Stilbenes are specialized metabolites that are particularly abundant in species. Although the biosynthetic pathways of stilbenes have been well-characterized, the role of specific peroxidases in stilbene oligomerization remains to be investigated. In this study, we used grapevine cell cultures to characterize the functional role of peroxidase 4 (VvPRX4) in the production of resveratrol oligomers after elicitation with methyl jasmonate (MeJA).
View Article and Find Full Text PDFA straightforward synthesis of carbohydrate templated isoxazolidines is described, by reaction of unprotected glycosylhydroxylamines (operating as 1,3-dipoles) with methyl acrylate using microwave activation. Rhamno- and erythro-isoxazolidines are recognized by plant cells, resulting in a strong ROS-production as a plant immune response, and exert a high antifungal activity against Botrytis cinerea.
View Article and Find Full Text PDFFew point prevalence surveys (PPS) have been conducted in Vietnam on Surgical Site Infections (SSI) or antimicrobial use in surgery. The objective of this study was to evaluate the PPSs of SSI before and after implementation of antibiotic stewardship programs (ASP) and infection control (IC) in a Vietnamese tertiary care hospital. ASP and IC practices were implemented in operating rooms and the orthopedic department, including antibiotic training, skin preparation, hand hygiene, gloves and sterile instruments, and SSIs risk factors.
View Article and Find Full Text PDFPlants have to constantly face pathogen attacks. To cope with diseases, they have to detect the invading pathogen as early as possible via the sensing of conserved motifs called invasion patterns. The first step of perception occurs at the plasma membrane.
View Article and Find Full Text PDFPlant innate immunity is activated upon perception of invasion pattern molecules by plant cell-surface immune receptors. Several bacteria of the genera and produce rhamnolipids (RLs) from l-rhamnose and ()-3-hydroxyalkanoate precursors (HAAs). RL and HAA secretion is required to modulate bacterial surface motility, biofilm development, and thus successful colonization of hosts.
View Article and Find Full Text PDFRhamnolipids are a specific class of microbial surfactants, which hold great biotechnological and therapeutic potential. However, their exploitation at the industrial level is hampered because they are mainly produced by the opportunistic pathogen . The non-human pathogenic bacterium is an alternative producer of rhamnolipid-like metabolites containing glucose instead of rhamnose residues.
View Article and Find Full Text PDFBackground: The optimal duration of intravenous antibiotic therapy in Staphylococcus aureus prosthetic bone and joint infection has not been established. The objective of this study was to compare the effect of early and late intravenous-to-oral antibiotic switch on treatment failure.
Patients And Methods: We retrospectively analyzed all adult cases of S.
Biosurfactants are amphiphilic surface-active molecules that are produced by a variety of microorganisms including fungi and bacteria. , , and species are known to secrete rhamnolipids and lipopeptides that are used in a wide range of industrial applications. Recently, these compounds have been studied in a context of plant-microbe interactions.
View Article and Find Full Text PDFPlants are able to effectively cope with invading pathogens by activating an immune response based on the detection of invasion patterns (IPs) originating from the pathogen or released by the plant after infection. At a first level, this perception takes place at the plasma membrane through cell surface immune receptors and although the involvement of proteinaceous pattern recognition receptors (PRRs) is well established, increasing data are also pointing out the role of membrane lipids in the sensing of IPs. In this review, we discuss the evolution of various conceptual models describing plant immunity and present an overview of well-characterized IPs from different natures and origins.
View Article and Find Full Text PDFMembers of the genus colonize diverse ecological niches. Among the plant-associated strains, PsJN is an endophyte with a broad host range. In a spatially structured environment (unshaken broth cultures), biofilm-constructing specialists of PsJN colonizing the air-liquid interface arose at high frequency.
View Article and Find Full Text PDFStimulation of plant innate immunity by natural and synthetic elicitors is a promising alternative to conventional pesticides for a more sustainable agriculture. Sugar-based bolaamphiphiles are known for their biocompatibility, biodegradability and low toxicity. In this work, we show that Synthetic Rhamnolipid Bolaforms (SRBs) that have been synthesized by green chemistry trigger Arabidopsis innate immunity.
View Article and Find Full Text PDFPathogen infection of plant results in modification of photosynthesis and defense mechanisms. Beneficial microorganisms are known to improve plant tolerance to stresses. Burkholderia phytofirmans PsJN (Bp), a beneficial endophytic bacterium, promotes growth of a wide range of plants and induces plant resistance against abiotic and biotic stresses such as coldness and infection by a necrotrophic pathogen.
View Article and Find Full Text PDFThe major advances achieved in devising successful combined antiretroviral therapy (cART) have enabled the sustained control of HIV replication. However, this is associated with costly lifelong treatment, partial immune restoration, chronic inflammation and persistent viral reservoirs. In this context, new therapeutic strategies deserve investigation as adjuncts to cART so as to potentiate immune responses that are capable of completely containing HIV pathogenicity, particularly if cART is discontinued.
