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Ranaviruses can cause mass mortality events in amphibians, thereby becoming a threat to populations that are already facing dramatic declines. Ranaviruses affect all life stages and persist in multiple amphibian hosts. The detrimental effects of ranavirus infections to amphibian populations have already been observed in the UK and in North America. In Central and South America, the virus has been reported in several countries, but the presence of the genus Ranavirus (Rv) in Colombia is unknown. To help fill this knowledge gap, we surveyed for Rv in 60 species of frogs (including one invasive species) in Colombia. We also tested for co-infection with Batrachochytrium dendrobatidis (Bd) in a subset of individuals. For Rv, we sampled 274 vouchered liver tissue samples collected between 2014 and 2019 from 41 localities covering lowlands to mountaintop páramo habitat across the country. Using quantitative polymerase chain reaction (qPCR) and end-point PCR, we detected Rv in 14 individuals from 8 localities, representing 6 species, including 5 native frogs of the genera Osornophryne, Pristimantis and Leptodactylus, and the invasive American bullfrog Rana catesbeiana. Bd was detected in 7 of 140 individuals, with 1 co-infection of Rv and Bd in an R. catesbeiana specimen collected in 2018. This constitutes the first report of ranavirus in Colombia and should set off alarms about this new emerging threat to amphibian populations in the country. Our findings provide some preliminary clues about how and when Rv may have spread and contribute to understanding how the pathogen is distributed globally.
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Anfíbios , Infecções por Vírus de DNA , Ranavirus , Animais , Anfíbios/microbiologia , Anfíbios/virologia , Anuros/microbiologia , Anuros/virologia , Batrachochytrium/fisiologia , Coinfecção/veterinária , Colômbia/epidemiologia , Infecções por Vírus de DNA/complicações , Infecções por Vírus de DNA/epidemiologia , Infecções por Vírus de DNA/veterinária , Micoses/complicações , Micoses/veterinária , Rana catesbeiana/microbiologia , Rana catesbeiana/virologia , Ranavirus/fisiologiaRESUMO
Avian diversification has been influenced by global climate change, plate tectonic movements, and mass extinction events. However, the impact of these factors on the diversification of the hyperdiverse perching birds (passerines) is unclear because family level relationships are unresolved and the timing of splitting events among lineages is uncertain. We analyzed DNA data from 4,060 nuclear loci and 137 passerine families using concatenation and coalescent approaches to infer a comprehensive phylogenetic hypothesis that clarifies relationships among all passerine families. Then, we calibrated this phylogeny using 13 fossils to examine the effects of different events in Earth history on the timing and rate of passerine diversification. Our analyses reconcile passerine diversification with the fossil and geological records; suggest that passerines originated on the Australian landmass â¼47 Ma; and show that subsequent dispersal and diversification of passerines was affected by a number of climatological and geological events, such as Oligocene glaciation and inundation of the New Zealand landmass. Although passerine diversification rates fluctuated throughout the Cenozoic, we find no link between the rate of passerine diversification and Cenozoic global temperature, and our analyses show that the increases in passerine diversification rate we observe are disconnected from the colonization of new continents. Taken together, these results suggest more complex mechanisms than temperature change or ecological opportunity have controlled macroscale patterns of passerine speciation.
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Passeriformes , Animais , Austrália , Biodiversidade , Evolução Biológica , Fósseis , Nova Zelândia , Passeriformes/classificação , Passeriformes/genética , Passeriformes/fisiologia , FilogeniaRESUMO
BACKGROUND/OBJECTIVES: We postulated that renal replacement therapy (RRT) in ICH patients with advanced chronic kidney disease (CKD) is associated with increased frequency and size of perihematomal edema (PHE) expansion and worse patient outcomes. METHODS: The Get With the Guidelines-Stroke Registry was queried for all patients admitted with ICH (N = 1089). Secondary causes, brainstem ICH, and initial HV < 7 cc were excluded. We identified patients with advanced CKD with and without RRT following admission for ICH. ABC/2 formula was used to measure hematoma volume (HV) and PHE. Patient outcomes were 30-day mortality, 90-day modified Rankin Scale score, and discharge disposition. We used propensity scores and optimal matching to adjust for multiple covariates. RESULTS: At 48 h post-ICH, PHE expansion was a significant predictor of poor patient outcomes in our cohort. Patients with CKD who received sustained low-efficacy dialysis (SLED) treatment had larger 48 h PHE growth compared to both untreated CKD group (average treatment effect (ATE), 11.5; 95% CI, 4.9-18.1; p < 0.01) and all untreated patients (ATE, 7.43; 95% CI, 4.7-10.2; p < 0.01). Moreover, patients with RRT had significantly worse functional and mortality outcomes. CONCLUSIONS: SLED treatment in ICH patients with CKD was associated with significant increase in rate and frequency of PHE expansion. Absolute increase in PHE during 48-h post-ICH was associated with increased mortality and worse functional outcomes. Further prospective and multicenter evaluation is needed to differentiate the effects of RRT on hematoma dynamics and patient outcomes from those attributed to CKD.
