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antiquorum sensing activities

Nina M Høyland-Kroghsbo, Jon Paczkowski, Sampriti Mukherjee, Jenny Broniewski, Edze Westra, Joseph Bondy-Denomy, Bonnie L Bassler
CRISPR-Cas are prokaryotic adaptive immune systems that provide protection against bacteriophage (phage) and other parasites. Little is known about how CRISPR-Cas systems are regulated, preventing prediction of phage dynamics in nature and manipulation of phage resistance in clinical settings. Here, we show that the bacterium Pseudomonas aeruginosa PA14 uses the cell-cell communication process, called quorum sensing, to activate cas gene expression, to increase CRISPR-Cas targeting of foreign DNA, and to promote CRISPR adaptation, all at high cell density...
January 3, 2017: Proceedings of the National Academy of Sciences of the United States of America
Adeline Conceição Rodrigues, Flávia Guimarães Zola, Brígida D' Ávila Oliveira, Nayara Thais Barbosa Sacramento, Elis Regina da Silva, Michele Corrêa Bertoldi, Jason Guy Taylor, Uelinton Manoel Pinto
We describe the characterization of the centesimal composition, mineral and phenolic content of Eugenia uniflora fruit and the determination of the antioxidant, antimicrobial and quorum quenching activities of the pulp phenolic extract. Centesimal composition was determined according to standard methods; trace elements were measured by total reflection X-ray fluorescence spectroscopy. The phenolic compounds were extracted by solid-phase chromatography and quantified by spectrophotometry. Antioxidant activity was determined by using 3 different methods...
October 2016: Journal of Food Science
Katja Bezek, Marija Kurinčič, Elvira Knauder, Anja Klančnik, Peter Raspor, Franz Bucar, Sonja Smole Možina
Thermophilic campylobacters are a major cause of bacterial food-borne diarrhoeal disease. Adherence and biofilm formation are key elements of Campylobacter jejuni persistence in unfavourable environmental conditions. The phytochemical analysis of Euodia ruticarpa fruit ethanol solution extract (EREE) indicated that the major compounds were evodiamine (1), rutaecarpine (2) and evocarpine (9). E. ruticarpa fruit ethanol solution extract, compounds 1 and 2 as well as a mixture of quinolinone alkaloids with 41...
September 2016: Phytotherapy Research: PTR
Saad Musbah Alasil, Rahmat Omar, Salmah Ismail, Mohd Yasim Yusof
Quorum sensing (QS) is a key regulator of virulence factors and biofilm formation in Gram-negative bacteria such as Pseudomonas aeruginosa. Microorganisms that inhabit soil are of strategic importance in the discovery of compounds with anti-QS properties. The objective of the study was to test the culture extract of a taxonomically novel species of Paenibacillus strain 139SI for its inhibitory effects on the QS-controlled virulence factors and biofilm formation of Pseudomonas aeruginosa both in vitro and in vivo...
2015: International Journal of Bacteriology
Alejandro Bucio-Cano, Alicia Reyes-Arellano, José Correa-Basurto, Martiniano Bello, Jenifer Torres-Jaramillo, Héctor Salgado-Zamora, Everardo Curiel-Quesada, Javier Peralta-Cruz, Alcives Avila-Sorrosa
To counteract bacterial resistance, we investigated the interruption of quorum sensing mediated by non-classical bioisosteres of the N-hexanoyl homoserine lactone with an azoline core. For this purpose, a set of selected 2-substituted azolines was synthesized, establishing the basis for a new protocol to synthesize 2-amino imidazolines. The synthesized compounds were evaluated as inhibitors of violacein production in Chromobacterium violaceum. Theoretical studies on bioisostere-protein interactions were performed using CviR...
December 15, 2015: Bioorganic & Medicinal Chemistry
Boris Pejin, Ana Ciric, Ivo Karaman, Mladen Horvatovic, Jasmina Glamoclija, Milos Nikolic, Marina Sokovic
The antibiofilm and possible antiquorum sensing effects against the strain Pseudomonas aeruginosa PAO1 of five crude extracts of the freshwater bryozoan Hyalinella punctata (Hancock, 1850) were evaluated in vitro for the first time. H. punctata ethyl acetate extract (HpEtAc) exhibited the highest antibiofilm activity reducing the biofilm formation of P. aeruginosa PAO1 in the range of 80.63-88.13%. While all tested extracts reduced the twitching motility of the aforementioned bacterial strain, HpEtAc showed to be the most effective...
