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1.
Fungal Biol ; 126(1): 75-81, 2022 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-34930560

RESUMO

Mycoviruses may influence the pathogenicity of disease-causing fungi. Although mycoviruses have been found in some chytrid fungi, limited testing has not detected them in Batrachochytrium dendrobatidis (Bd), the cause of the devastating amphibian disease, chytridiomycosis. Here we conducted a survey for mycovirus presence in 38 Bd isolates from Australia (n = 31), Brazil (n = 5) and South Korea (n = 2) with a combination of modern high-throughput sequencing and conventional dsRNA cellulose chromatography. Mycoviruses were not detected in any isolates. This result was unexpected, given the long evolutionary history of Bd, as well as the high prevalence of mycoviruses in related fungal species. Given our widespread sampling in Australia and the limited number of Bd introductions, we suggest that mycoviruses are uncommon or absent from Australian Bd. Testing more isolates from regions where Bd originated, as well as regions with high diversity or low fungal virulence may identify mycoviruses that could aid in disease control.

2.
Toxins (Basel) ; 13(11)2021 Nov 19.
Artigo em Inglês | MEDLINE | ID: mdl-34822600

RESUMO

The genus Brachycephalus is a fascinating group of miniaturized anurans from the Brazilian Atlantic Forest, comprising the conspicuous, brightly colored pumpkin-toadlets and the cryptic flea-toads. Pumpkin-toadlets are known to contain tetrodotoxins and therefore, their bright colors may perform an aposematic function. Previous studies based on a limited number of mitochondrial and nuclear-encoded markers supported the existence of two clades containing species of pumpkin-toadlet phenotype, but deep nodes remained largely unresolved or conflicting between data sets. We use new RNAseq data of 17 individuals from nine Brachycephalus species to infer their evolutionary relationships from a phylogenomic perspective. Analyses of almost 5300 nuclear-encoded ortholog protein-coding genes and full mitochondrial genomes confirmed the existence of two separate pumpkin-toadlet clades, suggesting the convergent evolution (or multiple reversals) of the bufoniform morphology, conspicuous coloration, and probably toxicity. In addition, the study of the mitochondrial gene order revealed that three species (B. hermogenesi, B. pitanga, and B. rotenbergae) display translocations of different tRNAs (NCY and CYA) from the WANCY tRNA cluster to a position between the genes ATP6 and COIII, showing a new mitochondrial gene order arrangement for vertebrates. The newly clarified phylogeny suggests that Brachycephalus has the potential to become a promising model taxon to understand the evolution of coloration, body plan and toxicity. Given that toxicity information is available for only few species of Brachycephalus, without data for any flea-toad species, we also emphasize the need for a wider screening of toxicity across species, together with more in-depth functional and ecological study of their phenotypes.

3.
Sensors (Basel) ; 21(21)2021 Oct 26.
Artigo em Inglês | MEDLINE | ID: mdl-34770389

RESUMO

In this article, a combination of rectangular loop array and slot radiator for multiband applications is presented. The antenna is configured by arranging, concentrically, a set of rectangular loop radiators excited by electromagnetic coupling provided by a dumbbell slot. The size of the loops is calculated to obtain the desired resonant frequencies, which are almost independent of the adjacent rings. The exciting slot is designed to operate in a wideband frequency range to cover the upper desired resonance. In addition, to obtain directive radiation patterns, a reflector shaped like a box is introduced, giving a stable gain, radiation pattern shape, and port matching at the selected frequencies. The configuration presents great results, since to the authors' knowledge, even a similar configuration given in the open literature presents some disadvantages compared to this one; moreover, not just any structure can be employed as the resonating elements, obtaining multiband behavior at the same time.

