Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 80
Filtrar
1.
Nat Commun ; 15(1): 3988, 2024 May 11.
Artículo en Inglés | MEDLINE | ID: mdl-38734682

RESUMEN

Tick-borne bacteria of the genera Ehrlichia and Anaplasma cause several emerging human infectious diseases worldwide. In this study, we conduct an extensive survey for Ehrlichia and Anaplasma infections in the rainforests of the Amazon biome of French Guiana. Through molecular genetics and metagenomics reconstruction, we observe a high indigenous biodiversity of infections circulating among humans, wildlife, and ticks inhabiting these ecosystems. Molecular typing identifies these infections as highly endemic, with a majority of new strains and putative species specific to French Guiana. They are detected in unusual rainforest wild animals, suggesting they have distinctive sylvatic transmission cycles. They also present potential health hazards, as revealed by the detection of Candidatus Anaplasma sparouinense in human red blood cells and that of a new close relative of the human pathogen Ehrlichia ewingii, Candidatus Ehrlichia cajennense, in the tick species that most frequently bite humans in South America. The genome assembly of three new putative species obtained from human, sloth, and tick metagenomes further reveals the presence of major homologs of Ehrlichia and Anaplasma virulence factors. These observations converge to classify health hazards associated with Ehrlichia and Anaplasma infections in the Amazon biome as distinct from those in the Northern Hemisphere.


Asunto(s)
Anaplasma , Animales Salvajes , Ehrlichia , Filogenia , Bosque Lluvioso , Garrapatas , Anaplasma/genética , Anaplasma/aislamiento & purificación , Anaplasma/patogenicidad , Anaplasma/clasificación , Ehrlichia/genética , Ehrlichia/aislamiento & purificación , Ehrlichia/clasificación , Humanos , Animales , Garrapatas/microbiología , Animales Salvajes/microbiología , Anaplasmosis/microbiología , Anaplasmosis/epidemiología , Anaplasmosis/transmisión , Guyana Francesa , Ehrlichiosis/microbiología , Ehrlichiosis/epidemiología , Ehrlichiosis/veterinaria , Ehrlichiosis/transmisión , Metagenómica/métodos , Genoma Bacteriano/genética , ARN Ribosómico 16S/genética
2.
mSystems ; 8(5): e0038823, 2023 Oct 26.
Artículo en Inglés | MEDLINE | ID: mdl-37650612

RESUMEN

IMPORTANCE: Myrmecophagous mammals are specialized in the consumption of ants and/or termites. They do not share a direct common ancestor and evolved convergently in five distinct placental orders raising questions about the underlying adaptive mechanisms involved and the relative contribution of natural selection and phylogenetic constraints. Understanding how these species digest their prey can help answer these questions. More specifically, the role of their gut microbial symbionts in the digestion of the insect chitinous exoskeleton has not been investigated in all myrmecophagous orders. We generated 29 new gut metagenomes from nine myrmecophagous species to reconstruct more than 300 bacterial genomes in which we identified chitin-degrading enzymes. Studying the distribution of these chitinolytic bacteria among hosts revealed both shared and specific bacteria between ant-eating species. Overall, our results highlight the potential role of gut symbionts in the convergent dietary adaptation of myrmecophagous mammals and the evolutionary mechanisms shaping their gut microbiota.


Asunto(s)
Microbioma Gastrointestinal , Embarazo , Animales , Femenino , Microbioma Gastrointestinal/genética , Filogenia , Quitina , Placenta , Mamíferos/microbiología , Digestión
3.
Zookeys ; 1167: 241-264, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37388777

RESUMEN

Mazamanemorivaga (Cuvier, 1817) is a gray brocket deer that inhabits the Amazon region. An assessment of previous studies revealed inconsistencies in its current taxonomic classification, suggesting the need for an update in its genus classification. A taxonomic repositioning of this species is proposed through the collection of a specimen from its type locality (French Guiana) with subsequent morphological (coloring pattern, body measurements, and craniometry), cytogenetics (G Band, C Band, conventional Giemsa, Ag-NOR staining, and BAC probe mapping), and molecular phylogenetic analysis (mitochondrial genes Cyt B of 920 bp, COI I of 658 bp, D-loop 610 bp), and comparisons with other specimens of the same taxon, as well as other Neotropical deer species. The morphological and cytogenetic differences between this and other Neotropical Cervidae confirm the taxon as a unique and valid species. The phylogenetic analysis evidenced the basal position of the M.nemorivaga specimens within the Blastocerina clade. This shows early diversification and wide divergence from the other species, suggesting that the taxon should be transferred to a different genus. A taxonomic update of the genus name is proposed through the validation of Passalites Gloger, 1841, with Passalitesnemorivagus (Cuvier, 1817) as the type species. Future research should focus on evaluating the potential existence of other species within the genus Passalites, as suggested in the literature.

