The Life Cycle of Toxoplasma gondii in the Natural Environment

Chapitre 1International audienc

Transmission ecosystems of Echinococcus multilocularis in China and Central Asia

From continental to regional scales, the zoonosis alveolar echinococcosis (AE) (caused by Echinococcus multilocularis) forms discrete patches of endemicity within which transmission hotspots of much larger prevalence may occur. Since the late 80s, a number of hotspots have been identified in continental Asia, mostly in China, wherein the ecology of intermediate host communities has been described. This is the case in south Gansu, at the eastern border of the Tibetan plateau, in south Ningxia, in the western Tian Shan of Xinjiang, and in the Alay valley of south Kyrgyzstan. Here we present a comparative natural history and characteristics of transmission ecosystems or ecoscapes. On this basis, regional types of transmission and their ecological characteristics have been proposed in a general framework. Combining climatic, land cover and intermediate host species distribution data, we identified and mapped 4 spatially distinct types of transmission ecosystems typified by the presence of one of the following small mammal ‘flagship' species: Ellobius tancrei, Ochotona curzoniae, Lasiopodomys brandtii or Eospalax fontanierii. Each transmission ecosystem had its own characteristics which can serve as a reference for further in-depth research in the transmission ecology of E. multilocularis. This approach may be used at fine spatial scales to characterize other poorly known transmission systems of the large Eurasian endemic zone, and help in consideration of surveillance systems and intervention

Core outcomes in neonatology: Development of a core outcome set for neonatal research

Background Neonatal research evaluates many different outcomes using multiple measures. This can prevent synthesis of trial results in meta-analyses and selected outcomes may not be relevant to former patients, parents and health professionals. Objective To define a core outcome set (COS) for research involving infants receiving neonatal care in a high income setting. Design Outcomes reported in neonatal trials and qualitative studies were systematically reviewed. Stakeholders were recruited for a three-round international Delphi survey. A consensus meeting was held to confirm the final COS, based upon the survey results. Participants Four hundred and fourteen former patients, parents, healthcare professionals and researchers took part in the eDelphi survey; 173 completed all 3 rounds. Sixteen stakeholders participated in the consensus meeting. Results The literature reviews identified 104 outcomes; these were included in round one. Participants proposed ten additional outcomes; 114 outcomes were scored in round two and three. Round one scores showed different stakeholder groups prioritised contrasting outcomes. Twelve outcomes were included in the final COS: survival, sepsis, necrotising enterocolitis, brain injury on imaging, general gross motor ability, general cognitive ability, quality of life, adverse events, visual impairment/blindness, hearing impairment /deafness, retinopathy of prematurity and chronic lung disease/bronchopulmonary dysplasia. 6 Conclusions and relevance A COS for clinical trials and other research studies involving infants receiving neonatal care in a high-income setting has been identified. This COS for neonatology will help standardise outcome selection in clinical trials and ensure these are relevant to those most affected by neonatal care

ATLANTIC EPIPHYTES: a data set of vascular and non-vascular epiphyte plants and lichens from the Atlantic Forest

Epiphytes are hyper-diverse and one of the frequently undervalued life forms in plant surveys and biodiversity inventories. Epiphytes of the Atlantic Forest, one of the most endangered ecosystems in the world, have high endemism and radiated recently in the Pliocene. We aimed to (1) compile an extensive Atlantic Forest data set on vascular, non-vascular plants (including hemiepiphytes), and lichen epiphyte species occurrence and abundance; (2) describe the epiphyte distribution in the Atlantic Forest, in order to indicate future sampling efforts. Our work presents the first epiphyte data set with information on abundance and occurrence of epiphyte phorophyte species. All data compiled here come from three main sources provided by the authors: published sources (comprising peer-reviewed articles, books, and theses), unpublished data, and herbarium data. We compiled a data set composed of 2,095 species, from 89,270 holo/hemiepiphyte records, in the Atlantic Forest of Brazil, Argentina, Paraguay, and Uruguay, recorded from 1824 to early 2018. Most of the records were from qualitative data (occurrence only, 88%), well distributed throughout the Atlantic Forest. For quantitative records, the most common sampling method was individual trees (71%), followed by plot sampling (19%), and transect sampling (10%). Angiosperms (81%) were the most frequently registered group, and Bromeliaceae and Orchidaceae were the families with the greatest number of records (27,272 and 21,945, respectively). Ferns and Lycophytes presented fewer records than Angiosperms, and Polypodiaceae were the most recorded family, and more concentrated in the Southern and Southeastern regions. Data on non-vascular plants and lichens were scarce, with a few disjunct records concentrated in the Northeastern region of the Atlantic Forest. For all non-vascular plant records, Lejeuneaceae, a family of liverworts, was the most recorded family. We hope that our effort to organize scattered epiphyte data help advance the knowledge of epiphyte ecology, as well as our understanding of macroecological and biogeographical patterns in the Atlantic Forest. No copyright restrictions are associated with the data set. Please cite this Ecology Data Paper if the data are used in publication and teaching events. © 2019 The Authors. Ecology © 2019 The Ecological Society of Americ

