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Impact of Temperature on Dengue Virus Transmission by Aedes aegypti in New Caledonia
No full textInternational audienceBackground:Dengue virus (DENV) is a major public health concern in tropical and subtropical regions, with transmission dynamics strongly influenced by environmental factors. Temperature is recognized as a major driver of transmission by mosquito vectors. In the Pacific region, where the impact of climate change is increasingly noticeable, understanding how rising temperatures may alter transmission is essential to better anticipate future dengue risk and disease burdens.Methods:This study aimed to evaluate how temperature variations influence the transmission potential of DENV by Aedes aegypti mosquitoes from New Caledonia. Mosquitoes were orally exposed to infectious blood meals containing two different DENV titres (1.10⁵ and 1.10⁷ FFU/mL) and incubated under constant (26.6°C, 28.1°C, 29.6°C, and 31.1°C). Mosquitoes were collected at several time points post-infection (3, 5, 7, 10, and 14 days) and analysed by immunofluorescence to determine DENV presence in their bodies, heads, and saliva. Viral titres in bodies and heads of mosquitoes exposed to an infectious blood meal at 1.107FFU/mL was determined.Results:Preliminary analyses demonstrated that infection rates were higher at 28.1°C, regardless of the viral blood meal titre used. In contrast, significantly higher viral titres were observed in the bodies and heads of mosquitoes held at 31.1°C compared to 26.6°C (bodies: p=0.0063; heads: p=0.0091). We were unable to test if this increase could also be observed for saliva.Conclusion:Although high temperatures do not promote infection rates, they do appear to increase the viral replication in infected Ae. aegypti mosquitoes. However, contrasting, these results highlight the importance of studying the effects of temperature on DENV transmission in the vector in a context of climate change
Combining political ecology and pragmatist sociology to repoliticise agrifood systems' transformations at the territorial scale
No full textInternational audienceRecent crises (especially Covid-19 and the Russia-Ukraine war) have led to an increased framing of agrifood systems transformations through the lens of food supply at different scales (global, national, territorial), sometimes justifying a neo-productivist perspective, often at the expense of environmental issues and social justice. In turn, this has produced a broader depoliticisation of food systems transformations despite an institutional politicisation, i.e., an increased integration in policy narratives, often with limited real effects. We suggest that pragmatist sociology and political ecology might offer fruitful insights for addressing food systems transformations in a repoliticised way. These two literatures demonstrate how people identify problems affecting agri-food systems and collectively work to find solutions, while also recognising the plurality of understandings of transition pathways and highlighting the mechanisms through which some actors and worldviews are neglected when defining possible paths of transformation. Inspired by these literatures, we have established three key guiding questions dealing with the processes of defining food systems' transformations as a shared and collective problem, the analysis of the reconfigurations of power relations, and the recognition of the diversity of visions of the food system. These guiding questions emerged and were tested through our involvement in three territorial case studies in France and Brazil. They appear useful not only for the analysis of de/ repoliticisation processes, primarily because they reveal the contrasted effects of the increasing institutionalisation and legitimisation of agrifood transitions, but also for developing a transformative approach aimed at repoliticising this issue
Analysis of genetic predisposition to familial non-medullary thyroid cancer by whole genome sequencing
No full textInternational audienceBackground: Several putative susceptibility genes for familial papillary thyroid carcinoma, or familial non-medullary thyroid carcinoma (FNMTC), have been identified. However, in most families the molecular basis for FNMTC remains elusive.Methods: Two families with ≥ 3 first-degree relatives in ≥ 2 generations and ≥ 2 unaffected relatives were selected. Germline DNA from 2 patients and 2 unaffected individuals per family were analyzed by whole genome sequencing. All individuals were genotyped for putative pathogenic variants by Sanger sequencing, and minor allele frequency (MAF) was determined in 179 PTC-free European controls and the GnomAD data base. Methylation analysis of candidate genes was carried out by EPIC BeadChips or pyrosequencing on germline and tumoral DNA.Results: Heterozygous variants in cancer-related genes expressed in thyroid tissue and predicted to impact protein function were identified in patients from both families. In F8, the best candidate was the P2RX5 p.Leu32Gln variant previously reported in another PTC family. However, its relatively high MAF in European controls (0.43%) casts doubt on its pathogenic role. In F17, the most relevant variant was c.345del in MST1R encoding the tyrosine kinase receptor RON. The variant is predicted to encode a truncated isoform. Further analysis of tumor and germline DNA showed no clear evidence of an expression switch from the long to the short oncogenic RON isoform.Conclusion: Our data provide novel insight on the genetics of FNMTC. The P2RX5 p.Leu32Gln variant should be considered either as low-penetrant or not associated with PTC predisposition. MST1R appears as a new putative susceptibility gene for FNMTC that warrants further consideration
