Le Mort dans la ville

Le développement de rites mortuaires complexes dans l’histoire de l’Homme a résulté dans un rôle croissant joué par les pratiques funéraires utilisées comme moyen de resserrer les liens à l’intérieur d’une même communauté. À cet égard, le singulier usage d'inhumer un individu au cœur de la communauté révèle avec acuité la force de cette relation que pouvaient entretenir les vivants et les morts. Les découvertes archéologiques récentes ont souligné l’importance de telles pratiques liées aux inhumations intra-muros en Anatolie. Bien qu’il semble possible de tisser un lien continu entre ces coutumes, les contextes dans lesquels s’inscrivent la pratique d’inhumer une personne au cœur même de la communauté, depuis l’enfant du Néolithique à Çatalhöyük à la libraire de Celsius à Ephèse, en passant par le Mausolée d'Halicarnasse, ont néanmoins radicalement changés en fonction des époques et des lieux. L’objectif de ce volume, en rassemblant des spécialistes de périodes et d’horizons différents, est d’offrir non seulement un point général de nos connaissances sur ces questions, mais aussi un éclairage concernant le mécanisme de ces pratiques, leur contexte et leur impact en Anatolie, du début de l’Âge du Bronze à l’époque romaine

Identification of Biofilm-Associated Cluster (bac) in Pseudomonas aeruginosa Involved in Biofilm Formation and Virulence

Biofilms are prevalent in diseases caused by Pseudomonas aeruginosa, an opportunistic and nosocomial pathogen. By a proteomic approach, we previously identified a hypothetical protein of P. aeruginosa (coded by the gene pA3731) that was accumulated by biofilm cells. We report here that a ΔpA3731 mutant is highly biofilm-defective as compared with the wild-type strain. Using a mouse model of lung infection, we show that the mutation also induces a defect in bacterial growth during the acute phase of infection and an attenuation of the virulence. The pA3731 gene is found to control positively the ability to swarm and to produce extracellular rhamnolipids, and belongs to a cluster of 4 genes (pA3729–pA3732) not previously described in P. aeruginosa. Though the protein PA3731 has a predicted secondary structure similar to that of the Phage Shock Protein, some obvious differences are observed compared to already described psp systems, e.g., this unknown cluster is monocistronic and no homology is found between the other proteins constituting this locus and psp proteins. As E. coli PspA, the amount of the protein PA3731 is enlarged by an osmotic shock, however, not affected by a heat shock. We consequently named this locus bac for biofilm-associated cluster

Recherche de nouvelles cibles moléculaires contre la bactérie Pseudomonas aeruginosa organisée en biofilm

Pseudomonas aeruginosa est la bactérie majoritaire colonisant, sous la forme de biofilms, le tractus respiratoire des patients atteints de mucoviscidose. Suite à une étude protéomique globale, nous avons identifié 48 protéines spécifiquement accumulées par P. aeruginosa organisée en biofilm. Des travaux sur le membranome ont également permis de caractériser 9 protéines membranaires sur-exprimées à l'état biofilm. Nous avons alors entrepris d'évaluer, par mutagénèse dirigée, le rôle de ces protéines dans le phénotype biofilm, à savoir dans les capacités d'adhésion et de résistance aux antibiotiques des bactéries. Une quinzaine de mutants présentent une diminution de plus de 50% de leur capacité d'adhésion par rapport à la souche sauvage. Dans une dernière partie, nous proposons un nouveau modèle pour élaborer les biofilms, plus proche des conditions in vivo et compatible avec la protéomique. Nous avons ainsi réalisé des biofilms âgés de 6 heures sur une monocouche de pneumocytes.Pseudomonas aeruginosa is the leading source of chronic lung infection in cystic fibrosis patients. These infections are due to the formation of biofilms. By a proteomic approach, we have identified 48 proteins that were accumulated by sessile P. aeruginosa cells. A study on the membranome allowed to characterize 9 OMPs that were over expressed by cells. In order to determine the role of these protein in the biofilm phenotype, we used a mutagenesis approach. Fifteen mutants exhibited an important increase in their ability to adhere as compared with the wild strain. In the last part of the manuscript, we propose a new in vitro model of biofilm, close to in vivo conditions and compatible with proteomic studies. We performed 6-hours-old biofilms on an epithelium cell monolayer and compared the protein pattern of sessile bacteria with that of planktonic counterparts.ROUEN-BU Sciences (764512102) / SudocSudocFranceF

Biofilm et ulcère de jambe

International audienc

[Biofilm and leg ulcers].

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Various methods to combine hyaluronic acid and antimicrobial peptides coatings and evaluation of their antibacterial behaviour

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Elaboration of antibacterial plastic surfaces by a combination of antiadhesive and biocidal coatings of natural products

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An overview of techniques for the characterization and quantification of microbial colonization on stone monuments

International audienceBiodeterioration can be defined as any undesired change of the properties of a material having an economic, historical or artistic value caused by biological activity of living organisms. The biodeterioration of stone materials is related to the production of pigments (aesthetic action), to cell metabolism (biochemical action) and to the mechanical action of the biomass colonizing the material during its growth (physical action). Quantification of the sessile biomass and characterization of microbial communities colonizing stone are essential first steps to ensure the diagnosis of biodeterioration processes and to implement control strategies and appropriate treatment. Different destructive and non-destructive approaches can be used to sample stone specimens to study microbial colonization and biodeterioration of monuments: scraping, swab using, and cutting. Different methods can be used depending on the type of microorganism sought: determination of chlorophyll content and colour measurements for pigmented microorganisms; bacterial quantification by confocal laser scanning microscopy observations after CTC staining for active biomass; classical microbiological methods, which consist in cultivation of microorganisms on synthetic media. Molecular methods for the study of microbial biodiversity based on the polymorphism of molecular markers are now widely used in many areas, but little bibliographic data exist regarding the application of these methods to the analysis of microbial flora responsible for colonization and deterioration of building stone. The aim of this review is to present the different biodeterioration mechanisms with a particular focus on the techniques that can be used to characterize and quantify the biodeterioration biomass

Bacterial diversity on rock surface of the ruined part of a French historic monument: The Chaalis abbey

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Kinetic development of biofilm on NF membranes at the Méry-sur-Oise plant, France

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