View Article and Find Full Text PDFPhytoalexins are low molecular weight antimicrobial compounds that are produced by plants as a response to biotic and abiotic stresses. As such they take part in an intricate defense system which enables plants to control invading microorganisms. In this review we present the key features of this diverse group of molecules, namely their chemical structures, biosynthesis, regulatory mechanisms, biological activities, metabolism and molecular engineering.
View Article and Find Full Text PDFObjective: We wanted to compare the first line intravenous administration of ceftriaxone to a subcutaneous administration in patients more than 75 years of age.
Method: We performed a retrospective monocentric study on all patients more than 75 years of age admitted to the Ales hospital between January 1 and December 31, 2011, having received at least two doses of ceftriaxone intravenously (IV) or subcutaneously (SC).
Results: One hundred and forty-eight patients (70 females/78 males patients) were included, 110 received ceftriaxone IV and 38 SC.
Objective: HIV-infected immunological nonresponders (InRs) patients fail to show satisfactory CD4+ T-cell recovery despite virologically effective HAART. We propose that NKp44L, the cellular ligand of an activating natural killer (NK) receptor, expressed only on uninfected bystander CD4+ T cells from HIV-1 infected patients, could play a major role in this phenomenon by sensitizing these cells to NK killing.
Design: Phenotype and multifunctional status of CD4+ T cells, especially the subsets expressing and not expressing NKp44L, were characterized for HIV-infected patients receiving HAART for at least 2 years, during which their viral load remained less than 40 copies/ml; 53 were InRs (CD4 cell count always <350 cells/µl), and 82 immunological responders (CD4 cell count always ≥350 cells/µl).
Our aim is to describe an original method for estimating the statistical properties of regions of interest (ROIs) in emission tomography. Drawn upon the works of Louis on the approximate inverse, we propose a dual formulation of the ROI estimation problem to derive the ROI activity and variance directly from the measured data without any image reconstruction. The method requires the definition of an ROI characteristic function that can be extracted from a co-registered morphological image.
View Article and Find Full Text PDFBackground: The induction of neutralizing antibodies against conserved regions of the human immunodeficiency virus type 1 (HIV-1) envelope protein is a major goal of vaccine strategies. We previously identified 3S, a critical conserved motif of gp41 that induces the NKp44L ligand of an activating NK receptor. In vivo, anti-3S antibodies protect against the natural killer (NK) cell-mediated CD4 depletion that occurs without efficient viral neutralization.
View Article and Find Full Text PDFATP-binding cassette transporters are involved in the active transport of a wide variety of metabolites in prokaryotes and eukaryotes. One subfamily, the Pleiotropic Drug Resistance (PDR) transporters, or full-size ABCG transporters, are found only in fungi and plants. NtPDR1 was originally identified in Nicotiana tabacum suspension cells (BY2), in which its expression was induced by microbial elicitors.
View Article and Find Full Text PDFObjective: We propose a statistical stopping criterion for iterative reconstruction in emission tomography based on a heuristic statistical description of the reconstruction process.
Methods: The method was assessed for MLEM reconstruction. Based on Monte-Carlo numerical simulations and using a perfectly modeled system matrix, our method was compared with classical iterative reconstruction followed by low-pass filtering in terms of Euclidian distance to the exact object, noise, and resolution.
Eur J Clin Microbiol Infect Dis
August 2012
There is evidence for the interest of (18)F-fluoro-deoxyglucose positron emission tomography with computed tomography ((18)F-FDG-PET/CT) in fever of unknown origin (FUO) clinical investigation. However, little and conflicting data exist about its place in the investigation procedure. The aim of this work was to evaluate the clinical value of (18)F-FDG-PET/CT in patients with FUO and identify patients who need early (18)F-FDG-PET/CT rather than a last-resort procedure.
View Article and Find Full Text PDFJ Acquir Immune Defic Syndr
November 2012
The immunodeficiency-defining AIDS results from a progressive decline of CD4 cell count. We previously showed that 3S, a unique motif of the HIV-1 gp41 envelop protein, is highly conserved in HIV-1 strains and induces expression of NKp44L, rendering CD4 cells sensitive to NK killing. Here we found from a well-characterized cohort of 244 untreated HIV-1 seroconverters that high levels of anti-3S antibodies significantly delay spontaneous disease progression in the first years after seroconversion; this effect was not mediated through baseline viral load or CD4.
View Article and Find Full Text PDFObjective: Candiduria is a common finding in the growing population of very old patients that has not been previously studied. The objective was to study candiduria in the population aged 85 and over, including an estimation of the incidence, factor of acquisition, and evaluation of treatment and mortality.
Methods: Retrospective monocentric study.