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Quorum sensing

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https://www.readbyqxmd.com/read/28636078/microbial-lipopeptide-production-and-purification-bioprocesses-current-progress-and-future-challenges
#1
REVIEW
François Coutte, Didier Lecouturier, Krasimir Dimitrov, Jean-Sébastien Guez, Frank Delvigne, Pascal Dhulster, Philippe Jacques
Lipopeoptides are amphiphilic compounds combining interesting physicochemical properties and biological activities. Due to their high foaming capacity in aerated bioreactor, the development of scalable bioprocesses for their production is a major bottleneck. In addition, the genes involved in the biosynthesis of these lipopeptides are mainly regulated by the quorum sensing, a global regulatory mechanism depending on cell density and known to be activated in biofilms. Several approaches have thus been considered in literature taking into account two criteria, on one side, to favor, control or avoid foam formation and on the other side, to use planktonic or immobilized (biofilm) cells...
June 21, 2017: Biotechnology Journal
https://www.readbyqxmd.com/read/28634237/the-pseudomonas-aeruginosa-psl-polysaccharide-is-a-social-but-noncheatable-trait-in-biofilms
#2
Yasuhiko Irie, Aled E L Roberts, Kasper N Kragh, Vernita D Gordon, Jaime Hutchison, Rosalind J Allen, Gavin Melaugh, Thomas Bjarnsholt, Stuart A West, Stephen P Diggle
Extracellular polysaccharides are compounds secreted by microorganisms into the surrounding environment, and they are important for surface attachment and maintaining structural integrity within biofilms. The social nature of many extracellular polysaccharides remains unclear, and it has been suggested that they could function as either cooperative public goods or as traits that provide a competitive advantage. Here, we empirically tested the cooperative nature of the PSL polysaccharide, which is crucial for the formation of biofilms in Pseudomonas aeruginosa We show that (i) PSL is not metabolically costly to produce; (ii) PSL provides population-level benefits in biofilms, for both growth and antibiotic tolerance; (iii) the benefits of PSL production are social and are shared with other cells; (iv) the benefits of PSL production appear to be preferentially directed toward cells which produce PSL; (v) cells which do not produce PSL are unable to successfully exploit cells which produce PSL...
June 20, 2017: MBio
https://www.readbyqxmd.com/read/28633201/rapid-start-up-of-denitrifying-granular-sludge-by-dosing-with-semi-starvation-fluctuation-c-n-ratio-strategy
#3
Wenyu Niu, Jianbo Guo, Jing Lian, Yuanyuan Song, Caicai Lu, Haibo Li, Yi Han, Pengna Yin
This study cultivated denitrifying granular sludge in three UASB reactors by the semi-starvation fluctuation C/N ratio strategy (reactor 1 (R1): constant C/N ratio; R2: regular fluctuation C/N ratio; and R3: semi-starvation fluctuation C/N ratio (SSF)). Microbial aggregates appeared in R1, R2 and R3 on days 28, 14 and 6, respectively. Compared with the results in R1 and R2, the guanosine tetraphosphate (ppGpp) concentration was highest, the acyl homoserine lactones (AHLs) concentration quickly reached a certain threshold, and more protein (PN) of extracellular polymeric substances (EPS) secretion resulted in the rapid formation of denitrifying granular sludge in R3...
June 1, 2017: Bioresource Technology
https://www.readbyqxmd.com/read/28630204/a-low-molecular-weight-alginate-oligosaccharide-disrupts-pseudomonal-microcolony-formation-and-enhances-antibiotic-effectiveness
#4
Manon F Pritchard, Lydia C Powell, Alison A Jack, Kate Powell, Konrad Beck, Hannah Florance, Julian Forton, Philip D Rye, Arne Dessen, Katja E Hill, David W Thomas
In chronic respiratory disease the formation of dense, 3-dimensional 'micro colonies' by Pseudomonas aeruginosa within the airway plays an important role in contributing to resistance to treatment. An in vitro biofilm model of pseudomonal microcolony formation using artificial sputum (AS) medium was established to study the effects of low molecular weight alginate oligomers (OligoG CF-5/20) on pseudomonal growth, microcolony formation and the efficacy of colistin. The studies employed clinical cystic fibrosis (CF) isolates (n=3) and reference non-mucoid and mucoid multi-drug resistant (MDR) CF isolates (n=7)...