Advancing standardization of diagnostics and antimicrobial susceptibility testing for pathogenic mycoplasmas of livestock origin: insights from the MyMIC network
No full textInternational audienceAbstract Background Mycoplasma infections pose a significant economic burden and represent a serious health and welfare concern for the livestock sector. Their control often requires repeated antimicrobial treatments. Antimicrobial susceptibility testing (AST) procedures for veterinary mycoplasmas lack standardization. Furthermore, clinical breakpoints (CBPs) are not available to interpret AST data (i.e., Minimum Inhibitory Concentration, MIC values) and categorize isolates as susceptible, resistant, or intermediate to the different antimicrobials used in livestock, nor epidemiological cut-offs (ECOFFs), which are a prerequisite to define CBPs. In 2023, the MyMIC network - a consortium of 22 laboratories specializing in veterinary mycoplasmas- was established to support efforts in standardizing diagnostics and AST, including clinical interpretation. Its initial goals were to (i) review routine diagnostic practices in frontline laboratories and examine veterinarians’ prescribing habits and (ii) assess practices for culture, identification and AST used in expert laboratories and how these practices may affect MIC results as collected for five major livestock pathogens (M. bovis , M. gallisepticum , M. synoviae , M. hyopneumoniae and M. hyorhinis ). Results A first survey targeting veterinarians from the avian, porcine, and ruminant livestock sectors provided 468 complete responses from 39 countries worldwide, giving an account of current trends in the treatment and first-line diagnosis of veterinary mycoplasmoses. Macrolides, tetracyclines, pleuromutilins, florfenicol and fluoroquinolones were the most frequently administered antimicrobials, with usage varying by livestock sector. Veterinarians reported requesting diagnostic in 40–75% of clinical cases, but only one-third requested AST regularly. A separate survey within the consortium highlighted significant variability in the media and methods used by specialized laboratories, particularly for MIC determination, which relied mostly on in-house broth dilution techniques. This methodological diversity limited our ability to aggregate collected MIC data for establishing ECOFFs. Conclusions Several concerns regarding best practices for antimicrobial treatments of mycoplasma infections may be linked to the lack of AST in frontline laboratories. Based on information collected in expert laboratories, we identified multiple sources contributing to inconsistent MIC results. The next step will be to establish consensus gold-standard AST methods tailored to specific mycoplasma-antimicrobial combinations to generate reliable MIC data for defining ECOFFs. Subsequently, the development of ready-to-use commercial MIC plates for use in frontline laboratory will support veterinarians in selecting appropriate treatments
Contrôle transcriptionnel de la plasticité hépato-cholangiocytaire
No full textThe liver’s regenerative capacity depends on the plasticity of its epithelial cells.Particularly, the hepatocyte-to-cholangiocytes transdifferentiation process (HCT) hasbeen described as a pro-regenerative mechanism in cholestatic animal models and isa feature of some end-stage human chronic liver diseases. During this process,hepatocytes loose some of their physiological functions, due to a decreased of activityof hepatocytes identity transcription factors and a reduction of chromatin accessibilityat their promoters. However, how the cholangiocyte transcriptional program isactivated during HCT is poorly defined. Here, we show that HCT does not involvedtransitioning through a progenitor-like cell state. Our results indicate that HCT involvesinduction of an archetypal monopolarized epithelial cell transcriptional program, initiallyrepressed in healthy hepatocytes. Indeed, HCT requires the removal of the polycombdependantrepressive epigenetic mark H3K27me3 to activate transcription factorencoding genes driving the cholangiocyte program. Especially, our study identified thetranscription factor GRHL2 as a key player in this process, through direct induction ofcholangiocyte/epithelial genes. In line, GRHL2 was detected in human hepatocytesundergoing HCT in human livers from patients with advanced chronic liver disease.Les capacités régénératives du foie sont majoritairement permises par laplasticité de ses cellules épithéliales. En particulier, la transdifférenciation deshépatocytes en cholangiocytes (HCT) est décrite comme un mécanisme derégénération des hépatocytes dans les modèles murins de cholestase et qui sembleêtre également présent dans les pathologies hépatiques de stades avancés. Pendantce processus, les hépatocytes perdent une partie de leurs caractéristiquesphysiologiques. Cette perte est causée par une diminution de l’activité des facteurs detranscription hépatocytaire, et une réduction de l’accessibilité de la chromatine auniveau de leurs promoteurs. Cependant, la manière dont le programmetranscriptionnel cholangiocytaire est activé est peu décrit. Cette thèse montre que HCTn’implique pas le passage par un état de cellule progénitrice. Nos résultats indiquentque ce mécanisme passe par l’induction d’un programme transcriptionnelcaractéristique d’une cellule épithéliale monopolarisée, réprimé dans un hépatocytesain. En effet, HCT nécessite la levée de la marque épigénétique de répressionH3K27me3, dépendante du complexe Polycomb2, afin d’activer les gènes codantspour les facteurs de transcription du programme cholangiocytaire. En particulier, notreétude a identifié le facteur de transcription GRHL2 comme un acteur clé de ceprocessus, induisant de manière directe les gènes cholangiocytaires/épithéliaux. Parailleurs, ce facteur a été détecté dans les hépatocytes humains en cours d’HCT chezdes patients atteints de maladies hépatiques chroniques en phase terminale
