RESUMO
BACKGROUND: Leptospirosis is the world's most common zoonotic disease. Mitigation and control rely on pathogen identification and understanding the roles of potential reservoirs in cycling and transmission. Underreporting and misdiagnosis obscure the magnitude of the problem and confound efforts to understand key epidemiological components. Difficulties in culturing hamper the use of serological diagnostics and delay the development of DNA detection methods. As a result, especially in complex ecosystems, we know very little about the importance of different mammalian host species in cycling and transmission to humans. METHODOLOGY/PRINCIPAL FINDINGS: We sampled dogs from five indigenous Kichwa communities living in the Yasuní National Park in the Ecuadorian Amazon basin. Blood and urine samples from domestic dogs were collected to assess the exposure of these animals to Leptospira and to identify the circulating species. Microscopic Agglutination Tests with a panel of 22 different serovars showed anti-leptospira antibodies in 36 sampled dogs (75%), and 7 serogroups were detected. Two DNA-based detection assays revealed pathogenic Leptospira DNA in 18 of 19 dog urine samples (94.7%). Amplicon sequencing and phylogenetic analysis of 16S rRNA and SecY genes from 15 urine samples revealed genetic diversity within two of three different Leptospira species: noguchii (n = 7), santarosai (n = 7), and interrogans (n = 1). CONCLUSIONS/SIGNIFICANCE: The high prevalence of antibodies and Leptospira DNA provides strong evidence for high rates of past and current infections. Such high prevalence has not been previously reported for dogs. These dogs live in the peridomestic environment in close contact with humans, yet they are free-ranging animals that interact with wildlife. This complex web of interactions may explain the diverse types of pathogenic Leptospira observed in this study. Our results suggest that domestic dogs are likely to play an important role in the cycling and transmission of Leptospira. Future studies in areas with complex ecoepidemiology will enable better parsing of the significance of genotypic, environmental, and host characteristics.
Assuntos
Leptospira , Leptospirose , Animais , Cães , Humanos , Ecossistema , Filogenia , RNA Ribossômico 16S/genética , Leptospirose/epidemiologia , Leptospirose/veterinária , Animais Selvagens , DNA , MamíferosRESUMO
This study aimed to analyze the application of the Phytoplankton Community Index-PCI and Functional Groups-FG in determining the water quality of the Guamá River (Pará, Amazônia, Brazil). Samplings occurred monthly for analyses of phytoplankton and physical and chemical parameters, for two years, at the station where water was collected for human supply consumption. Seasonality influenced electrical conductivity, total suspended solids, dissolved oxygen, transparency, winds, true color, and N-ammoniacal. The ebb tide showed high turbidity and suspended solids. The density varied seasonally with the highest values occurring in September and December (61.1 ind mL-1 and 60.2 ind mL-1, respectively). Chlorophyll-a was more elevated in December (21.0 ± 4.7 µg L-1) and chlorophyll-c higher in relation to clorophyll- b indicated the dominance of diatoms. Functional Group P prevailed in the study months. Through the PCI índex the waters of Guamá River varied from reasonable to excellent and the TSI ranged from oligo to mesotrophic. The use of Functional Groups proved to be a promising tool in the determination of water quality since it covered the most abundant species in the Environment, but the PCI is not adequate to characterize Amazonian white-waters rivers, which have diatoms as the leading dominant group.
Assuntos
Diatomáceas , Intervenção Coronária Percutânea , Humanos , Fitoplâncton , Rios/química , Brasil , Clorofila/análise , Estações do Ano , Monitoramento AmbientalRESUMO
The decline in the quality of water resources in the Amazon is very rapid in cities suffering from unplanned urban growth. The region has two defined seasons, winter (wet) and summer (dry), which directly affect the behavior of contaminants in aquatic ecosystems. The aim of this study was to assess the ecological and human health risks associated with the use of the watershed. In addition, an ecological index was proposed: the Quality Index for Aquatic Life, for the risk of contaminants to aquatic life. Sampling was carried out at six points in the Juá watershed. Physicochemical parameters, major anions, metals and total phosphorus were analyzed at both stations between 2020 and 2021. The highest concentrations of contaminants were found in the rainy season, due to the washing away of the banks. In this sense, Cl presented a concentration more than 307 times higher than that permitted by Brazilian legislation (wet). The ecological index showed that the watershed has a high risk of metals such as Cr III and Cr VI for the biota. The human health risk analysis showed a low risk; however, the lack of basic sanitation in the city indicates that monitoring of urban water resources is necessary.