4.
Viruses ; 15(6)2023 05 29.
Artículo en Inglés | MEDLINE | ID: mdl-37376570

RESUMEN

French Guiana (FG), a French overseas territory in South America, is susceptible to tropical diseases, including arboviruses. The tropical climate supports the proliferation and establishment of vectors, making it difficult to control transmission. In the last ten years, FG has experienced large outbreaks of imported arboviruses such as Chikungunya and Zika, as well as endemic arboviruses such as dengue, Yellow fever, and Oropouche virus. Epidemiological surveillance is challenging due to the differing distributions and behaviors of vectors. This article aims to summarize the current knowledge of these arboviruses in FG and discuss the challenges of arbovirus emergence and reemergence. Effective control measures are hampered by the nonspecific clinical presentation of these diseases, as well as the Aedes aegypti mosquito's resistance to insecticides. Despite the high seroprevalence of certain viruses, the possibility of new epidemics cannot be ruled out. Therefore, active epidemiological surveillance is needed to identify potential outbreaks, and an adequate sentinel surveillance system and broad virological diagnostic panel are being developed in FG to improve disease management.


Asunto(s)
Aedes , Infecciones por Arbovirus , Arbovirus , Fiebre Chikungunya , Dengue , Infección por el Virus Zika , Virus Zika , Animales , Humanos , Infecciones por Arbovirus/diagnóstico , Infecciones por Arbovirus/epidemiología , Guyana Francesa/epidemiología , Estudios Seroepidemiológicos , Fiebre Chikungunya/epidemiología , Infección por el Virus Zika/epidemiología , América del Sur/epidemiología , Dengue/diagnóstico , Dengue/epidemiología
5.
Int J Infect Dis ; 133: 9-13, 2023 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-37116577

RESUMEN

In light of current international public health challenges, calls for inter- and transdisciplinary research are increasing, particularly in response to complex and intersecting issues. Although widely used under the One Health flag, it is still unclear how inter- and transdisciplinary science should be applied to infectious disease research, public health, and the different stakeholders. Here, we present and discuss our common scientific and biomedical experience in French Guiana, South America to conduct and enrich research in vector-borne and zoonotic infectious diseases, with the aim to translate findings to public health and political stakeholders. We highlight the successful progressive dissolution of disciplinary boundaries that go beyond One Health positive-driven assumptions and argue that specific local conditions, as well as strong support from research and medical institutions, have facilitated an emulsion toward inter- and transdisciplinary science. This argument is intended to improve responses to public health concerns in French Guiana and other countries and regions of the world.


Asunto(s)
Enfermedades Transmisibles Emergentes , Humanos , Guyana Francesa/epidemiología , Enfermedades Transmisibles Emergentes/epidemiología , Enfermedades Transmisibles Emergentes/prevención & control , Investigación Interdisciplinaria , Pandemias , América del Sur/epidemiología
6.
Mol Ecol ; 32(3): 628-643, 2023 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-36336814

RESUMEN

Hybridization is known to be part of many species' evolutionary history. Sea turtles have a fascinating hybridization system in which species separated by as much as 43 million years are still capable of hybridizing. Indeed, the largest nesting populations in Brazil of loggerheads (Caretta caretta) and hawksbills (Eretmochelys imbricata) have a high incidence of hybrids between these two species. A third species, olive ridleys (Lepidochelys olivacea), is also known to hybridize although at a smaller scale. Here, we used restriction site-associated DNA sequencing (RAD-Seq) markers, mitogenomes, and satellite-telemetry to investigate the patterns of hybridization and introgression in the Brazilian sea turtle population and their relationship with the migratory behaviours between feeding and nesting aggregations. We also explicitly test if the mixing of two divergent genomes in sea turtle hybrids causes mitochondrial paternal leakage. We developed a new species-specific PCR-assay capable of detecting mitochondrial DNA (mtDNA) inheritance from both parental species and performed ultra-deep sequencing to estimate the abundance of each mtDNA type. Our results show that all adult hybrids are first generation (F1) and most display a loggerhead migratory behaviour. We detected paternal leakage in F1 hybrids and different proportions of mitochondria from maternal and paternal species. Although previous studies showed no significant fitness decrease in hatchlings, our results support genetically-related hybrid breakdown possibly caused by cytonuclear incompatibility. Further research on hybrids from other populations in addition to Brazil and between different species will show if backcross inviability and mitochondrial paternal leakage is observed across sea turtle species.


