad3 in the nuclear region (immunofluorescence assay) and promoted the enrichment of Smad3 at the binding sites of the promoters of Gja1 (Cx43) and Panx1 (ChIP assay), thereby initiating the enhanced gene expression. These results provide a deep understanding of the molecular mechanisms involved in the modulation of cell–cell communication in osteocytes induced by TGF-β1.

Bacterial Quorum Sensing During Infection

2020 ◽  
Vol 74 (1) ◽  
pp. 201-219 ◽  
Author(s):  
Sheyda Azimi ◽  
Alexander D. Klementiev ◽  
Marvin Whiteley ◽  
Stephen P. Diggle
Keyword(s):  
Quorum Sensing ◽  
Bacterial Infections ◽  
Pathogenic Bacteria ◽  
Human Infection ◽  
Future Research ◽  
Virulence Determinants ◽  
Plant Laboratory ◽  
Bacterial Quorum Sensing ◽  
Bacterial Quorum

Bacteria are highly interactive and possess an extraordinary repertoire of intercellular communication and social behaviors, including quorum sensing (QS). QS has been studied in detail at the molecular level, so mechanistic details are well understood in many species and are often involved in virulence. The use of different animal host models has demonstrated QS-dependent control of virulence determinants and virulence in several human pathogenic bacteria. QS also controls virulence in several plant pathogenic species. Despite the role QS plays in virulence during animal and plant laboratory-engineered infections, QS mutants are frequently isolated from natural infections, demonstrating that the function of QS during infection and its role in pathogenesis remain poorly understood and are fruitful areas for future research. We discuss the role of QS during infection in various organisms and highlight approaches to better understand QS during human infection. This is an important consideration in an era of growing antimicrobial resistance, when we are looking for new ways to target bacterial infections.

scholarly journals Erratum: A cell-cell communication signal integrates quorum sensing and stress response

2013 ◽  
Vol 9 (6) ◽  
pp. 406-406
Author(s):  
Jasmine Lee ◽  
Jien Wu ◽  
Yinyue Deng ◽  
Jing Wang ◽  
Chao Wang ◽  
...  
Keyword(s):  
Stress Response ◽  
Quorum Sensing ◽  
Cell Communication ◽  
Communication Signal ◽  
A Cell ◽  
Cell Cell

scholarly journals LitR of Vibrio salmonicida Is a Salinity-Sensitive Quorum-Sensing Regulator of Phenotypes Involved in Host Interactions and Virulence

2012 ◽  
Vol 80 (5) ◽  
pp. 1681-1689 ◽  
Author(s):  
Ane Mohn Bjelland ◽  
Henning Sørum ◽  
Daget Ayana Tegegne ◽  
Hanne C. Winther-Larsen ◽  
Nils Peder Willassen ◽  
...  
Keyword(s):  
Quorum Sensing ◽  
Biofilm Formation ◽  
Molecular Mechanisms ◽  
Cold Water ◽  
Bacterial Species ◽  
Cell Communication ◽  
Cell Aggregation ◽  
Fish Host ◽  
Content Type ◽  
Vibrio Salmonicida

ABSTRACTVibrio(Aliivibrio)salmonicidais the causal agent of cold-water vibriosis, a fatal bacterial septicemia primarily of farmed salmonid fish. The molecular mechanisms of invasion, colonization, and growth ofV. salmonicidain the host are still largely unknown, and few virulence factors have been identified. Quorum sensing (QS) is a cell-to-cell communication system known to regulate virulence and other activities in several bacterial species. The genome ofV. salmonicidaLFI1238 encodes products presumably involved in several QS systems. In this study, the gene encoding LitR, a homolog of the master regulator of QS inV. fischeri, was deleted. Compared to the parental strain, thelitRmutant showed increased motility, adhesion, cell-to-cell aggregation, and biofilm formation. Furthermore, thelitRmutant produced less cryptic bioluminescence, whereas production of acylhomoserine lactones was unaffected. Our results also indicate a salinity-sensitive regulation of LitR. Finally, reduced mortality was observed in Atlantic salmon infected with thelitRmutant, implying that the fish were more susceptible to infection with the wild type than with the mutant strain. We hypothesize that LitR inhibits biofilm formation and favors planktonic growth, with the latter being more adapted for pathogenesis in the fish host.

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