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https://www.readbyqxmd.com/read/28818490/inhibition-of-quorum-sensing-controlled-biofilm-formation-in-pseudomonas-aeruginosa-by-quorum-sensing-inhibitors
#1
Kalaiarasan Ellappan, Kottha Thirumalaswamy, Belgode Narasimha Harish, Gnanasambandam Vasuki, Veeresh Kumar Sali, James John
Antimicrobial therapy against extensively drug-resistant (XDR) P. aeruginosa biofilms is less efficient compared to the treatment of equal bacterial counts of free-floating planktonic cells, which has become a serious threat in hospital environment. P. aeruginosa regulate their cooperative activities and physiological process through a cell to cell chemical communication process called Quorum sensing (QS). This attracted our interest to synthesize, and to chemically characterize two anti-QS compounds, N-(4-{4-fluoroanilno} butanoyl) -L-homoserine lactone (FABHL) and N-(4-{4-chlororoanilno} butanoyl) -L-homoserine lactone (CABHL) to inhibit biofilm formation via disabling the QS circuits...
August 14, 2017: Microbial Pathogenesis
https://www.readbyqxmd.com/read/28810631/hyperoside-inhibits-biofilm-formation-of-pseudomonas-aeruginosa
#2
Yixuan Sun, Fengjun Sun, Wei Feng, Xuewen Qiu, Yao Liu, Bo Yang, Yongchuan Chen, Peiyuan Xia
Pseudomonas aeruginosa (P. aeruginosa) is a common pathogen in hospital-acquired infection and is readily able to form biofilms. Due to its high antibiotic resistance, traditional antibacterial treatments exert a limited effect on P. aeruginosa biofilm infections. It has been indicated that hyperoside inhibits P. aeruginosa PAO1 (PAO1) biofilm formation without affecting growth. Therefore, the current study examined the biofilm formation and quorum sensing (QS) system of PAO1 in the presence of hyperoside. Confocal laser scanning microscopy analysis demonstrated that hyperoside significantly inhibited biofilm formation...
August 2017: Experimental and Therapeutic Medicine
https://www.readbyqxmd.com/read/28799693/the-small-rna-real-a-novel-regulatory-element-embedded-in-the-pseudomonas-aeruginosa-quorum-sensing-networks
#3
Sara Carloni, Raffaella Macchi, Sara Sattin, Silvia Ferrara, Giovanni Bertoni
The small RNA ReaL of the opportunistic pathogen Pseudomonas aeruginosa has been characterized. Our results indicate that ReaL contributes to P. aeruginosa virulence. In the Galleria mellonella infection model, reaL gene deletion resulted in decreased virulence, while ReaL overexpression resulted in a hyper-virulent phenotype. We also demonstrate that ReaL is embedded in the P. aeruginosa quorum sensing (QS) with the role of linking las to pqs systems. We show that ReaL is negatively regulated by the las regulator LasR and impacts positively the synthesis of the pqs quinolone signal PQS by a positive post-transcriptional effect on the pqsC gene...
August 11, 2017: Environmental Microbiology
https://www.readbyqxmd.com/read/28798903/anti-quorum-sensing-and-anti-biofilm-activity-of-delftia-tsuruhatensis-extract-by-attenuating-the-quorum-sensing-controlled-virulence-factor-production-in-pseudomonas-aeruginosa
#4
Vijay K Singh, Avinash Mishra, Bhavanath Jha
Multidrug-resistance bacteria commonly use cell-to-cell communication that leads to biofilm formation as one of the mechanisms for developing resistance. Quorum sensing inhibition (QSI) is an effective approach for the prevention of biofilm formation. A Gram-negative bacterium, Delftia tsuruhatensis SJ01, was isolated from the rhizosphere of a species of sedge (Cyperus laevigatus) grown along the coastal-saline area. The isolate SJ01 culture and bacterial crude extract showed QSI activity in the biosensor plate containing the reference strain Chromobacterium violaceum CV026...
2017: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/28792229/eugenol-exhibits-anti-virulence-properties-by-competitively-binding-to-quorum-sensing-receptors
#5
Prasanth Rathinam, H S Vijay Kumar, Pragasam Viswanathan
The primary objective of this study was to ascertain the anti-biofilm and anti-virulence properties of sub-minimum inhibitory concentration (MIC) levels of eugenol against the standard strain PAO1 and two multi-drug resistant P. aeruginosa clinical isolates utilizing quorum sensing inhibition (QSI). Eugenol at 400 μM significantly reduced biofilm formation on urinary catheters and the virulence factors (VF) including extracellular polysaccharides, rhamnolipid, elastase, protease, pyocyanin, and pyoverdine (p < 0...