June 19, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28630071/albumin-inhibits-pseudomonas-aeruginosa-quorum-sensing-and-alters-polymicrobial-interactions
#5
Allie Clinton Smith, Anne Rice, Bryan Sutton, Rebecca Gabrilska, Aimee K Wessel, Marvin Whiteley, Kendra P Rumbaugh
Polymicrobial interactions are complex and can influence the course of an infection, as is the case when two or more species exhibit a synergism that produces a disease state not seen with any of the individual species alone. Cell-to-cell signaling is key to many of these interactions, but little is understood about how the host environment influences polymicrobial interactions or signaling between bacteria. Chronic wounds are typically polymicrobial, with Staphylococcus aureus and Pseudomonas aeruginosa being the two most commonly isolated species...
June 19, 2017: Infection and Immunity
https://www.readbyqxmd.com/read/28627870/encapsulation-of-autoinducer-sensing-reporter-bacteria-in-reinforced-alginate-based-microbeads
#6
Ping Li, Mareike Müller, Matthew Wook Chang, Martin Frettlöh, Holger Schönherr
Quorum sensing, in which bacteria communities use signaling molecules for inter- and intracellular communication, has been intensively studied in recent decades. In order to fabricate highly sensitive easy-to-handle point of care biosensors that detect quorum sensing molecules, we have developed, as is reported here, reporter bacteria entrapped alginate-methacrylate (alginate-MA) hydrogel beads. The alginate-MA beads, which were obtained by electrostatic extrusion, were reinforced by photo-crosslinking to increase stability and thereby to reduce bacteria leaching...
June 19, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28624619/quorum-sensing-signals-enhance-the-electrochemical-activity-and-energy-recovery-of-mixed-culture-electroactive-biofilms
#7
Shanshan Chen, Xianyue Jing, Jiahuan Tang, Yanlun Fang, Shungui Zhou
The impacts of exogenous or endogenous quorum sensing (QS) signaling molecules on mixed-culture electroactive biofilms (EABs), especially extracellular polymeric substances (EPS) and exoelectrogens using direct electron transfer mechanism inside EABs are poorly understood. This research focuses on the influence of acylhomoserine lactones (AHLs), the most common QS signaling molecules for gram negative bacteria, on mixed-culture EABs. Results indicated that both exogenous and endogenous AHLs played the role as regulators to improve the electrochemical activities of EABs...
June 13, 2017: Biosensors & Bioelectronics
https://www.readbyqxmd.com/read/28620784/inhibitory-effect-of-taurine-on-biofilm-formation-during-alkane-degradation-in-acinetobacter-oleivorans-dr1
#8
Hyo Jung Eom, Woojun Park
Taurine, 2-aminoethanesulfonate, is known to function as an antioxidant or membrane stabilizer in eukaryotic cells, but its role in bacteria has been poorly characterized. Biofilm formation of Acinetobacter oleivorans DR1 was significantly reduced by taurine only during alkane degradation, suggesting that taurine affects alkane-induced cell surface. Structurally similar compounds harboring an amine group such as hypotaurine or ethylenediamine have a similar effect, which was not observed with sulfonate-containing chemicals such as ethanesulfonic acid, hexanesulfonic acid...
June 15, 2017: Microbial Ecology
https://www.readbyqxmd.com/read/28613253/terpenoids-from-platostoma-rotundifolium-briq-a-j-paton-alter-the-expression-of-quorum-sensing-related-virulence-factors-and-the-formation-of-biofilm-in-pseudomonas-aeruginosa-pao1
#9
Tsiry Rasamiravaka, Jérémie Ngezahayo, Laurent Pottier, Sofia Oliveira Ribeiro, Florence Souard, Léonard Hari, Caroline Stévigny, Mondher El Jaziri, Pierre Duez
Platostoma rotundifolium (Briq.) A. J. Paton aerial parts are widely used in Burundi traditional medicine to treat infectious diseases. In order to investigate their probable antibacterial activities, crude extracts from P. rotundifolium were assessed for their bactericidal and anti-virulence properties against an opportunistic bacterial model, Pseudomonas aeruginosa PAO1. Whereas none of the tested extracts exert bacteriostatic and/or bactericidal proprieties, the ethyl acetate and dichloromethane extracts exhibit anti-virulence properties against Pseudomonas aeruginosa PAO1 characterized by an alteration in quorum sensing gene expression and biofilm formation without affecting bacterial viability...