4.
Surg Innov ; : 15533506211037091, 2021 Aug 06.
Artigo em Inglês | MEDLINE | ID: mdl-34358428

RESUMO

Background. This article aims to present an innovative design of a steerable surgical instrument for conventional and single-site minimally invasive surgery (MIS), which improves the dexterity and maneuverability of the surgeon while offering a solution to the limitations of current tools. Methods. The steerable MIS instrument consists of a deflection structure with a curved sliding joints design that articulates the distal tip in two additional degrees of freedom (DoFs), relative to the instrument shaft, using transmission by cables. A passive ball-joint mechanism articulates the handle relative to the instrument shaft, improves wrist posture, and prevents collision of instrument handles during single-site MIS procedures. The two additional DoFs of the articulating tip are activated by a thumb-controlled device, using a joystick design mounted on the handle. This steerable MIS instrument was developed by additive manufacturing in a 3D printer using PLA polymer. Results. Prototype testing showed a maximum tip deflection of 60° in the left and right directions, with a total deflection of 120°. With the passive ball-joint fully offset, the steerable tip achieved a deflection of 90° for the right and 40° for the left direction, with a total deflection of 130°. Furthermore, the passive ball-joint mechanism in the handle obtained a maximum range of motion of 60°. Conclusions. This steerable MIS instrument concept offers an alternative to enhance the application fields of conventional and single-site MIS, increasing manual dexterity of the surgeon and the ability to reach narrow anatomies from other directions.

5.
Artigo em Inglês | MEDLINE | ID: mdl-34202470

RESUMO

The use of ICT (information communication technology) as an educational resource is becoming more evident in the education systems of most countries, even more so with the COVID-19 crisis. When it comes to disability and education, ICT becomes a tool for social and educational inclusion. This study presents the validation and evaluation of a measurement scale on ICT literacy for inclusive education. In addition, based on previous literature, a conceptual model is proposed and validated through PLS (partial least squares) using a sample of 142 teachers from all educational stages. The results show that teachers' ICT knowledge to ensure inclusion consists of five dimensions on specific needs. ICT knowledge has a positive impact on teacher motivation and ICT use. Teachers at primary and early childhood education levels have a lower motivation and use of ICT, although they have a higher knowledge of disability. The results found allow progress to be made in measuring the educational inclusion of schools and the ICT knowledge needed to ensure care and support for all people. A notable implication is the need for training on ICT and disability within educational policies.


Assuntos
COVID-19 , Pessoas com Deficiência , Pré-Escolar , Comunicação , Humanos , SARS-CoV-2 , Instituições Acadêmicas
6.
Dis Aquat Organ ; 145: 79-88, 2021 Jun 17.
Artigo em Inglês | MEDLINE | ID: mdl-34137378

RESUMO

Chytridiomycosis, an emergent infectious disease caused by the fungus Batrachochytrium dendrobatidis (Bd), is considered one of the drivers of the current amphibian biodiversity loss. To inform endangered species conservation efforts, it is essential to improve our knowledge about the abiotic and biotic factors that influence Bd infection dynamics in the wild. Here, we analyzed variation of Bd infection in the redbelly toad Melanophryniscus montevidensis, a threatened bufonid from Uruguay. We tested the influence of temperature, precipitation, season, and host population size on Bd prevalence and intensity. Additionally, considering the sub-lethal effects of Bd, we tested if these variables, potentially through their effect on Bd, also explain the variation in host body condition. We determined a high Bd prevalence of 41% (100/241), and that population size influenced both Bd prevalence and infection intensity. We identified an effect of precipitation and season on Bd infection intensity and an effect of season on toad body condition. In addition, we found a negative effect of infection intensity on body condition; moreover, while some toads cleared the infection, their body condition did not improve, suggesting a long-term cost. This is the first report on host population size as an important factor in Bd infection dynamics in a threatened anuran species, and seasonal demographic changes appear to play an important role in the dynamics. Finally, we highlight the need for monitoring Bd in this and other endangered amphibian populations, especially those within the genus Melanophryniscus, which includes several Endangered and Data Deficient species in South America.


Assuntos
Quitridiomicetos , Animais , Batrachochytrium , Bufonidae , Espécies em Perigo de Extinção , Estações do Ano , América do Sul , Uruguai/epidemiologia
7.
Rev. cuba. cir ; 60(2): e1016, graf
Artigo em Espanhol | LILACS, CUMED | ID: biblio-1280222

RESUMO

Introducción: El empiema de necesidad o empiema necessitatis (del latín) es un hallazgo raro en la actualidad y la tuberculosis es la causa más común, sobre todo en pacientes inmunodeprimidos. Objetivo: Presentar un caso con un empiema de necesidad como complicación de la tuberculosis extrapulmonar Caso clínico: Paciente de sexo femenino de 47 años de edad, sin antecedentes de enfermedad conocidos. Ingresa por una neumonía de la base derecha y como complicación un empiema de necesidad de naturaleza tuberculosa. Es tratada de forma médica y quirúrgica, tuvo una evolución favorable. Conclusiones: El conocimiento de la epidemiología de la zona donde se diagnosticó la enferma y la medicina personalizada contribuyeron a un diagnóstico rápido y a un tratamiento médico y quirúrgico acorde a los protocolos establecidos para la tuberculosis extrapleural(AU)