Asunto(s)
ADN Mitocondrial , Tortugas , Animales , ADN Mitocondrial/genética , Tortugas/genética , Mitocondrias/genética , Evolución Biológica , Reacción en Cadena de la Polimerasa
7.
Mol Ecol ; 32(8): 1817-1831, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-35000240

RESUMEN

Changes in biodiversity may impact infectious disease transmission through multiple mechanisms. We explored the impact of biodiversity changes on the transmission of Amazonian leishmaniases, a group of wild zoonoses transmitted by phlebotomine sand flies (Psychodidae), which represent an important health burden in a region where biodiversity is both rich and threatened. Using molecular analyses of sand fly pools and blood-fed dipterans, we characterized the disease system in forest sites in French Guiana undergoing different levels of human-induced disturbance. We show that the prevalence of Leishmania parasites in sand flies correlates positively with the relative abundance of mammal species known as Leishmania reservoirs. In addition, Leishmania reservoirs tend to dominate in less diverse mammal communities, in accordance with the dilution effect hypothesis. This results in a negative relationship between Leishmania prevalence and mammal diversity. On the other hand, higher mammal diversity is associated with higher sand fly density, possibly because more diverse mammal communities harbor higher biomass and more abundant feeding resources for sand flies, although more research is needed to identify the factors that shape sand fly communities. As a consequence of these antagonistic effects, decreased mammal diversity comes with an increase of parasite prevalence in sand flies, but has no detectable impact on the density of infected sand flies. These results represent additional evidence that biodiversity changes may simultaneously dilute and amplify vector-borne disease transmission through different mechanisms that need to be better understood before drawing generalities on the biodiversity-disease relationship.


Asunto(s)
Leishmania , Leishmaniasis , Psychodidae , Animales , Humanos , Leishmania/genética , Biodiversidad , Zoonosis , Mamíferos
8.
Conserv Genet ; 23(6): 995-1010, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36397975

RESUMEN

Globally distributed marine taxa are well suited for investigations of biogeographic impacts on genetic diversity, connectivity, and population demography. The sea turtle genus Lepidochelys includes the wide-ranging and abundant olive ridley (L. olivacea), and the geographically restricted and 'Critically Endangered' Kemp's ridley (L. kempii). To investigate their historical biogeography, we analyzed a large dataset of mitochondrial DNA (mtDNA) sequences from olive (n = 943) and Kemp's (n = 287) ridleys, and genotyped 15 nuclear microsatellite loci in a global sample of olive ridleys (n = 285). We found that the ridley species split ~ 7.5 million years ago, before the Panama Isthmus closure. The most ancient mitochondrial olive ridley lineage, located in the Indian Ocean, was dated to ~ 2.2 Mya. Both mitochondrial and nuclear markers revealed significant structure for olive ridleys between Atlantic (ATL), East Pacific (EP), and Indo-West Pacific (IWP) areas. However, the divergence of mtDNA clades was very recent (< 1 Mya) with low within- clade diversity, supporting a recurrent extinction-recolonization model for these ocean regions. All data showed that ATL and IWP groups were more closely related than those in the EP, with mtDNA data supporting recent recolonization of the ATL from the IWP. Individual olive ridley dispersal between the ATL, EP, and IN/IWP could be interpreted as more male- than female-biased, and genetic diversity was lowest in the Atlantic Ocean. All populations showed signs of recent expansion, and estimated time frames were concordant with their recent colonization history. Investigating species abundance and distribution changes over time is central to evolutionary biology, and this study provides a historical biogeographic context for marine vertebrate conservation and management. Supplementary Information: The online version contains supplementary material available at 10.1007/s10592-022-01465-3.

