Common Cell Shape Evolution of Two Nasopharyngeal Pathogens

Respiratory infectious diseases are the third cause of worldwide death. The nasopharynx is the portal of entry and the ecological niche of many microorganisms, of which some are pathogenic to humans, such as Neisseria meningitidis and Moraxella catarrhalis. These microbes possess several surface structures that interact with the actors of the innate immune system. In our attempt to understand the past evolution of these bacteria and their adaption to the nasopharynx, we first studied differences in cell wall structure, one of the strongest immune-modulators. We were able to show that a modification of peptidoglycan (PG) composition (increased proportion of pentapeptides) and a cell shape change from rod to cocci had been selected for along the past evolution of N. meningitidis. Using genomic comparison across species, we correlated the emergence of the new cell shape (cocci) with the deletion, from the genome of N. meningitidis ancestor, of only one gene: yacF. Moreover, the reconstruction of this genetic deletion in a bacterium harboring the ancestral version of the locus together with the analysis of the PG structure, suggest that this gene is coordinating the transition from cell elongation to cell division. Accompanying the loss of yacF, the elongation machinery was also lost by several of the descendants leading to the change in the PG structure observed in N. meningitidis. Finally, the same evolution was observed for the ancestor of M. catarrhalis. This suggests a strong selection of these genetic events during the colonization of the nasopharynx. This selection may have been forced by the requirement of evolving permissive interaction with the immune system, the need to reduce the cellular surface exposed to immune attacks without reducing the intracellular storage capacity, or the necessity to better compete for adhesion to target cells

Etude observationnelle sur la version par manoeuvres externes réalisée chez les patientes ayant un antécédent de césarienne (à propos d'une cohorte de 136 patientes)

Objectifs : L'objectif de notre étude est d'évaluer une politique de service consistant à proposer systématiquement une VME chez une patiente ayant une présentation foetale non céphalique et un antécédent de césarienne. Outre les taux de succès et les modes d'accouchements, nous nous intéresserons particulièrement à la morbidité maternelle et néonatale liée à cette pratique. Population et méthodes : Il s'agit d'une étude observationnelle réalisée au CHU de Poitiers sur une période de 21 ans, concernant 136 patientes ayant bénéficié d'une VME pour présentation non céphalique après 35 SA, avec antécédent de césarienne. Résultats : La VME a réussi chez 71 patientes (52,2%). Il y a eu 78 (57,3%) intentions de voie basses et 52 (38,2%) accouchements par voie basse. Il y a eu 27 césariennes en urgence, dont 24 dans le groupe succès de VME. Les complications maternelles ou néonatales, semblant pouvoir être totalement ou partiellement en relation avec la VME, concernent 4 patientes (2,9%) : - 2 cas de césariennes en urgence dans les suites immédiates de la VME, dont 1 cas de prématurité à 35SA+6J ; - 1 cas de rupture utérine en cours de travail, avec hémorragie de la délivrance de 3000mL, transfusion, hystérectomie et hypoxie néonatale sévère ; - 1 cas de prématurité à 36SA+2J suite à une rupture prématurée des membranes quelques heures après une VME. Conclusion : Si la VME sur utérus cicatriciel est facile à pratiquer avec un taux de succès satisfaisant, le nombre de césarienne évité est moins important qu'attendu, concernant environ un tiers des patientes. L'analyse des complications met en évidence un aspect multifactoriel, dont la VME ne constitue qu'un élément. Cela impose lors de sa proposition, d'effectuer l'analyse de dossier au cas par cas, en toute transparence avec la patiente, afin qu'elle appréhende la réalité des bénéfices, en balance avec son surcroît de morbidité propre, ainsi que liée à l'utérus cicatriciel.POITIERS-BU Médecine pharmacie (861942103) / SudocSudocFranceF

Transcriptional profiling of Klebsiella pneumoniae defines signatures for planktonic, sessile and biofilm-dispersed cells

International audienceBackgroundSurface-associated communities of bacteria, known as biofilms, play a critical role in the persistence and dissemination of bacteria in various environments. Biofilm development is a sequential dynamic process from an initial bacterial adhesion to a three-dimensional structure formation, and a subsequent bacterial dispersion. Transitions between these different modes of growth are governed by complex and partially known molecular pathways.ResultsUsing RNA-seq technology, our work provided an exhaustive overview of the transcriptomic behavior of the opportunistic pathogen Klebsiella pneumoniae derived from free-living, biofilm and biofilm-dispersed states. For each of these conditions, the combined use of Z-scores and principal component analysis provided a clear illustration of distinct expression profiles. In particular, biofilm-dispersed cells appeared as a unique stage in the bacteria lifecycle, different from both planktonic and sessile states. The K-means cluster analysis showed clusters of Coding DNA Sequences (CDS) and non-coding RNA (ncRNA) genes differentially transcribed between conditions. Most of them included dominant functional classes, emphasizing the transcriptional changes occurring in the course of K. pneumoniae lifestyle transitions. Furthermore, analysis of the whole transcriptome allowed the selection of an overall of 40 transcriptional signature genes for the five bacterial physiological states.ConclusionsThis transcriptional study provides additional clues to understand the key molecular mechanisms involved in the transition between biofilm and the free-living lifestyles, which represents an important challenge to control both beneficial and harmful biofilm. Moreover, this exhaustive study identified physiological state specific transcriptomic reference dataset useful for the research community

