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Nature Reviews. Microbiology Jun 2019Quorum sensing is a process of bacterial cell-to-cell chemical communication that relies on the production, detection and response to extracellular signalling molecules... (Review)
Review
Quorum sensing is a process of bacterial cell-to-cell chemical communication that relies on the production, detection and response to extracellular signalling molecules called autoinducers. Quorum sensing allows groups of bacteria to synchronously alter behaviour in response to changes in the population density and species composition of the vicinal community. Quorum-sensing-mediated communication is now understood to be the norm in the bacterial world. Elegant research has defined quorum-sensing components and their interactions, for the most part, under ideal and highly controlled conditions. Indeed, these seminal studies laid the foundations for the field. In this Review, we highlight new findings concerning how bacteria deploy quorum sensing in realistic scenarios that mimic nature. We focus on how quorums are detected and how quorum sensing controls group behaviours in complex and dynamically changing environments such as multi-species bacterial communities, in the presence of flow, in 3D non-uniform biofilms and in hosts during infection.
Topics: Bacterial Physiological Phenomena; Biofilms; Host Microbial Interactions; Microbiota; Quorum Sensing
PubMed: 30944413
DOI: 10.1038/s41579-019-0186-5 -
Brazilian Journal of Microbiology :... Dec 2021The assembly of microorganisms over a surface and their ability to develop resistance against available antibiotics are major concerns of interest. To survive against... (Review)
Review
The assembly of microorganisms over a surface and their ability to develop resistance against available antibiotics are major concerns of interest. To survive against harsh environmental conditions including known antibiotics, the microorganisms form a unique structure, referred to as biofilm. The mechanism of biofilm formation is triggered and regulated by quorum sensing, hostile environmental conditions, nutrient availability, hydrodynamic conditions, cell-to-cell communication, signaling cascades, and secondary messengers. Antibiotic resistance, escape of microbes from the body's immune system, recalcitrant infections, biofilm-associated deaths, and food spoilage are some of the problems associated with microbial biofilms which pose a threat to humans, veterinary, and food processing sectors. In this review, we focus in detail on biofilm formation, its architecture, composition, genes and signaling cascades involved, and multifold antibiotic resistance exhibited by microorganisms dwelling within biofilms. We also highlight different physical, chemical, and biological biofilm control strategies including those based on plant products. So, this review aims at providing researchers the knowledge regarding recent advances on the mechanisms involved in biofilm formation at the molecular level as well as the emergent method used to get rid of antibiotic-resistant and life-threatening biofilms.
Topics: Anti-Bacterial Agents; Bacterial Physiological Phenomena; Biofilms; Drug Resistance, Microbial; Quorum Sensing
PubMed: 34558029
DOI: 10.1007/s42770-021-00624-x -
Future Medicinal Chemistry 2015Biofilms are communities of microorganisms that are attached to a surface and play a significant role in the persistence of bacterial infections. Bacteria within a... (Review)
Review
Biofilms are communities of microorganisms that are attached to a surface and play a significant role in the persistence of bacterial infections. Bacteria within a biofilm are several orders of magnitude more resistant to antibiotics, compared with planktonic bacteria. Thus far, no drugs are in clinical use that specifically target bacterial biofilms. This is probably because until recently the molecular details of biofilm formation were poorly understood. Bacteria integrate information from the environment, such as quorum-sensing autoinducers and nutrients, into appropriate biofilm-related gene expression, and the identity of the key players, such as cyclic dinucleotide second messengers and regulatory RNAs are beginning to be uncovered. Herein, we highlight the current understanding of the processes that lead to biofilm formation in many bacteria.
Topics: Anti-Infective Agents; Bacterial Infections; Biofilms; Drug Resistance, Microbial; Humans; Quorum Sensing
PubMed: 25875875
DOI: 10.4155/fmc.15.6 -
MBio May 2018Many bacteria use a cell-cell communication system called quorum sensing to coordinate population density-dependent changes in behavior. Quorum sensing involves... (Review)
Review
Many 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.
