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From macro to micro: De novo genomes of Aedes mosquitoes enable comparative genomics among close and distant relatives
No full textInternational audienceThe yellow fever mosquito (Aedes aegypti) is an organism of high medical importance because it is the primary vector for diseases such as yellow fever, Zika, dengue, and chikungunya. Its medical importance has made it a subject of numerous efforts to understand their biology. One such effort, was the development of a high-quality reference genome (AaegL5). However, this reference genome was sourced from a highly inbred laboratory strain with unknown geographic origin. Thus, the reference is not representative of a wild mosquito, let alone one from its native range in sub-Saharan Africa. To better understand the genetic architecture of Ae. aegypti and their sister species, we developed two de novo chromosome-scale genomes with sequences sourced from single individuals: one of Ae. aegypti formosus (Aaf) from Burkina Faso and one of Ae. mascarensis (Am) from Mauritius. Both genomes exhibit high contiguity and gene completeness, comparable to AaegL5. While Aaf exhibits high degree of synteny to AaegL5, it also exhibits several large inversions. We also conducted comparative genomic analyses using our genomes and other publicly available culicid reference genomes to find extensive chromosomal rearrangements between major lineages. The expanded gene families common to Aaf, AaegL5, and Am revealed that while the overarching category of genes that have expanded are similar, the specific genes that have expanded differ. Our findings elucidate novel insights into chromosome evolution at both microevolutionary and macroevolutionary scales. The genomic resources we present are additions to a growing arsenal for biologists in understanding mosquito biology and genome evolution
Chromosomal Inversions and Their Potential Impact on the Evolution of Arboviral Vector Aedes aegypti
No full textInternational audienceChromosomal inversions play a crucial role in evolution and have been found to regulate epidemiologically significant traits in malaria mosquitoes. However, they have not been characterized in Aedes aegypti, the primary vector of arboviruses, due to the poor structure of its polytene chromosomes. The Hi-C proximity ligation approach was used to identify chromosomal inversions in 25 strains of A. aegypti obtained from its worldwide distribution and in one strain of Aedes mascarensis. The study identified 21 multimegabase polymorphic inversions ranging in size from 5 to 55 Mbp. Inversions were more abundant in African than in non-African strains, 15 versus 3 inversions, with the highest number observed in West Africa. All inversions were grouped into two geographic clusters of African or non-African origin, suggesting their association with A. aegypti subspecies. Inversions were unevenly distributed along chromosomal arms, with the highest number found in the 1q and 3p arms homologous to the inversion-rich 2R chromosomal arm in the malaria vector Anopheles gambiae. Direct comparison of inversions between A. aegypti and An. gambiae revealed significant overlap in their genomic locations. This finding may explain the parallel evolution of the two species under similar environmental conditions. Some of the inversions colocalized with chemoreceptor genes and quantitative trait loci associated with pathogen infection, suggesting their potential role in host preference and disease transmission. Our study revealed the large pool of structural variations in the A. aegypti genome and provides the foundation for future studies of their impact on the biology of this important arboviral vector
First report of Aedes albopictus in Saint Barthélemy (French West Indies) confirmed by morphological, molecular and MALDI-TOF mass spectrometry approaches