ETUDE DE LA DYNAMIQUE DE LA TRANSMISSION DE TOXOPLASMA GONDII DANS DES MILIEUX CONTRASTES

We studied the dynamic of the transmission of a parasite with complex life-cycle, Toxoplasma gondii, in contrasted environments. First, the dynamic of the parasite transmission was studied in an urban area where a population of domestic cats (Felis catus) live at high density. Our results raise the hypothesis that the parasite transmission could occur via a simple life-cycle when intermediate hosts are in very low density, relative to cats. We also highlighted the presence of localised areas contaminated by T. gondii oocysts, which correspond to defecation site of cats. Second, we studied the dynamic of the transmission of T. gondii in environments where intermediate hosts are in high density. We found indicators of the interspecific variability in the level of infection of intermediate hosts, such as body mass or habitat. Moreover, we showed that environment composition, climate fluctuations and the level of infection of toxoplasmosis in domestic cats and wildcats (Felis silvestris) could be related. The whole study shows the interest of an eco-epidemiological approach to understand the variability of the life-cycle of T. gondii.Ce travail a porté sur l'étude de la dynamique de la transmission d'un parasite à cycle complexe, Toxoplasma gondii, dans des milieux contrastés. Dans une première partie, la dynamique de la transmission du parasite est étudiée dans un site urbain abritant une population très dense de chats domestiques (Felis catus). Nos travaux permettent de poser l'hypothèse d'un cycle de transmission parasitaire simple lorsque les hôtes intermédiaires sont en densité très faible relativement à celle des chats. Par ailleurs, nous mettons en évidence l'existence de zones de contamination du sol par les oocystes de T. gondii, qui sont très localisées, et qui correspondent aux zones de défécation communes des chats. Dans une deuxième partie, la variabilité de la dynamique de transmission de T. gondii dans les milieux riches en hôtes intermédiaires est abordée. Nous mettons notamment en évidence des indicateurs de la variabilité interspécifique du niveau d'infection chez les hôtes intermédiaires (masse corporelle spécifique et habitat). Par ailleurs, nous montrons qu'il existe des relations entre la composition de l'environnement, la variabilité du climat, et le niveau d'infection de la toxoplasmose chez le chat domestique et le chat forestier (Felis silvestris). L'ensemble du travail montre l'intérêt d'une approche éco-épidémiologique dans la compréhension de la variabilité du cycle de T. gondii, notamment par l'utilisation du suivi à long terme de plusieurs populations de chats vivant dans différents environnements. Il ouvre la voie à différentes perspectives de recherche, tant sur le plan appliqué (amélioration de la détection d'oocystes) que sur un aspect de modélisation

RHINO-URB. Impact de différents modèles de croissance urbaine sur la connectivité écologique et la dispersion génétique des populations, test sur le petit rhinolophe en Franche-Comté

Rapport de recherche pour la Fondation pour la Recherche sur la Biodiversité

Transmission of Toxoplasma gondii in an urban population of domestic cats (Felis catus).

International audienceToxoplasma gondii is a protozoan parasite that infects humans and animal species worldwide. The relative importance of each potential transmission route in the complex life cycle of this coccidia is largely unknown, due to the lack of studies taking into account all routes simultaneously. In this study, we analyzed the transmission of T. gondii in an urban population of stray cats captured between 1993 and 2004. Analyzing prevalence, our aim was to determine which factors influence transmission in this population. Specific anti-T. gondii IgG antibodies were detected using the modified agglutination test. Firstly, we analyzed the kinetics of antibody titers in cats captured several times, using mixed linear models and correspondence analysis. We showed that antibody titers did not vary significantly with time and that titer 40 was the best threshold to separate individuals into two serological groups. Overall, prevalence was only 18.6%, thus transmission of T. gondii is infrequent in this population. As expected, a highly significant association was detected between age and presence of IgG antibodies. Prevalence was lowest in kittens aged 3-4 months, suggesting that newborn kittens may carry maternal antibodies and that vertical transmission is rare. After taking into account the effect of age, logistic regression showed that antibody carriage was related to factors that possibly related to the survival of oocysts: localization in the study site, origin of the cats, maximal temperatures and rain. Our results suggest that in this population, vertical transmission is rare, low predation limits prevalence, and oocyst survival is a determining factor in the risk of infection. We discuss the more general importance of conditions determining oocyst survival in the life cycle of T. gondii

Paysage et biodiversité en Franche-Comté. Les chauves-souris peuvent-elles se maintenir durablement ? Exemple du petit rhinolophe

Rapport de recherche pour le Conseil Régional de Franche-Comté