June 14, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28612602/oxygen-dependent-globin-coupled-sensor-signaling-modulates-motility-and-virulence-of-the-plant-pathogen-pectobacterium-carotovorum
#10
Justin L Burns, Parth B Jariwala, Shannon Rivera, Benjamin M Fontaine, Laura Briggs, Emily E Weinert
Bacterial pathogens utilize numerous signals to identify the presence of their host and coordinate changes in gene expression that allow for infection. Within plant pathogens, these signals typically include small molecules and/or proteins from their plant hosts and bacterial quorum sensing molecules to ensure sufficient bacterial cell density for successful infection. In addition, bacteria use environmental signals to identify conditions when the host defenses are weakened and potentially to signal entry into an appropriate host/niche for infection...
June 14, 2017: ACS Chemical Biology
https://www.readbyqxmd.com/read/28611251/erratum-for-mund-et-al-the-fitness-of-pseudomonas-aeruginosa-quorum-sensing-signal-cheats-is-influenced-by-the-diffusivity-of-the-environment
#11
Anne Mund, Stephen P Diggle, Freya Harrison
No abstract text is available yet for this article.
June 13, 2017: MBio
https://www.readbyqxmd.com/read/28610994/manganese-induced-sex-specific-gut-microbiome-perturbations-in-c57bl-6-mice
#12
Liang Chi, Bei Gao, Xiaoming Bian, Pengcheng Tu, Hongyu Ru, Kun Lu
Overexposure to manganese (Mn) leads to toxic effects, such as promoting the development of Parkinson's-like neurological disorders. The gut microbiome is deeply involved in immune development, host metabolism, and xenobiotics biotransformation, and significantly influences central nervous system (CNS) via the gut-brain axis, i.e. the biochemical signaling between the gastrointestinal tract and the CNS. However, it remains unclear whether Mn can affect the gut microbiome and its metabolic functions, particularly those linked to neurotoxicity...
June 10, 2017: Toxicology and Applied Pharmacology
https://www.readbyqxmd.com/read/28610927/quorum-sensing-molecule-farnesol-increased-the-production-and-biological-activities-of-extracellular-polysaccharide-from-trametes-versicolor
#13
Ke-Feng Wang, Kun-Yan Sui, Chen Guo, Chun-Zhao Liu
A novel strategy of exposing 2-day-old mycelia cultures to 0.8mM farnesol was developed to stimulate extracellular polysaccharide (EPS) production in Trametes versicolor submerged cultures. Farnesol, a quorum sensing molecule in fungi, could significantly increase EPS production by promoting polysaccharide biosynthesis and regulating mycelial morphology. EPS yield reached a maximum of 2.56g/L that was 2.7-fold greater than that of control cultures. Farnesol made T. versicolor develop into fluffy, loose and multi-hyphae morphology, which facilitated the excretion of intracellular polysaccharide into culture medium...
June 10, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28609183/farnesol-signalling-in-candida-albicans-more-than-just-communication
#14
Melanie Polke, Ines Leonhardt, Oliver Kurzai, Ilse D Jacobsen
Candida albicans is a successful colonizer of the human host, which can, under certain circumstances cause a range of clinically diverse infections. Important virulence-associated traits of the fungus, such as the dimorphic switch and biofilm formation, are controlled by the quorum sensing molecule farnesol. Given the potential of farnesol as a novel antifungal drug, there has been increasing research into the mechanism underlying farnesol sensing and action in C. albicans. However, despite the identification of various factors involved in farnesol signalling, its exact mode of action remains largely unclear...
June 13, 2017: Critical Reviews in Microbiology
https://www.readbyqxmd.com/read/28608866/a-small-wolbachia-protein-directly-represses-phage-lytic-cycle-genes-in-candidatus-liberibacter-asiaticus-within-psyllids
#15
Mukesh Jain, Laura A Fleites, Dean W Gabriel
Huanglongbing (HLB) is a severe disease of citrus caused by an uncultured alphaproteobacterium "Candidatus Liberibacter asiaticus" and transmitted by Asian citrus psyllids (Diaphorina citri). Two prophage genomes, SC1 and SC2, integrated in "Ca. Liberibacter asiaticus" strain UF506 were described previously, and very similar prophages are found resident in the majority of "Ca. Liberibacter asiaticus" strains described worldwide. The SC1 lytic cycle is marked by upregulation of prophage late genes, including a functional holin (SC1_gp110); these late genes are activated when "Ca...