Assuntos
Metais Pesados , Poluentes Químicos da Água , Humanos , Qualidade da Água , Monitoramento Ambiental , Ecossistema , Poluentes Químicos da Água/análise , Medição de Risco , Metais Pesados/análise , Rios , ChinaRESUMO
Tropical forests cover large areas of equatorial Africa and play a substantial role in the global carbon cycle. However, there has been a lack of biometric measurements to understand the forests' gross and net primary productivity (GPP, NPP) and their allocation. Here we present a detailed field assessment of the carbon budget of multiple forest sites in Africa, by monitoring 14 one-hectare plots along an aridity gradient in Ghana, West Africa. When compared with an equivalent aridity gradient in Amazonia, the studied West African forests generally had higher productivity and lower carbon use efficiency (CUE). The West African aridity gradient consistently shows the highest NPP, CUE, GPP, and autotrophic respiration at a medium-aridity site, Bobiri. Notably, NPP and GPP of the site are the highest yet reported anywhere for intact forests. Widely used data products substantially underestimate productivity when compared to biometric measurements in Amazonia and Africa. Our analysis suggests that the high productivity of the African forests is linked to their large GPP allocation to canopy and semi-deciduous characteristics.
Assuntos
Florestas , Árvores , Ciclo do Carbono , Gana , Carbono , Ecossistema , Clima TropicalRESUMO
Soil quality monitoring in mining rehabilitation areas is a crucial step to validate the effectiveness of the adopted recovery strategy, especially in critical areas for environmental conservation, such as the Brazilian Amazon. The use of portable X-ray fluorescence (pXRF) spectrometry allows a rapid quantification of several soil chemical elements, with low cost and without residue generation, being an alternative for clean and accurate environmental monitoring. Thus, this work aimed to assess soil quality in mining areas with different stages of environmental rehabilitation based on predictions of soil fertility properties through pXRF along with four machine learning algorithms (projection pursuit regression, PPR; support vector machine, SVM; cubist regression, CR; and random forest, RF) in the Eastern Brazilian Amazon. Sandstone and iron mines in different chronological stages of rehabilitation (initial, intermediate, and advanced) were evaluated, in addition to non-rehabilitated and native forest areas. A total of 81 soil samples (26 from sandstone mine and 55 from iron mine) were analyzed by both traditional wet-chemistry methods and pXRF. The available/exchangeable contents of K, Ca, B, Fe, and Al, in addition to H+Al, cation exchange capacity at pH = 7, Al saturation, soil organic matter, pH, sum of bases, base saturation, clay, and sand were accurately predicted (R2 > 0.70) using pXRF data, with emphasis on the prediction of Fe (R2 = 0.93), clay content (R2 = 0.81), H+Al (R2 = 0.81), and K+ (R2 = 0.85). The best predictive models were developed by RF and CR (86%) and when considering pXRF data + mining area + stage of rehabilitation (73%). The results highlight the potential of pXRF to accurately assess soil properties in environmental rehabilitation areas in the Amazon region (yet scarcely evaluated under this approach), promoting a more agile and cheaper preliminary diagnosis compared to traditional methods.
