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"quorum sensing inhibition", "pseudomonas aeruginosa"

Israel Castillo-Juarez, Luis Esaú López-Jácome, Gloria Soberón-Chávez, María Tomás, Jintae Lee, Paulina Castañeda-Tamez, Iván Ángelo Hernández-Bárragan, Martha Yumiko Cruz-Muñiz, Toshinari Maeda, Thomas K Wood, Rodolfo García-Contreras
Pseudomonas aeruginosa and Acinetobacter baumannii are two of the main bacteria responsible for nosocomial infections; both organisms are resistant to several classes of antibiotics making their infections very difficult to treat. Moreover, they possess a remarkable ability to form biofilms, which further enhances their antimicrobial resistance. Both organisms coordinate their formation of biofilms and their expression of virulence factors through quorum sensing, a system that regulates gene expression at high cell densities and that plays a key role in the establishment of bacterial infections...
January 5, 2017: Current Topics in Medicinal Chemistry
Sivaramakrishnan Subramaniyan, Sasikumar Divyasree, Girija Sadasivan Sandhia
BACKGROUND: Quorum sensing or the bacterial information flow in an orchestrated manner is an essential feature of many pathogenic bacteria. Quorum quenching molecules (QQ) can inhibit the growth of such bacteria. OBJECTIVE: The purpose of this study is to evaluate the potential of plant extracts as quorum quenchers and monitor the recent patents. METHODS: Many available reports and patents are on synthetic ligand molecules or even compounds isolated from cyanobacteria (Honaucin A) and other microorganisms inhibiting quorum sensing molecules...
2016: Recent Patents on Biotechnology
Barış Gökalsın, Nüzhet Cenk Sesal
Cystic Fibrosis is a genetic disease and it affects the respiratory and digestive systems. Pseudomonas aeruginosa infections in Cystic Fibrosis are presented as the main cause for high mortality and morbidity rates. Pseudomonas aeruginosa populations can regulate their virulence gene expressions via the bacterial communication system: quorum sensing. Inhibition of quorum sensing by employing quorum sensing inhibitors can leave the bacteria vulnerable. Therefore, determining natural sources to obtain potential quorum sensing inhibitors is essential...
September 2016: World Journal of Microbiology & Biotechnology
Ramadan Hassan, Mona I Shaaban, Fatma M Abdel Bar, Areej M El-Mahdy, Shadi Shokralla
Quorum sensing (QS) systems communicate bacterial population and stimulate microbial pathogenesis through signaling molecules. Inhibition of QS signals potentially suppresses microbial infections. Antimicrobial properties of Streptomyces have been extensively studied, however, less is known about quorum sensing inhibitory (QSI) activities of Streptomyces. This study explored the QSI potential of Streptomyces isolated from soil. Sixty-five bacterial isolates were purified from soil samples with morphological characteristics of Streptomyces...
2016: Frontiers in Microbiology
Manon Ruffin, Claudia Bilodeau, Émilie Maillé, Shantelle L LaFayette, Geoffrey A McKay, Nguyen Thu Ngan Trinh, Trevor Beaudoin, Martin-Yvon Desrosiers, Simon Rousseau, Dao Nguyen, Emmanuelle Brochiero
Chronic Pseudomonas aeruginosa lung infections are associated with progressive epithelial damage and lung function decline. In addition to its role in tissue injury, the persistent presence of P. aeruginosa-secreted products may also affect epithelial repair ability, raising the need for new antivirulence therapies. The purpose of our study was to better understand the outcomes of P. aeruginosa exoproducts exposure on airway epithelial repair processes to identify a strategy to counteract their deleterious effect...
September 2016: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
Benedict Wu, Joseph Capilato, Michelle P Pham, Jean Walker, Bernd Spur, Ana Rodriguez, Lark J Perez, Kingsley Yin
Bacterial infections can quickly turn into sepsis, with its attendant clinical sequelae of inflammation, tissue injury, and organ failure. Paradoxically, sustained inflammation in sepsis may lead to immune suppression, because of which the host is unable to clear the existing infection. Use of agents that suppress the inflammatory response may accelerate host immune suppression, whereas use of traditional antibiotics does not significantly affect inflammation. In this study, we investigated whether lipoxin A4 (LXA4), a specialized, proresolution lipid mediator, could increase neutrophil phagocytic activity as well as reduce bacterial virulence...
