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https://www.readbyqxmd.com/read/29348452/combination-therapy-strategy-of-quorum-quenching-enzyme-and-quorum-sensing-inhibitor-in-suppressing-multiple-quorum-sensing-pathways-of-p-aeruginosa
#1
July Fong, Chaodong Zhang, Renliang Yang, Zhao Zhi Boo, Soon Keat Tan, Thomas E Nielsen, Michael Givskov, Xue-Wei Liu, Wu Bin, Haibin Su, Liang Yang
The threat of antibiotic resistant bacteria has called for alternative antimicrobial strategies that would mitigate the increase of classical resistance mechanism. Many bacteria employ quorum sensing (QS) to govern the production of virulence factors and formation of drug-resistant biofilms. Targeting the mechanism of QS has proven to be a functional alternative to conventional antibiotic control of infections. However, the presence of multiple QS systems in individual bacterial species poses a challenge to this approach...
January 18, 2018: Scientific Reports
https://www.readbyqxmd.com/read/29302024/tuning-the-dynamic-range-of-bacterial-promoters-regulated-by-ligand-inducible-transcription-factors
#2
Ye Chen, Joanne M L Ho, David L Shis, Chinmaya Gupta, James Long, Daniel S Wagner, William Ott, Krešimir Josić, Matthew R Bennett
One challenge for synthetic biologists is the predictable tuning of genetic circuit regulatory components to elicit desired outputs. Gene expression driven by ligand-inducible transcription factor systems must exhibit the correct ON and OFF characteristics: appropriate activation and leakiness in the presence and absence of inducer, respectively. However, the dynamic range of a promoter (i.e., absolute difference between ON and OFF states) is difficult to control. We report a method that tunes the dynamic range of ligand-inducible promoters to achieve desired ON and OFF characteristics...
January 4, 2018: Nature Communications
https://www.readbyqxmd.com/read/29184024/identification-of-fitness-determinants-during-energy-limited-growth-arrest-in-pseudomonas-aeruginosa
#3
David W Basta, Megan Bergkessel, Dianne K Newman
Microbial growth arrest can be triggered by diverse factors, one of which is energy limitation due to scarcity of electron donors or acceptors. Genes that govern fitness during energy-limited growth arrest and the extent to which they overlap between different types of energy limitation are poorly defined. In this study, we exploited the fact that Pseudomonas aeruginosa can remain viable over several weeks when limited for organic carbon (pyruvate) as an electron donor or oxygen as an electron acceptor. ATP values were reduced under both types of limitation, yet more severely in the absence of oxygen...
November 28, 2017: MBio
https://www.readbyqxmd.com/read/29177135/quorum-sensing-down-regulation-counteracts-the-negative-impact-of-pseudomonas-aeruginosa-on-cftr-channel-expression-function-and-rescue-in-human-airway-epithelial-cells
#4
Émilie Maillé, Manon Ruffin, Damien Adam, Hatem Messaoud, Shantelle L Lafayette, Geoffrey McKay, Dao Nguyen, Emmanuelle Brochiero
The function of cystic fibrosis transmembrane conductance regulator (CFTR) channels is crucial in human airways. However unfortunately, chronic Pseudomonas aeruginosa infection has been shown to impair CFTR proteins in non-CF airway epithelial cells (AEC) and to alter the efficiency of new treatments with CFTR modulators designed to correct the basic CFTR default in AEC from cystic fibrosis (CF) patients carrying the F508del mutation. Our aim was first to compare the effect of laboratory strains, clinical isolates, engineered and natural mutants to determine the role of the LasR quorum sensing system in CFTR impairment, and second, to test the efficiency of a quorum sensing inhibitor to counteract the deleterious impact of P...