Introduction: Empyema of necessity (or empyema necessitatis) is, at present, a rare finding, of which tuberculosis is the most common cause, especially in immunosuppressed patients. Objective: To present a case of empyema of necessity as a complication of extrapulmonary tuberculosis. Clinical case: 47-year-old female patient, without known history of disease, who was admitted due to pneumonia of the right base and, as a complication, an empyema of necessity of a tubercular nature. She was treated medically and surgically, and had a favorable evolution. Conclusions: Knowledge of the epidemiology of the area where the patient was diagnosed, together with personalized medical care, contributed to a rapid diagnosis, as well as to the medical and surgical treatment provided according to the protocols established for extrapleural tuberculosis(AU)


Assuntos
Humanos , Feminino , Pessoa de Meia-Idade , Cuidados Médicos , Empiema Tuberculoso/cirurgia , Empiema Tuberculoso/complicações , Mycobacterium tuberculosis/efeitos dos fármacos
8.
Dis Aquat Organ ; 144: 133-142, 2021 May 06.
Artigo em Inglês | MEDLINE | ID: mdl-33955851

RESUMO

Complex interactions among hosts, pathogens, and the environment affect the vulnerability of amphibians to the emergence of infectious diseases such as chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd). Boana curupi is a forest-dwelling amphibian endemic to the southern Atlantic Forest of South America, a severely fragmented region. Here, we evaluated whether abiotic factors (including air and water temperature, relative air humidity, and landscape) are correlated with chytrid infection intensity and prevalence in B. curupi. We found individuals infected with Bd in all populations sampled. Prevalence ranged from 25-86%, and the infection burden ranged from 1 to over 130000 zoospore genomic equivalents (g.e.) (mean ± SD: 4913 ± 18081 g.e.). The infection load differed among populations and was influenced by forest cover at scales of 100, 500, and 1000 m, with the highest infection rates recorded in areas with a higher proportion of forest cover. Our results suggest that the fungus is widely distributed in the populations of B. curupi in southern Brazil. Population and disease monitoring are necessary to better understand the relationships between host, pathogen, and environment, especially when, as in the case of B. curupi, threatened species are involved.


Assuntos
Quitridiomicetos , Micoses , Anfíbios , Animais , Anuros , Brasil/epidemiologia , Florestas , Micoses/epidemiologia , Micoses/veterinária
9.
Dis Aquat Organ ; 144: 99-106, 2021 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-33830073

RESUMO

Environmental variation along elevational gradients shapes conditions for pathogen development, which influences disease outcomes. Chytridiomycosis is a non-vectored disease caused by the aquatic fungus Batrachochytrium dendrobatidis (Bd) and is responsible for massive declines of amphibian populations all over the world. Several biotic and abiotic factors are known to influence Bd infection dynamics in amphibians, including temperature and host species richness. Here, we quantified Bd prevalence and load along an elevational gradient in the Caparaó National Park (CNP), Brazil, and tested for associations of Bd infections with elevation, temperature, and species richness. We hypothesized that Bd infections would increase as local species richness decreased with elevation. We detected Bd along the entire elevational gradient and found a negative association between infection load and elevation. We did not detect significant associations between infection prevalence and elevation. Our findings are consistent with other wide elevational gradient studies, but are contrary to 2 other studies performed in the Atlantic Forest. We did not find the minimum elevational range that should be sampled to detect the influence of elevation on Bd variation. Our study represents the widest elevational gradient that has been sampled in Brazil and contributes to a better understanding of Bd distribution and dynamics in natural systems.