June 2016: FASEB Journal: Official Publication of the Federation of American Societies for Experimental Biology
Wai-Kean Goh, Christopher R Gardner, Kondapalli V G Chandra Sekhar, Nripendra N Biswas, Shashidhar Nizalapur, Scott A Rice, Mark Willcox, David StC Black, Naresh Kumar
Gram-negative bacteria such as Pseudomonas aeruginosa and Escherichia coli use N-acylated l-homoserine lactones (AHLs) as autoinducers (AIs) for quorum sensing (QS), a chief regulatory and cell-to-cell communication system. QS is responsible for social adaptation, virulence factor production, biofilm production and antibiotic resistance in bacteria. Fimbrolides, a class of halogenated furanones isolated from the red marine alga Delisea pulchra, have been shown to exhibit promising QS inhibitory activity against various Gram-negative and Gram-positive bacterial strains...
December 1, 2015: Bioorganic & Medicinal Chemistry
Ji-Yang Sheng, Tong-Tong Chen, Xiao-Juan Tan, Ting Chen, Ai-Qun Jia
Stilbenoids, known an important phytoalexins in plants, were renowned for their beneficial effects on cardiovascular, neurological and hepatic systems. In the present study, quorum sensing inhibition activity of ten stilbenoids were tested using Chromobacterium violaceum CV026 as the bio-indicator strain and the structure-activity relationship was also investigated. Among them, resveratrol (1), piceatannol (2) and oxyresveratrol (3) showed potential anti-QS activities. At the sub-MIC concentrations, 1-3 demonstrated a statistically significant reduction of violacein in C...
November 15, 2015: Bioorganic & Medicinal Chemistry Letters
Han-Shin Kim, Sang-Hoon Lee, Youngjoo Byun, Hee-Deung Park
Pseudomonas aeruginosa is a well-known pathogenic bacterium that forms biofilms and produces virulence factors via quorum sensing (QS). Interfering with normal QS interactions between signal molecules and their cognate receptors is a developing strategy for attenuating its virulence. Here we tested the hypothesis that 6-gingerol, a pungent oil of fresh ginger, reduces biofilm formation and virulence by antagonistically binding to P. aeruginosa QS receptors. In silico studies demonstrated molecular binding occurs between 6-gingerol and the QS receptor LasR through hydrogen bonding and hydrophobic interactions...
2015: Scientific Reports
Evelina Papaioannou, Putri Dwi Utari, Wim J Quax
Bacteria, although considered for decades to be antisocial organisms whose sole purpose is to find nutrients and multiply are, in fact, highly communicative organisms. Referred to as quorum sensing, cell-to-cell communication mechanisms have been adopted by bacteria in order to co-ordinate their gene expression. By behaving as a community rather than as individuals, bacteria can simultaneously switch on their virulence factor production and establish successful infections in eukaryotes. Understanding pathogen-host interactions requires the use of infection models...
2013: International Journal of Molecular Sciences
Karen Tait, Jon Havenhand
Increased settlement on bacterial biofilms has been demonstrated for a number of marine invertebrate larvae, but the nature of the cue(s) responsible is not well understood. We tested the hypothesis that the bay barnacle Balanus improvisus utilizes the bacterial signal molecules N-acylhomoserine lactones (AHLs) as a cue for the selection of sites for permanent attachment. Single species biofilms of the AHL-producing bacteria Vibrio anguillarum, Aeromonas hydrophila and Sulfitobacter sp. BR1 were attractive to settling cypris larvae of B...
May 2013: Molecular Ecology
Ashima K Bhardwaj, Kittappa Vinothkumar, Neha Rajpara
Quorum sensing (QS) is a bacterial communication process that depends on the bacterial population density. It involves small diffusible signaling molecules which activate the expression of myriad genes that control diverse array of functions like bioluminescence, virulence, biofilm formation, sporulation, to name a few. Since QS is responsible for virulence in the clinically relevant bacteria, inhibition of QS appears to be a promising strategy to control these pathogenic bacteria. With indiscriminate use of antibiotics, there has been an alarming increase in the number of antibiotic resistant pathogens...
April 2013: Recent Patents on Anti-infective Drug Discovery
Edisson Tello, Leonardo Castellanos, Catalina Arévalo-Ferro, Carmenza Duque
Three new cembranoid diterpenes, knightine (1), 11(R)-hydroxy-12(20)-en-knightal (2), and 11(R)-hydroxy-12(20)-en-knightol acetate (3), were isolated as minor constituents of the Caribbean gorgonian Eunicea knighti, along with the known cembranoids 4-8. The stereostructures of the new compounds were determined by detailed spectroscopic analyses and a combination of chemical transformations and modified Mosher's methods. All isolated cembranoids were tested against fouling using a quorum-sensing inhibition (QSI) assay and a biofilm inhibition test...