August 9, 2017: Biofouling
https://www.readbyqxmd.com/read/28738346/synergistic-activity-of-berberine-with-azithromycin-against-pseudomonas-aeruginosa-isolated-from-patients-with-cystic-fibrosis-of-lung-in-vitro-and-in-vivo
#6
YongTao Li, JianRong Huang, LanJuan Li, LinSheng Liu
BACKGROUND/AIMS: Pseudomonas aeruginosa (PA) is one of the major opportunistic pathogens which can cause chronic lung infection of cystic fibrosis (CF). The formation of PA biofilm promotes CF development and restricts the antimicrobial efficacies of current antibiotics. METHODS: The antimicrobial effects of azithromycin (AZM) and berberine (BER) alone and in combination were evaluated using microdilution method, checkerboard assay, time-kill test, qRT-PCR analysis and absorption method...
July 24, 2017: Cellular Physiology and Biochemistry
https://www.readbyqxmd.com/read/28729210/deficiency-of-quorum-sensing-system-inhibits-the-resistance-selection-of-pseudomonas-aeruginosa-to-ciprofloxacin-and-levofloxacin-in-vitro
#7
Yating Gao, Jinju Duan, Xin Geng, Zhiqi Zhang, Ruiqin Zhang, Xiaoxia Li, Shuyun Wang, Jianbang Kang, Donghong Yin, Yan Song
OBJECTIVES: The objective was to investigate how deficient of quorum sensing system (QS) affects minimal inhibitory concentrations (MICs) of Pseudomonas aeruginosa strains to ciprofloxacin (CIP) and levofloxacin (LEV) in vitro. METHODS: Collected the clinical Pseudomonas aeruginosa isolates. Screened the strains deficient of QS genes by the PCR agarose electrophoresis, and then randomly picked out normal strains with the same number of deficient ones. All strains incubated on the different CIP-concentration Mueller-Hinton agars for five days, the different concentrations of CIP respectively refered to 0...
July 17, 2017: Journal of Global Antimicrobial Resistance
https://www.readbyqxmd.com/read/28712963/anti-quorum-sensing-activity-of-pistacia-atlantica-against-pseudomonas-aeruginosa-pao1-and-identification-of-its-bioactive-compounds
#8
H Kordbacheh, F Eftekhar, S N Ebrahimi
Pseudomonas aeruginosa is a multidrug resistant opportunistic pathogen and an important cause of nosocomial infections. Quorum-sensing (QS) is a process in which bacterial cell-cell communication can regulates production of many virulence factors including pigment formation and the ability to form biofilm which is essential for establishment of chronic infections. We examined the inhibitory effect of Pistacia atlantica (Anacardiaceae) methanolic leaf extract and its bioactive components on biofilm formation and pigment production by P...
July 14, 2017: Microbial Pathogenesis
https://www.readbyqxmd.com/read/28708999/splicing-activation-by-rbfox-requires-self-aggregation-through-its-tyrosine-rich-domain
#9
Yi Ying, Xiao-Jun Wang, Celine K Vuong, Chia-Ho Lin, Andrey Damianov, Douglas L Black
Proteins of the Rbfox family act with a complex of proteins called the Large Assembly of Splicing Regulators (LASR). We find that Rbfox interacts with LASR via its C-terminal domain (CTD), and this domain is essential for its splicing activity. In addition to LASR recruitment, a low-complexity (LC) sequence within the CTD contains repeated tyrosines that mediate higher-order assembly of Rbfox/LASR and are required for splicing activation by Rbfox. This sequence spontaneously aggregates in solution to form fibrous structures and hydrogels, suggesting an assembly similar to the insoluble cellular inclusions formed by FUS and other proteins in neurologic disease...
July 13, 2017: Cell
https://www.readbyqxmd.com/read/28698104/pseudomonas-aeruginosa-quorum-sensing-modulates-immune-responses-an-updated-review-article
#10
REVIEW
Ashraf Kariminik, Majid Baseri-Salehi, Babak Kheirkhah
Pseudomonas aeruginosa is an opportunistic bacterium which induces some complications in immunocompromised patients. Pseudomonas aeruginosa is a quorum-sensing using bacterium which regulates its genes expression. The bacterium uses two famous pathways for quorum sensing entitled LasI/LasR and RhlI/RhlR systems. It has been documented that the bacteria which use quorum sensing are able to overcome immune responses. This review article aims to present recent information regarding the effects of Pseudomonas aeruginosa quorum sensing systems on the host immune responses...
