Molecular prevalence, genetic characterization and patterns of Toxoplasma gondii infection in domestic small mammals from Cotonou, Benin

Toxoplasmosis, one of the most prevalent parasitic infections in humans and animals, is caused by the intracellular protozoan parasite Toxoplasma gondii. Small mammals play a key role as intermediate reservoir hosts in the maintenance of the T. gondii life cycle. In this study, we estimated the molecular prevalence and provide genetic diversity data for T. gondii in 632 small mammals sampled in four areas of Cotonou city, Benin. Both the brain and heart of each individual were screened through T. gondii-targeting qPCR, and positive samples were then genotyped using a set of 15 T. gondii-specific microsatellites. Prevalence data were statistically analyzed in order to assess the relative impact of individual host characteristics, spatial distribution, composition of small mammal community, and urban landscape features. An overall T. gondii molecular prevalence of 15.2% was found and seven genotypes, all belonging to the Africa 1 lineage, could be retrieved from the invasive black rat Rattus rattus and the native African giant shrew Crocidura olivieri. Statistical analyses did not suggest any significant influence of the environmental parameters used in this study. Rather, depending on the local context, T. gondii prevalence appeared to be associated either with black rat, shrew, or mouse abundance or with the trapping period. Overall, our results highlight the intricate relationships between biotic and abiotic factors involved in T. gondii epidemiology and suggest that R. rattus and C. olivieri are two competent reservoirs for the Africa 1 lineage, a widespread lineage in tropical Africa and the predominant lineage in Benin

Beach litter sources around Nuuk, Greenland: An analysis by UArctic summer school graduate course students

Modeling studies illustrate the potential for long-range transport of plastics into the Arctic, although the degree to which this occurs remains relatively undocumented. We utilised a teaching exercise at a UArctic summer school graduate course in Nuuk, Greenland to conduct a preliminary in-depth analysis of beach litter sources in the Nuup Kangerlua fjord. Students and instructors collected and analysed 1800 litter items weighing 200 kg from one location in the fjord and another at its mouth. The results suggest a predominance of local sources to macrolitter, rather than long-range transport from Europe. Fisheries-related items and rope were common. Packaging which could be identified was largely suspected to be products distributed in Greenland, and soft plastics, which rarely disperse far from its source, were also common. The results suggest local measures to reduce mismanaged waste and emissions from fisheries are important for reducing marine litter in West Greenland.publishedVersio

Extracorporeal Membrane Oxygenation for Severe Acute Respiratory Distress Syndrome associated with COVID-19: An Emulated Target Trial Analysis.

RATIONALE: Whether COVID patients may benefit from extracorporeal membrane oxygenation (ECMO) compared with conventional invasive mechanical ventilation (IMV) remains unknown. OBJECTIVES: To estimate the effect of ECMO on 90-Day mortality vs IMV only Methods: Among 4,244 critically ill adult patients with COVID-19 included in a multicenter cohort study, we emulated a target trial comparing the treatment strategies of initiating ECMO vs. no ECMO within 7 days of IMV in patients with severe acute respiratory distress syndrome (PaO2/FiO2 <80 or PaCO2 ≥60 mmHg). We controlled for confounding using a multivariable Cox model based on predefined variables. MAIN RESULTS: 1,235 patients met the full eligibility criteria for the emulated trial, among whom 164 patients initiated ECMO. The ECMO strategy had a higher survival probability at Day-7 from the onset of eligibility criteria (87% vs 83%, risk difference: 4%, 95% CI 0;9%) which decreased during follow-up (survival at Day-90: 63% vs 65%, risk difference: -2%, 95% CI -10;5%). However, ECMO was associated with higher survival when performed in high-volume ECMO centers or in regions where a specific ECMO network organization was set up to handle high demand, and when initiated within the first 4 days of MV and in profoundly hypoxemic patients. CONCLUSIONS: In an emulated trial based on a nationwide COVID-19 cohort, we found differential survival over time of an ECMO compared with a no-ECMO strategy. However, ECMO was consistently associated with better outcomes when performed in high-volume centers and in regions with ECMO capacities specifically organized to handle high demand. This article is open access and distributed under the terms of the Creative Commons Attribution Non-Commercial No Derivatives License 4.0 (http://creativecommons.org/licenses/by-nc-nd/4.0/)

Quantifying the impact of bottom trawling on soft-bottom megafauna communities using video and scanning-sonar data on the continental slope off Vancouver Island, British Columbia

<p>Megafauna found along transect R1075 grouped by 250m with habitat attributes</p

Quantifying the impact of bottom trawling on soft-bottom megafauna communities using video and scanning-sonar data on the continental slope off Vancouver Island, British Columbia.