9.
Proc Natl Acad Sci U S A ; 119(30): e2122165119, 2022 07 26.
Artículo en Inglés | MEDLINE | ID: mdl-35867831

RESUMEN

Successful infectious disease interventions can result in large reductions in parasite prevalence. Such demographic change has fitness implications for individual parasites and may shift the parasite's optimal life history strategy. Here, we explore whether declining infection rates can alter Plasmodium falciparum's investment in sexual versus asexual growth. Using a multiscale mathematical model, we demonstrate how the proportion of polyclonal infections, which decreases as parasite prevalence declines, affects the optimal sexual development strategy: Within-host competition in multiclone infections favors a greater investment in asexual growth whereas single-clone infections benefit from higher conversion to sexual forms. At the same time, drug treatment also imposes selection pressure on sexual development by shortening infection length and reducing within-host competition. We assess these models using 148 P. falciparum parasite genomes sampled in French Guiana over an 18-y period of intensive intervention (1998 to 2015). During this time frame, multiple public health measures, including the introduction of new drugs and expanded rapid diagnostic testing, were implemented, reducing P. falciparum malaria cases by an order of magnitude. Consistent with this prevalence decline, we see an increase in the relatedness among parasites, but no single clonal background grew to dominate the population. Analyzing individual allele frequency trajectories, we identify genes that likely experienced selective sweeps. Supporting our model predictions, genes showing the strongest signatures of selection include transcription factors involved in the development of P. falciparum's sexual gametocyte form. These results highlight how public health interventions impose wide-ranging selection pressures that affect basic parasite life history traits.


Asunto(s)
Malaria Falciparum , Plasmodium falciparum , Animales , Antimaláricos/farmacología , Frecuencia de los Genes , Humanos , Malaria Falciparum/tratamiento farmacológico , Malaria Falciparum/epidemiología , Malaria Falciparum/parasitología , Modelos Biológicos , Plasmodium falciparum/efectos de los fármacos , Plasmodium falciparum/genética , Plasmodium falciparum/crecimiento & desarrollo , Prevalencia
10.
Ecology ; 103(9): e3738, 2022 09.
Artículo en Inglés | MEDLINE | ID: mdl-35567292

RESUMEN

The Amazon forest has the highest biodiversity on Earth. However, information on Amazonian vertebrate diversity is still deficient and scattered across the published, peer-reviewed, and gray literature and in unpublished raw data. Camera traps are an effective non-invasive method of surveying vertebrates, applicable to different scales of time and space. In this study, we organized and standardized camera trap records from different Amazon regions to compile the most extensive data set of inventories of mammal, bird, and reptile species ever assembled for the area. The complete data set comprises 154,123 records of 317 species (185 birds, 119 mammals, and 13 reptiles) gathered from surveys from the Amazonian portion of eight countries (Brazil, Bolivia, Colombia, Ecuador, French Guiana, Peru, Suriname, and Venezuela). The most frequently recorded species per taxa were: mammals: Cuniculus paca (11,907 records); birds: Pauxi tuberosa (3713 records); and reptiles: Tupinambis teguixin (716 records). The information detailed in this data paper opens up opportunities for new ecological studies at different spatial and temporal scales, allowing for a more accurate evaluation of the effects of habitat loss, fragmentation, climate change, and other human-mediated defaunation processes in one of the most important and threatened tropical environments in the world. The data set is not copyright restricted; please cite this data paper when using its data in publications and we also request that researchers and educators inform us of how they are using these data.


Asunto(s)
Bosques , Mamíferos , Animales , Biodiversidad , Aves , Brasil , Humanos , Reptiles , Vertebrados
11.
Viruses ; 13(9)2021 08 26.
Artículo en Inglés | MEDLINE | ID: mdl-34578272

RESUMEN

Rodents are important reservoirs of numerous viruses, some of which have significant impacts on public health. Ecosystem disturbances and decreased host species richness have been associated with the emergence of zoonotic diseases. In this study, we aimed at (a) characterizing the viral diversity in seven neotropical rodent species living in four types of habitats and (b) exploring how the extent of environmental disturbance influences this diversity. Through a metagenomic approach, we identified 77,767 viral sequences from spleen, kidney, and serum samples. These viral sequences were attributed to 27 viral families known to infect vertebrates, invertebrates, plants, and amoeba. Viral diversities were greater in pristine habitats compared with disturbed ones, and lowest in peri-urban areas. High viral richness was observed in savannah areas. Differences in these diversities were explained by rare viruses that were generally more frequent in pristine forest and savannah habitats. Moreover, changes in the ecology and behavior of rodent hosts, in a given habitat, such as modifications to the diet in disturbed vs. pristine forests, are major determinants of viral composition. Lastly, the phylogenetic relationships of four vertebrate-related viral families (Polyomaviridae, Flaviviridae, Togaviridae, and Phenuiviridae) highlighted the wide diversity of these viral families, and in some cases, a potential risk of transmission to humans. All these findings provide significant insights into the diversity of rodent viruses in Amazonia, and emphasize that habitats and the host's dietary ecology may drive viral diversity. Linking viral richness and abundance to the ecology of their hosts and their responses to habitat disturbance could be the starting point for a better understanding of viral emergence and for future management of ecosystems.