Plastics in WEEE Screens: Difficulties and Opportunities to Improve the Recycling Rate

Nowadays the screens collected by the official e-waste schemes in France are mostly comprised of Cathode Ray Tube (CRT). Nevertheless, Flat Panel Display (FPD) collection should increase in the following years. Among other differences in material compositions, FPD screens have higher plastic content. In order to keep complying with the recycling targets for screens, as well as to increase the recycling performance per material, it is necessary to improve plastics recycling. The goal of this study is to quantify the plastic flows in screens generated, collected and recycled in France and to identify the current scenario of plastic recycling. The presence of flame retardants and additives in the plastics, the variety of polymer types, as well as the high volumes of black plastics are among the main challenges in plastics sorting and recycling. From the economic outlook, it is necessary to develop the market that uses secondary raw materials to ensure the profitability of the WEEE chain

Colonization and immune modulation properties of Klebsiella pneumoniae biofilm-dispersed cells

Biofilm-dispersal is a key determinant for further dissemination of biofilm-embedded bacteria. Recent evidence indicates that biofilm-dispersed bacteria have transcriptional features different from those of both biofilm and planktonic bacteria. In this study, the in vitro and in vivo phenotypic properties of Klebsiella pneumoniae cells spontaneously dispersed from biofilm were compared with those of planktonic and sessile cells. Biofilm-dispersed cells, whose growth rate was the same as that of exponential planktonic bacteria but significantly higher than those of sessile and stationary planktonic forms, colonized both abiotic and biotic surfaces more efficiently than their planktonic counterparts regardless of their initial adhesion capabilities. Microscopy studies suggested that dispersed bacteria initiate formation of microcolonies more rapidly than planktonic bacteria. In addition, dispersed cells have both a higher engulfment rate and better survival/multiplication inside macrophages than planktonic cells and sessile cells. In an in vivo murine pneumonia model, the bacterial load in mice lungs infected with biofilm-dispersed bacteria was similar at 6, 24 and 48 h after infection to that of mice lungs infected with planktonic or sessile bacteria. However, biofilm-dispersed and sessile bacteria trend to elicit innate immune response in lungs to a lesser extent than planktonic bacteria. Collectively, the findings from this study suggest that the greater ability of K. pneumoniae biofilm-dispersed cells to efficiently achieve surface colonization and to subvert the host immune response confers them substantial advantages in the first steps of the infection process over planktonic bacteria

Additional file 3: Table S2. of Transcriptional profiling of Klebsiella pneumoniae defines signatures for planktonic, sessile and biofilm-dispersed cells

Data relative to the 19 selected ncRNA genes. (XLSX 18 kb

G-SWAF a 10 years dataset of global water dynamics from L-Band microwave: from concept to applications

International audienceMonitoring of in-land waters has gained a big interest in the last decade due to the high stacks related to water resources and the increased availability of satellite-based Earth Observation (EO) data for the detection of water surfaces. L-band passive microwave while providing deca-Kilometric spatial resolution observations is able to monitor water surfaces at high temporal resolution (<3days) under dense vegetated areas globally. Here, we present the algorithms basis of the latest 10 years dataset of Global Surface WAter Fraction (G-SWAF) available at www.catds.fr (Al Bitar et al. 2020). G-SWAF is based on multi-angular and dual-pole observation from the Soil Moisture and Ocean Salinity satellite. Level3 Angle binned Horizontal (HH) and Vertical (VV) polarization, Top of Atmosphere (TOA) Brightness Temperatures (TB) (Al Bitar et al. 2017) at 32.5 to 52.5 incidence angles are used to retrieve the surface water fractions. The retrieval is based on minimizing the quadratic difference between the modeled and the observed TB. Surface emission for forest is considered from spatio-temporal observations while the TB for water surfaces is modeled using radiative transfer principals. We present the validation and comparison of the G-SWAF product against water surfaces from microwave (SWAMP, GIEMS), SAR (ALOS-PALSAR), optical (MODIS), and altimetry (Jason2, Sentinel-3) (Parrens et al. 2017, Fatra et al. 2020). Fusion of the SWAF data with digital elevation models (SRTM, MERIT) and optical data (GSW) provides enhanced 1km resolution surface water maps (SWAF-HR) (Parrens et al. 2020). Several applications are also illustrated showing the added value of the G-SWAF product. Namely, the forcing of hydrodynamic models (MGB,SWAT) in tropical basins, a first EO based quantification of denitrification in the Amazon river (Guilerne et al. 2020, Martinez, et al. 2020), the monitoring of the floods in the Congo River Basin (Fatras et al. 2020), In the last section, we show how the combination of the G-SWAF with altimetric data can provide monitoring of water volumes in densely vegetated areas in preparation of the SWOT mission

Common Cell Shape Evolution of Two Nasopharyngeal Pathogens.