September 28, 2012: Journal of Natural Products
Khadar Syed Musthafa, Bhagavathi Sundaram Sivamaruthi, Shunmugiah Karutha Pandian, Arumugam Veera Ravi
In Pseudomonas aeruginosa, quorum sensing (QS) autoinducer known as acyl homoserine lactone (AHL) acts as a key regulator in the expression of pathogenic characters. In this work, the efficiency of phenylacetic acid (PAA) in reducing the production of AHL-dependent factors in P. aeruginosa PAO1 was studied. PAA at a concentration of 200 μg ml(-1) displayed significant reduction in QS-dependent pyocyanin, exopolysaccharide, and protease and elastase production in PAO1. In swimming inhibition assay, PAA-treated PAO1 cells exhibited poor motility in swimming agar plate...
November 2012: Current Microbiology
Nathaniel C Cady, Kurt A McKean, Jason Behnke, Roman Kubec, Aaron P Mosier, Stephen H Kasper, David S Burz, Rabi A Musah
Using a microplate-based screening assay, the effects on Pseudomonas aeruginosa PAO1 biofilm formation of several S-substituted cysteine sulfoxides and their corresponding disulfide derivatives were evaluated. From our library of compounds, S-phenyl-L-cysteine sulfoxide and its breakdown product, diphenyl disulfide, significantly reduced the amount of biofilm formation by P. aeruginosa at levels equivalent to the active concentration of 4-nitropyridine-N-oxide (NPO) (1 mM). Unlike NPO, which is an established inhibitor of bacterial biofilms, our active compounds did not reduce planktonic cell growth and only affected biofilm formation...
2012: PloS One
K Syed Musthafa, V Saroja, S Karutha Pandian, A Veera Ravi
Antipathogenic therapy is an outcome of the quorum-sensing inhibition (QSI) mechanism, which targets autoinducer-dependent virulent gene expression in bacterial pathogens. N-acyl homoserine lactone (AHL) acts as a key regulator in the production of virulence factors and biofilm formation in Pseudomonas aeruginosa PAO1 and violacein pigment production in Chromobacterium violaceum. In the present study, the marine bacterial strain SS4 showed potential QSI activity in a concentration-dependent manner (0.5-2 mg/ml) against the AHL-mediated violacein production in C...
March 2011: Journal of Biosciences
Kaia J Sappington, Ajai A Dandekar, Ken-Ichi Oinuma, E Peter Greenberg
Many members of the LuxR family of acyl-homoserine lactone (acyl-HSL)-dependent quorum-sensing transcriptional activators are thought to have the unusual characteristics of requiring the signal ligand during polypeptide synthesis to fold into an active conformation and of binding signal extraordinarily tightly. This is the case for the N-3-oxo-dodecanoyl-HSL-dependent Pseudomonas aeruginosa virulence regulator LasR. We present evidence that LasR can fold into an active conformation in vivo in the absence of the acyl-HSL ligand...
2011: MBio
Morten T Rybtke, Peter Ø Jensen, Niels Høiby, Michael Givskov, Tim Tolker-Nielsen, Thomas Bjarnsholt
Biofilm formation by bacteria is recognized as a major problem in chronic infections due to their recalcitrance against the immune defense and available antibiotic treatment schemes. The opportunistic pathogen Pseudomonas aeruginosa has drawn special attention in this regard due to its severity of infection in the lungs of cystic fibrosis patients and in chronic wounds. In this review we address the molecular basis of biofilm development by P. aeruginosa as well as the mechanisms employed by this bacterium in the increased tolerance displayed against antimicrobials...
April 2011: Inflammation & Allergy Drug Targets
Devendra H Dusane, Pratiek Matkar, Valayam P Venugopalan, Ameeta Ravi Kumar, Smita S Zinjarde
Enhancement or induction of antimicrobial, biosurfactant, and quorum-sensing inhibition property in marine bacteria due to cross-species and cross-genera interactions was investigated. Four marine epibiotic bacteria (Bacillus sp. S3, B. pumilus S8, B. licheniformis D1, and Serratia marcescens V1) displaying antimicrobial activity against pathogenic or biofouling fungi (Candida albicans CA and Yarrowia lipolytica YL), and bacteria (Pseudomonas aeruginosa PA and Bacillus pumilus BP) were chosen for this study...
March 2011: Current Microbiology
Tim Holm Jakobsen, Maria van Gennip, Louise Dahl Christensen, Thomas Bjarnsholt, Michael Givskov
The formation of biofilms in conjunction with quorum sensing (QS)-regulated expression of virulence by opportunistic pathogens contributes significantly to immune evasion and tolerance to a variety of antimicrobial treatments. The present protocol describes methods to determine the in vitro efficacy of potential quorum sensing inhibitors (QSIs). Work on Pseudomonas aeruginosa has shown that chemical blockage of QS is a promising new antimicrobial strategy. Several live bacterial reporter systems been developed to screen extracts and pure compounds for QSI activity...
2011: Methods in Molecular Biology
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