July 8, 2017: Immunology Letters
https://www.readbyqxmd.com/read/28686323/exploration-of-phytoconstituents-from-mussaenda-roxburghii-and-studies-of-their-antibiofilm-effect
#11
Ranjit Ghosh, Manash C Das, Arpita Sarkar, Antu Das, Padmani Sandhu, Biswanath Dinda, Yusuf Akhter, Surajit Bhattacharjee, Utpal Ch De
In the context of ethno botanical importance with no phytochemical investigations, Mussaenda roxburghii have been investigated to explore it's phytoconstituents and studies of their antibiofilm activity. Four compounds have been isolated from the aerial parts of this plant and were characterized as 2α, 3β, 19α, 23-tetrahydroxyurs-12-en-28-oic acid (1), β-sitosterol glucoside (4), lupeol palmitate (5) and myoinositol (6). All these compounds were tested for antibacterial and antibiofilm activity against Pseudomonas aeruginosa...
July 7, 2017: Chemistry & Biodiversity
https://www.readbyqxmd.com/read/28627870/encapsulation-of-autoinducer-sensing-reporter-bacteria-in-reinforced-alginate-based-microbeads
#12
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 loaded alginate-methacrylate (alginate-MA) hydrogel beads. The alginate-MA beads, which were obtained by electrostatic extrusion, were reinforced by photo-cross-linking to increase stability and thereby to reduce bacteria leaching...
July 12, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/28591849/pseudomonas-aeruginosa-quorum-sensing-response-in-the-absence-of-functional-lasr-and-lasi-proteins-the-case-of-strain-148-a-virulent-dolphin-isolate
#13
Estefanía Morales, Abigail González-Valdez, Luis Servín-González, Gloria Soberón-Chávez
Pseudomonas aeruginosa is an opportunistic pathogen that presents a complex regulatory network called 'quorum-sensing', which is responsible for the transcription of genes coding for several traits implicated in its pathogenicity. Strain 148 is a dolphin-isolate that has been shown to produce quorum-sensing regulated virulence-traits and to be virulent in a mouse model, despite the fact that it contains a 20 kbp deletion that eliminates from the chromosome the lasR gene and the lasI promoter. LasR is a key quorum-sensing transcriptional regulator that, when coupled with the autoinducer 3-oxo-dodecanoyl homoserine lactone (3O-C12-HSL) produced by LasI, activates transcription of genes coding for some virulence-associated traits such as elastase, lasI, rhlI and rhlR...
June 7, 2017: FEMS Microbiology Letters
https://www.readbyqxmd.com/read/28591665/inhibition-of-pseudomonas-aeruginosa-quorum-sensing-by-subinhibitory-concentrations-of-curcumin-with-gentamicin-and-azithromycin
#14
Shahin Bahari, Habib Zeighami, Hesam Mirshahabi, Shekoufeh Roudashti, Fakhri Haghi
OBJECTIVES: Pseudomonas aeruginosa quorum sensing (QS) circuits regulate virulence factors and co-ordinate bacterial pathogenicity. This study aimed to investigate the inhibitory activity of subinhibitory concentrations of curcumin with azithromycin and gentamicin against P. aeruginosa QS-related genes and virulence factors. METHODS: The minimum inhibitory concentrations (MICs) and synergistic activity of curcumin with azithromycin and gentamicin against P. aeruginosa PAO1 were determined using broth microdilution and checkerboard titration methods, respectively...
June 4, 2017: Journal of Global Antimicrobial Resistance
https://www.readbyqxmd.com/read/28527130/pulse-generation-in-the-quorum-machinery-of-pseudomonas-aeruginosa
#15
Cicik Alfiniyah, Martin A Bees, A Jamie Wood
Pseudomonas aeruginosa is a Gram-negative bacterium that is responsible for a wide range of infections in humans. Colonies employ quorum sensing (QS) to coordinate gene expression, including for virulence factors, swarming motility and complex social traits. The QS signalling system of P. aeruginosa is known to involve multiple control components, notably the las, rhl and pqs systems. In this paper, we examine the las system and, in particular, the repressive interaction of rsaL, an embedded small regulative protein, employing recent biochemical information to aid model construction...