2017: Frontiers in Cellular and Infection Microbiology
https://www.readbyqxmd.com/read/29135250/structure-activity-relationships-of-6-and-8-gingerol-analogs-as-anti-biofilm-agents
#5
Hyunsuk Choi, So-Young Ham, Eunji Cha, Yujin Shin, Han-Shin Kim, Jeong Kyu Bang, Sang-Hyun Son, Hee-Deung Park, Youngjoo Byun
Pseudomonas aeruginosa is a causative agent of chronic infections in immunocompromised patients. Disruption of quorum sensing circuits is an attractive strategy for treating diseases associated with P. aeruginosa infection. In this study, we designed and synthesized a series of gingerol analogs targeting LasR, a master regulator of quorum sensing networks in P. aeruginosa. Structure-activity relationship studies showed that a hydrogen-bonding interaction in the head section, stereochemistry and rotational rigidity in the middle section, and optimal alkyl chain length in the tail section are important factors for the enhancement of LasR-binding affinity and for the inhibition of biofilm formation...
November 14, 2017: Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/29130181/a-coculture-based-approach-for-screening-campaigns-aimed-at-identifying-novel-pseudomonas-aeruginosa-quorum-sensing-inhibitors
#6
Giordano Rampioni, Giulia Giallonardi, Francesca D'Angelo, Livia Leoni
Quorum sensing (QS) is recognized as a promising target for the identification of anti-virulence drugs hampering Pseudomonas aeruginosa adaptability to the host environment and pathogenicity. Consequently, a number of studies in the last decade focused on the identification of small molecules or proteins with anti-QS activity, mainly targeting the las QS system, which is based on N-3-oxododecanoyl-homoserine lactone (3OC12-HSL) as signal molecule. Different experimental approaches have been successfully used to identify QS blockers interfering with the activity/stability of the 3OC12-HSL receptor LasR, with the functionality of the 3OC12-HSL synthase LasI, or with the stability/bioavailability of the 3OC12-HSL signal molecule itself...
2018: Methods in Molecular Biology
https://www.readbyqxmd.com/read/29099398/electric-field-based-dressing-disrupts-mixed-species-bacterial-biofilm-infection-and-restores-functional-wound-healing
#7
Kasturi Ganesh Barki, Amitava Das, Sriteja Dixith, Piya Das Ghatak, Shomita Mathew-Steiner, Elizabeth Schwab, Savita Khanna, Daniel J Wozniak, Sashwati Roy, Chandan K Sen
OBJECTIVE: This study was designed to employ electroceutical principles, as an alternative to pharmacological intervention, to manage wound biofilm infection. Mechanism of action of a United States Food and Drug Administration-cleared wireless electroceutical dressing (WED) was tested in an established porcine chronic wound polymicrobial biofilm infection model involving inoculation with Pseudomonas aeruginosa PAO1 and Acinetobacter baumannii 19606. BACKGROUND: Bacterial biofilms represent a major wound complication...
November 2, 2017: Annals of Surgery
https://www.readbyqxmd.com/read/29098138/antiquorum-sensing-activity-of-silver-nanoparticles-in-p-aeruginosa-an-in-silico-study
#8
Syed Ghazanfar Ali, Mohammad Azam Ansari, Qazi Mohd Sajid Jamal, Haris M Khan, Mohammad Jalal, Hilal Ahmad, Abbas Ali Mahdi
Pseudomonas aeruginosa an opportunistic pathogen regulates its virulence through Quorum sensing (QS) mechanism comprising of Las and Rhl system. Targeting of QS mechanism could be an ideal strategy to combat infection caused by P. aeruginosa. Silver nanoparticles (AgNPs) have been broadly applied as antimicrobial agents against a number of pathogenic bacterial and fungal strains, but have not been reported as an anti-QS agent. Therefore, the aim of present work was to show the computational analysis for the interaction of AgNPs with the QS system using an In silico approach...