Asunto(s)
Ecosistema , Variación Genética , Roedores/virología , Virus/clasificación , Virus/genética , Zoonosis/virología , Animales , Ecología , Bosques , Metagenoma , Filogenia , Zoonosis/transmisión
12.
Infect Genet Evol ; 93: 104916, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34004361

RESUMEN

French Guiana is a European ultraperipheric region located on the northern Atlantic coast of South America. It constitutes an important forested region for biological conservation in the Neotropics. Although very sparsely populated, with its inhabitants mainly concentrated on the Atlantic coastal strip and along the two main rivers, it is marked by the presence and development of old and new epidemic disease outbreaks, both research and health priorities. In this review paper, we synthetize 15 years of multidisciplinary and integrative research at the interface between wildlife, ecosystem modification, human activities and sociodemographic development, and human health. This study reveals a complex epidemiological landscape marked by important transitional changes, facilitated by increased interconnections between wildlife, land-use change and human occupation and activity, human and trade transportation, demography with substantial immigration, and identified vector and parasite pharmacological resistance. Among other French Guianese characteristics, we demonstrate herein the existence of more complex multi-host disease life cycles than previously described for several disease systems in Central and South America, which clearly indicates that today the greater promiscuity between wildlife and humans due to demographic and economic pressures may offer novel settings for microbes and their hosts to circulate and spread. French Guiana is a microcosm that crystallizes all the current global environmental, demographic and socioeconomic change conditions, which may favor the development of ancient and future infectious diseases.


Asunto(s)
Animales Salvajes , Demografía , Ecosistema , Enfermedades Transmitidas por Vectores , Zoonosis , Animales , Guyana Francesa/epidemiología , Actividades Humanas , Humanos , Incidencia , Investigación Interdisciplinaria , Prevalencia , Enfermedades Transmitidas por Vectores/epidemiología , Enfermedades Transmitidas por Vectores/transmisión , Zoonosis/epidemiología , Zoonosis/etiología , Zoonosis/transmisión
13.
Mol Ecol Resour ; 21(6): 1875-1888, 2021 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-33787010

RESUMEN

Environmental DNA (eDNA) metabarcoding has emerged as one of the most efficient methods to assess aquatic species presence. While the method can in theory be used to investigate nonaquatic fauna, its development for inventorying semi-aquatic and terrestrial fauna is still at an early stage. Here we investigated the potential of aquatic eDNA metabarcoding for inventorying mammals in Neotropical environments, be they aquatic, semi-aquatic or terrestrial. We collected aquatic eDNA in 96 sites distributed along three Guianese watersheds and compared our inventories to expected species distributions and field observations derived from line transects located throughout French Guiana. Species occurrences and emblematic mammalian fauna richness patterns were consistent with the expected distribution of fauna and our results revealed that aquatic eDNA metabarcoding brings additional data to line transect samples for diurnal nonaquatic (terrestrial and arboreal) species. Aquatic eDNA also provided data on species not detectable in line transect surveys such as semi-aquatic, aquatic and nocturnal terrestrial and arboreal species. Although the application of eDNA to inventory mammals still needs some developments to optimize sampling efficiency, it can now be used as a complement to traditional surveys.


Asunto(s)
ADN Ambiental , Mamíferos , Agua , Animales , Biodiversidad , Código de Barras del ADN Taxonómico , Monitoreo del Ambiente , Guyana Francesa , Mamíferos/clasificación , Mamíferos/genética
14.
Infect Genet Evol ; 90: 104769, 2021 06.
Artículo en Inglés | MEDLINE | ID: mdl-33588065