<p>Megafauna found along transect R1074 grouped by 250m with habitat attributes.</p

Pain Management After Bone Reconstruction Surgery Using an Analgesic Bone Cement: A Functional Noninvasive In Vivo Study Using Gait Analysis

International audienceAbstract: Postoperative pain after bone reconstruction is a serious complication that could jeopardize the global success of a surgery. This pain must be controlled and minimized during the first 3 to 4 postoperative days to prevent it from becoming chronic. In this study, a critical-size bone defect was created at the femoral distal end of rats and filled by an injectable calcium phosphate cement (CPC) loaded or not with local anesthetics (bupivacaine or ropivacaine). A functional evaluation of the gait was performed using the CatWalk system to compare the postoperative pain relief enhanced by the different CPCs after such a bone filling surgery. The results demonstrated significant pain relief during the short-term postoperative period, as shown by the print area and intensity parameters of the operated paw. At 24 hours, the print area decreased by 65%, 42%, and 24%, and the intensity decreased by 25%, 9%, and 1% for unloaded, ropivacaine-loaded, and bupivacaine-loaded CPCs, respectively, compared with the preoperative values. Bupivacaine-loaded CPC provided an earlier return to full functional recovery than ropivacaine-loaded CPC. Moreover, the CPCs retained their biologic and mechanical properties. For all these reasons, anesthetic-loaded CPCs could be part of the global pain management protocol after bone reconstruction surgery such as iliac crest bone grafting procedures.Perspective: Bupivacaine-loaded CPC provided an earlier return to full gait function than ropiva-caine-loaded CPC, with preserved bone filling properties. Such analgesic CPCs deserve further in vivo investigation and may be part of the global pain management protocol after bone reconstruction or bone augmentation surgery such as iliac crest bone grafting

Reconciling the evolutionary origin of bread wheat (Triticum aestivum)

In PressThe origin of bread wheat (Triticum aestivum; AABBDD) has been a subject of controversy and of intense debate in the scientific community over the last few decades. In 2015, three articles published in New Phytologist discussed the origin of hexaploid bread wheat (AABBDD) from the diploid progenitors Triticum urartu (AA), a relative of Aegilops speltoides (BB) and Triticum tauschii (DD). Access to new genomic resources since 2013 has offered the opportunity to gain novel insights into the paleohistory of modern bread wheat, allowing characterization of its origin from its diploid progenitors at unprecedented resolution. We propose a reconciled evolutionary scenario for the modern bread wheat genome based on the complementary investigation of transposable element and mutation dynamics between diploid, tetraploid and hexaploid wheat. In this scenario, the structural asymmetry observed between the A, B and D subgenomes in hexaploid bread wheat derives from the cumulative effect of diploid progenitor divergence, the hybrid origin of the D subgenome, and subgenome partitioning following the polyploidization events

A straightforward approach to enhance the textural, mechanical and biological properties of injectable calcium phosphate apatitic cements (CPCs): CPC/blood composites, a comprehensive study

International audienceTwo commercial formulations of apatitic calcium phosphate cements (CPCs), Graftys Ò Quickset (QS) and Graftys Ò HBS (HBS), similar in composition but with different initial setting time (7 and 15 min, respectively), were combined to ovine whole blood. Surprisingly, although a very cohesive paste was obtained after a few minutes, the setting time of the HBS/blood composite dramatically delayed when compared to its QS analogue and the two blood-free references. Using solid state NMR, scanning electron microscopy and high frequency impedance measurements, it was shown that, in the particular case of the HBS/blood composite, formation of a reticulated and porous organic network occurred in the intergranular space, prior to the precipitation of apatite crystals driven by the cement setting process. The resulting microstructure conferred unique biological properties to this material upon implantation in bone defects, since its degradation rate after 4 and 12 weeks was more than twice that for the three other CPCs, with a significant replacement by newly formed bone. Statement of Significance A major challenge in the design of bone graft substitutes is the development of injectable, cohesive, resorbable and self-setting calcium phosphate cement (CPC) that enables rapid cell invasion with initial mechanical properties as close as bone ones. Thus, we describe specific conditions in CPC-blood composites where the formation of a 3D clot-like network can interact with the precipitated apatite crystals formed during the cement setting process. The resulting microstructure appears more ductile at short-term and more sensitive to biological degradation which finally promotes new bone formation. This important and original paper reports the design and in-depth chemical and physical characterization of this groundbreaking technology