2017: In Silico Pharmacology
https://www.readbyqxmd.com/read/29089927/autoinducer-2-facilitates-pseudomonas-aeruginosa-pao1-pathogenicity-in-vitro-and-in-vivo
#9
Hongdong Li, Xingyuan Li, Chao Song, Yunhui Zhang, Zhengli Wang, Zhenqiu Liu, Hong Wei, Jialin Yu
Bacterial communication systems, such as quorum sensing (QS), have provided new insights of alternative approaches in antimicrobial treatment. We recently reported that one QS signal, named as autoinducer-2 (AI-2), can affect the behaviors of Pseudomonas aeruginosa PAO1 in a dose-dependent manner. In this study, we aimed to investigate the effects of AI-2 on P. aeruginosa PAO1 biofilm formation and virulence factors production in vitro, and in vivo using a pulmonary infection mouse model. Exogenous AI-2 resulted in increased biofilms architecture, the number of viable cells, and the yield of pyocyanin and elastase virulence factors in wild type P...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/29078729/virulence-genes-flic-toxa-and-phzs-are-common-among-pseudomonas-aeruginosa-isolates-from-diabetic-foot-infections
#10
Bulent M Ertugrul, Erman Oryasin, Benjamin A Lipsky, Ayşe Willke, Bulent Bozdogan
BACKGROUND: Outcomes of antibiotic treatment of diabetic foot infections (DFIs) may depend not only on the antimicrobial susceptibility of the aetiologic agents, but also their ability to produce virulence factors. This study aimed to use polymerase chain reaction (PCR) with specific primers to investigate the presence of virulence genes among isolates of Pseudomonas aeruginosa isolates cultured from specimens from diabetic foot and other infections. METHODS: We examined 63 P...
October 27, 2017: Infectious Diseases
https://www.readbyqxmd.com/read/29076756/virtual-screening-and-biological-evaluation-of-biofilm-inhibitors-on-dual-targets-in-quorum-sensing-system
#11
Yinqiu Xu, Xupeng Tong, Pinghua Sun, Leming Bi, Kejiang Lin
AIM: Resistance to conventional antibiotics has spurred interest in exploring new antimicrobial strategies. Suppressing quorum sensing within biofilm is a promising antimicrobial strategy. LasR in quorum sensing system of the Gram-negative bacteria, Pseudomonas aeruginosa, directly enhances virulence and antibiotic resistance, with QscR as its indirect suppressor, so targeting both of them can synergistically take the effect. METHODOLOGY/RESULTS: An in silico protocol combining pharmacophores with molecular docking was applied...
October 27, 2017: Future Medicinal Chemistry
https://www.readbyqxmd.com/read/29042302/attenuation-of-pseudomonas-aeruginosa-quorum-sensing-virulence-and-biofilm-formation-by-extracts-of-andrographis-paniculata
#12
Malabika Banerjee, Soumitra Moulick, Kunal Kumar Bhattacharya, Debaprasad Parai, Subrata Chattopadhyay, Samir Kumar Mukherjee
Quorum-sensing (QS) is known to play an essential role in regulation of virulence factors and toxins during Pseudomonas aeruginosa infection which may frequently cause antibiotic resistance and hostile outcomes of inflammatory injury. Therefore, it is an urgent need to search for a novel agent with low risk of resistance development that can target QS and inflammatory damage prevention as well. Andrographis paniculata, a herbaceous plant under the family Acanthaceae, native to Asian countries and also cultivated in Scandinavia and some parts of Europe, has a strong traditional usage with its known antibacterial, anti-inflammatory, antipyretic, antiviral and antioxidant properties...
October 14, 2017: Microbial Pathogenesis
https://www.readbyqxmd.com/read/29038255/studies-of-pseudomonas-aeruginosa-mutants-indicate-pyoverdine-as-the-central-factor-in-inhibition-of-aspergillus-fumigatus-biofilm
#13
Gabriele Sass, Hasan Nazik, John Penner, Hemi Shah, Shajia Rahman Ansari, Karl V Clemons, Marie-Christine Groleau, Anna-Maria Dietl, Paolo Visca, Hubertus Haas, Eric Déziel, David A Stevens
Pseudomonas aeruginosa (Pa) and Aspergillus fumigatus (Af) are common opportunistic bacterial and fungal pathogens, respectively. They often co-exist in airways of immunocompromised patients and individuals with cystic fibrosis, where they form biofilms and cause acute and chronic illnesses. Hence the interactions between them have long been of interest, and it is known that Pa can inhibit Af in vitro We have approached the definition of the inhibitory Pa molecules by studying 24 Pa mutants, with various virulence genes deleted, for their ability to inhibit Af biofilms...