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Edema Encefálico , Terapia de Substituição Renal Híbrida , Edema Encefálico/etiologia , Edema Encefálico/terapia , Hemorragia Cerebral/complicações , Hemorragia Cerebral/terapia , Hematoma , Humanos , Resultado do TratamentoRESUMO
Rapid diversification limits our ability to resolve evolutionary relationships and examine diversification history, as in the case of the Neotropical cotingas. Here we present an analysis with complete taxon sampling for the cotinga genera Lipaugus and Tijuca, which include some of the most range-restricted (e.g., T. condita) and also the most widespread and familiar (e.g., L. vociferans) forest birds in the Neotropics. We used two datasets: (1) Sanger sequencing data sampled from eight loci in 34 individuals across all described taxa and (2) sequence capture data linked to 1,079 ultraconserved elements and conserved exons sampled from one or two individuals per species. Phylogenies estimated from the Sanger sequencing data failed to resolve three nodes, but the sequence capture data produced a well-supported tree. Lipaugus and Tijuca formed a single, highly supported clade, but Tijuca species were not sister and were embedded within Lipaugus. A dated phylogeny confirmed Lipaugus and Tijuca diversified rapidly in the Miocene. Our study provides a detailed evolutionary hypothesis for Lipaugus and Tijuca and demonstrates that increasing genomic sampling can prove instrumental in resolving the evolutionary history of recent radiations.
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Bases de Dados Genéticas , Loci Gênicos , Genômica , Passeriformes/genética , Animais , Evolução Biológica , Especiação Genética , Geografia , Filogenia , Análise de Sequência de DNARESUMO
High tropical species diversity is often attributed to evolutionary dynamics over long timescales. It is possible, however, that latitudinal variation in diversification begins when divergence occurs within species. Phylogeographic data capture this initial stage of diversification in which populations become geographically isolated and begin to differentiate genetically. There is limited understanding of the broader implications of intraspecific diversification because comparative analyses have focused on species inhabiting and evolving in restricted regions and environments. Here, we scale comparative phylogeography up to the hemisphere level and examine whether the processes driving latitudinal differences in species diversity are also evident within species. We collected genetic data for 210 New World bird species distributed across a broad latitudinal gradient and estimated a suite of metrics characterizing phylogeographic history. We found that lower latitude species had, on average, greater phylogeographic diversity than higher latitude species and that intraspecific diversity showed evidence of greater persistence in the tropics. Factors associated with species ecologies, life histories, and habitats explained little of the variation in phylogeographic structure across the latitudinal gradient. Our results suggest that the latitudinal gradient in species richness originates, at least partly, from population-level processes within species and are consistent with hypotheses implicating age and environmental stability in the formation of diversity gradients. Comparative phylogeographic analyses scaled up to large geographic regions and hundreds of species can show connections between population-level processes and broad-scale species-richness patterns.
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Aves/genética , Distribuição Animal , Animais , Ecossistema , Evolução Molecular , Especiação Genética , Modelos Genéticos , América do Norte , Filogenia , Filogeografia , América do Sul , Clima TropicalRESUMO
[This corrects the article DOI: 10.1371/journal.pbio.2001073.].