Assuntos
Quitridiomicetos , Micoses , Anfíbios , Animais , Brasil/epidemiologia , Florestas , Micoses/epidemiologia , Micoses/veterinária
10.
Einstein (Sao Paulo) ; 19: eAO5701, 2021.
Artigo em Inglês, Português | MEDLINE | ID: mdl-33729286

RESUMO

OBJECTIVE: To examine epidemiologic, anthropometric and clinical variables associated with stress urinary incontinence in obese women, before and after bariatric surgery, and to identify predictive factors of stress urinary incontinence resolution. METHODS: Prospective observational study with women enrolled in a bariatric surgery program between 2015 and 2016. Patients were assessed prior to and 6 months after bariatric surgery using the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form, the Patient Global Impression of Improvement and the Visual Analogue Scale. Patient assessment also included physical examination and bladder stress tests. RESULTS: A total of 43 women completed the study. There was a 72.7% reduction in stress urinary incontinence (p=0.021). Predictive factors for preoperative diagnosis of stress urinary incontinence included age (p=0.024) and abdominal waist circumference (p=0.048). Urinary symptoms improved after weight loss, especially nocturia (p=0.001) and stress urinary incontinence (p=0.026). Menopause was the most significant predictive factor for persistence of stress urinary incontinence within six months of bariatric surgery (p=0.046). Self-reported outcomes and scores obtained in the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form, the Patient Global Impression of Improvement and the Visual Analogue Scale were associated with significant improvement (p=0.012, p=0.025, and p=0.002 respectively). CONCLUSION: Older women with larger waist circumference have a higher risk of developing stress urinary incontinence prior to bariatric surgery. Menopausal women are highly prone to persistent stress urinary incontinence, even after weight loss. Weight loss achieved through bariatric surgery improved stress urinary incontinence symptoms and mitigated related impacts on quality of life in the vast majority of women.


Assuntos
Cirurgia Bariátrica , Obesidade Mórbida , Incontinência Urinária por Estresse , Fatores Etários , Feminino , Humanos , Menopausa , Obesidade Mórbida/complicações , Obesidade Mórbida/cirurgia , Estudos Prospectivos , Qualidade de Vida , Inquéritos e Questionários , Resultado do Tratamento , Incontinência Urinária por Estresse/etiologia , Circunferência da Cintura
11.
Rev. cuba. med. mil ; 50(1): e725, 2021.
Artigo em Espanhol | LILACS-Express | LILACS | ID: biblio-1289501

RESUMO

RESUMEN Introducción: El cáncer de pulmón predomina a nivel mundial, en la tercera edad de la vida y exhibe cifras bajas de supervivencia. Se realiza una búsqueda en bases bibliográficas biomédicas; se seleccionaron 25 de 58 artículos sobre el tema. Objetivos: Describir y analizar algunas características específicas del cáncer de pulmón con énfasis en aspectos epidemiológicos, etiopatogénicos y de la estadificación nodular linfática. Desarrollo: La clasificación tumor, ganglio, metástasis (TNM) para el cáncer de pulmón en su 8va versión, se publicó en 2016 y está vigente con nuevas categorías de los componentes tumor (T) y metástasis (M), así como la aparición de nuevos estadios, pero sin cambios en el componente ganglios (N); a pesar de lo cual la valoración nodular linfática del mediastino (pN) tiene implicaciones pronósticas y terapéuticas de gran importancia en los pacientes con cáncer de pulmón de células no pequeñas. Conclusiones: El cáncer de pulmón de células no pequeñas es el más frecuente y mortal a escala mundial, en una población ya envejecida, en la cual los factores moleculares, genéticos y ambientales juegan un papel en su desarrollo y son objeto de estudio, de ahí que la estadificación TNM sea de vital importancia al determinar las decisiones del tratamiento y del pronóstico. La correcta identificación de la afectación ganglionar es indispensable, puesto que, en ausencia de metástasis, marcará el pronóstico. La metodología utilizada para crear las diferentes ediciones de la clasificación TNM está en continua evolución, acorde al desarrollo científico contemporáneo.


ABSTRACT Introduction: Lung cancer is predominant worldwide, in the third age of life and exhibits low survival rates. A search is carried out in biomedical bibliographic databases; 25 of 58 articles on the topic were selected. Objectives: To describe and analyze some specific characteristics of lung cancer with an emphasis on epidemiological, etiopathogenic and lymphatic nodular staging aspects. Development: The TNM classification for lung cancer in its 8th version, was published in 2016 and is in force with new categories of components T and M, as well as the appearance of new stages but without changes in component N; Despite this, lymph node evaluation of the mediastinum (pN) has important prognostic and therapeutic implications in patients with non-small cell lung cancer. Conclusions: Non-small cell lung cancer is the most frequent and deadly worldwide, in an aging population, where molecular, genetic and environmental factors play a role in its development and continue to be the subject of studies; hence TNM staging is vital when determining treatment and prognosis decisions. The correct identification of lymph node involvement is essential, since in the absence of metastasis, it will determine the prognosis. The methodology used to create the different editions of the TNM classification is in continuous evolution, according to contemporary scientific development.