October 16, 2017: Journal of Bacteriology
https://www.readbyqxmd.com/read/28939255/inhibition-of-quorum-sensing-related-virulence-factors-of-pseudomonas-aeruginosa-by-pyridoxal-lactohydrazone
#14
Azam Heidari, Nader Noshiranzadeh, Fakhri Haghi, Rahman Bikas
Pseudomonas aeruginosa quorum sensing (QS) system is a cell to cell signaling mechanism that regulates virulence factors and pathogenicity. Therefore, the QS system in P. aeruginosa may be an important target for pharmacological intervention. The present study aimed to investigate the effects of sub-MIC concentrations of (S,E)-2-hydroxy-N-(3-hydroxy-5-(hydroxymethyl)-2-methylpyridin-4-yl)propane hydrazide (pyridoxal lactohydrazone) against P. aeruginosa QS related virulence factors. We investigated the effect of sub-MIC concentrations of chiral pyridoxal lactohydrazone, which formed by the reaction of chiral lactic acid hydrazide and pyridoxal (one form of Vitamin B6) as bioactive reagents, on virulence factors...
September 20, 2017: Microbial Pathogenesis
https://www.readbyqxmd.com/read/28934400/genomic-characterisation-of-environmental-pseudomonas-aeruginosa-isolated-from-dental-unit-waterlines-revealed-the-insertion-sequence-ispa11-as-a-chaotropic-element
#15
Antony T Vincent, Luca Freschi, Julie Jeukens, Irena Kukavica-Ibrulj, Jean-Guillaume Emond-Rheault, Annie Leduc, Brian Boyle, Fabrice Jean-Pierre, Marie-Christine Groleau, Eric Déziel, Jean Barbeau, Steve J Charette, Roger C Levesque
The bacterium Pseudomonas aeruginosa is well known to have a remarkable adaptive capacity allowing it to colonise many environments. A recent study on environmental isolates from dental unit waterlines (DUWLs) hinted at a genetic clustering into two groups. Isolates from one of these groups, named cluster III, were shown to have unusual phenotypes for environmental isolates, such as an increased biofilm production. To have a better ecological view, more specifically on isolates from cluster III, the complete genomes of 39 isolates including 16 from DUWLs were sequenced...
September 1, 2017: FEMS Microbiology Ecology
https://www.readbyqxmd.com/read/28928721/onion-peel-ethylacetate-fraction-and-its-derived-constituent-quercetin-4-o-%C3%AE-d-glucopyranoside-attenuates-quorum-sensing-regulated-virulence-and-biofilm-formation
#16
Hanan M Al-Yousef, Atallah F Ahmed, Nasser A Al-Shabib, Sameen Laeeq, Rais A Khan, Md T Rehman, Ali Alsalme, Mohamed F Al-Ajmi, Mohammad S Khan, Fohad M Husain
The resistance and pathogenesis of bacteria could be related to their ability to sense and respond to population density, termed quorum sensing (QS). Inhibition of the QS system is considered as a novel strategy for the development of antipathogenic agents, especially for combating drug-resistant bacterial infections. In the present study, the anti-QS activity of Onion peel ethylacetate fraction (ONE) was tested against Chromobacterium violaceum CV12472 and Pseudomonas aeruginosa PAO1. ONE inhibit the QS-mediated virulence factors production such as violacein in C...