August 2016: Natural Product Research
Nadia S El-Gohary, Mona I Shaaban
New series of isoindoline-1,3-diones 2-9, pyrazolo[5,1-a]isoindoles 10-14, and pyridines 16-18 were synthesized. Twenty of the synthesized compounds were screened for their antibacterial activity against S. aureus, B. cereus, and E. coli. Compound 5 was proved to be the most active member in this study, showing the highest antibacterial activity against the three selected microorganisms. The antifungal activity of these compounds was also tested against C. albicans and A. flavus 3375. Compounds 4, 5, 8, and 17a exhibited the best antifungal activity against A...
September 2015: Archiv der Pharmazie
Fohad Mabood Husain, Iqbal Ahmad, Mohd Shahnawaz Khan, Nasser Abdulatif Al-Shabib
Trigonella foenum-graecum L. (Fenugreek) is an important plant of the Leguminosae family known to have medicinal properties. However, fraction based antiquorum sensing and antibiofilm activities have not been reported from this plant. In the present study T. foenum-graecum seed extract was sequentially fractionated and sub-MICs were tested for above activities. The methanol fraction of the extract demonstrated significant inhibition of AHL regulated virulence factors: protease, LasB elastase, pyocyanin production, chitinase, EPS, and swarming motility in Pseudomonas aeruginosa PAO1 and PAF79...
2015: Evidence-based Complementary and Alternative Medicine: ECAM
Essam Mohamed Ahmed, Mohamed Ibrahim Farag Ammar
Many bacteria detect their critical cell numbers through a mechanism known as quorum sensing (QS). Acyl homoserine lactones (AHLs) mediated QS systems have been shown to operate in important human pathogens. The aim of this study was to evaluate the inhibitory effect generated by zoosporic freshwater fungi on AHLs production. A potent strain of zoosporic fungi, Leptolegniella keratinophilum, was isolated after extended screening study. A new cheap medium was used to support the anti-AHLs activities. Statistical strategy depending on two levels factorial model and three levels quadratic model were applied to guide a production maximization process...
2014: Polish Journal of Microbiology
Nadia S El-Gohary, Mona I Shaaban
New series of [1,3,4]thiadiazoles and fused [1,3,4]thiadiazoles were synthesized. The newly synthesized compounds were screened for their antibacterial activity against Staphylococcus aureus, Bacillus cereus, and Escherichia coli. Compounds 3b and 10a displayed the highest activity against E. coli with MIC value of 78.125 μg/mL. In addition, compound 10a exhibited the highest activity against B. cereus with MIC value of 156.25 μg/mL. The antifungal activity of these compounds was also tested against Candida albicans and Aspergillus flavus 3375...
April 2015: Archiv der Pharmazie
Jasmina Glamočlija, Ana Ćirić, Miloš Nikolić, Ângela Fernandes, Lillian Barros, Ricardo C Calhelha, Isabel C F R Ferreira, Marina Soković, Leo J L D van Griensven
ETHNOPHARMACOLOGICAL RELEVANCE: In Russian traditional medicine, an extract from the mushroom Inonotus obliquus (Fr.) Pil´at is used as an anti-tumor medicine and diuretic. It has been reported that Inonotus obliquus has therapeutic effects, such as anti-inflammatory, immuno-modulatory and hepatoprotective effects. This study was designed to investigate the chemical composition and biological properties of aqueous and ethanolic extracts of Inonotus obliquus from Finland, Russia, and Thailand...
March 13, 2015: Journal of Ethnopharmacology
P S Rajesh, V Ravishankar Rai
AHL-lactonase has gained renewed interest due to biotechnological applications such as antiquorum sensing, antibiofilm strategies, biofouling, etc. In our study, the production of AHL-lactonase from endophytic bacteria Enterobacter aerogenes VT66 was optimized by response surface methodology (RSM) using central composite design (CCD) for four different cultural conditions. The relative activity of AHL-lactonase was correlated with amplification of aiiA homologous gene amplification with respect to cultural conditions...
January 2015: International Journal of Biological Macromolecules
A Ahmad, A M Viljoen, H Y Chenia
UNLABELLED: Studies describing the use of essential oil constituents as antimicrobial agents have steadily increased; however, some phyto-constituents are often overlooked due to unfavourable minimum inhibitory concentration (MIC) values. Virulence depends on transcriptional factors which are regulated by cell-to-cell communication called quorum sensing (QS). This study was undertaken to evaluate the antimicrobial and anti-QS properties of 29 compounds commonly found in essential oils using two bioreporter strains...