International audienceRespiratory infectious diseases are the third cause of worldwide death. The nasopharynx is the portal of entry and the ecological niche of many microorganisms, of which some are pathogenic to humans, such as Neisseria meningitidis and Moraxella catarrhalis. These microbes possess several surface structures that interact with the actors of the innate immune system. In our attempt to understand the past evolution of these bacteria and their adaption to the nasopharynx, we first studied differences in cell wall structure, one of the strongest immune-modulators. We were able to show that a modification of peptidoglycan (PG) composition (increased proportion of pentapeptides) and a cell shape change from rod to cocci had been selected for along the past evolution of N. meningitidis. Using genomic comparison across species, we correlated the emergence of the new cell shape (cocci) with the deletion, from the genome of N. meningitidis ancestor, of only one gene: yacF. Moreover, the reconstruction of this genetic deletion in a bacterium harboring the ancestral version of the locus together with the analysis of the PG structure, suggest that this gene is coordinating the transition from cell elongation to cell division. Accompanying the loss of yacF, the elongation machinery was also lost by several of the descendants leading to the change in the PG structure observed in N. meningitidis. Finally, the same evolution was observed for the ancestor of M. catarrhalis. This suggests a strong selection of these genetic events during the colonization of the nasopharynx. This selection may have been forced by the requirement of evolving permissive interaction with the immune system, the need to reduce the cellular surface exposed to immune attacks without reducing the intracellular storage capacity, or the necessity to better compete for adhesion to target cells

G-SWAF a 10 years dataset of global water dynamics from L-Band microwave: from concept to applications

International audienceMonitoring of in-land waters has gained a big interest in the last decade due to the high stacks related to water resources and the increased availability of satellite-based Earth Observation (EO) data for the detection of water surfaces. L-band passive microwave while providing deca-Kilometric spatial resolution observations is able to monitor water surfaces at high temporal resolution (<3days) under dense vegetated areas globally. Here, we present the algorithms basis of the latest 10 years dataset of Global Surface WAter Fraction (G-SWAF) available at www.catds.fr (Al Bitar et al. 2020). G-SWAF is based on multi-angular and dual-pole observation from the Soil Moisture and Ocean Salinity satellite. Level3 Angle binned Horizontal (HH) and Vertical (VV) polarization, Top of Atmosphere (TOA) Brightness Temperatures (TB) (Al Bitar et al. 2017) at 32.5 to 52.5 incidence angles are used to retrieve the surface water fractions. The retrieval is based on minimizing the quadratic difference between the modeled and the observed TB. Surface emission for forest is considered from spatio-temporal observations while the TB for water surfaces is modeled using radiative transfer principals. We present the validation and comparison of the G-SWAF product against water surfaces from microwave (SWAMP, GIEMS), SAR (ALOS-PALSAR), optical (MODIS), and altimetry (Jason2, Sentinel-3) (Parrens et al. 2017, Fatra et al. 2020). Fusion of the SWAF data with digital elevation models (SRTM, MERIT) and optical data (GSW) provides enhanced 1km resolution surface water maps (SWAF-HR) (Parrens et al. 2020). Several applications are also illustrated showing the added value of the G-SWAF product. Namely, the forcing of hydrodynamic models (MGB,SWAT) in tropical basins, a first EO based quantification of denitrification in the Amazon river (Guilerne et al. 2020, Martinez, et al. 2020), the monitoring of the floods in the Congo River Basin (Fatras et al. 2020), In the last section, we show how the combination of the G-SWAF with altimetric data can provide monitoring of water volumes in densely vegetated areas in preparation of the SWOT mission

Cell shape and PG structure evolution among the <i>Moraxellaceae</i> family.

<p>Schematic phylogeny of the <i>Moraxellaceae</i> family, based on 16s analysis, along with scanning electronic microscopy images of representative species. The mean ratio (GM4+GM4_GM4)/(GM5+GM5_GM4) is presented (with standard deviation) for the different lineages (*** p≤0.001; ** p≤0.01; * p≤0.05). Each dote, represents an independent isolate (tested for <i>pbpX</i> presence) from the CNRM collection that have been classified as <i>M</i>. <i>catharrhalis</i> (3), <i>M</i>. <i>sp LNP20863</i> (1), <i>M</i>. <i>bovis (gift from Dr</i>. <i>S</i>. <i>Higlander—1) M</i>. <i>osloensis</i> (1), <i>M</i>. <i>sp</i>. LNP 26500 (1), <i>A</i>. <i>lwoffi</i> (2). Finally, the right part displays the deletion detected at the node of evolution by presenting the genomic organization of species that diverged before node 1 (assessed from the genome sequence of <i>M</i>. <i>bovis</i> and <i>A</i>. <i>lwoffi</i>) and after node 1 (from the <i>M</i>. <i>catharrhalis</i> genome).</p