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Ana Ortins-Pina, Mar Llamas-Velasco, Sara Turpin, Luís Soares-de-Almeida, Paulo Filipe, Heinz Kutzner
BACKGROUND: Accurate distinction of epithelioid hemangioma (EH) from its malignant mimics is paramount but it remains challenging due to its wide morphological spectrum and lack of objective molecular markers. FOSB oncogenic activation was recently identified as a key event in endothelial proliferation. We sought to investigate the FOSB staining pattern in EH with angiolymphoid hyperplasia with eosinophilia morphology (EH-AHLE) and to evaluate its value in differential diagnosis of epithelioid vascular tumors...
March 12, 2018: Journal of Cutaneous Pathology
So-Young Ham, Han-Shin Kim, Eunji Cha, Jeong-Hoon Park, Hee-Deung Park
In this study, a quorum-quenching (QQ) bacterium named HEMM-1 was isolated at a membrane bioreactor (MBR) plant. HEMM-1 has diplococcal morphology and 99% sequence identity to Enterococcus species. The HEMM-1 cell-free supernatant (CFS) showed higher QQ activities than the CFS of other QQ bacteria, mostly by degrading N-acyl homoserine lactones (AHLs) with short acyl chains. Instrumental analyses revealed that HEMM-1 CFS degraded AHLs via lactonase activity. Under static, flow, and shear conditions, the HEMM-1 CFS was effective in reducing bacterial and activated-sludge biofilms formed on membrane surfaces...
March 2, 2018: Bioresource Technology
Siphathele Sibanda, Stanford Kwenda, Collins K Tanui, Divine Y Shyntum, Teresa A Coutinho, Lucy N Moleleki
Pantoea ananatis LMG 2665T synthesizes and utilizes acyl homoserine lactones (AHLs) for signalling. The complete set of genes regulated by the EanI/R quorum sensing (QS) system in this strain is still not fully known. In this study, RNA-sequencing (RNA-seq) was used to identify the EanI/R regulon in LMG 2665T . Pairwise comparisons of LMG 2665T in the absence of AHLs (Optical density (OD)600 = 0.2) and in the presence of AHLs (OD600 = 0.5) were performed. Additionally, pairwise comparisons of LMG 2665T and its QS mutant at OD600 = 0...
March 7, 2018: Genes
Rajesh Padumane Shastry, Stephen K Dolan, Yassmin Abdelhamid, Ravishankar Rai Vittal, Martin Welch
The quorum quenching (QQ) activity of endophytic bacteria associated with medicinal plants was explored. Extracts of the Gram-negative Enterobacter sp. CS66 possessed potent N-acylhomoserine lactone (AHL) hydrolytic activity in vitro. Using degenerate primers, we PCR-amplified an open reading frame (denoted aiiE) from CS66 that was 96% identical to the well-characterised AHL-lactonase AiiA from Bacillus thuringiensis, but only 30% identical to AHL-lactonases from other Gram-negative species. This confirms that close AiiA homologs can be found in both Gram-positive and Gram-negative bacteria...
March 6, 2018: FEMS Microbiology Letters
Gael Pérez-Rodríguez, Sónia Dias, Martín Pérez-Pérez, Florentino Fdez-Riverola, Nuno F Azevedo, Anália Lourenço
Experimental incapacity to track microbe-microbe interactions in structures like biofilms, and the complexity inherent to the mathematical modelling of those interactions, raises the need for feasible, alternative modelling approaches. This work proposes an agent-based representation of the diffusion of N-acyl homoserine lactones (AHL) in a multicellular environment formed by Pseudomonas aeruginosa and Candida albicans. Depending on the spatial location, C. albicans cells were variably exposed to AHLs, an observation that might help explain why phenotypic switching of individual cells in biofilms occurred at different time points...
March 8, 2018: Biofouling
Sean M McClure, Patrick L Ahl, Jeffrey T Blue
PURPOSE: The purpose was to evaluate DSF for high throughput screening of protein thermal stability (unfolding/ aggregation) across a wide range of formulations. Particular focus was exploring PROTEOSTAT® - a commercially available fluorescent rotor dye - for detection of aggregation in surfactant containing formulations. Commonly used hydrophobic dyes (e.g. SYPRO™ Orange) interact with surfactants, complicating DSF measurements. METHODS: CRM197 formulations were prepared and analyzed in standard 96-well plate rT-PCR system, using SYPRO™ Orange and PROTEOSTAT® dyes...
March 5, 2018: Pharmaceutical Research
Servane Le Guillouzer, Marie-Christine Groleau, Eric Déziel
The bacterium Burkholderia thailandensis possesses three N -acyl-L -homoserine lactone (AHL) quorum sensing (QS) systems designated BtaI1/BtaR1 (QS-1), BtaI2/BtaR2 (QS-2), and BtaI3/BtaR3 (QS-3). These QS systems are associated with the biosynthesis of N -octanoyl-homoserine lactone (C8 -HSL), N -3-hydroxy-decanoyl-homoserine lactone (3OHC10 -HSL), and N -3-hydroxy-octanoyl-homoserine lactone (3OHC8 -HSL), which are produced by the LuxI-type synthases BtaI1, BtaI2, and BtaI3, and modulated by the LuxR-type transcriptional regulators BtaR1, BtaR2, and BtaR3...