Assuntos
Poluentes do Solo , Solo , Solo/química , Argila , Brasil , Monitoramento Ambiental/métodos , Poluentes do Solo/análise , Ferro/análiseRESUMO
Fish is an important source of animal protein for local communities in the Amazon basin, whose food safety must be assured. However, certain potential toxicants elements, can bioaccumulate in fish species, which inhabit anthropogenically polluted waters, ultimately posing a risk to human health. In the present study, the concentrations of nine elements (Al, As, Cd, Cr, Cu, Hg, Ni, Pb and Zn) were determined in raw and cooked samples of eight fish species consumed in Santarém (northern Brazil, Amazon biome). The potential for non- carcinogenic human health risks linked to the consumption of cooked fish were evaluated for adults and children in two different scenarios. Four carnivores, three omnivores and one detritivore, all of them regularly marketed and consumed by the Santarém population, were the target species. The safety reference values set by national and international guidelines for humans, in both raw and cooked preparations, were used. In most cases, the cooking process showed a trend to increase elements concentrations compared to raw samples, however the differences were not significant. Moreover, the risk assessment showed danger for children in relation to Hg from the consumption of fish, in both scenarios evaluated. For adults, in one of the scenarios, there was a health risk associated to Hg as a result of carnivorous fish consumption. In a context of combined exposure to all elements, children were at risk when consuming fish, especially carnivorous and omnivorous species. For adults, the mixture of elements posed a risk to health human only for carnivorous fish consumption. The results reveal an environmental scenario of Hg contamination, which requires monitoring actions to preserve the aquatic biodiversity and human health in the Brazilian Amazon biome.
Assuntos
Mercúrio , Metais Pesados , Poluentes Químicos da Água , Criança , Adulto , Animais , Humanos , Brasil , Monitoramento Ambiental/métodos , Poluentes Químicos da Água/análise , Peixes , Mercúrio/análise , Ecossistema , Medição de Risco , Culinária , Metais Pesados/análiseRESUMO
Zoonotic parasitic diseases in dogs are particularly concerning in regions with low human development indices due to inadequate sanitary services and insufficient environmental and health education. This study aimed to assess the parasitological status of dogs living in households and evaluate their owners' knowledge about zoonoses. A total of 183 dogs from Rolim de Moura, Rondônia State, were screened for the presence of ectoparasites, and 163 fecal samples were collected for analysis. The results showed that 74.23% (112/163) of the animals had at least one species of endoparasite. The most identified pathogens were Ancylostoma spp. (68.71%, 112/163), Trichuris vulpis (11.66%, 19/163), Toxocara canis (6.75%, 11/163), Cystoisospora canis (4.91%, 8/163), Dipylidium caninum (1.23%, 2/163), and Hammondia/Neospora (0.61%, 1/163). Ectoparasites were observed in 43.17% (79/183) of the evaluated animals, with Rhipicephalus sanguineus found in 31.15% (57/183) and Ctenocephalides felis felis in 20.77% (38/183). Only 11.48% (7/61) of the owners were familiar with the term "Zoonoses." However, a significant majority (83.61%, 51/61) believed that dogs can transmit diseases to humans. Our findings highlight the prevalence of parasites in the studied area and associated risk factors, underscoring the urgent need for educational interventions to raise awareness about these diseases and their risks to human health.
Assuntos
Doenças do Cão , Enteropatias Parasitárias , Parasitos , Humanos , Animais , Cães , Enteropatias Parasitárias/epidemiologia , Zoonoses/epidemiologia , Ecossistema , Fezes/parasitologia , Prevalência , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , PercepçãoRESUMO
Oropouche virus (OROV) is characterized as a re-emerging arbovirus of great concern for public health, being responsible for several outbreaks of acute fever identified in Latin American countries, registering more than half a million reported cases. The incidence of reports of this virus is intrinsically favored by environmental conditions, in which such characteristics are related to the increase and distribution of the vector population to areas of human traffic. Moreover, there is a problem regarding the lack of diagnosis in Brazil that aggregates the success of the etiologic agent. Thus, by means of molecular techniques, we identified 27 positive cases of the OROV circulating in border locations in western Amazon, with 44.44% (12/27) of the cohort characterized as infected individuals with reported symptoms, mainly ranging from fever, myalgia, and back pain. Among the positive samples, it was possible to obtain a total of 48.14% (13/27) samples to analyze the S and M segments of Oropouche, which showed similarities among the Brazilian sequences. Thus, it was possible to verify the circulation of the OROV in Rondonia and border areas, in which the tracking of neglected arboviruses is necessary for the genomic surveillance of emerging and re-emerging viruses.IMPORTANCEThe western Amazon region is known for outbreaks of acute febrile illnesses, to which the lack of specific diagnostics for different pathogens hinders the management of patients in healthcare units. The Oropouche virus has already been recorded in the region in the 1990s. However, this is the first study, after this record, to perform the detection of individuals with acute febrile illness using a screening test to exclude Zika, dengue, and chikungunya, confirmed by sequencing the circulation of the virus in the state of Rondonia and border areas. We emphasize the importance of including diagnostics for viruses such as Oropouche, which suffers underreporting for years and is related to seasonal periods in Western Amazon locations, a factor that has a direct influence on public health in the region. In addition, we emphasize the importance of genomic surveillance in the elucidation of outbreaks that affect the resident population of these locations.