January 2015: Letters in Applied Microbiology
S A El-Mowafy, M I Shaaban, K H Abd El Galil
AIMS: Quorum sensing circuits regulate virulence factors in Pseudomonas aeruginosa and coordinate bacterial pathogenicity. We are interested in exploring available medications for their antiquorum sensing activity. METHODS AND RESULTS: First, we determined the MIC of ascorbate against Ps. aeruginosa strain PAO1, and all further experiments used concentrations below the MIC so that results could not be caused by reduced viability. Tests of subinhibitory concentrations of sodium ascorbate on cell signals were performed using a reporter strain assay...
November 2014: Journal of Applied Microbiology
Md Akil Hossain, Ji-Yong Park, Jin-Yoon Kim, Joo-Won Suh, Seung-Chun Park
Salmonellosis is a common and widely distributed food borne disease where Salmonella typhimurium is one of the most important etiologic agents. The purpose of this study was to investigate the antimicrobial activity of Nymphaea tetragona alone and in combination with antibiotics against S. typhimurium. It also aimed to assess the plant for quorum sensing inhibition (QSI) activity and to identify the bioactive compounds. The antibacterial activities of the extract were assessed using broth microdilution method...
2014: BioMed Research International
Marina Soković, Ana Ćirić, Jasmina Glamočlija, Miloš Nikolić, Leo J L D van Griensven
The edible mushroom Agaricus blazei Murill is known to induce protective immunomodulatory action against a variety of infectious diseases. In the present study we report potential anti-quorum sensing properties of A. blazei hot water extract. Quorum sensing (QS) plays an important role in virulence, biofilm formation and survival of many pathogenic bacteria, including the Gram negative Pseudomonas aeruginosa, and is considered as a novel and promising target for anti-infectious agents. In this study, the effect of the sub-MICs of Agaricus blazei water extract on QS regulated virulence factors and biofilm formation was evaluated against P...
2014: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Ruchira Mukherji, Asmita Prabhune
Essential oils (EOs) form an important part of traditional medicine so their anti-microbial and, in the recent past, antiquorum sensing activity has been well studied. However it is likely that due to their hydrophobic nature and reduced solubility in aqueous environments full potential of their activity cannot be realized. hence it is only rational to formulate a process to make these molecules more polar in nature. The present paper reports synthesis of sophorolipids using 12 different essential oils as substrates, thus providing surfactant-like properties to these EOs...
2014: TheScientificWorldJournal
Weihua Chu, Shuxin Zhou, Yan Jiang, Wei Zhu, Xiyi Zhuang, Jiangyan Fu
Traditional Chinese herbal medicines (TCHMs) were tested for their ability of antiquorum sensing. Water extracts of Rhubarb, Fructus gardeniae, and Andrographis paniculata show antiquorumsensing activity when using Chromobacterium violaceum CV12472 as reporter; the sub-MIC concentrations of these TCHMs were tested against AHL-dependent phenotypic expressions of PAO1. Results showed significant reduction in pyocyanin pigment, protease, elastase production, and biofilm formation in PAO1 without inhibiting the bacterial growth, revealing that the QSI by the extracts is not related to static or killing effects on the bacteria...
2013: Evidence-based Complementary and Alternative Medicine: ECAM
Florinda Fratianni, Filomena Nazzaro, Aurelio Marandino, Maria Del Rosario Fusco, Raffaele Coppola, Vincenzo De Feo, Laura De Martino
We studied the polyphenol composition and antioxidant activity of the ethanolic and ethyl acetate extracts of Hypericum connatum (Guttiferae), in addition to their antimicrobial and antiquorum-sensing (AQS) properties. The extracts exhibited a similar polyphenol content and a notable antioxidant activity, which was stronger in the ethanolic extract (EC50=3.2 μg/mL). Ultrahigh-performance liquid chromatography analyses revealed different polyphenol profiles, with rutin and apigen being the main components of the ethanolic extract and caffeic acid, (-)-epicatechin and p-coumaric acid being abundant in the ethyl acetate extract...
May 2013: Journal of Medicinal Food
Nadia S El-Gohary, Mona I Shaaban
New series of [1,3,4]thiadiazolo[3,2-a]pyrimidines, benzo[h][1,3,4]thiadiazolo[2,3-b]quinazolines, benzothiadiazolotriazocine, and imidazo[2,1-b][1,3,4]thiadiazoles have been synthesized and characterized by analytical and spectrometrical methods (IR, MS, (1)H and (13)C NMR). Twenty of the synthesized compounds were screened for antibacterial activity against Escherichia coli, Staphylococcus aureus and Bacillus cereus. They were found to be either moderately active, slightly active or inactive against the tested microorganisms...
May 2013: European Journal of Medicinal Chemistry
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