March 5, 2018: Journal of Bacteriology
Xi Tang, Yongzhao Guo, Bo Jiang, Sitong Liu
Increasing attention has been paid to the anammox community for its significant function in high-efficiency wastewater treatment. However, bacterial interaction in terms of bacterial communication is still elusive. This study firstly explored the intra- and interspecific communication of bacteria in the anammox community using metagenomic sequence data obtained during bioreactor operation. We verified the existence of multiple bacterial communication gene (BCG) subtypes by alignment with the constructed BCG database containing 11 identified gene subtypes...
February 28, 2018: Water Research
Kamal Kumar, Savithri Purayannur, Vemula Chandra Kaladhar, Swarup Kumar Parida, Praveen Kumar Verma
Ascochyta blight (AB) caused by the fungal pathogen Ascochyta rabiei is a serious foliar disease of chickpea (Cicer arietinum L.). Despite many genetic studies on chickpea-Ascochyta interaction, genome-wide scan of chickpea for the identification of AB associated quantitative trait loci (QTLs) and their gene(s) has not been accomplished. To elucidate narrow QTLs for AB resistance, here we report the use of multiple QTL-sequencing (mQTL-seq) approach on two sets of extreme AB phenotype bulks derived from Cicer intraspecific and interspecific crosses...
March 1, 2018: Plant, Cell & Environment
Debaprasad Parai, Malabika Banerjee, Pia Dey, Arindam Chakraborty, Ekramul Islam, Samir Kumar Mukherjee
This study aimed to evaluate the effect of reserpine, a plant-derived indole-alkaloid, against Pseudomonas aeruginosa PAO1 biofilms. The anti-biofilm activity of reserpine was evaluated by crystal violet staining, MTT assay, confocal laser scanning microscopy and scanning electron microscopy. Reserpine effects were also assessed by qRT-PCR of quorum sensing (QS)-regulated genes and biochemical quantification of the QS-mediated virulence factors pyocyanin, rhamnolipids, proteases and elastases. Reserpine reduced biofilm formation, cell motility, virulence factor production, and QS-controlled gene expression...
February 27, 2018: Biofouling
Jonathan D Clapp, George Luta, Brent J Small, Tim A Ahles, James C Root, Deena Graham, Arti Hurria, Paul B Jacobsen, Heather Jim, Brenna C McDonald, Robert A Stern, Andrew J Saykin, Jeanne S Mandelblatt
Objective: To evaluate how use of different reference populations affects estimates of breast cancer-related cognitive impairment rates. Methods: Patients aged ≥60 years with stage 0-3 breast cancer (n = 371) and matched non-cancer controls (n = 370) completed 13 neuropsychological tests prior to systemic therapy or at enrollment (controls). The tests captured three domains: attention, processing speed and executive function; learning and memory; and visual-spatial function...
February 17, 2018: Archives of Clinical Neuropsychology: the Official Journal of the National Academy of Neuropsychologists
Xiaoxiang Liu, Lei Ji, Xu Wang, Jianrong Li, Junli Zhu, Aihua Sun
Microorganism activities are considered the main cause of most food spoilage, leading to great economic losses. Pseudomonas fluorescens is a Gram-negative bacterium that is widely found in food and has high spoilage activity. RpoS is considered an important global regulator involved in stress survival and virulence in many pathogens. Thus, it is very possible that RpoS plays an important role in spoilage regulation in P. fluorescens. In this study an in-frame deletion mutation of rpoS was constructed to explore its function in P...
February 14, 2018: International Journal of Food Microbiology
Alison A Jack, Saira Khan, Lydia C Powell, Manon F Pritchard, Konrad Beck, Hina Sadh, Lucy Sutton, Alessandra Cavaliere, Hannah Florance, Philip D Rye, David W Thomas, Katja E Hill
Pseudomonas aeruginosa plays a major role in many chronic infections. Its ability to readily form biofilms contributes to its success as an opportunistic pathogen and its resistance/tolerance to antimicrobial/antibiotic therapy. A low molecular weight alginate oligomer (OligoG CF-5/20), derived from marine algae, has previously been shown to impair motility in P. aeruginosa biofilms and disrupt pseudomonal biofilm assembly. As these bacterial phenotypes are regulated by quorum sensing (QS), we hypothesized that OligoG CF-5/20 may induce alterations in QS signalling in P...
