keyword
MENU ▼
Read by QxMD icon Read
search

lasR

keyword
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
#1
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
#2
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
#3
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
#4
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
#5
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
#6
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
https://www.readbyqxmd.com/read/28818490/inhibition-of-quorum-sensing-controlled-biofilm-formation-in-pseudomonas-aeruginosa-by-quorum-sensing-inhibitors
#7
Ellappan Kalaiarasan, Kottha Thirumalaswamy, Belgode Narasimha Harish, Vasuki Gnanasambandam, 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 processes 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
#8
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
#9
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
#10
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
#11
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
#12
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
#13
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...
September 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
#14
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
#15
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
#16
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
#17
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
#18
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
#19
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...
July 3, 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
#20
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...
September 2017: Journal of Global Antimicrobial Resistance
keyword
keyword
62949
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"