Assuntos
Orthobunyavirus , Infecção por Zika virus , Zika virus , Humanos , Orthobunyavirus/genética , Brasil/epidemiologia , Febre , Surtos de DoençasRESUMO
The aim of this study was to develop artificial neural network (ANN) models to predict floods in the Branco River, Amazon basin. The input data for the models included the river levels and the average rainfall within the drainage area of the basin, which was estimated from the remotely sensed rainfall product PDIRnow. The hourly water level data used in the study were recorded by fluviometric telemetric stations belonging to the National Agency of Water. The multilayer perceptron was used as the neural framework of the ANNs, and the number of neurons in each layer of the model was determined via optimization with the SCE-UA algorithm. Most of the fitted ANN models showed Nash-Sutcliffe efficiency index values greater than 0.9. It is possible to conclude that the ANNs are effective for predicting the flood levels of the Branco River, with horizons of 6, 12 and 24 h; thus, constituting a viable option for use in river-flood warning systems in the Amazon basin. For the forecast with a 24-h horizon, it is essential to include the average rainfall of the basin that accumulated over the last 48 h as input data into the ANNs, along with the levels measured by the streamflow stations. The indirect rainfall estimates provided by PDIRnow are an excellent alternative as input data for ANN models used to predict floods and constitute a viable solution for regions where the density of rain gauge stations is low, as is the case in the Amazon basin.
Assuntos
Monitoramento Ambiental , Inundações , Redes Neurais de Computação , Algoritmos , ÁguaRESUMO
The evaluation of environmental and spatial influence in freshwater systems is crucial for the conservation of aquatic diversity. So, we evaluated communities of Odonata in streams inside and outside sustainable use areas in the Brazilian western Amazon. We predicted that these streams would differ regarding habitat integrity and species α and ß diversity. We also predict that environmental and spatial variables will be important for both suborders, but with more substantial effects on Zygoptera species, considering their nature of forest-specialist. The study was conducted in 35 streams, 19 inside and 16 outside sustainable use areas. The streams outside presented high species richness, abundance, and number of exclusive forest-specialist species from Zygoptera and higher scores of habitat integrity. In contrast, one sustainable use area presented the lowest values of these metrics. Besides, we found that environmental and spatial variables were significantly associated to Zygoptera species composition, but not with Anisoptera, which can be explained by their cosmopolitan nature. Our results indicated that an interplay between environmental and spatial processes determines the structure of the metacommunities of Zygoptera. The less effective dispersal rates and narrow ecological tolerance of Zygoptera species make them more influenced by local conditions and dispersal limitation, and more sensible to habitat modifications. We highlight the importance of improving the local management of the sustainable use areas by environmental agencies, mainly on areas that are losing their capacity to maintain the aquatic fauna, and implementation of social policies toward traditional people.