No full textInternational audienceAedes albopictus is a mosquito vector of arboviruses that is native to southeast Asia. However, this invasive species has spread worldwide. It arrived in the Caribbean in 1993, but had never been recorded in the French Territories of the Americas. We report here the first detection of Aedes albopictus in Saint Barthélemy, Guadeloupe confirmed by morphological criteria, matrix-assisted laser desorption ionization-time-of-flight mass spectrometry (MALDI-TOF MS), and cytochrome c oxidase 1 (cox1) gene barcoding. The presence of this invasive mosquito species in Saint Barthélemy, an island with daily aerial or maritime connections to the French Departments of the Americas, raises concerns about the risk of its introduction into these territories, as well as into other Caribbean countries. It also emphasizes the urgent need to locally reinforce vector surveillance and control measures to prevent the further spread of this mosquito vector.</div
Diagnostic value of biological parameters in biopsy-confirmed thrombotic microangiopathy-MATRIX consortium group
No full textInternational audienceIntroductionThe diagnosis of thrombotic microangiopathy (TMA) relies on common biological parameters which diagnostic value is unknown.MethodsThe presence of common biological parameters was assessed in 967 patients with TMA during the 2009-2023 period (ClinicalTrials.gov: NCT05991245).ResultsMedian age was 49 [36-64] and 53.2% were male. All TMA causes were represented (atypical hemolytic uremic syndrome (HUS): 41.6%; drugs: 24.9%; malignancy: 21.4%; auto-immune: 18.8%; infection: 7.6%, complement-mediated HUS (C-HUS): 6.8%, organ transplantation: 5.8%, pregnancy: 3.8%, bone marrow transplantation (BMT): 2.9%, shigatoxin (STEC-HUS): 0.6%, thrombotic thrombocytopenic purpura (TTP) (0.6%).The presence of TMA-related parameters concerned virtually all patients with TTP but varied widely for the other patients: anemia 81.7% (anemia (81.7%), high lactate deshydrogenase (LDH) (75.4%), low haptoglobin (53.7%), thrombocytopenia (40.3%). Their diagnostic performance was accurate only for TTP. Eleven distinct ways were used for schistocyte metrics and reporting. Relying on schistocytes presence as the single diagnostic criterion would lead to missed diagnosis in 23.8% (shigatoxin HUS) to 86.4% (bone marrow transplantation) of patients (for anemia: 8.2% to 22.3%; thrombocytopenia: 31.8% to 67.9%; high LDH: 10.0% to 40.7%, low haptoglobin: 0% to 70.4%, according to the causes of TMA). The overall risk of missed diagnosis using these parameters was ≥ 50% in all TMA, except in TTP.The best diagnostic performances were obtained when fibrinogen levels were <5 g/L, creatinine ≥300 μmol/L, prothrombin time (PT) <90% and when TMA causes were TTP, STEC-HUS, infection or complement-mediated HUS.ConclusionsCommon biological parameters miss the diagnosis in more than 50% of TMA except when fibrinogen is <5 g/L, creatinine ≥300 μmol/L and prothrombin time (PT) <90%. Schistocyte reporting is heterogenous, and its results are usually deceptive in TMA
Identification of early genes in the pathophysiology of fibrotic interstitial lung disease in a new model of pulmonary fibrosis
No full textInternational audienceSome interstitial lung diseases involve pulmonary fibrosis, which is a process that is characterized by the excessive and abnormal accumulation of extracellular matrix in the pulmonary interalveolar space. Although the current anti-fibrotic therapy aims at slowing down the progression of pulmonary fibrosis, it does not reverse it, and many of the drugs that were identified in basic-research studies failed in clinical phases, mainly because of the lack of a model that can recapitulate the pathophysiological mechanisms of human pulmonary fibrosis. We developed a novel experimental model of pulmonary fibrosis induced by a cocktail of molecules on an air/liquid interface culture of mouse embryonic lung explants. Histological analyses revealed a pattern of usual interstitial pneumonia, the worst-prognosis form of pulmonary fibrosis. We performed a transcriptomics analysis at the single-cell level after the induction of fibrosis and before any histological signs of fibrosis could be observed. The results revealed increased expression of several gene families that are involved in early inflammation, fibrosis and iron homeostasis, as well as potential new genetic targets
La surveillance des eaux usées peut-elle améliorer le suivi génomique des agents pathogènes liés au climat ?