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Since the recognition that allopatric speciation can be induced by large-scale reconfigurations of the landscape that isolate formerly continuous populations, such as the separation of continents by plate tectonics, the uplift of mountains or the formation of large rivers, landscape change has been viewed as a primary driver of biological diversification. This process is referred to in biogeography as vicariance. In the most species-rich region of the world, the Neotropics, the sundering of populations associated with the Andean uplift is ascribed this principal role in speciation. An alternative model posits that rather than being directly linked to landscape change, allopatric speciation is initiated to a greater extent by dispersal events, with the principal drivers of speciation being organism-specific abilities to persist and disperse in the landscape. Landscape change is not a necessity for speciation in this model. Here we show that spatial and temporal patterns of genetic differentiation in Neotropical birds are highly discordant across lineages and are not reconcilable with a model linking speciation solely to landscape change. Instead, the strongest predictors of speciation are the amount of time a lineage has persisted in the landscape and the ability of birds to move through the landscape matrix. These results, augmented by the observation that most species-level diversity originated after episodes of major Andean uplift in the Neogene period, suggest that dispersal and differentiation on a matrix previously shaped by large-scale landscape events was a major driver of avian speciation in lowland Neotropical rainforests.
Assuntos
Aves/classificação , Aves/genética , Especiação Genética , Filogenia , Floresta Úmida , Clima Tropical , Animais , Biodiversidade , Modelos Biológicos , Dados de Sequência Molecular , Panamá , Rios , América do SulRESUMO
An implicit assumption of speciation biology is that population differentiation is an important stage of evolutionary diversification, but its significance as a rate-limiting control on phylogenetic speciation dynamics remains largely untested. If population differentiation within a species is related to its speciation rate over evolutionary time, the causes of differentiation could also be driving dynamics of organismal diversity across time and space. Alternatively, geographic variants might be short-lived entities with rates of formation that are unlinked to speciation rates, in which case the causes of differentiation would have only ephemeral impacts. By pairing population genetics datasets from 173 New World bird species (>17,000 individuals) with phylogenetic estimates of speciation rate, we show that the population differentiation rates within species are positively correlated with their speciation rates over long timescales. Although population differentiation rate explains relatively little of the variation in speciation rate among lineages, the positive relationship between differentiation rate and speciation rate is robust to species-delimitation schemes and to alternative measures of both rates. Population differentiation occurs at least three times faster than speciation, which suggests that most populations are ephemeral. Speciation and population differentiation rates are more tightly linked in tropical species than in temperate species, consistent with a history of more stable diversification dynamics through time in the Tropics. Overall, our results suggest that the processes responsible for population differentiation are tied to those that underlie broad-scale patterns of diversity.
Assuntos
Aves/genética , Especiação Genética , Animais , Aves/classificação , Evolução Molecular , Genes Mitocondriais , Genética Populacional , Filogenia , Filogeografia , Dinâmica Populacional , Fatores de Tempo , Clima TropicalRESUMO
We infer phylogenetic relationships, divergence times, and the diversification history of the avian Neotropical antpitta genera Hylopezus and Myrmothera (Grallariidae), based on sequence data (3,139 base pairs) from two mitochondrial (ND2 and ND3) and three nuclear nuclear introns (TGFB2, MUSK and FGB-I5) from 142 individuals of the 12 currently recognized species in Hylopezus and Myrmothera and 5 outgroup species. Phylogenetic analyses recovered 19 lineages clustered into two major clades, both distributed in Central and South America. Hylopezus nattereri, previously considered a subspecies of H. ochroleucus, was consistently recovered as the most divergent lineage within the Grallaricula/Hylopezus/Myrmothera clade. Ancestral range estimation suggested that modern lowland antpittas probably originated in the Amazonian Sedimentary basin during the middle Miocene, and that most lineages within the Hylopezus/Myrmothera clade appeared in the Plio-Pleistocene. However, the rate of diversification in the Hylopezus/Myrmothera clade appeared to have remained constant through time, with no major shifts over the 20 million years. Although the timing when most modern lineages of the Hylopezus/Myrmothera clade coincides with a period of intense landscape changes in the Neotropics (Plio-Pleistocene), the absence of any significant shifts in diversification rates over the last 20 million years challenges the view that there is a strict causal relationship between intensification of landscape changes and cladogenesis. The relative old age of the Hylopezus/Myrmothera clade coupled with an important role ascribed to dispersal for its diversification, favor an alternative scenario whereby long-term persistence and dispersal across an ever-changing landscape might explain constant rates of cladogenesis through time.