Topics: Animals; Bacteria; Bacterial Infections; Bacterial Physiological Phenomena; Humans; Microbial Interactions; Quorum Sensing
PubMed: 29789364
DOI: 10.1128/mBio.02331-17 -
Nature Nov 2017This Review highlights how we can build upon the relatively new and rapidly developing field of research into bacterial quorum sensing (QS). We now have a depth of... (Review)
Review
This Review highlights how we can build upon the relatively new and rapidly developing field of research into bacterial quorum sensing (QS). We now have a depth of knowledge about how bacteria use QS signals to communicate with each other and to coordinate their activities. In recent years there have been extraordinary advances in our understanding of the genetics, genomics, biochemistry, and signal diversity of QS. We are beginning to understand the connections between QS and bacterial sociality. This foundation places us at the beginning of a new era in which researchers will be able to work towards new medicines to treat devastating infectious diseases, and use bacteria to understand the biology of sociality.
Topics: Animals; Bacteria; Bacterial Infections; Biofilms; Ecosystem; Humans; Phylogeography; Quorum Sensing; Research
PubMed: 29144467
DOI: 10.1038/nature24624 -
Molecules (Basel, Switzerland) Mar 2020Antimicrobial resistance represents an enormous global health crisis and one of the most serious threats humans face today. Some bacterial strains have acquired... (Review)
Review
Antimicrobial resistance represents an enormous global health crisis and one of the most serious threats humans face today. Some bacterial strains have acquired resistance to nearly all antibiotics. Therefore, new antibacterial agents are crucially needed to overcome resistant bacteria. In 2017, the World Health Organization (WHO) has published a list of antibiotic-resistant priority pathogens, pathogens which present a great threat to humans and to which new antibiotics are urgently needed the list is categorized according to the urgency of need for new antibiotics as critical, high, and medium priority, in order to guide and promote research and development of new antibiotics. The majority of the WHO list is Gram-negative bacterial pathogens. Due to their distinctive structure, Gram-negative bacteria are more resistant than Gram-positive bacteria, and cause significant morbidity and mortality worldwide. Several strategies have been reported to fight and control resistant Gram-negative bacteria, like the development of antimicrobial auxiliary agents, structural modification of existing antibiotics, and research into and the study of chemical structures with new mechanisms of action and novel targets that resistant bacteria are sensitive to. Research efforts have been made to meet the urgent need for new treatments; some have succeeded to yield activity against resistant Gram-negative bacteria by deactivating the mechanism of resistance, like the action of the β-lactamase Inhibitor antibiotic adjuvants. Another promising trend was by referring to nature to develop naturally derived agents with antibacterial activity on novel targets, agents such as bacteriophages, DCAP(2-((3-(3,6-dichloro-9-carbazol-9-yl)-2-hydroxypropyl)amino)-2(hydroxymethyl)propane1,3-diol, Odilorhabdins (ODLs), peptidic benzimidazoles, quorum sensing (QS) inhibitors, and metal-based antibacterial agents.
Topics: Anti-Bacterial Agents; Gram-Negative Bacteria; Humans; Microbial Sensitivity Tests; Patient Education as Topic; Quorum Sensing
PubMed: 32187986
DOI: 10.3390/molecules25061340 -
Proceedings of the National Academy of... Oct 2013Quorum sensing is a chemical communication process that bacteria use to regulate collective behaviors. Disabling quorum-sensing circuits with small molecules has been...
