A New High-Throughput Tool to Screen Mosquito-Borne Viruses in Zika Virus Endemic/Epidemic Areas

International audienceMosquitoes are vectors of arboviruses affecting animal and human health. Arboviruses circulate primarily within an enzootic cycle and recurrent spillovers contribute to the emergence of human-adapted viruses able to initiate an urban cycle involving anthropophilic mosquitoes. The increasing volume of travel and trade offers multiple opportunities for arbovirus introduction in new regions. This scenario has been exemplified recently with the Zika pandemic. To incriminate a mosquito as vector of a pathogen, several criteria are required such as the detection of natural infections in mosquitoes. In this study, we used a high-throughput chip based on the BioMark™ Dynamic arrays system capable of detecting 64 arboviruses in a single experiment. A total of 17,958 mosquitoes collected in Zika-endemic/epidemic countries (Brazil, French Guiana, Guadeloupe, Suriname, Senegal, and Cambodia) were analyzed. Here we show that this new tool can detect endemic and epidemic viruses in different mosquito species in an epidemic context. Thus, this fast and low-cost method can be suggested as a novel epidemiological surveillance tool to identify circulating arboviruses

Amélioration du diagnostic des encéphalites virales équines

National audienc

Diversity of Escherichia coli strains isolated from day-old broiler chicks, their environment and colibacillosis lesions in 80 flocks in France

International audienceAvian colibacillosis is the most common bacterial disease affecting broilers. To better evaluate the diversity and the origin of the causative Escherichia coli strains infecting birds, we conducted a study on 80 broiler flocks. Just before the arrival of chicks on the farm, samples were collected in the farm environment (walls, feeders, air inlets, etc.) and, upon delivery, day-old chicks (DOCs) and the transport boxes were also sampled. Isolates were obtained from these samples, and from organs of chickens exhibiting typical colibacillosis symptoms. The isolates were characterized using high-throughput qPCR to detect a range of genetic markers (phylogroups, main serogroups virulence markers, etc.). A total of 967 isolates were studied, including 203 from 28 colibacillosis episodes, 484 from DOCs, 162 from transport boxes and 118 from the farm environment. These isolates yielded 416 different genetic profiles, of which 267 were detected in single isolates, and the others were observed in up to 44 isolates from nine farms. The distributions of isolates across phylogroups and the main serogroups varied with the origin of isolation. The isolates obtained from colibacillosis cases either shared a single genetic profile or were different. In a few cases, we observed the same profile for isolates obtained from DOCs and colibacillosis lesions in the same flock or different flocks. However, some flocks receiving DOCs contaminated with isolates bearing the genetic profile of colibacillosis cases identified in other flocks remained healthy. This study highlights the huge diversity among avian E. coli isolated from diseased and non diseased birds

Noninvasive detection of Zika virus in mosquito excreta sampled from wild mosquito populations in French Guiana

International audienceArboviruses can be difficult to detect in the field due to relatively low prevalence in mosquito populations. The discovery that infected mosquitoes can release viruses in both their saliva and excreta gave rise to low-cost methods for the detection of arboviruses during entomological surveillance. We implemented both saliva and excreta-based entomological surveillance during the emergence of Zika virus (ZIKV) in French Guiana in 2016 by trapping mosquitoes around households of symptomatic cases with confirmed ZIKV infection. ZIKV was detected in mosquito excreta and not in mosquito saliva in 1 trap collection out of 85 (1.2%). One female Ae. aegypti L. (Diptera: Culicidae) was found with a ZIKV systemic infection in the corresponding trap. The lag time between symptom onset in a ZIKV-infected individual living near the trap site and ZIKV detection in this mosquito was 1 wk. These results highlight the potential of detection in excreta from trapped mosquitoes as a sensitive and cost-effective method to non invasively detect arbovirus circulation

Monitoring Silent Spillovers Before Emergence: A Pilot Study at the Tick/Human Interface in Thailand