Serologic evidence of orthomarburgviruses and an orthoebolavirus in frugivorous Malagasy bats
No full textInternational audienceRecent outbreaks of Marburg virus disease in regions of sub-Saharan Africa without prior record such as Ghana, Tanzania, Equatorial Guinea, and Rwanda challenge the current understanding of areas at-risk for filovirus spillover. The orthomarburgvirus host Rousettus aegyptiacus exists in these regions, and has a sister species, Rousettus madagascariensis , native only to the island of Madagascar. We expand on previous surveillance of frugivorous bats in Madagascar, and detect seroreactivity against an orthoebolavirus antigenically-related to Bundibugyo virus at 1.50–5.06% seroprevalence in Rousettus madagascariensis . Notably, we identify R. madagascariensis as an orthomarburgvirus-host species of interest in Madagascar, the first record of this virus genus on the island. We document seroprevalences of 15.36–29.78% for Ravn virus and 12.55–33.33% for Marburg virus in R. madagascariensis . These findings will guide future biosurveillance efforts to assess filovirus spillover risk in Madagascar
Increase in human West Nile and Usutu virus infections, Austria, 2018
No full textInternational audienceencéphalite japonaise (JEV) Responsables d'épidémies/épizooties notoires</div
Identification of ESBL-producing enterobacterales from vegetable plants: Preliminary findings from a small cross-sectional study in a rural area of Madagascar
No full textSource Agritrop Cirad (https://agritrop.cirad.fr/616078/) * Autres projets (id;sigle;titre): I2016-1731-0006632;;(EU) GURDT//International audienceExtended-spectrum beta-lactamases (ESBL)-producing enterobacterales are considered a key indicator for antimicrobial resist- ance (AMR) epidemiological surveillance in animal, human, and environment compartments. In this study, we aim to investi- gate the presence and genetic diversity of ESBL-producing enterobacterales on vegetable plants. We isolated beta-lactam resistant enterobacterales from several vegetable plants and sequenced their whole genome. Utilising standard genomic and phylogenetic methods, we sought to (i) characterise the resistance genes and plasmid content of the plant-isolated strains, (ii) investigate their genetic structure, and (iii) determine their relationships with strains from other reservoirs. Among the 22 strains collected from vegetable plants, 6 showed resistance to beta-lactam antibiotics, with 5 of them identified as ESBL producers. Our results indi- cated the presence of multidrug-resistant (MDR) strains containing multiple antibiotic resistance genes (ARGs). Importantly, no host-specific lineages were identified among the plant-isolated ESBL-producing E. coli (ESBL-Ec). Instead, these strains ex- hibited genetic and epidemiological connections with strains isolated from animals, humans, and the environment, suggesting transfer of ESBL-Ec between plants and other sources in rural Madagascar. These preliminary findings suggest that vegetable plants are contaminated as a result of human activities, posing a potential risk of human and animal exposure to antibiotic- resistant bacteria and genes
A chromosomal reference genome sequence for the malaria mosquito, Anopheles (Nyssorhynchus) aquasalis, Curry, 1932
No full textInternational audienceWe present a genome assembly from an individual female Anopheles (Nyssorhynchus) aquasalis (a malaria mosquito; Arthropoda; Insecta; Diptera; Culicidae), from a wild population in French Guiana. The genome sequence is 177 megabases in span. The majority of the assembly is scaffolded into four chromosomal pseudomolecules with the X sex chromosome assembled into two arms, XR and XL. The complete mitochondrial genome was also assembled and is 15.4 kilobases in length
Associations between external eating cues, diet history and weight history in French subjects with obesity
No full textInternational audienceObesity remains a serious public health concern. Historically, restrictive diets were the first line of treatment for obesity and are still frequently followed by subjects with obesity. However, some studies showed that dieting may contribute to long-term weight gain. External eating cues might be implicated in this deleterious effect. We then wanted to determine whether the history of dieting was associated with higher reliance on external eating cues (such as emotional eating, uncontrolled eating, or ending a food intake because of the stomach overfullness or the plate emptiness) in individuals with obesity, and to examine whether these associations differed between subjects with different weight history. We included 1093 subjects with obesity from the GECCOS study and examined the association between external eating cues and dieting history (if < 3 diets or ≥ 3 diets) in the sample and in clusters (defined by hierarchical ascending classification on their weight history (based on current BMI, BMI at 20 years old and age of 1st diet)). Three clusters were obtained: a "early-onset obesity" group, a "late-onset obesity" group and an "intermediate" group. Having followed at least 3 diets was associated with higher BMI, higher emotional eating and with eating until stomach overfullness in the global population, but it was not associated with uncontrolled eating or for ending the meal when the plate is empty. These associations were not always detected in each cluster, showing that weight history modulated these associations. To conclude, dieting history is associated with certain external eating cues such as emotional eating and stopping the meal at stomach overfullness in subjects with obesity, even when their weight history is taken into account