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Passeriformes/classificação , Animais , Biodiversidade , DNA Mitocondrial/química , DNA Mitocondrial/classificação , DNA Mitocondrial/genética , Variação Genética , Íntrons , Passeriformes/genética , Filogenia , Filogeografia , Análise de Sequência de DNA , América do Sul , Fator de Crescimento Transformador beta2/classificação , Fator de Crescimento Transformador beta2/genética , Fator de Crescimento Transformador beta2/metabolismoRESUMO
Simultaneous examination of evolutionary history in island forms and closely related mainland relatives can provide reciprocal insight into the evolution of island and mainland faunas. The Cocos Flycatcher (Nesotriccus ridgwayi) is a small tyrant flycatcher (Tyrannidae) endemic to Cocos Island, an oceanic island in the eastern Pacific Ocean. We first established its close relationship to the mainland species Mouse-colored Tyrannulet (Phaeomyias murina) using a phylogeny from genome-wide ultraconserved elements and exons. We then used mitochondrial DNA to explore the relationships between Nesotriccus and Phaeomyias populations from across its distribution in Central and South America. We found that Nesotriccus is nested within the Phaeomyias evolutionary tree, and that Phaeomyias represents a complex of at least four evolutionarily distinct species that differ in plumage, voice, and habitat association. Nesotriccus underwent a population bottleneck subsequent to its divergence from Central American and northern South American Phaeomyias populations in the middle Pleistocene. The 46 UCE loci containing alleles that are fixed between the two species are widely distributed across the genome, which suggests that selective or neutral processes responsible for divergence have occurred genome-wide. Overall, our simultaneous examination of Phaeomyias and Nesotriccus revealed divergent levels of genetic diversity and evolutionary histories between island and mainland forms.
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Ilhas , Filogenia , Aves Canoras/classificação , Animais , Teorema de Bayes , Variação Genética , Genética Populacional , Genoma , Haplótipos/genética , Aves Canoras/genética , Especificidade da EspécieRESUMO
In the Andes, humid-forest organisms frequently exhibit pronounced genetic structure and geographic variation in phenotype, often coincident with physical barriers to dispersal. However, phylogenetic relationships of clades have often been difficult to resolve due to short internodes. Consequently, even in taxa with well-defined genetic structure, the temporal and geographic sequences of dispersal and vicariance events that led to this differentiation have remained opaque, hindering efforts to test the association between diversification and earth history and to understand the assembly of species-rich communities on Andean slopes. Here, we use mitochondrial DNA and thousands of short-read sequences generated with genotyping by sequencing (GBS) to examine the geographic history of speciation in a lineage of passerine birds found in the humid forest of the Andes, the 'bay-backed' antpitta complex (Grallaria hypoleuca s. l). Mitochondrial DNA genealogies documented genetic structure among clade but were poorly resolved at nodes relevant for biogeographic inference. By contrast, relationships inferred from GBS loci were highly resolved and suggested a biogeographic history in which the ancestor originated in the northern Andes and dispersed south. Our results are consistent with a scenario of vicariant speciation wherein the range of a widespread ancestor was fragmented as a result of geologic or climatic change, rather than a stepping-stone series of dispersal events across pre-existing barriers. However, our study also highlights challenges of distinguishing dispersal-mediated speciation from static vicariance. Our results further demonstrate the substantial evolutionary timescale over which the diverse biota of the Andes was assembled.
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Especiação Genética , Genética Populacional , Passeriformes/classificação , Filogenia , Animais , DNA Mitocondrial/genética , Genótipo , Modelos Genéticos , Passeriformes/genética , Análise de Sequência de DNA , América do SulRESUMO
Most widespread birds of Neotropical cloud forests exhibit phenotypic variation that is partitioned geographically suggesting allopatric divergence, but little is known about the extent to which such phenotypic differentiation is consistent with genetic variation. We studied geographic patterns of genetic differentiation in the Three-striped Warbler (Basileuterus tristriatus), a polytypic and widespread understory bird of the foothills and mid-elevation zone of the tropical Andes and adjacent mountains of Central and South America. We sequenced mitochondrial DNA for 196 samples covering the entire range of B. tristriatus, as well as 22 samples of its putative closest relatives: the Three-banded (B. trifasciatus) and Santa Marta (B. basilicus) warblers. We found deep genetic structure across the range of B. tristriatus, which consisted of ten major clades including B. trifasciatus, a species that was nested within B. tristriatus. In contrast, B. basilicus was not closely related to B. tristriatus but part of a clade of Myiothlypis warblers. Geographic boundaries among clades were clearly related to lowland gaps separating subspecies groups. The subspecies melanotis of the mountains of Central America was sister to a large clade including B. t. tacarcunae, and the rest of South American clades, including B. trifasciatus. Five clades are found in the northern Andes, where no signs of gene flow were found across barriers such as the Táchira Depression or the Magdalena valley. Our study highlights the importance of valleys in promoting and maintaining divergence in a lower montane forest bird. The substantial genetic and phenotypic differentiation, and the paraphyly uncovered in B. tristriatus, may call for revising its species boundaries.