No full textInternational audienceClimate change heightens the threat of infectious diseases in Europe, necessitating innovative surveillance methods. Based on 390 scientific papers, for the first time, this review associates climate-related pathogens, data related to their presence in wastewater, and associated available genomic detection methods. This deep analysis reveals a wide range of pathogens that can be tracked through methods such as quantitative and digital PCR, as well as genomic pathogen enrichment in combination with sequencing and metagenomics. Nevertheless, significant gaps remain in the development of methods, particularly for vector-borne pathogens, and in their general harmonization relating to performance criteria. By offering an overview of recent advancements while identifying critical gaps, we advocate for collaborative research and validation to integrate detection techniques into surveillance frameworks. This will enhance public health resilience against emerging infectious diseases driven by climate change.Le changement climatique accroît la menace des maladies infectieuses en Europe, ce qui nécessite des méthodes de surveillance innovantes. Sur la base de 390 articles scientifiques, cette étude associe pour la première fois les agents pathogènes liés au climat, les données relatives à leur présence dans les eaux usées et les méthodes de détection génomique disponibles associées. Cette analyse approfondie révèle un large éventail d'agents pathogènes qui peuvent être suivis grâce à des méthodes telles que la PCR quantitative et numérique, ainsi que l'enrichissement génomique des agents pathogènes en combinaison avec le séquençage et la métagénomique. Néanmoins, des lacunes importantes subsistent dans le développement des méthodes, en particulier pour les agents pathogènes vecteurs, et dans leur harmonisation générale en ce qui concerne les critères de performance. En offrant un aperçu des progrès récents tout en identifiant les lacunes critiques, nous préconisons une recherche collaborative et une validation afin d'intégrer les techniques de détection dans les cadres de surveillance. Cela permettra de renforcer la résilience de la santé publique face aux maladies infectieuses émergentes liées au changement climatique
Vers une meilleure compréhension des mécanismes de co-infection par les virus West Nile et Usutu chez l’hôte aviaire
No full textInternational audienc
Les tiques et les maladies transmises par les tiques au Cambodge
No full textTicks and tick-borne diseases (TBDs) pose an increasing threat to public and animal health worldwide, and significant knowledge gaps remain in Cambodia. This study presents the first comprehensive assessment of tick species and the associated tick-borne pathogens (TBPs) throughout the country. It combines a regional literature review, field surveillance, and multiple methods for detecting pathogens. Ticks were collected from 1,093 animals, totaling 21,139 ticks, across 13 different host species, which included livestock, pets, reptiles, and wildlife. Additionally, 11,384 ticks were gathered from vegetation through flagging and dragging techniques. A total of fifteen tick species were identified, seven of which have not been previously recorded in Cambodia, there are Carios batuensis, D. steini, D. filippovae, Haemaphysalis canestrinii, H. formosensis, H. hystricis, and H. wellingtoni. A serological analysis of 109 cattle serum samples revealed a seropositivity rate of 93.6% for at least one pathogen, including Anaplasma, Ehrlichia, Babesia, or Theileria. Molecular screening of 352 tick pools, which contained approximately 1,526 ticks, was conducted using conventional PCR. This screening detected Anaplasma marginale (1.1%), Ehrlichia minasensis (0.9%), A. platys (0.3%), and unidentified strains of Babesia canis (2.0%), Anaplasma spp. (6.6%), Ehrlichia spp. (1.7%), and Babesia spp. (0.9%). Additionally, Coxiella-like endosymbionts were prevalent, found in 15.3% of samples, while pathogenic Coxiella spp. were rare, occurring in only 0.3%.Next-generation sequencing of 40 cattle ticks revealed the presence of five viruses: Guangdong Manly virus, Jingmen tick virus, Mogiana tick virus, Rhipicephalus-associated rhabdo-like virus, and Zhangzhou totiv tick virus 1.Seasonal trends indicated that cattle infestations were higher during dry and peak in rainy season, with adult ticks being more collected than immature stages. Ticks were the most commonly attached to the ears and necks on the cattle. All results showed the timing and body sites for targeted treatments to help for control efficiency. In conclusion, our study significantly enhances our understanding of tick diversity and the circulation of TBPs on domestic animals in Cambodia. Despite facing challenges such as restricted access to forests, logistical constraints, and incomplete characterization of pathogens, these findings establish a critical baseline for future surveillance efforts. The inability to include human data due to consent barriers