RESUMEN

Bats are recognized as reservoirs of numerous viruses. Among them, paramyxoviruses, for example, Hendra and Nipah viruses, are highly pathogenic to humans. Nothing is known regarding the circulation of this viral family in bats from French Guiana. To search for the presence of paramyxoviruses in this territory, 103 bats of seven different species were sampled and screened using a molecular approach. Four distinct paramyxovirus sequences were detected from three bat species (Desmodus rotundus, Carollia perspicillata, and Pteronotus alitonus) at high prevalence rates. In D. rotundus, two types of paramyxovirus co-circulate, with most of the bats co-infected. The phylogenetic analysis of these sequences revealed that three of them were closely related to previously characterized sequences from D. rotundus, C. perspicillata, and P. parnellii from Brazil and Costa Rica. The fourth sequence, identified in D. rotundus, was closely related to the one detected in P. alitonus in French Guiana and to previously described sequences detected in P. parnellii in Costa Rica. All paramyxovirus sequences detected in this study are close to the Jeilongvirus genus. Altogether, our results and those of previous studies indicate a wide geographical distribution of these paramyxoviruses (from Central to South America) and suggest potential cross-species transmissions of paramyxoviruses between two different bat families: Mormoopidae (P. alitonus) and Phyllostomidae (D. rotundus). In addition, their closeness to paramyxoviruses identified in rodents emphasizes the need to investigate the role of these animals as potential reservoirs or incidental hosts. Finally, the high prevalence rates of some paramyxoviruses in certain bat species, associated with the presence of large bat colonies and, in some cases, their potential proximity with humans are all parameters that can contribute to the risk of cross-species transmission between bat species and to the emergence of new paramyxoviruses in humans, a risk that deserves further investigation.


Asunto(s)
Quirópteros , Infecciones por Paramyxoviridae/veterinaria , Paramyxoviridae/fisiología , Animales , Guyana Francesa/epidemiología , Infecciones por Paramyxoviridae/epidemiología , Infecciones por Paramyxoviridae/virología
15.
PLoS Negl Trop Dis ; 14(10): e0008658, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-33017419

RESUMEN

BACKGROUND: From the end of 2016 until the beginning of 2019, Brazil faced a massive sylvatic yellow fever (YF) outbreak. The 2016-2019 YF epidemics affected densely populated areas, especially the Southeast region, causing thousands of deaths of humans and non-human primates (NHP). METHODOLOGY/PRINCIPAL FINDINGS: We conducted a molecular investigation of yellow fever virus (YFV) RNA in 781 NHP carcasses collected in the urban, urban-rural interface, and rural areas of Minas Gerais state, from January 2017 to December 2018. Samples were analyzed according to the period of sampling, NHP genera, sampling areas, and sampling areas/NHP genera to compare the proportions of YFV-positive carcasses and the estimated YFV genomic loads. YFV infection was confirmed in 38.1% of NHP carcasses (including specimens of the genera Alouatta, Callicebus, Callithrix, and Sapajus), from the urban, urban-rural interface, and rural areas. YFV RNA detection was positively associated with epidemic periods (especially from December to March) and the rural environment. Higher median viral genomic loads (one million times) were estimated in carcasses collected in rural areas compared to urban ones. CONCLUSIONS/SIGNIFICANCE: The results showed the wide occurrence of YF in Minas Gerais in epidemic and non-epidemic periods. According to the sylvatic pattern of YF, a gradient of viral dissemination from rural towards urban areas was observed. A high YF positivity was observed for NHP carcasses collected in urban areas with a widespread occurrence in 67 municipalities of Minas Gerais, including large urban centers. Although there was no documented case of urban/Aedes YFV transmission to humans in Brazil during the 2016-2019 outbreaks, YFV-infected NHP in urban areas with high infestation by Aedes aegypti poses risks for YFV urban/Aedes transmission and urbanization.


Asunto(s)
Fiebre Amarilla/epidemiología , Fiebre Amarilla/prevención & control , Fiebre Amarilla/transmisión , Zoonosis/virología , Aedes/virología , Alouatta/virología , Animales , Brasil/epidemiología , Callicebus/virología , Callithrix/virología , Reservorios de Enfermedades/virología , Epidemias , Genoma Viral , Humanos , Mosquitos Vectores/virología , Primates/virología , Sapajus/virología , Virus de la Fiebre Amarilla/aislamiento & purificación , Virus de la Fiebre Amarilla/patogenicidad , Zoonosis/epidemiología , Zoonosis/transmisión
16.
PLoS Negl Trop Dis ; 14(10): e0008691, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-33001982