12.
FEMS Microbiol Ecol ; 97(4)2021 04 06.
Artigo em Inglês | MEDLINE | ID: mdl-33580951

RESUMO

Amphibian skin bacteria may confer protection against the fungus Batrachochytrium dendrobatidis (Bd), but responses of skin bacteria to different Bd lineages are poorly understood. The global panzootic lineage (Bd-GPL) has caused amphibian declines and extinctions globally. However, other lineages are enzootic (Bd-Asia-2/Brazil). Increased contact rates between Bd-GPL and enzootic lineages via globalization pose unknown consequences for host-microbiome-pathogen dynamics. We conducted a laboratory experiment and used 16S rRNA amplicon-sequencing to assess: (i) whether two lineages (Bd-Asia-2/Brazil and Bd-GPL) and their recombinant, in single and mixed infections, differentially affect amphibian skin bacteria; (ii) and the changes associated with the transition to laboratory conditions. We determined no clear differences in bacterial diversity among Bd treatments, despite differences in infection intensity. However, we observed an additive effect of mixed infections on bacterial alpha diversity and a potentially antagonistic interaction between Bd genotypes. Additionally, observed changes in community composition suggest a higher ability of Bd-GPL to alter skin bacteria. Lastly, we observed a drastic reduction in bacterial diversity and a change in community structure in laboratory conditions. We provide evidence for complex interactions between Bd genotypes and amphibian skin bacteria during coinfections, and expand on the implications of experimental conditions in ecological studies.


Assuntos
Quitridiomicetos , Micoses , Animais , Bactérias/genética , Brasil , Quitridiomicetos/genética , RNA Ribossômico 16S/genética
17.
Einstein (Säo Paulo) ; 19: eAO5701, 2021. tab, graf
Artigo em Inglês | LILACS | ID: biblio-1154090

RESUMO

ABSTRACT Objective: To examine epidemiologic, anthropometric and clinical variables associated with stress urinary incontinence in obese women, before and after bariatric surgery, and to identify predictive factors of stress urinary incontinence resolution. Methods: Prospective observational study with women enrolled in a bariatric surgery program between 2015 and 2016. Patients were assessed prior to and 6 months after bariatric surgery using the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form, the Patient Global Impression of Improvement and the Visual Analogue Scale. Patient assessment also included physical examination and bladder stress tests. Results: A total of 43 women completed the study. There was a 72.7% reduction in stress urinary incontinence (p=0.021). Predictive factors for preoperative diagnosis of stress urinary incontinence included age (p=0.024) and abdominal waist circumference (p=0.048). Urinary symptoms improved after weight loss, especially nocturia (p=0.001) and stress urinary incontinence (p=0.026). Menopause was the most significant predictive factor for persistence of stress urinary incontinence within six months of bariatric surgery (p=0.046). Self-reported outcomes and scores obtained in the International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form, the Patient Global Impression of Improvement and the Visual Analogue Scale were associated with significant improvement (p=0.012, p=0.025, and p=0.002 respectively). Conclusion: Older women with larger waist circumference have a higher risk of developing stress urinary incontinence prior to bariatric surgery. Menopausal women are highly prone to persistent stress urinary incontinence, even after weight loss. Weight loss achieved through bariatric surgery improved stress urinary incontinence symptoms and mitigated related impacts on quality of life in the vast majority of women.