Prévalence moléculaire, caractérisation génétique et schémas d’infection par Toxoplasma gondii chez les petits mammifères domestiques de Cotonou, Bénin

This study is part of a long-term partnership between Cotonou Autonomous Seaport, the Polytechnic School of Abomey-Calavi, the French Institute of Research for Sustainable Development, and the Tropical Neurology Institute (Inserm U1094, IRD U270 EpiMaCT, University of Limoges). We are grateful to Ladji, Agla and Saint-Jean authorities as well as inhabitants who kindly authorized us to access their households for trapping and interview purposes. We thank the Autonomous Port of Cotonou authorities and staff who facilitated our access to their infrastructures. We also thank the CBGP Small Mammal Collection (Centre de Biologie pour la Gestion des Populations, 2018, “CBGP – Small mammal Collection”, https://doi.org/10.15454/WWNUPO) for the conservation of samples from Benin.International audienceToxoplasmosis, one of the most prevalent parasitic infections in humans and animals, is caused by the intracellular protozoan parasite Toxoplasma gondii. Small mammals play a key role as intermediate reservoir hosts in the maintenance of the T. gondii life cycle. In this study, we estimated the molecular prevalence and provide genetic diversity data for T. gondii in 632 small mammals sampled in four areas of Cotonou city, Benin. Both the brain and heart of each individual were screened through T. gondii-targeting qPCR, and positive samples were then genotyped using a set of 15 T. gondii-specific microsatellites. Prevalence data were statistically analyzed in order to assess the relative impact of individual host characteristics, spatial distribution, composition of small mammal community, and urban landscape features. An overall T. gondii molecular prevalence of 15.2% was found and seven genotypes, all belonging to the Africa 1 lineage, could be retrieved from the invasive black rat Rattus rattus and the native African giant shrew Crocidura olivieri. Statistical analyses did not suggest any significant influence of the environmental parameters used in this study. Rather, depending on the local context, T. gondii prevalence appeared to be associated either with black rat, shrew, or mouse abundance or with the trapping period. Overall, our results highlight the intricate relationships between biotic and abiotic factors involved in T. gondii epidemiology and suggest that R. rattus and C. olivieri are two competent reservoirs for the Africa 1 lineage, a widespread lineage in tropical Africa and the predominant lineage in Benin.La toxoplasmose, l’une des infections parasitaires les plus répandues chez l’homme et les animaux, est causée par le parasite protozoaire intracellulaire Toxoplasma gondii. Les petits mammifères jouent un rôle clé en tant qu’hôtes réservoirs intermédiaires dans le maintien du cycle de vie de T. gondii. Dans cette étude, nous estimons sa prévalence moléculaire et fournissons des données sur sa diversité génétique chez 632 petits mammifères échantillonnés dans quatre localités de la ville de Cotonou. Le cerveau et le cœur de chaque individu ont été analysés par qPCR ciblant T. gondii, et les échantillons positifs ont ensuite été génotypés à l’aide d’un ensemble de 15 microsatellites spécifiques à T. gondii. Les données de prévalence ont été analysées statistiquement afin d’évaluer l’impact relatif des caractéristiques individuelles de l’hôte, de la distribution spatiale, de la composition de la communauté des petits mammifères ainsi que des caractéristiques du paysage urbain. Une prévalence moléculaire globale de T. gondii de 15,2 % a été estimée et sept génotypes, tous appartenant à la lignée Africa 1, ont pu être extraits du rat noir Rattus rattus, espèce envahissante, et de la musaraigne Crocidura olivieri, espèce indigène. Les analyses statistiques n’ont pas suggéré d’influence significative des paramètres environnementaux utilisés dans cette étude. Au contraire, selon le contexte local, la prévalence de T. gondii semble être associée à l’abondance de rats noirs, de musaraignes ou de souris ainsi qu’à la période de piégeage. Dans l’ensemble, nos résultats mettent en évidence les relations complexes entre les facteurs biotiques et abiotiques impliqués dans l’épidémiologie de T. gondii et suggèrent que R. rattus et C. olivieri sont deux réservoirs compétents pour la lignée Africa 1, une lignée répandue en Afrique tropicale et prédominante au Bénin