International audienceEmerging zoonoses caused by previously unknown agents are one of the most important challenges for human health because of their inherent inability to be predictable, conversely to emergences caused by previously known agents that could be targeted by routine surveillance programs. Emerging zoonotic infections either originate from increasing contacts between wildlife and human populations, or from the geographical expansion of hematophagous arthropods that act as vectors, this latter being more capable to impact large-scale human populations. While characterizing the viral communities from candidate vectors in high-risk geographical areas is a necessary initial step, the need to identify which viruses are able to spill over and those restricted to their hosts has recently emerged. We hypothesized that currently unknown tick-borne arboviruses could silently circulate in specific biotopes where mammals are highly exposed to tick bites, and implemented a strategy that combined high-throughput sequencing with broad-range serological techniques to both identify novel arboviruses and tick-specific viruses in a ticks/mammals interface in Thailand. The virome of Thai ticks belonging to the Rhipicephalus, Amblyomma, Dermacentor, Hyalomma, and Haemaphysalis genera identified numerous viruses, among which several viruses could be candidates for future emergence as regards to their phylogenetic relatedness with known tick-borne arboviruses. Luciferase immunoprecipitation system targeting external viral proteins of viruses identified among the Orthomyxoviridae, Phenuiviridae, Flaviviridae, Rhabdoviridae, and Chuviridae families was used to screen human and cattle Thai populations highly exposed to tick bites. Although no positive serum was detected for any of the six viruses selected, suggesting that these viruses are not infecting these vertebrates, or at very low prevalence (upper estimate 0.017% and 0.047% in humans and cattle, respectively), the virome of Thai ticks presents an extremely rich viral diversity, among which novel tick-borne arboviruses are probably hidden and could pose a public health concern if they emerge. The strategy developed in this pilot study, starting from the inventory of viral communities of hematophagous arthropods to end by the identification of viruses able (or likely unable) to infect vertebrates, is the first step in the prediction of putative new emergences and could easily be transposed to other reservoirs/vectors/susceptible hosts interfaces

Les sous-communs: planification fugitive et étude noire

The Undercommons: Fugitive Planning & Black Study, Minor Compositions, 2013).Les sous-communs, planification fugitive et étude noire est une série d'essais publiée en 2013 par deux amis, Stefano Harney et Fred Moten. Au fil de ces textes, les auteurs proposent une critique du capitalisme racial et de ses outils (gouvernance, crédit, université) ainsi que des modes d'expérimentation sociale en forme de résistance au colonial. La recherche passe par l'étude et se déroule bien au-delà de l'université, au travail, lors d'une pause cigarette, en famille, autour d'un repas, à la lisière de la lutte et de la fuite, à l'intérieur d'un mouvement de tremblement des fondations impérialistes, d'un mouvement de refus des termes du combat tel qu'il est imposé par le système dominant, vers la construction d'un espace social et politique en perpétuel déplacement. Le lieu et l'être sous-communs relèvent de l'incertitude de la création collective, de l'habitation par l'échange, de l'improvisation comme critique.Les sous-communs s'écrit dans le sillage de la tradition radicale noire de manière à la fois théorique et poétique, auprés d'auteur*ices comme Cedric Robinson, Saidiya Hartman, Frantz Fanon et Édouard Glissant .La multitude profite de chaque temps calme, chaque crépuscule, chaque instant de préservation militante, pour planifier ensemble, lancer, composer (dans) son temps surréel.- Moten et Harney, p. 92.Stefano Harney est chercheur en sociologie et enseignant. Co-fondateur de la résidence de lecture Ground Provisions et du collectif d'enseignant*es School for Study, il est l'auteur de The Liberal Arts and Management Education (2020), Nationalism & Identity Culture (2006) et State Work: Public Administration and Mass Intellectuality (2002).Fred Moten est poète et professeur au département de Performance Studies de l'Université de New York, Tisch School of the Arts. Il est l'auteur de la trilogie consent not to be a single being, The Universal Machine (2018) ; Stolen Life (2018) et Black and Blur, (2017) ; The Service Porch (2016) ; B Jenkins (2010) ; In the Break: The Aesthetics of the Black Radical Tradition (2003)