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Demografia , Variação Genética , Aves Canoras/classificação , Aves Canoras/genética , Animais , Sequência de Bases , Teorema de Bayes , América Central , DNA Mitocondrial/genética , Modelos Genéticos , Dados de Sequência Molecular , Filogeografia , Análise de Sequência de DNA , América do SulRESUMO
Colombia has one of the largest burdens of Chagas disease globally, with about 438,000 people affected according to 2015 estimates. Despite this, < 1% of the population has had access to diagnosis and treatment. A patient-centered roadmap for Chagas disease was developed from 2015 onwards to address access barriers and increase diagnostic and therapeutic coverage and was implemented in five municipalities where Chagas disease is endemic. The mean number of people tested per year increased from 37 before the project to 262 following implementation, and the average days between medical order and diagnostic confirmation results decreased from 258 to 19. The mean days from diagnostic confirmation to treatment initiation decreased from 354 before the project to 135 after implementation. The 5,654 people tested included 3,467 women of childbearing age. The prevalence of T. cruzi infection was 11.5%, and thus far 266 people have received antitrypanosomal treatment. Collaborative creation and implementation of a patient-centered roadmap can address access barriers in specific contexts, helping to reduce the invisibility and burden of this neglected disease.
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Doença de Chagas , Trypanosoma cruzi , Doença de Chagas/diagnóstico , Doença de Chagas/tratamento farmacológico , Doença de Chagas/epidemiologia , Colômbia/epidemiologia , Feminino , Humanos , PrevalênciaRESUMO
Trypanosoma cruzi, the causal agent of Chagas disease, is mainly transmitted by insects of the Triatominae subfamily. In Colombia, there are 26 triatomine species, and 16 of them are naturally infected with the parasite. The parasite loads of naturally infected vectors can be significant in targeting specific species that can affect the epidemiology of the disease. Studying their ecology and behavior is vital to understand their role in T. cruzi transmission dynamics. We evaluated the parasite loads of 182 field-collected triatomines corresponding to 10 species in 13 departments across Colombia. We standardized a methodology to quantify T. cruzi DNA in these insects. We obtained a LOD (limit of detection) of 3.05 p-eq/mL. The 82% of triatomines we evaluated were positive for T. cruzi infection, with loads ranging from hundreds to millions of equivalent parasites per milliliter. Panstrongylus geniculatus, Rhodnius prolixus, and Triatoma dimidiata were the species with the highest loads of T. cruzi; however, other species whose role as vectors is still unknown were also found with high loads of parasites. Our results suggest the relevance of secondary species for T. cruzi transmission in Colombia. We hope our data can help improve entomological surveillance and vector control programs in the country and the region.
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BACKGROUND: The aim of this paper is to describe the prevalence of Delirium and the factors associated with its presentation and complications identified in a geriatric unit in Colombia. MATERIAL AND METHODS: This is a retrospective observational study that included all patients admitted consecutively for two years in a geriatric unit of a hospital in Bogotá, Colombia. We assessed delirium prevalence with the Confusion Assessment Method (CAM). The independent variables were age, sex, functional impairment (Barthel<90), malnutrition (MNA<12), pressure ulcers at admission, state of the social support network, number of comorbidities, polypharmacy (5 or more drugs), complications such as ICU requirement, hospital stay, in-hospital functional impairment and mortality were also evaluated. As an exclusion criterion: not having CAM registered in the medical record, all the patients had this information. RESULTS: We studied 1599 subjects with a mean age of 86 years (IQR 9). Delirium prevalence was 51.03%. Delirium was associated with a higher rate of: pressure ulcers on admission [OR 3.76 (CI 2.60-5.43 p<0.001)], functional impairment [OR 2.38 (CI 1.79-3.16 p<0.001)], malnutrition [OR 2.06 (CI 1.56-2.73 p<0.001)], and infection [OR 1.46 (CI 1.17-1.82 p<0.001)]. Moreover delirium has a higher association with mortality [OR 2.80 (1.03-7.54 p=0.042)], in-hospital functional decline [OR 1.82 (1.41-2.36 p<0.001)], and longer hospital stay [OR 1.04 (1.04-1.09 p=0.006)]; independently of age, sex, pressure ulcers on admission, functional impairment, malnutrition, dementia, infection and limited social network. CONCLUSION: Our study suggests that infectious diseases and geriatric syndromes such as, functional dependence, pressure ulcers, malnutrition or major cognitive impairment are independently associated with the presence of delirium on admission. Additionally, the presence of delirium is independently associated during hospitalization with complications, longer hospital stay, functional impairment and mortality.