Prévalence moléculaire, caractérisation génétique et schémas d’infection par Toxoplasma gondii chez les petits mammifères domestiques de Cotonou, Bénin

This study is part of a long-term partnership between Cotonou Autonomous Seaport, the Polytechnic School of Abomey-Calavi, the French Institute of Research for Sustainable Development, and the Tropical Neurology Institute (Inserm U1094, IRD U270 EpiMaCT, University of Limoges). We are grateful to Ladji, Agla and Saint-Jean authorities as well as inhabitants who kindly authorized us to access their households for trapping and interview purposes. We thank the Autonomous Port of Cotonou authorities and staff who facilitated our access to their infrastructures. We also thank the CBGP Small Mammal Collection (Centre de Biologie pour la Gestion des Populations, 2018, “CBGP – Small mammal Collection”, https://doi.org/10.15454/WWNUPO) for the conservation of samples from Benin.International audienceToxoplasmosis, one of the most prevalent parasitic infections in humans and animals, is caused by the intracellular protozoan parasite Toxoplasma gondii. Small mammals play a key role as intermediate reservoir hosts in the maintenance of the T. gondii life cycle. In this study, we estimated the molecular prevalence and provide genetic diversity data for T. gondii in 632 small mammals sampled in four areas of Cotonou city, Benin. Both the brain and heart of each individual were screened through T. gondii-targeting qPCR, and positive samples were then genotyped using a set of 15 T. gondii-specific microsatellites. Prevalence data were statistically analyzed in order to assess the relative impact of individual host characteristics, spatial distribution, composition of small mammal community, and urban landscape features. An overall T. gondii molecular prevalence of 15.2% was found and seven genotypes, all belonging to the Africa 1 lineage, could be retrieved from the invasive black rat Rattus rattus and the native African giant shrew Crocidura olivieri. Statistical analyses did not suggest any significant influence of the environmental parameters used in this study. Rather, depending on the local context, T. gondii prevalence appeared to be associated either with black rat, shrew, or mouse abundance or with the trapping period. Overall, our results highlight the intricate relationships between biotic and abiotic factors involved in T. gondii epidemiology and suggest that R. rattus and C. olivieri are two competent reservoirs for the Africa 1 lineage, a widespread lineage in tropical Africa and the predominant lineage in Benin.La toxoplasmose, l’une des infections parasitaires les plus répandues chez l’homme et les animaux, est causée par le parasite protozoaire intracellulaire Toxoplasma gondii. Les petits mammifères jouent un rôle clé en tant qu’hôtes réservoirs intermédiaires dans le maintien du cycle de vie de T. gondii. Dans cette étude, nous estimons sa prévalence moléculaire et fournissons des données sur sa diversité génétique chez 632 petits mammifères échantillonnés dans quatre localités de la ville de Cotonou. Le cerveau et le cœur de chaque individu ont été analysés par qPCR ciblant T. gondii, et les échantillons positifs ont ensuite été génotypés à l’aide d’un ensemble de 15 microsatellites spécifiques à T. gondii. Les données de prévalence ont été analysées statistiquement afin d’évaluer l’impact relatif des caractéristiques individuelles de l’hôte, de la distribution spatiale, de la composition de la communauté des petits mammifères ainsi que des caractéristiques du paysage urbain. Une prévalence moléculaire globale de T. gondii de 15,2 % a été estimée et sept génotypes, tous appartenant à la lignée Africa 1, ont pu être extraits du rat noir Rattus rattus, espèce envahissante, et de la musaraigne Crocidura olivieri, espèce indigène. Les analyses statistiques n’ont pas suggéré d’influence significative des paramètres environnementaux utilisés dans cette étude. Au contraire, selon le contexte local, la prévalence de T. gondii semble être associée à l’abondance de rats noirs, de musaraignes ou de souris ainsi qu’à la période de piégeage. Dans l’ensemble, nos résultats mettent en évidence les relations complexes entre les facteurs biotiques et abiotiques impliqués dans l’épidémiologie de T. gondii et suggèrent que R. rattus et C. olivieri sont deux réservoirs compétents pour la lignée Africa 1, une lignée répandue en Afrique tropicale et prédominante au Bénin