Assuntos
Odonatos , Humanos , Animais , Rios , Brasil , Monitoramento Ambiental , Ecossistema , Insetos , BiodiversidadeRESUMO
The Amazon region abounds in precious mineral resources including gold, copper, iron, and coltan. Artisanal and small-scale gold mining (ASGM) poses a severe risk in this area due to considerable mercury release into the surrounding ecosystems. Nonetheless, the impact of mercury on both the overall microbiota and the microbial populations involved in mercury transformation is not well understood. In this study we evaluated microbial diversity in samples of soil, sediment and water potentially associated with mercury contamination in two localities (Taraira and Tarapacá) in the Colombian Amazon Forest. To this end, we characterized the bacterial community structure and mercury-related functions in samples from sites with a chronic history of mercury contamination which today have different levels of total mercury content. We also determined mercury bioavailability and mobility in the samples with the highest THg and MeHg levels (up to 43.34 and 0.049 mg kg-1, respectively, in Taraira). Our analysis of mercury speciation showed that the immobile form of mercury predominated in soils and sediments, probably rendering it unavailable to microorganisms. Despite its long-term presence, mercury did not appear to alter the microbial community structure or composition, which was primarily shaped by environmental and physicochemical factors. However, an increase in the relative abundance of merA genes was detected in polluted sediments from Taraira. Several Hg-responsive taxa in soil and sediments were detected in sites with high levels of THg, including members of the Proteobacteria, Acidobacteria, Actinobacteria, Firmicutes and Chloroflexi phyla. The results suggest that mercury contamination at the two locations sampled may select mercury-adapted bacteria carrying the merA gene that could be used in bioremediation processes for the region.
Assuntos
Ecossistema , Mercúrio , Água/análise , Ouro/análise , Solo/química , Colômbia , Mercúrio/análise , Bactérias/genética , Mineração , Monitoramento Ambiental/métodosRESUMO
The possibility that the Amazon forest system could soon reach a tipping point, inducing large-scale collapse, has raised global concern1-3. For 65 million years, Amazonian forests remained relatively resilient to climatic variability. Now, the region is increasingly exposed to unprecedented stress from warming temperatures, extreme droughts, deforestation and fires, even in central and remote parts of the system1. Long existing feedbacks between the forest and environmental conditions are being replaced by novel feedbacks that modify ecosystem resilience, increasing the risk of critical transition. Here we analyse existing evidence for five major drivers of water stress on Amazonian forests, as well as potential critical thresholds of those drivers that, if crossed, could trigger local, regional or even biome-wide forest collapse. By combining spatial information on various disturbances, we estimate that by 2050, 10% to 47% of Amazonian forests will be exposed to compounding disturbances that may trigger unexpected ecosystem transitions and potentially exacerbate regional climate change. Using examples of disturbed forests across the Amazon, we identify the three most plausible ecosystem trajectories, involving different feedbacks and environmental conditions. We discuss how the inherent complexity of the Amazon adds uncertainty about future dynamics, but also reveals opportunities for action. Keeping the Amazon forest resilient in the Anthropocene will depend on a combination of local efforts to end deforestation and degradation and to expand restoration, with global efforts to stop greenhouse gas emissions.
Assuntos
Florestas , Aquecimento Global , Árvores , Secas/estatística & dados numéricos , Retroalimentação , Aquecimento Global/prevenção & controle , Aquecimento Global/estatística & dados numéricos , Árvores/crescimento & desenvolvimento , Incêndios Florestais/estatística & dados numéricos , Incerteza , Recuperação e Remediação Ambiental/tendênciasRESUMO
Monitoring is essential to ensure that environmental goals are being achieved, including those of sustainable agriculture. Growing interest in environmental monitoring provides an opportunity to improve monitoring practices. Approaches that directly monitor land cover change and biodiversity annually by coupling the wall-to-wall coverage from remote sensing and the site-specific community composition from environmental DNA (eDNA) can provide timely, relevant results for parties interested in the success of sustainable agricultural practices. To ensure that the measured impacts are due to the environmental projects and not exogenous factors, sites where projects have been implemented should be benchmarked against counterfactuals (no project) and control (natural habitat) sites. Results can then be used to calculate diverse sets of indicators customized to monitor different projects. Here, we report on our experience developing and applying one such approach to assess the impact of shaded cocoa projects implemented by the Instituto de Manejo e Certificação Florestal e Agrícola (IMAFLORA) near São Félix do Xingu, in Pará, Brazil. We used the Continuous Degradation Detection (CODED) and LandTrendr algorithms to create a remote sensing-based assessment of forest disturbance and regeneration, estimate carbon sequestration, and changes in essential habitats. We coupled these remote sensing methods with eDNA analyses using arthropod-targeted primers by collecting soil samples from intervention and counterfactual pasture field sites and a control secondary forest. We used a custom set of indicators from the pilot application of a coupled monitoring framework called TerraBio. Our results suggest that, due to IMAFLORA's shaded cocoa projects, over 400 acres were restored in the intervention area and the community composition of arthropods in shaded cocoa is closer to second-growth forests than that of pastures. In reviewing the coupled approach, we found multiple aspects worked well, and we conclude by presenting multiple lessons learned.