February 20, 2018: Antimicrobial Agents and Chemotherapy
Andrea Muras, Mario López-Pérez, Celia Mayer, Ana Parga, Jaime Amaro-Blanco, Ana Otero
There is increasing evidence being accumulated regarding the importance of N -acyl homoserine lactones (AHL)-mediated quorum-sensing (QS) and quorum-quenching (QQ) processes in the marine environment, but in most cases, data has been obtained from specific microhabitats, and subsequently little is known regarding these activities in free-living marine bacteria. The QS and QQ activities among 605 bacterial isolates obtained at 90 and 2000 m depths in the Mediterranean Sea were analyzed. Additionally, putative QS and QQ sequences were searched in metagenomic data obtained at different depths (15-2000 m) at the same sampling site...
February 16, 2018: Genes
Jun Myoung Yu, Dongping Wang, Tessa R Ries, Leland S Pierson, Elizabeth A Pierson
Phenazines are bacterial secondary metabolites and play important roles in the antagonistic activity of the biological control strain P. chlororaphis 30-84 against take-all disease of wheat. The expression of the P. chlororaphis 30-84 phenazine biosynthetic operon (phzXYFABCD) is dependent on the PhzR/PhzI quorum sensing system located immediately upstream of the biosynthetic operon as well as other regulatory systems including Gac/Rsm. Bioinformatic analysis of the sequence between the divergently oriented phzR and phzX promoters identified features within the 5'-untranslated region (5'-UTR) of phzX that are conserved only among 2OHPCA producing Pseudomonas...
2018: PloS One
Noora Tuomilehto, Antti Sommarhem, Aarno Y Nietosvaara
Background and purpose - The long-term outcome of pin-fixed supracondylar humerus fractures (SCHF) in children is not well known. We assessed the 7- to 12-year outcome in 168 children. Patients and methods - During 2002-2006, 210 domestic children (age 7 (1-14) years) with SCHF (Gartland III 79%, Gartland II 19%, and flexion type 2%) were pin fixed in Helsinki. 36 (17%) patients had a nerve palsy. Radiographic alignment was regarded as satisfactory in 81% of patients (Baumann angle (BA) within ±10˚ of normal range and whose anterior humeral line (AHL) crossed the capitulum)...
February 16, 2018: Acta Orthopaedica
Zhangjian Hu, Shujun Shao, Chenfei Zheng, Zenghui Sun, Junying Shi, Jingquan Yu, Zhenyu Qi, Kai Shi
N-decanoyl-homoserine lactone activates plant systemic resistance against Botrytis cinerea in tomato plants, which is largely dependent on jasmonic acid biosynthesis and signal transduction pathways. Rhizosphere bacteria secrete N-acylated-homoserine lactones (AHLs), a type of specialized quorum-sensing signal molecule, to coordinate their population density during communication with their eukaryotic hosts. AHLs behave as low molecular weight ligands that are sensed by plants and promote the host's resistance against foliar pathogens...
February 14, 2018: Planta
Christina L Wysoczynski-Horita, Michelle E Boursier, Ryan Hill, Kirk Hansen, Helen E Blackwell, Mair E A Churchill
Pseudomonas aeruginosa is an opportunistic pathogen that uses the process of quorum sensing (QS) to coordinate the expression of many virulence genes. During quorum sensing, N-acyl-homoserine lactone (AHL) signaling molecules regulate the activity of three LuxR-type transcription factors, LasR, RhlR, and QscR. To better understand P. aeruginosa QS signal reception, we examined the mechanism underlying the response of QscR to synthetic agonists and antagonists using biophysical and structural approaches. The structure of QscR bound to a synthetic agonist reveals a novel mode of ligand binding supporting a general mechanism for agonist activity...
February 13, 2018: Molecular Microbiology
Abayomi Babatunde Alayande, Mar Mar Aung, In S Kim
Bacteria, when adhered to a substratum, can form biofilms. Nevertheless, many factors dictate biofilm formation and virulence factor production, including a response by the bacteria to their surroundings. This system is referred to as Quorum sensing (QS) also known as cell-cell communication. Pseudomonas aeruginosa is an infection causing agent in immune-compromised patients, it uses acyl-homoserine lactone (AHL) to coordinate its QS systems. In this work, the connection between some members of AHL produced by P...
February 9, 2018: Current Microbiology
Kenji Kai
Gram-negative bacteria communicate with each other by producing and sensing diffusible signaling molecules. This mechanism is called quorum sensing (QS) and regulates many bacterial activities from gene expression to symbiotic/pathogenic interactions with hosts. Therefore, the elucidation and control of bacterial QS systems have been attracted increasing attention over the past two decades. The most common QS signals in Gram-negative bacteria are N-acyl homoserine lactones (AHLs). There are also bacteria that employ different QS systems, for example, the plant pathogen Ralstonia solanacearum utilizes 3-hydroxy fatty acid methyl esters as its QS signals...
February 9, 2018: Bioscience, Biotechnology, and Biochemistry
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