RESUMEN

Optimise control strategies of infectious diseases, identify factors that favour the circulation of pathogens, and propose risk maps are crucial challenges for global health. Ecological niche modelling, once relying on an adequate framework and environmental descriptors can be a helpful tool for such purposes. Despite the existence of a vaccine, yellow fever (YF) is still a public health issue. Brazil faced massive sylvatic YF outbreaks from the end of 2016 up to mid-2018, but cases in human and non-human primates have been recorded until the beginning of 2020. Here we used both human and monkey confirmed YF cases from two epidemic periods (2016/2017 and 2017/2018) to describe the spatial distribution of the cases and explore how biotic and abiotic factors drive their occurrence. The distribution of YF cases largely overlaps for humans and monkeys, and a contraction of the spatial extent associated with a southward displacement is observed during the second period of the epidemics. More contributive variables to the spatiotemporal heterogeneity of cases were related to biotic factors (mammal richness), abiotic factors (temperature and precipitation), and some human-related variables (population density, human footprint, and human vaccination coverage). Both projections of the most favourable conditions showed similar trends with a contraction of the more at-risk areas. Once extrapolated at a large scale, the Amazon basin remains at lower risk, although surrounding forest regions and notably the North-West region, would face a higher risk. Spatial projections of infectious diseases often relied on climatic variables only; here for both models, we instead highlighted the importance of considering local biotic conditions, hosts vulnerability, social and epidemiological factors to run the spatial risk analysis correctly: all YF cases occurring later on, in 2019 and 2020, were observed in the predicted at-risk areas.


Asunto(s)
Epidemias , Fiebre Amarilla/epidemiología , Brasil/epidemiología , Demografía , Ecosistema , Humanos , Modelos Biológicos , Factores de Riesgo
17.
PeerJ ; 8: e9690, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32983632

RESUMEN

BACKGROUND: Ecological adaptations of mammals are reflected in the morphological diversity of their feeding apparatus, which includes differences in tooth crown morphologies, variation in snout size, or changes in muscles of the feeding apparatus. The adaptability of their feeding apparatus allowed them to optimize resource exploitation in a wide range of habitats. The combination of computer-assisted X-ray microtomography (µ-CT) with contrast-enhancing staining protocols has bolstered the reconstruction of three-dimensional (3D) models of muscles. This new approach allows for accurate descriptions of muscular anatomy, as well as the quick measurement of muscle volumes and fiber orientation. Ant- and termite-eating (myrmecophagy) represents a case of extreme feeding specialization, which is usually accompanied by tooth reduction or complete tooth loss, snout elongation, acquisition of a long vermiform tongue, and loss of the zygomatic arch. Many of these traits evolved independently in distantly-related mammalian lineages. Previous reports on South American anteaters (Vermilingua) have shown major changes in the masticatory, intermandibular, and lingual muscular apparatus. These changes have been related to a functional shift in the role of upper and lower jaws in the evolutionary context of their complete loss of teeth and masticatory ability. METHODS: We used an iodine staining solution (I2KI) to perform contrast-enhanced µ-CT scanning on heads of the pygmy (Cyclopes didactylus), collared (Tamandua tetradactyla) and giant (Myrmecophaga tridactyla) anteaters. We reconstructed the musculature of the feeding apparatus of the three extant anteater genera using 3D reconstructions complemented with classical dissections of the specimens. We performed a description of the musculature of the feeding apparatus in the two morphologically divergent vermilinguan families (Myrmecophagidae and Cyclopedidae) and compared it to the association of morphological features found in other myrmecophagous placentals. RESULTS: We found that pygmy anteaters (Cyclopes) present a relatively larger and architecturally complex temporal musculature than that of collared (Tamandua) and giant (Myrmecophaga) anteaters, but shows a reduced masseter musculature, including the loss of the deep masseter. The loss of this muscle concurs with the loss of the jugal bone in Cyclopedidae. We show that anteaters, pangolins, and aardvarks present distinct anatomies despite morphological and ecological convergences.

18.
Zookeys ; 958: 143-164, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32863720

RESUMEN

Mazama americana (red brocket deer) is the genus-type species (first species described for this genus) and the basis for the identity of other Mazama species. Mazama americana is one of the most abundant and widely distributed deer species in the neotropical forest. However, recent studies suggest that this taxon belongs to a species complex. Our goal was to collect an animal at the type locality (topotype) in French Guiana with the aim of characterizing the morphological (biometric, craniometric), cytogenetic (Giemsa, C-banding, G-banding and NOR) and molecular (mitochondrial DNA) features. The comparisons showed that the collected specimen was very similar morphologically to specimens from other South American populations, but it was cytogenetically and molecularly very different from any of the cytotypes already described for this species, corroborating the existence of a complex of cryptic species. The data suggest that the M. americana topotype is a different species from all the cytotypes already described in the literature and which occupy the southern region of the Amazon River. The characterization and designation of the M. americana neotype is the first step toward a taxonomic reorganization of the genus Mazama, with the potential identification of new species.