Assuntos
DNA Ambiental , Tecnologia de Sensoriamento Remoto , Brasil , Agricultura , Florestas , Biodiversidade , Conservação dos Recursos Naturais , Monitoramento Ambiental/métodosRESUMO
Amazon is a hotspot for mercury (Hg) contamination and Terra do Meio region, despite its protected status for sustainable use, has never been monitored for this element. Looking to address this gap, this study aimed to quantify capillary Hg concentration in riverine populations of Terra do Meio (Xingu Basin, Central Amazon, Brazil) and associated factors with high Hg levels (90 percentile). Hair samples from 182 individuals from Iriri, Riozinho do Anfrísio and Xingu Extractive Reserves (RESEX), aged between 18 and 70 years old, were collected to measure total mercury levels (HgT), and socioeconomic, demographic, and clinical-epidemiological data were annotated. Overall, high levels of Hg were observed (mean 4.985 µg/g, median 3.531 µg/g) with significant differences between localities. Among the factors related to high capillary Hg levels, male gender, smoking habit, work in agriculture, livestock or extractivism, and residence in Iriri and Riozinho do Anfrísio RESEX were highlighted. A high prevalence of symptoms related to Hg intoxication, including anxiety, memory deficit, and lower limb problems, was observed. Overall, the results reveal that communities in these RESEXs are exposed to Hg and appear to be suffering from chronic health effects. Considering the increased anthropogenic alterations observed recently in the Amazon region and the subsequent amplified environmental bioavailability of Hg, further studies and mitigating actions are critical. This includes better surveillance of illegal anthropic activities and provision of ongoing education on this matter and incentives for dietary adaptations.
Assuntos
Peixes , Mercúrio , Animais , Humanos , Masculino , Adolescente , Adulto Jovem , Adulto , Pessoa de Meia-Idade , Idoso , Brasil/epidemiologia , Mercúrio/análise , Dieta , Disponibilidade Biológica , Monitoramento Ambiental , Contaminação de AlimentosRESUMO
The present study investigated the contamination of oysters farmed in Amazonian estuaries by microplastics (MPs). A total of 120 adult oysters (Crassostrea gasar) were collected from four sites along the Mangrove Coast of Pará/Brazil: S1, S2, S3 and S4, with 30 oyster for each. Overall, 58.33 % of the oyster samples contained microplastics, with mean concentrations of 0.23 MPs/g and 1.9 MPs/ind. The concentration of microplastics varied among the four sites, where S1 and S3 had the highest values while S4 had the lowest. PA fibers were the majority of particles (91 %), followed by PS fragments (9 %). The hepatopancreas and the gonad concentrated more microplastics than the rest of the body. As an important species for aquaculture in Amazon, we recommend additional regulation to reduce human exposure to microplastics, such as the installation of depuration facilities and constant monitoring of the contamination of oysters from farms in the region.
