6 research outputs found
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 BioMarkâą 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
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 1Â 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 Ă©tude noire
The Undercommons: Fugitive Planning & Black Study, Minor Compositions, 2013).Les sous-communs, planification fugitive et Ă©tude noire est une sĂ©rie d'essais publiĂ©e 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, crĂ©dit, universitĂ©) ainsi que des modes d'expĂ©rimentation sociale en forme de rĂ©sistance au colonial. La recherche passe par l'Ă©tude et se dĂ©roule bien au-delĂ de l'universitĂ©, au travail, lors d'une pause cigarette, en famille, autour d'un repas, Ă la lisiĂšre de la lutte et de la fuite, Ă l'intĂ©rieur d'un mouvement de tremblement des fondations impĂ©rialistes, d'un mouvement de refus des termes du combat tel qu'il est imposĂ© par le systĂšme dominant, vers la construction d'un espace social et politique en perpĂ©tuel dĂ©placement. Le lieu et l'ĂȘtre sous-communs relĂšvent de l'incertitude de la crĂ©ation collective, de l'habitation par l'Ă©change, de l'improvisation comme critique.Les sous-communs s'Ă©crit dans le sillage de la tradition radicale noire de maniĂšre Ă la fois thĂ©orique et poĂ©tique, auprĂ©s d'auteur*ices comme Cedric Robinson, Saidiya Hartman, Frantz Fanon et Ădouard Glissant .La multitude profite de chaque temps calme, chaque crĂ©puscule, chaque instant de prĂ©servation militante, pour planifier ensemble, lancer, composer (dans) son temps surrĂ©el.- Moten et Harney, p. 92.Stefano Harney est chercheur en sociologie et enseignant. Co-fondateur de la rĂ©sidence 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 poĂšte et professeur au dĂ©partement de Performance Studies de l'UniversitĂ© 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)