Ecological host fitting of Trypanosoma cruzi TcI in Bolivia: mosaic population structure, hybridization and a role for humans in Andean parasite dispersal.

An improved understanding of how a parasite species exploits its genetic repertoire to colonize novel hosts and environmental niches is crucial to establish the epidemiological risk associated with emergent pathogenic genotypes. Trypanosoma cruzi, a genetically heterogeneous, multi-host zoonosis, provides an ideal system to examine the sylvatic diversification of parasitic protozoa. In Bolivia, T. cruzi I, the oldest and most widespread genetic lineage, is pervasive across a range of ecological clines. High-resolution nuclear (26 loci) and mitochondrial (10 loci) genotyping of 199 contemporaneous sylvatic TcI clones was undertaken to provide insights into the biogeographical basis of T. cruzi evolution. Three distinct sylvatic parasite transmission cycles were identified: one highland population among terrestrial rodent and triatomine species, composed of genetically homogenous strains (Ar = 2.95; PA/L = 0.61; DAS = 0.151), and two highly diverse, parasite assemblages circulating among predominantly arboreal mammals and vectors in the lowlands (Ar = 3.40 and 3.93; PA/L = 1.12 and 0.60; DAS = 0.425 and 0.311, respectively). Very limited gene flow between neighbouring terrestrial highland and arboreal lowland areas (distance ~220 km; FST = 0.42 and 0.35) but strong connectivity between ecologically similar but geographically disparate terrestrial highland ecotopes (distance >465 km; FST = 0.016-0.084) strongly supports ecological host fitting as the predominant mechanism of parasite diversification. Dissimilar heterozygosity estimates (excess in highlands, deficit in lowlands) and mitochondrial introgression among lowland strains may indicate fundamental differences in mating strategies between populations. Finally, accelerated parasite dissemination between densely populated, highland areas, compared to uninhabited lowland foci, likely reflects passive, long-range anthroponotic dispersal. The impact of humans on the risk of epizootic Chagas disease transmission in Bolivia is discussed

Adipose-derived mesenchymal stromal cells improve the healing of colonic anastomoses following high dose of irradiation through anti-inflammatory and angiogenic processes

Cancer patients treated with radiotherapy (RT) could develop severe late side effects that affect their quality of life. Long-term bowel complications after RT are mainly characterized by a transmural fibrosis that could lead to intestinal obstruction. Today, surgical resection is the only effective treatment. However, preoperative RT increases the risk of anastomotic leakage. In this study, we attempted to use mesenchymal stromal cells from adipose tissue (Ad-MSCs) to improve colonic anastomosis after high-dose irradiation. MSCs were isolated from the subcutaneous fat of rats, amplified in vitro, and characterized by flow cytometry. An animal model of late radiation side effects was induced by local irradiation of the colon. Colonic anastomosis was performed 4 wk after irradiation. It was analyzed another 4 wk later (i.e., 8 wk after irradiation). The Ad-MSC-treated group received injections several times before and after the surgical procedure. The therapeutic benefit of the Ad-MSC treatment was determined by colonoscopy and histology. The inflammatory process was investigated using Fluorine-182-Fluoro-2-Deoxy-d-Glucose Positron Emission Tomography and Computed Tomography (F-18-FDG-PET/CT) imaging and macrophage infiltrate analyses. Vascular density was assessed using immunohistochemistry. Results show that Ad-MSC treatment reduces ulcer size, increases mucosal vascular density, and limits hemorrhage. We also determined that 1 Ad-MSC injection limits the inflammatory process, as evaluated through F-18-FDG-PET-CT (at 4 wk), with a greater proportion of type 2 macrophages after iterative cell injections (8 wk). In conclusion, Ad-MSC injections promote anastomotic healing in an irradiated colon through enhanced vessel formation and reduced inflammation. This study also determined parameters that could be improved in further investigations

EuReCa ONE—27 Nations, ONE Europe, ONE Registry A prospective one month analysis of out-of-hospital cardiac arrest outcomes in 27 countries in Europe