Assuntos
Crassostrea , Poluentes Químicos da Água , Animais , Humanos , Microplásticos , Plásticos , Estuários , Aquicultura , Poluentes Químicos da Água/análise , Monitoramento AmbientalRESUMO
BACKGROUND: The repercussions of the syphilis epidemic differ according to populations. Identifying and acknowledging the differences and specificities of populations is fundamental in the design and implementation of policies aimed at assisting the groups most vulnerable to syphilis. OBJECTIVE: To estimate the prevalence of antibodies against Treponema pallidum and associated vulnerability factors among riverside populations of a capital city in the Brazilian Amazon. METHODS: Cross-sectional study was conducted among residents of the periurban islands in Belém, northern Brazil, from August 2020 to January 2021. The inclusion criterion was being a resident of the riverside communities of the Combú Environmental Protection Area, aged 18 years or over. The participants responded to questionnaire and were tested for syphilis using rapid test. Data were analyzed using multiple logistic regression by Minitab version 20® software. RESULTS: Overall, a total of 325 riverine were included. Age varied from 18 to 91 years (average 40 years). Prevalence of markers for syphilis was 5.9% (95% CI: 3.3%-8.4%). The multiple regression showed that as age increases, the chances of having syphilis also increase (p = 0.001; aOR: 1.04) and riverside dwellers with more than one sexual partner in the last 6 months had more than four chances of having syphilis compared to people who had only one sexual partner (p = 0.007; aOR: 4.20). CONCLUSION: Syphilis circulates among traditional populations in the Amazon and is associated with factors of social and individual vulnerability.
Assuntos
Infecções por HIV , Sífilis , Humanos , Sífilis/epidemiologia , Brasil/epidemiologia , Estudos Transversais , Fatores de Risco , Treponema pallidum , Prevalência , Infecções por HIV/epidemiologiaRESUMO
Paracoccidioidomycosis is an infection with the potential for environmental dissemination, especially in regions of hot and humid climate, where human cases have been recorded in the Southwestern Amazon of Brazil, specifically in the state of Acre. Despite studies providing information about the presence of these fungi in soil and animal samples, such as armadillos, further investigations are still needed to determine the epidemiological distribution of the genus Paracoccidioides. The aim of this study was to detect the occurrence of Paracoccidioides fungi in the Southwestern Amazon. To achieve this, 60 soil samples were collected from armadillo burrows on rural properties in the in the municipalities of Acrelândia, Bujari, Plácido de Castro, Rio Branco, Sena Madureira, and Senador Guiomard, located in the state of Acre, Brazil. Fungal DNA was extracted from these samples using the DNEASY® PowerSoil kit-Quiagen, followed by Nested PCR technique with ITS4 and ITS5 as external primers, and PBITS-E and PBITS-R as internal primers. DNA amplification products of about 380 bp compatible with Paracoccidioides spp. were detected in six samples (10%), being sequenced and identified as P. brasiliensis. These findings indicate that the soils of the Acre state could be considered a potential source for Paracoccidioides spp., suggesting that local infections are likely.
Assuntos
Paracoccidioides , Paracoccidioidomicose , Animais , Humanos , Paracoccidioides/genética , Microbiologia do Solo , Fungos , Solo , Paracoccidioidomicose/epidemiologia , Paracoccidioidomicose/microbiologia , Brasil/epidemiologiaRESUMO
In Brazil, studies evaluating the concentration of trace metals in fish farms are scarce. Therefore, studies investigating the presence and levels of these metals in aquatic biota, particularly in fish tissues, are crucial for developing appropriate strategies to mitigate the impact of possible toxic metals. Herein, we investigated the levels of trace metals (Cr, Mn, Co, Ni, Cu, Zn, Al, Ag, Cd, Pb, Fe, Na, Mg, Ca, K, and Ba) in water, feed, and sediment, as well as the bioconcentration and bioaccumulation factors in tambaqui muscles (Colossoma macropomum). For this purpose, eight commercial fish farms, which are also engaged in other agricultural activities, were selected. Fe, Zn, Mg, and Cr concentration in tambaqui muscles exceeded the limits set by the Brazilian regulations for daily consumption by adults. Mn, Zn, Al, Pb, Fe, Na, Cu, Co, Ag, Cd, and Ba levels were substantially higher in the liver tissue of tambaquis than those in the muscle tissue. The most prevalent metals found in the feed were Ca, K, Na, Mg, and Fe. However, the levels of Cr and Cd in the sediment, as well as Pb, Mn, Cu, and Fe in the water, exceeded the maximum limits allowed by the Brazilian legislation. The highest bioconcentration factors were observed for the metals, Na, Zn, and K, with concentrations up to 4.74, 12.61, and 72.08 times, respectively, higher in tambaqui muscle compared to those in water. The bioaccumulation factors for Ca, Zn, Mg, Na, and K were 2.90, 6.96, 21.21, 212.33, and 492.02 times, respectively, higher in the muscle tissue than those in the sediment values in fishponds across all fish farms. Therefore, our findings suggest that tambaquis have a remarkable ability to bioaccumulate trace metals, particularly the essential ones, and can be categorized as a bioindicator species for environmental quality. Furthermore, we observed that, although water exhibits the highest prevalence and diversity of elements above the values recommended by the Brazilian legislation, sediment is the primary source of trace metal contamination for tambaquis.