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Delírio , Avaliação Geriátrica , Idoso , Colômbia/epidemiologia , Delírio/epidemiologia , Mortalidade Hospitalar , Hospitalização , Humanos , Prevalência , Estudos Retrospectivos , Fatores de RiscoRESUMO
Populations in the Rufous Antpitta (Grallaria rufula) complex occupy humid montane forests of the Andes from northern Colombia and adjacent Venezuela to central Bolivia. Their tawny to cinnamon-colored plumages are generally uniform, featuring subtle variation in hue and saturation across this range. In contrast to their conservative plumage, substantial vocal differences occur among geographically isolated or parapatric populations. Working within the framework of a comprehensive molecular phylogeny, we reexamined species limits in the G. rufula complex, basing taxonomic recommendations on diagnostic differences in vocalizations and considering identifiable differences in plumage where pertinent. We identified 16 populations for species designation, including seven populations previously described as subspecies and, remarkably, six new species described herein. Within one of these species, we identified less robust vocal differences between populations that we designate as subspecies. Geographic variation exists within another species, but its critical evaluation requires additional material. Taxonomic revisions of groups consisting of cryptic species, like the Grallaria rufula complex, are imperative for their conservation. Rather than widespread species as currently defined, these complexes can comprise many range-restricted taxa at higher risk of extinction given the continuing human pressures on their habitats.
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Passeriformes , Animais , FilogeniaRESUMO
BACKGROUND: Triatomines are hematophagous insects that play an important role as vectors of Trypanosoma cruzi, the causative agent of Chagas disease. These insects have adapted to multiple blood-feeding sources that can affect relevant aspects of their life-cycle and interactions, thereby influencing parasitic transmission dynamics. We conducted a characterization of the feeding sources of individuals from the primary circulating triatomine genera in Colombia using amplicon-based next-generation sequencing (NGS). METHODS: We used 42 triatomines collected in different departments of Colombia. DNA was extracted from the gut. The presence of T. cruzi was identified using real-time PCR, and discrete typing units (DTUs) were determined by conventional PCR. For blood-feeding source identification, PCR products of the vertebrate 12S rRNA gene were obtained and sequenced by next-generation sequencing (NGS). Blood-meal sources were inferred using blastn against a curated reference dataset containing the 12S rRNA sequences belonging to vertebrates with a distribution in South America that represent a potential feeding source for triatomine bugs. Mean and median comparison tests were performed to evaluate differences in triatomine blood-feeding sources, infection state, and geographical regions. Lastly, the inverse Simpson's diversity index was calculated. RESULTS: The overall frequency of T. cruzi infection was 83.3%. TcI was found as the most predominant DTU (65.7%). A total of 67 feeding sources were detected from the analyses of approximately 7 million reads. The predominant feeding source found was Homo sapiens (76.8%), followed by birds (10.5%), artiodactyls (4.4%), and non-human primates (3.9%). There were differences among numerous feeding sources of triatomines of different species. The diversity of feeding sources also differed depending on the presence of T. cruzi. CONCLUSIONS: To the best of our knowledge, this is the first study to employ amplicon-based NGS of the 12S rRNA gene to depict blood-feeding sources of multiple triatomine species collected in different regions of Colombia. Our findings report a striking read diversity that has not been reported previously. This is a powerful approach to unravel transmission dynamics at microgeographical levels.