AbstractIntroductionThe aim of the EuReCa ONE study was to determine the incidence, process, and outcome for out of hospital cardiac arrest (OHCA) throughout Europe.MethodsThis was an international, prospective, multi-centre one-month study. Patients who suffered an OHCA during October 2014 who were attended and/or treated by an Emergency Medical Service (EMS) were eligible for inclusion in the study. Data were extracted from national, regional or local registries.ResultsData on 10,682 confirmed OHCAs from 248 regions in 27 countries, covering an estimated population of 174 million. In 7146 (66%) cases, CPR was started by a bystander or by the EMS. The incidence of CPR attempts ranged from 19.0 to 104.0 per 100,000 population per year. 1735 had ROSC on arrival at hospital (25.2%), Overall, 662/6414 (10.3%) in all cases with CPR attempted survived for at least 30 days or to hospital discharge.ConclusionThe results of EuReCa ONE highlight that OHCA is still a major public health problem accounting for a substantial number of deaths in Europe.EuReCa ONE very clearly demonstrates marked differences in the processes for data collection and reported outcomes following OHCA all over Europe. Using these data and analyses, different countries, regions, systems, and concepts can benchmark themselves and may learn from each other to further improve survival following one of our major health care events

Genomic epidemiology and ecology of cryptococcus neoformans var. grubii in southern Africa

Despite the increased availability of antiretroviral therapy, cryptococcal meningitis remains a neglected disease that is responsible for up to 30% of AIDS related deaths. In the light of next generation sequencing technologies, this thesis investigates the molecular epidemiology of Cryptococcus neoformans var. grubii (Cng) in southern Africa. Sampling in the field and laboratory isolation yielded 37 environmental Cng and 38 C. gattii (Cg) from various ecotypes in Zambia and South Africa. In Zambia, the two sister-species were associated with different ecoregions (p <0.001). Cng was predominantly found inhabiting the Zambezi Mopane Wood- lands, a previously described ecological niche for the pathogen, whereas Cg was more frequently isolated from wet Miombo Woodlands. The fungal community structure associated with these two saprophytes was explored using a high-throughput metabarcoding approach. Changes in the microbial assemblages were observed between the different ecoregions (RANOSIM >0.350, p <0.001) and these differences were more pronounced when climatic (temperature and precipi- tation) and spatial factors were considered. This work confirmed the local adaptation of these fungal species to their specific ecoregions, both at the level of the fungal community and their associated environmental variables. The characterisation of Cryptococcus biotic environments will help to understand where the pathogen might emerge and to predict a potential spillover of the pathogen into susceptible host populations as well as uninfected ecoregions. Whole-genome sequencing of 50 environmental Cng genomes revealed the presence of 26 isolates that grouped into lineage VNI, and 24 isolates that grouped into lineage VNB. Genome-scans were performed to uncover genetic ‘outliers’that were putatively under selection within each molecular type. Genomes of environmental VNB isolates were found to group into two statistically-supported clades and 32% of VNB isolates possessed the MAT a mating-type locus. Recombination was shown to occur frequently within the VNB molecular type, whereas VNI isolates displayed a more clonal profile with the MAT a mating-type being much more rare (4%). VNI infections were shown to be more often associated with urban centres while VNB Cng are mainly present across the Colophospermum mopane region, therefore VNB infection most likely occurs in rural settings. Subsequently, a comparison between environmental and clinical VNB isolates was performed to understand whether the genetic makeup of Cryptococcus neoformans isolated in patients is linked to specific environmental genotypes. Genetic variants associated with clinical isolates were uncovered. Nineteen genes with a known-virulence function were found to be un- der selection in the environment and were also found to be also associated with clinical isolates. In vitro phenotypic assays were performed to identify variations between clinical and environ- mental isolates. Clinical isolates were found to be thermotolerant, produced larger capsule and were more easily phagocytosed than environmental isolates. Clinical VNI isolates replicated faster at 37◦ C than clinical VNB isolates (p <0.002). This finding might be a reflection of the evolutionary relationship between the VNI molecular type and its association with domestic and feral pigeons. Finally, the epidemiology of the VNI molecular type with isolates from the African and Asian continents (n=155) was investigated in the light of whole-genome sequence data. Phylogenetic analyses revealed eight genetic clusters. A ten-fold increase in population size was observed in each VNI cluster in the past 200 to 8,000 years, suggesting the role of the domestication of the pigeon in the global spread of the VNI molecular type. These find- ings indicate that each cluster is likely to contribute differently to the neglected epidemic of Cryptococcus neoformans var. grubii worldwide.Open Acces