June 2017: Bulletin of Mathematical Biology
https://www.readbyqxmd.com/read/28494227/spontaneous-quorum-sensing-mutation-modulates-electroactivity-of-pseudomonas-aeruginosa-pa14
#16
Carola Berger, Miriam A Rosenbaum
Pseudomonas aeruginosa is able to interact with the anode of a bioelectrochemical system through redox active phenazines. Earlier studies showed that this interaction is strain and carbon source dependent. With a spontaneously formed ΔlasR mutant of P. aeruginosa PA14 and the wildtype, we investigated the connection between the complex quorum sensing network and current production. Depending on the carbon source, phenazine production and subsequently current generation are effected differently in these two populations...
October 2017: Bioelectrochemistry
https://www.readbyqxmd.com/read/28486805/isolated-reporter-bacteria-in-supramolecular-hydrogel-microwell-arrays
#17
Ping Li, Xiaoqiu Dou, Chuanliang Feng, Mareike Müller, Matthew Wook Chang, Martin Frettlöh, Holger Schönherr
The combination of supramolecular hydrogels formed by low molecular weight gelator self-assembly via noncovalent interactions within a scaffold derived from polyethylene glycol (PEG) affords an interesting approach to immobilize fully functional, isolated reporter bacteria in novel microwell arrays. The PEG-based scaffold serves as a stabilizing element and provides physical support for the self-assembly of the C2-phenyl-derived gelator on the micrometer scale. Supramolecular hydrogel microwell arrays with various shapes and sizes were used to isolate single or small numbers of Escherichia coli TOP10 pTetR-LasR-pLuxR-GFP...
May 31, 2017: Langmuir: the ACS Journal of Surfaces and Colloids
https://www.readbyqxmd.com/read/28479904/glyceryl-trinitrate-is-a-novel-inhibitor-of-quorum-sensing-in-pseudomonas-aeruginosa
#18
Hisham A Abbas, Moutaz A Shaldam
BACKGROUND: Targeting quorum sensing is an alternative approach to antibiotics.Targeting quorum sensing-regulated virulence will disarm the pathogen without exerting pressure on its growth. As a result, emergence of resistance is avoided and the immune system can easily eradicate bacteria. OBJECTIVES: Investigation of the possible inhibition of quorum sensing-regulated virulence of Pseudomonas aeruginosa by glyceryltrinitrate. METHODS: The quorum sensing inhibiting activity of glyceryl trinitrate was assessed by inhibition of violacein production in Chromobacterium violaceum ATCC 12472...
December 2016: African Health Sciences
https://www.readbyqxmd.com/read/28466892/the-multi-output-incoherent-feedforward-loop-constituted-by-the-transcriptional-regulators-lasr-and-rsal-confers-robustness-to-a-subset-of-quorum-sensing-genes-in-pseudomonas-aeruginosa
#19
Roslen Bondí, Francesca Longo, Marco Messina, Francesca D'Angelo, Paolo Visca, Livia Leoni, Giordano Rampioni
Quorum sensing (QS) is an intercellular communication system which controls virulence-related phenotypes in the human pathogen Pseudomonas aeruginosa. LasR is the QS receptor protein which responds to the signal molecule N-(3-oxododecanoyl)homoserine lactone (3OC12-HSL) and promotes signal production by increasing the transcription of the 3OC12-HSL synthase gene, lasI. LasR also activates the expression of other genes, including rsaL, coding for the RsaL protein which acts as a transcriptional repressor of lasI...
May 3, 2017: Molecular BioSystems
https://www.readbyqxmd.com/read/28454561/a-comprehensive-multi-omics-approach-uncovers-adaptations-for-growth-and-survival-of-pseudomonas-aeruginosa-on-n-alkanes
#20
Sarah L Grady, Stephanie A Malfatti, Thusitha S Gunasekera, Brian K Dalley, Matt G Lyman, Richard C Striebich, Michael B Mayhew, Carol L Zhou, Oscar N Ruiz, Larry C Dugan
BACKGROUND: Examination of complex biological systems has long been achieved through methodical investigation of the system's individual components. While informative, this strategy often leads to inappropriate conclusions about the system as a whole. With the advent of high-throughput "omic" technologies, however, researchers can now simultaneously analyze an entire system at the level of molecule (DNA, RNA, protein, metabolite) and process (transcription, translation, enzyme catalysis)...
April 28, 2017: BMC Genomics
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