May 2017: MSphere
https://www.readbyqxmd.com/read/28607550/corrigendum-cross-talk-between-staphylococcus-aureus-and-other-staphylococcal-species-via-the-agr-quorum-sensing-system
#16
Jaime Canovas, Mara Baldry, Martin S Bojer, Paal S Andersen, Piotr K Grzeskowiak, Marc Stegger, Peter Damborg, Christian A Olsen, Hanne Ingmer
[This corrects the article on p. 1733 in vol. 7, PMID: 27877157.].
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28607020/targeting-quorum-sensing-signal-biosynthesis-to-fight-antibiotic-resistant-infections-ambuic-acid-as-a-model-inhibitor
#17
Daniel A Todd, Corey P Parlet, Heidi A Crosby, Cheryl L Malone, Kristopher P Heilmann, Alexander R Horswill, Nadja B Cech
There has been major interest by the scientific community in anti-virulence approaches against bacterial infections. However, partly due to a lack of viable lead compounds, anti-virulence therapeutics have yet to reach the clinic. Here we investigate the development of an anti-virulence lead targeting quorum sensing signal-biosynthesis, a process that is conserved in Gram positive bacterial pathogens. Some preliminary studies suggest that the small molecule ambuic acid is a signal biosynthesis inhibitor. To confirm this, we construct a methicillin-resistant Staphylococcus aureus (MRSA) strain that decouples AIP production from regulation, and demonstrate that AIP production is inhibited in this mutant...
June 12, 2017: Antimicrobial Agents and Chemotherapy
https://www.readbyqxmd.com/read/28606056/comparative-genome-and-transcriptome-analysis-reveals-distinctive-surface-characteristics-and-unique-physiological-potentials-of-pseudomonas-aeruginosa-atcc-27853
#18
Huiluo Cao, Yong Lai, Salim Bougouffa, Zeling Xu, Aixin Yan
BACKGROUND: Pseudomonas aeruginosa ATCC 27853 was isolated from a hospital blood specimen in 1971 and has been widely used as a model strain to survey antibiotics susceptibilities, biofilm development, and metabolic activities of Pseudomonas spp.. Although four draft genomes of P. aeruginosa ATCC 27853 have been sequenced, the complete genome of this strain is still lacking, hindering a comprehensive understanding of its physiology and functional genome. RESULTS: Here we sequenced and assembled the complete genome of P...
June 12, 2017: BMC Genomics
https://www.readbyqxmd.com/read/28605563/the-contribution-of-pseudomonas-aeruginosa-virulence-factors-and-host-factors-in-the-establishment-of-urinary-tract-infections
#19
J W Newman, R V Floyd, J L Fothergill
Pseudomonas aeruginosa can cause complicated urinary tract infections, particularly in people with catheters, which can lead to pyelonephritis. Whilst some subgroups appear more susceptible to infection, such as the elderly and women, the contribution of other host factors and bacterial virulence factors to successful infection remains relatively understudied. In this review, we explore the potential role of P. aeruginosa virulence factors including phenazines, quorum sensing, biofilm formation, and siderophores along with host factors such as Tamm-Horsfall protein, osmotic stress and iron specifically on establishment of successful infection in the urinary niche...
June 12, 2017: FEMS Microbiology Letters
https://www.readbyqxmd.com/read/28605194/discovery-of-two-bacterial-nitric-oxide-responsive-proteins-and-their-roles-in-bacterial-biofilm-regulation
#20
Sajjad Hossain, Lisa-Marie Nisbett, Elizabeth M Boon
Bacterial biofilms form when bacteria adhere to a surface and produce an exopolysaccharide matrix ( Costerton Science 1999 , 284 , 1318 ; Davies Science 1998 , 280 , 295 ; Flemming Nat. Rev. Microbiol. 2010 , 8 , 623 ). Because biofilms are resistant to antibiotics, they are problematic in many aspects of human health and welfare, causing, for instance, persistent fouling of medical implants such as catheters and artificial joints ( Brunetto Chimia 2008 , 62 , 249 ). They are responsible for chronic infections in the lungs of cystic fibrosis patients and in open wounds, such as those associated with burns and diabetes...
June 12, 2017: Accounts of Chemical Research
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