19.
Infect Genet Evol ; 84: 104367, 2020 10.
Artículo en Inglés | MEDLINE | ID: mdl-32450245

RESUMEN

In the past decade, a large number of studies have detected herpesvirus sequences from many bat species around the world. Nevertheless, the discovery of bat herpesviruses is geographically uneven. Of the various bat species tested to date, only a few were from the New World. Seeking to investigate the distribution and diversity of herpesviruses circulating in neotropical bats, we carried out molecular screening of 195 blood DNA samples from 11 species of three bat families (Phyllostomidae, Mormoopidae, and Molossidae). Using polymerase chain reaction amplification, with degenerate consensus primers targeting highly conserved amino acid motifs of the herpesvirus DNA polymerase and Glycoprotein B genes, we characterized novel viral sequences from all tested species. BLAST searches, pairwise nucleotide and amino acid sequence comparisons, as well as phylogenetic analyses confirmed that they all belonged to the Herpesviridae family, of the Beta- and Gammaherpesvirinae subfamilies. Fourteen partial DNA polymerase gene sequences, of which three beta- and 11 gamma-herpesviruses, were detected. A total of 12 partial Glycoprotein B gene sequences, all gamma-herpesviruses, were characterized. Every sequence was specific to a bat species and in some species (Desmodus rotundus, Carollia perspicillata, and Pteronotus rubiginosus) multiple viruses were found. Phylogenetic analyses of beta- and gammaherpesvirus sequences led to the identification of bat-specific clades. Those composed of sequences obtained from different bat species belonging to distinct subfamilies follow the taxonomy of bats. This study confirms the astonishing diversity of bat herpesviruses and broadens our knowledge of their host range. Nevertheless, it also emphasizes the fact that, to better appreciate the evolutionary history of these viruses, much remains to be done at various taxonomic levels.


Asunto(s)
Quirópteros/virología , Herpesviridae/genética , Filogenia , Proteínas Virales/genética , Animales , ADN Polimerasa Dirigida por ADN/genética , Exodesoxirribonucleasas/genética , Guyana Francesa , Gammaherpesvirinae/genética , Glicoproteínas/genética , Martinica
20.
Virol J ; 17(1): 9, 2020 01 23.
Artículo en Inglés | MEDLINE | ID: mdl-31973727

RESUMEN

Yellow fever (YF) is an acute viral disease, affecting humans and non-human primates (NHP), caused by the yellow fever virus (YFV). Despite the existence of a safe vaccine, YF continues to cause morbidity and mortality in thousands of people in Africa and South America. Since 2016, massive YF outbreaks have taken place in Brazil, reaching YF-free zones, causing thousands of deaths of humans and NHP. Here we reviewed the main epidemiological aspects, new clinical findings in humans, and issues regarding YFV infection in vectors and NHP in Brazil. The 2016-2019 YF epidemics have been considered the most significant outbreaks of the last 70 years in the country, and the number of human cases was 2.8 times higher than total cases in the previous 36 years. A new YFV lineage was associated with the recent outbreaks, with persistent circulation in Southeast Brazil until 2019. Due to the high number of infected patients, it was possible to evaluate severity and death predictors and new clinical features of YF. Haemagogus janthinomys and Haemagogus leucocelaenus were considered the primary vectors during the outbreaks, and no human case suggested the occurrence of the urban transmission cycle. YFV was detected in a variety of NHP specimens presenting viscerotropic disease, similar to that described experimentally. Further studies regarding NHP sensitivity to YFV, YF pathogenesis, and the duration of the immune response in NHP could contribute to YF surveillance, control, and future strategies for NHP conservation.


Asunto(s)
Fiebre Amarilla , Virus de la Fiebre Amarilla , Aedes/virología , Animales , Brasil/epidemiología , Culicidae/virología , Brotes de Enfermedades , Reservorios de Enfermedades/virología , Epidemias , Humanos , Mosquitos Vectores/virología , Primates/virología , Virosis/epidemiología , Fiebre Amarilla/epidemiología , Fiebre Amarilla/prevención & control , Fiebre Amarilla/transmisión , Virus de la Fiebre Amarilla/inmunología , Virus de la Fiebre Amarilla/aislamiento & purificación , Virus de la Fiebre Amarilla/patogenicidad , Zoonosis/epidemiología , Zoonosis/transmisión , Zoonosis/virología
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...