which highlight the need for integrated human-animal studies, improved diagnostic methods (such as multiplex PCR and serology), and targeted surveillance initiatives. These steps are essential for guiding evidence-based prevention strategies and mitigating emerging TBP threats in Cambodia, following a One Health approach.Les tiques et les maladies vectorielles à tiques sont une menace pour la santé publique et animale dans le monde. Seulement, d'importantes lacunes subsistent dans leurs connaissances au Cambodge. Cette thèse présente la première étude scientifique dédiée aux espèces de tiques présentes au Cambodge et aux agents pathogènes transmis par les tiques. Cette thèse combine une synthèse bibliographique de la littérature internationale et nationale, l'analyse de deux échantillonnages complémentaires - temporel et spatial- sur le terrain ainsi que l'utilisation de plusieurs méthodes pour la détection d'agents pathogènes. Un total de 21139 tiques a été prélevé sur 1093 animaux, appartenant à 13 espèces différentes. Ces hôtes étaient principalement du bétail et des animaux de compagnie, mais aussi quelques animaux de la faune sauvage. De plus, 11384 tiques ont été prélevées dans la végétation par les techniques du drapeau et du drap. Au total, 15 espèces de tiques ont été identifiées, dont sept n'avaient jamais été recensées au Cambodge : Carios batuensis, Dermacentor steini, D. filippovae, Haemaphysalis canestrinii, H. formosensis, H. hystricis et H. wellingtoni. Une sérologie réalisée sur 109 vaches a révélé un taux de séropositivité de 93,6 % pour au moins un agent pathogène : Anaplasma, Ehrlichia, Babesia ou Theileria. La détection moléculaire par PCR sur 352 pools de tiques a permis de détecter Anaplasma marginale (1,1%), Ehrlichia minasensis (0,9%), A. platys (0,3%) et des souches non identifiées de Babesia canis (2,0%), Anaplasma spp. (6,6%), Ehrlichia spp. (1,7%) et Babesia spp. (0,9 %). Enfin, les endosymbiontes de type Coxiella étaient présents dans 15,3 % des échantillons tandis que les pathogènes Coxiella spp. étaient rares et présents seulement dans 0,3 % des échantillons. Le séquençage de nouvelle génération (NGS) de 40 tiques récupérées sur bovins a révélé la présence de cinq virus déjà décrits : Guangdong Manly virus, Jingmen tick virus, Mogiana tick virus, Rhipicephalus-associated rhabdo-like virus et Zhangzhou totiv tick virus 1. Les tendances saisonnières indiquent que les infestations du bétail sont plus importantes pendant la saison sèche et atteignent leur maximum au début de la saison des pluies. Plus de tiques adultes ont été prélevées sur les hôtes, comparativement aux stades immatures. Les tiques étaient le plus souvent attachées aux oreilles ou au cou du bétail. Tous les résultats ont permis de préciser la meilleure période et localisation sur le bétail pour des traitements ciblés afin d'améliorer l'efficacité des traitements. Notre étude améliore la compréhension de la diversité des tiques et de la circulation des agents pathogènes transmis par les tiques sur les animaux au Cambodge. Malgré les difficultés rencontrées, telles que l'accès restreint aux forêts, les contraintes logistiques et la caractérisation incomplète des agents pathogènes, ces résultats établissent une base essentielle pour une possible surveillance. La non inclusion de données humaines en raison d'obstacles liés au consentement des patients souligne la nécessité de mener des études intégrées sur l'homme et l'animal, d'améliorer les méthodes de diagnostic (telles que la PCR multiplex et la sérologie) et d'initiatier des surveillances ciblées. Ces étapes sont essentielles pour orienter les stratégies de prévention fondées sur des données probantes et pour atténuer les menaces émergentes liées aux maladies vectorielles à tiques au Cambodge, avec une approche intégrée
Not here yet, but one bite away: Risk for vector-borne zoonotic diseases
No full textInternational audienceRecent data demonstrate that vector-borne diseases (VBDs) are expanding into new regions across the globe. This trend is intensified by the interconnected world characterized by rapid urbanization, environmental changes, and increased human mobility, all of which create favorable conditions for the spread of both vectors and pathogens. Despite this growing threat, many countries still rely on reactive surveillance strategies, responding only after outbreaks occur. This approach focuses mainly on well-known vector species, while other potentially important or emerging vectors remain overlooked. Proactive vector surveillance is essential to anticipate and potentially prevent future outbreaks and monitor the importation of pathogens. The authors call on relevant authorities, researchers, and stakeholders to expand and strengthen vector surveillance systems, with particular emphasis on the inclusion of lesser-known vector species.</div
Characterizing urban landscapes using very-high resolution satellite imagery to predict Ae. albopictus larval presence probability in public spaces