Assuntos
Caraciformes , Metais Pesados , Poluentes Químicos da Água , Animais , Cádmio , Monitoramento Biológico , Chumbo , Monitoramento Ambiental , Água , Agricultura , Metais Pesados/análise , Poluentes Químicos da Água/análiseRESUMO
The geochemical processes involved in the Amazon soils formation are not totally understood because its geological and pedological features were formed during different geological events and different times. The Southwestern region of Amazonas State is an example of a region where the soils were developed from rocks formed by sedimentary processes and, nowadays, the soils continue receiving seasonal inputs from the Andes sediments. Data on geochemical patterns of this region are scarce, and there is no information about the possible effects of the natural or unnatural enrichment of potentially toxic elements (PTEs). Thus, this study represents the first research into the geochemical patterns of PTEs in soils of Southwestern Amazonas State. Further, we carried out a human health risk assessment and a proposal for Quality Reference Values (QRV) for thirteen PTEs (As, Ba, Cd, Co, Cr, Cu, Mn, Ni, Pb, Ti, V, Zn and Zr). Our findings showed that the PTEs contents in soil samples collected in the lowland areas are strongly influenced by sediments inputs, while samples localized in the highland areas are weakly influenced by sediments inputs and present depletion of PTEs. Barium, Cr, Cu, Ni and Pb were the PTEs most influenced by sediment's deposition. The soil contamination assessment showed the existence of enrichment of the potentially toxic elements in soil samples, which may be a consequence of the natural inputs of the Andean sediments. Furthermore, Co and Cr exceed the safety zone for carcinogenic risk assessment, which indicates the need to monitor these elements and their possible effects on the health of the population in this region.
Assuntos
Metais Pesados , Poluentes do Solo , Humanos , Solo/química , Metais Pesados/análise , Monitoramento Ambiental , Brasil , Valores de Referência , Chumbo , Poluentes do Solo/análise , Medição de RiscoRESUMO
Artisanal and small-scale gold mining (ASGM) has become a major threat for Neotropical forests. This technique for obtaining gold is a substantial driver of small-scale deforestation and the largest contributor of Hg emissions to both the atmosphere and freshwater systems globally. Previous studies have demonstrated the impacts of Hg accumulation on various aquatic ecosystems and organisms. However, its consequences in other, more discrete systems such as phytotelmata (water-holding plant structures), and the organisms therein, have so far gone unnoticed. Here, we show high concentrations of Hg (mean ± SD: 1.43 ± 2.19 ppm) in phytotelmata and other small pools, the aquatic microenvironments used by the Neotropical poison frog Dendrobates tinctorius as tadpole-rearing sites. In 17 % of the cases, we detected Hg concentrations above the severe effect level (SEL = 2 ppm) for freshwater sediments. Hg concentrations varied depending on pool characteristics and tended to increase in proximity to known ASGM sites. We did not find an effect of Hg concentration on the number of D. tinctorius tadpoles in a given pool. Tadpoles were found in pools with concentrations of up to 8.68 ppm, suggesting that D. tinctorius fathers do not avoid pools with high Hg levels for tadpole deposition. While further research is needed to determine the potential effects of Hg on tadpole development, we found an intriguing tendency for tadpoles in later developmental stages to have lower body condition when occurring in pools with higher Hg concentrations. Our findings provide evidence of relevant Hg concentrations in the terrestrial water systems used by phytotelm-breeding anurans, and highlight the need of further field and experimental studies investigating the implications of Hg contamination for tadpole development and behaviour and the overall conservation of Amazonian biodiversity.