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Doença de Chagas/transmissão , Triatominae , Trypanosoma cruzi/isolamento & purificação , Animais , Aves/sangue , Aves/genética , Sangue , Doença de Chagas/parasitologia , Colômbia , DNA de Protozoário , Comportamento Alimentar , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Humanos , Insetos Vetores/genética , Insetos Vetores/parasitologia , Intestinos , Panstrongylus/genética , Panstrongylus/parasitologia , Primatas/sangue , Primatas/genética , Reação em Cadeia da Polimerase em Tempo Real , Rhodnius/genética , Rhodnius/parasitologia , Triatoma/genética , Triatoma/parasitologia , Triatominae/genética , Triatominae/parasitologia , Trypanosoma cruzi/genéticaRESUMO
The tropics are the source of most biodiversity yet inadequate sampling obscures answers to fundamental questions about how this diversity evolves. We leveraged samples assembled over decades of fieldwork to study diversification of the largest tropical bird radiation, the suboscine passerines. Our phylogeny, estimated using data from 2389 genomic regions in 1940 individuals of 1283 species, reveals that peak suboscine species diversity in the Neotropics is not associated with high recent speciation rates but rather with the gradual accumulation of species over time. Paradoxically, the highest speciation rates are in lineages from regions with low species diversity, which are generally cold, dry, unstable environments. Our results reveal a model in which species are forming faster in environmental extremes but have accumulated in moderate environments to form tropical biodiversity hotspots.
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Biodiversidade , Aves/classificação , Aves/genética , Animais , Especiação Genética , FilogeniaRESUMO
BACKGROUND: Chagas disease (CD) is caused by the protozoan parasite Trypanosoma cruzi, and is transmitted by hematophagous insects of the family Reduviidae. Psammolestes arthuri is a sylvatic triatomine distributed in Colombia and Venezuela which feeds on birds and there are a few studies that have reported Ps. arthuri naturally infected with T. cruzi. In Colombia, Ps. arthuri has been found in dwellings, making it important to evaluate its possible role in the T. cruzi transmission cycle. We aimed to evaluate the presence of T. cruzi and feeding sources of Ps. arthuri to elucidate new possible scenarios of T. cruzi transmission in the country. METHODS: A total of 60 Ps. arthuri were collected in Arauca and Casanare, Colombia. We detected and genotyped T. cruzi and identified feeding sources. The frequency of the presence of T. cruzi was obtained and compared with different eco-epidemiological variables. Multiple correspondence analysis was conducted to explore associations between eco-epidemiological variables and the presence of T. cruzi; with these results, a logistic regression was used to determine statistical associations. RESULTS: The infection rate of T. cruzi was 70.7% and was mostly associated with insect stage, sex, bird nest and feeding source. Regarding discrete typing units (DTUs), TcI was found in 54.7% samples, of which 21.7% (5/23) were TcIDom, 52.1% (12/23) had mixed infection (TcIDom-TcISylv), and single infection with TcISylv was not detected. Mixed infections (TcI/TcII-TcVI) were found in 9.52% (4/42) of the samples; of these, 14.2% (6/42) were TcII-TcVI. A total of 15 feeding sources were identified and the most frequent were: Cranioleuca baroni (35.85%), Homo sapiens (26.42%), Thraupis episcopus (11.32%) and Serinus albogularis (3.77%). CONCLUSIONS: Although Ps. arthuri is mainly ornithophilic, this species may be feeding on other animals that can be infected with T. cruzi, possibly playing a role maintaining the zoonotic cycle of the parasite. Further studies with molecular techniques and wider sampling are needed to improve information regarding infection rates, ecotopes and habits with the aim of evaluating whether Ps. arthuri could be a potential T. cruzi vector.
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Doença de Chagas/transmissão , Insetos Vetores/parasitologia , Triatominae/parasitologia , Trypanosoma cruzi/fisiologia , Animais , Aves/parasitologia , Colômbia , Comportamento Alimentar , Feminino , Técnicas de Genotipagem , Humanos , Masculino , Tipagem Molecular , Trypanosoma cruzi/genéticaRESUMO
We studied the phylogeography and plumage variation of the Russet-crowned Warbler (Myiothlypis coronata), from Venezuela to Bolivia, with focus on populations from Ecuador and northern Peru. We analyzed sequences of mitochondrial and nuclear genes, geographic distributions, as well as photographs of specimens deposited at museum collections. Phylogenetic analyses identified three major lineages formed by populations from: Venezuela and Colombia (M. c. regulus), Ecuador and northern Peru (M. elata, M. castaneiceps, M. orientalis, M. c. chapmani), and central Peru and Bolivia (M. c. coronata). We found further population structure within M. c. regulus and M. c. coronata, and population structure and complexity of plumage variation within the Ecuador-northern Peru lineage. Time-calibrated trees estimated that most intraspecific variation originated during the Pleistocene; however, this pattern may not be attributed to an increase in diversification rate during that period. We discuss these results in the context of the importance of geographic-ecological barriers in promoting lineage diversification along the Andes and put forward a preliminary taxonomic proposal for major lineages identified in this study.