No full textInternational audienceThe global spread of Aedes albopictus raises growing public health concerns due to its role in transmitting dengue, chikungunya, and Zika. In southern France, the increase in imported dengue cases and local transmission underlines the urgent need for effective vector control. While efforts primarily target private breeding sites, public spaces also contribute notably to larvae presence. Understanding the impact of urban landscapes on the distribution of breeding sites is crucial for optimizing vector control strategies, identifying high-risk areas, and reducing mosquito populations. This study aims to investigate how urban landscapes impact the distribution of Ae. albopictus larvae in public spaces, with a focus on storm drains and telecom cable chambers in Montpellier, France. Very high-resolution satellite imagery was used to characterize urban landscapes through textural analyses of spectral indices. Environmental bias was assessed by analyzing the representativity of sampled breeding sites within the diverse urban landscapes. Species distribution models (SDMs) were built, their predictive accuracy was evaluated, and an ensemble model was created to predict larval presence across the study area. SDMs predicted a high probability of larval presence in the western and northeastern parts of Montpellier, with low uncertainty. The most influential variables for predicting larval presence were the mean of Normalized Difference Vegetation Index (NDVI), texture indices from both NDVI, brightness index (BI), and the panchromatic image. Urban vegetation significantly influences larval presence, although higher vegetation index values correlate with a decreased probability of larval occurrence. Additionally, the combination of vegetation and urban structures plays a crucial role in determining the presence of Ae. albopictus larvae in public spaces, where small, organized urban objects and large patches of vegetation increase the likelihood of larval presence. This study highlights the potential of very high-resolution remote sensing and species distribution modeling for enhancing urban mosquito control strategies, ultimately contributing to improved public health policies outcomes in the face of vector-borne disease threats.La propagation mondiale d'Aedes albopictus soulève des préoccupations croissantes en matière de santé publique en raison de son rôle dans la transmission de la dengue, du chikungunya et du Zika. Dans le sud de la France, l'augmentation des cas de dengue importés et de la transmission locale souligne la nécessité urgente d'un contrôle vectoriel efficace. Alors que les efforts visent principalement les sites de reproduction privés, les espaces publics contribuent également notamment à la présence de larves. Il est essentiel de comprendre l'impact des paysages urbains sur la répartition des sites de reproduction pour optimiser les stratégies de lutte contre les vecteurs, identifier les zones à haut risque et réduire les populations de moustiques. Cette étude vise à étudier l’impact des paysages urbains sur la répartition des larves d’Ae. albopictus dans les espaces publics, en mettant l’accent sur les drains pluviaux et les chambres à câble de télécommunications à Montpellier, en France. Des images satellites à très haute résolution ont été utilisées pour caractériser les paysages urbains à travers des analyses texturales d'indices spectraux. Les biais environnementaux ont été évalués en analysant la représentativité des sites de reproduction échantillonnés dans les divers paysages urbains. Des modèles de distribution d'espèces (SDM) ont été construits, leur précision prédictive a été évaluée et un modèle d'ensemble a été créé pour prédire la présence de larves dans la zone d'étude. Les SDM ont prédit une forte probabilité de présence larvaire dans les parties ouest et nord-est de Montpellier, avec une faible incertitude. Les variables les plus influentes pour prédire la présence de larvaires étaient la moyenne de l'indice de végétation de différence normalisée (NDVI), des indices de texture à partir de NDVI, de l'indice de luminosité (BI) et de l'image panchromatique. La végétation urbaine influence de manière significative la présence de larves, bien que les valeurs de l'indice de végétation plus élevées soient en corrélation avec une probabilité réduite d'occurrence de larves. En outre, la combinaison de la végétation et des structures urbaines joue un rôle crucial dans la détermination de la présence de larves d'Ae. albopictus dans les espaces publics, où les petits objets urbains organisés et les grandes parcelles de végétation augmentent la probabilité de présence larvaire. Cette étude met en évidence le potentiel de modélisation de la télédétection et de la distribution d'espèces à très haute résolution pour améliorer les stratégies de lutte contre les moustiques urbains, contribuant finalement à l'amélioration des résultats des politiques de santé publique face aux menaces de maladies à transmission vectorielle