Quorum sensing is a chemical communication process that bacteria use to regulate collective behaviors. Disabling quorum-sensing circuits with small molecules has been proposed as a potential strategy to prevent bacterial pathogenicity. The human pathogen Pseudomonas aeruginosa uses quorum sensing to control virulence and biofilm formation. Here, we analyze synthetic molecules for inhibition of the two P. aeruginosa quorum-sensing receptors, LasR and RhlR. Our most effective compound, meta-bromo-thiolactone (mBTL), inhibits both the production of the virulence factor pyocyanin and biofilm formation. mBTL also protects Caenorhabditis elegans and human lung epithelial cells from killing by P. aeruginosa. Both LasR and RhlR are partially inhibited by mBTL in vivo and in vitro; however, RhlR, not LasR, is the relevant in vivo target. More potent antagonists do not exhibit superior function in impeding virulence. Because LasR and RhlR reciprocally control crucial virulence factors, appropriately tuning rather than completely inhibiting their activities appears to hold the key to blocking pathogenesis in vivo.
Topics: Animals; Bacterial Proteins; Biofilms; Caenorhabditis elegans; Cell Line; Escherichia coli; Humans; Lactones; Microarray Analysis; Molecular Structure; Pseudomonas aeruginosa; Pyocyanine; Quorum Sensing; Respiratory Mucosa; Sulfur Compounds; Trans-Activators; Virulence
PubMed: 24143808
DOI: 10.1073/pnas.1316981110 -
Cell Jan 2019Vibrio cholerae uses a quorum-sensing (QS) system composed of the autoinducer 3,5-dimethylpyrazin-2-ol (DPO) and receptor VqmA (VqmA), which together repress genes for...
Vibrio cholerae uses a quorum-sensing (QS) system composed of the autoinducer 3,5-dimethylpyrazin-2-ol (DPO) and receptor VqmA (VqmA), which together repress genes for virulence and biofilm formation. vqmA genes exist in Vibrio and in one vibriophage, VP882. Phage-encoded VqmA (VqmA) binds to host-produced DPO, launching the phage lysis program via an antirepressor that inactivates the phage repressor by sequestration. The antirepressor interferes with repressors from related phages. Like phage VP882, these phages encode DNA-binding proteins and partner antirepressors, suggesting that they, too, integrate host-derived information into their lysis-lysogeny decisions. VqmA activates the host VqmA regulon, whereas VqmA cannot induce phage-mediated lysis, suggesting an asymmetry whereby the phage influences host QS while enacting its own lytic-lysogeny program without interference. We reprogram phages to activate lysis in response to user-defined cues. Our work shows that a phage, causing bacterial infections, and V. cholerae, causing human infections, rely on the same signal molecule for pathogenesis.
Topics: Bacteriophages; Biofilms; DNA-Binding Proteins; Gene Expression Regulation, Bacterial; Lysogeny; Pyrazoles; Quorum Sensing; Vibrio; Vibrio cholerae; Virulence; Virus Latency
PubMed: 30554875
DOI: 10.1016/j.cell.2018.10.059 -
ELife Jul 2022A new model helps to predict under which conditions a species of bacteria will switch to a static lifestyle.
A new model helps to predict under which conditions a species of bacteria will switch to a static lifestyle.
Topics: Bacteria; Biofilms; Quorum Sensing
PubMed: 35861322
DOI: 10.7554/eLife.80891 -
Purinergic Signalling Jun 2022Quorum sensing indicates a communication process between bacteria based on a coordinate variation in gene expression aimed at coordinating a collective comportment...
Quorum sensing indicates a communication process between bacteria based on a coordinate variation in gene expression aimed at coordinating a collective comportment related to the bacterial population density. Increasing pieces of evidence pointed out that a quorum-sensing system can be a regulatory program also used in the immune field to organize the density of the various immune cell populations and to calibrate their responses. In particular, such equilibrium is achieved by the ability of immune cells to perceive the density of their own populations or those of other cells in their environment, through the release of several mediators able to finely shape the cell density via coordinated changes in gene expression and protein signaling. In this regard, adenosine displays the typical characteristics of a mediator involved in the regulation of quorum sensing, thus suggesting a putative role of this nucleoside in shaping the balance between diverse immune cell populations.
Topics: Adenosine; Quorum Sensing; Signal Transduction
PubMed: 35501535
DOI: 10.1007/s11302-022-09866-2