Dataset - Gene flow and migration routes in <i>Salmo trutta</i> L

Understanding gene flow can help biodiversity to mitigate habitat changes by contributing to inform and design protected areas. The seascape is composed of heterogeneous landscapes where resources are unevenly distributed. The brown trout, Salmo trutta, displays a multitude of life-history strategies and represents an ideal model for applications in conservation genetics. Information on trout migrations at sea and the effects of abiotic factors on the species dispersal remains limited. Using a panel of 185 single nucleotide polymorphism markers, the present study aimed to explore the population structure of the brown trout and in the English Channel. The genotypes of 2,729 individual trout from 88 rivers were obtained across England and France. Population structure revealed the presence isolation by distance (R2 = 0.464) and the presence of genetic clusters spatially located following an east/west gradient. The maximum threshold distance between genetic distance and geographic distance was 344 km. The measure appeared relative to the studied spatial environment and reflected Salmo trutta capacity to achieve long migration distances. A machine-learning framework derived from a gradient forest analysis was used to generate a resistance surface using changes in allelic frequencies and environmental predicators. The resulting surface identified areas limiting gene flow. On the British coast, a clear genetic break was observed along the Jurassic coast, whereas the Cotentin peninsula acted as a physical barrier to gene flow among French coastal populations. Salmo trutta populations appeared to be differently affected by environmental factors which might reflect demes preference to specific breeding ground. Using our resistance map, we extended from an IBD model to an isolation by resistance approach and computed the distance of maximum correlation (DMC) using cost distance which allowed the pruning of our genetic graph. The resulting least cost path connections were mapped to reveal the main dispersal routes. Finally, a prioritization analysis using connectivity surface was implemented to design potential MPAs.</p

Xylella fastidiosa: Insights into an Emerging Plant Pathogen.

The bacterium Xylella fastidiosa re-emerged as a plant pathogen of global importance in 2013 when it was first associated with an olive tree disease epidemic in Italy. The current threat to Europe and the Mediterranean basin, as well as other world regions, has increased as multiple X. fastidiosa genotypes have now been detected in Italy, France, and Spain. Although X. fastidiosa has been studied in the Americas for more than a century, there are no therapeutic solutions to suppress disease development in infected plants. Furthermore, because X. fastidiosa is an obligatory plant and insect vector colonizer, the epidemiology and dynamics of each pathosystem are distinct. They depend on the ecological interplay of plant, pathogen, and vector and on how interactions are affected by biotic and abiotic factors, including anthropogenic activities and policy decisions. Our goal with this review is to stimulate discussion and novel research by contextualizing available knowledge on X. fastidiosa and how it may be applicable to emerging diseases

Xylella fastidiosa: Insights into an Emerging Plant Pathogen

International audienceThe bacterium Xylella fastidiosa re-emerged as a plant pathogen of global importance in 2013 when it was first associated with an olive tree disease epidemic in Italy. The current threat to Europe and the Mediterranean basin, as well as other world regions, has increased as multiple X. fastidiosa genotypes have now been detected in Italy, France, and Spain. Although X. fastidiosa has been studied in the Americas for more than a century, there are no therapeutic solutions to suppress disease development in infected plants. Furthermore, because X. fastidiosa is an obligatory plant and insect vector colonizer, the epidemiology and dynamics of each pathosystem are distinct. They depend on the ecological interplay of plant, pathogen, and vector and on how interactions are affected by biotic and abiotic factors, including anthropogenic activities and policy decisions. Our goal with this review is to stimulate discussion and novel research by contextualizing available knowledge on X. fastidiosa and how it may be applicable to emerging diseases

Xylella fastidiosa: Insights into an Emerging Plant Pathogen

International audienceThe bacterium Xylella fastidiosa re-emerged as a plant pathogen of global importance in 2013 when it was first associated with an olive tree disease epidemic in Italy. The current threat to Europe and the Mediterranean basin, as well as other world regions, has increased as multiple X. fastidiosa genotypes have now been detected in Italy, France, and Spain. Although X. fastidiosa has been studied in the Americas for more than a century, there are no therapeutic solutions to suppress disease development in infected plants. Furthermore, because X. fastidiosa is an obligatory plant and insect vector colonizer, the epidemiology and dynamics of each pathosystem are distinct. They depend on the ecological interplay of plant, pathogen, and vector and on how interactions are affected by biotic and abiotic factors, including anthropogenic activities and policy decisions. Our goal with this review is to stimulate discussion and novel research by contextualizing available knowledge on X. fastidiosa and how it may be applicable to emerging diseases