2017: Frontiers in Microbiology
https://www.readbyqxmd.com/read/28893647/coexistence-of-multidrug-resistance-mechanisms-and-virulence-genes-in-carbapenem-resistant-pseudomonas-aeruginosa-strains-from-a-tertiary-care-hospital-south-india
#17
Kalaiarasan Ellappan, Harish Belgode Narasimha, Saravana Kumar
BACKGROUND: This study aimed to identify the multiple drug resistance mechanisms and various virulence genes in high level carbapenem resistant P. aeruginosa (CARPA) isolates collected from patients hospitalized in a tertiary care hospital, South India. METHODOLOGY: A total of 156 CARPA isolates were included in this study. Multiplex PCR was optimized to detect carbapenemases and extended-spectrum beta-lactamase (ESBL) genes, respectively. Semi-quantitative reverse transcriptase PCR (RT-PCR) was optimized to evaluate OprD deficiency...
September 8, 2017: Journal of Global Antimicrobial Resistance
https://www.readbyqxmd.com/read/28878043/the-rapid-in-vivo-evolution-of-pseudomonas-aeruginosa-in-ventilator-associated-pneumonia-patients-leads-to-attenuated-virulence
#18
Ke Wang, Yi-Qiang Chen, May M Salido, Gurjeet S Kohli, Jin-Liang Kong, Hong-Jie Liang, Zi-Ting Yao, Yan-Tong Xie, Hua-Yu Wu, Shuang-Qi Cai, Daniela I Drautz-Moses, Aaron E Darling, Stephan C Schuster, Liang Yang, Yichen Ding
Pseudomonas aeruginosa is an opportunistic pathogen that causes severe airway infections in humans. These infections are usually difficult to treat and associated with high mortality rates. While colonizing the human airways, P. aeruginosa could accumulate genetic mutations that often lead to its better adaptability to the host environment. Understanding these evolutionary traits may provide important clues for the development of effective therapies to treat P. aeruginosa infections. In this study, 25 P. aeruginosa isolates were longitudinally sampled from the airways of four ventilator-associated pneumonia (VAP) patients...
September 2017: Open Biology
https://www.readbyqxmd.com/read/28860065/chitosan-extracted-from-aspergillus-flavus-shows-synergistic-effect-eases-quorum-sensing-mediated-virulence-factors-and-biofilm-against-nosocomial-pathogen-pseudomonas-aeruginosa
#19
Sahira Nsayef Muslim, Israa M S Al Kadmy, Alaa Naseer Mohammed Ali, Batool Kadham Salman, Mohammad Ahmad, Saba Saadoon Khazaal, Nadheema Hammood Hussein, Sraa Nsayef Muslim
The biological methods for extraction of chitosan were used as alternative procedures for chemical methods In biological methods, the chitosan was extracted from A. flavus by using of Lactobacillus paracasei for demineralization and Bacillus subtilis for deproteinization. The yield of extracted chitosan reached to 53.8%, pH was 7.8 and complete solubility in 1% acitic acid. Purified chitosan had the ability to reduce the biofilm forming capacity of P. aeruginosa clearly visible in light microscopic staining and scanning electron microscopy...
August 28, 2017: International Journal of Biological Macromolecules
https://www.readbyqxmd.com/read/28829573/chemical-interrogation-of-luxr-type-quorum-sensing-receptors-reveals-new-insights-into-receptor-selectivity-and-the-potential-for-interspecies-bacterial-signaling
#20
Joseph P Gerdt, Danielle M Wittenwyler, Joshua B Combs, Michelle E Boursier, Jacob W Brummond, He Xu, Helen E Blackwell
Cell-cell signaling between bacteria, including quorum-sensing (QS) communication systems, may play a role in the establishment and maintenance of polymicrobial communities. To better understand and model these interactions, we must uncover the degree to which neighboring species recognize each another's signals. In the current study, we tested the likelihood of whether the QS systems of two opportunistic pathogens (Acinetobacter baumannii and Pseudomonas aeruginosa) that frequently arise in polymicrobial infections would be affected by the QS signals of neighboring species...
September 15, 2017: ACS Chemical Biology
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