RESUMO Objetivo: Examinar as variáveis epidemiológicas, antropométricas e clínicas associadas à incontinência urinária de esforço em mulheres obesas antes e após a cirurgia bariátrica e identificar fatores preditivos da resolução desse tipo de incontinência. Métodos: Estudo observacional prospectivo com mulheres de um programa de cirurgia bariátrica, realizado entre 2015 e 2016. As pacientes responderam ao International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form, à Clinical Global Impression-Improvement e à Escala Visual Analógica, sendo submetidas ao exame físico e ao teste de incontinência antes e 6 meses após cirurgia bariátrica. Resultados: Completaram o estudo 43 mulheres. Houve redução de 72,7% na incontinência urinária de esforço (p=0,021). Fatores preditivos para o diagnóstico pré-operatório da incontinência urinária incluíram idade (p=0,024) e circunferência abdominal (p=0,048). Todos os sintomas urinários demonstraram melhora após perda de peso, notadamente noctúria (p=0,001) e incontinência urinária de esforço (p=0,026). A menopausa foi o fator mais crítico para predizer a persistência da incontinência urinária de esforço 6 meses após a cirurgia bariátrica (p=0,046). Os resultados relatados do International Consultation on Incontinence Questionnaire-Urinary Incontinence Short Form, da Patient Global Impression of Improvement e da Escala Visual Analógica tiveram melhora significativa (p=0,012, p=0,025, p=0,002, respectivamente). Conclusão: Mulheres idosas e com maior circunferência abdominal têm maior risco de desenvolver incontinência urinária de esforço antes da cirurgia. Mulheres na menopausa são fortemente propensas a persistir com a incontinência urinária de esforço, mesmo após a perda de peso. A perda de peso após a cirurgia bariátrica melhora os sintomas de incontinência urinária de esforço e seus impactos na qualidade de vida na maioria das mulheres.


Assuntos
Humanos , Feminino , Incontinência Urinária por Estresse/etiologia , Obesidade Mórbida/cirurgia , Obesidade Mórbida/complicações , Cirurgia Bariátrica , Qualidade de Vida , Menopausa , Estudos Prospectivos , Inquéritos e Questionários , Fatores Etários , Resultado do Tratamento , Circunferência da Cintura
18.
Dis Aquat Organ ; 142: 171-176, 2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33331284

RESUMO

Infection by the chytrid fungus Batrachochytrium dendrobatidis (Bd) is a major threat to amphibians and has caused catastrophic global declines of amphibian populations. Some studies have detected a seasonal pattern of infection associated with the local climate, and although most of them have focused on investigating the seasonality of Bd in relation to its impacts on amphibians, fewer have aimed to understand the chytrid persistence in the amphibian assemblage over seasons by investigating reservoir hosts. Since tadpoles are generally tolerant to Bd infection, they often play a relevant role in local disease dynamics. Thus, we hypothesized that tadpoles of Boana faber, a species that can be found in permanent ponds throughout the seasons, would function as Bd reservoirs. We therefore investigated Bd infection prevalence in tadpoles of this species over 2 yr in a nature reserve. As expected, we detected a seasonal variation of Bd infection, with a higher prevalence of Bd during the coldest months (winter) when compared to the warmer months (summer). Interestingly, our seasonal-trend decomposition analysis showed that Bd prevalence is increasing annually in the area, which could represent either a natural fluctuation of this pathogen, or an imminent threat to that anuran assemblage. With this study, we highlight the tadpole of B. faber as a potential reservoir for Bd, and we suggest that monitoring Bd in such hosts could be a powerful tool for identifying priority areas for amphibian conservation.


Assuntos
Quitridiomicetos , Micoses , Anfíbios , Animais , Larva , Micoses/epidemiologia , Micoses/veterinária , Lagoas , Prevalência , Estações do Ano
19.
Dis Aquat Organ ; 142: 177-187, 2020 Dec 17.
Artigo em Inglês | MEDLINE | ID: mdl-33331285

RESUMO

Amphibians have been facing a pandemic caused by the deadly fungus Batrachochytrium dendrobatidis (Bd). Although studies have elucidated cutaneous and homeostatic disturbances, it is still unknown if the hepatic function can be affected or if hepatic effects differ among host species. Thus, we evaluated the effects of an experimental Bd infection on the liver (histopathology and the hepatosomatic index) of 2 anuran species (Xenopus laevis and Physalaemus albonotatus) with different susceptibilities to Bd infection and compared them to uninfected controls. Bd infection increased the melanomacrophage cell area and induced leukocyte infiltration in both species. The effects were more pronounced in the sensitive species, P. albonotatus, which showed severe reduction in glycogen stores and liver atrophy, due to energetic imbalance. Hepatocytes of P. albonotatus also showed ballooning degeneration (vacuolization), which could lead to cell death and liver failure. Our results provide evidence that although the sensitive species showed more severe effects, the tolerant species also had hepatic responses to the infection. These findings indicate that hepatic function can play an important role in detoxification and in immune responses to chytridiomycosis, and that it may be used as a new biomarker of health status in chytrid infections.


Assuntos
Quitridiomicetos , Micoses , Anfíbios , Animais , Anuros , Suscetibilidade a Doenças/veterinária , Fígado , Micoses/veterinária
20.
Sci Rep ; 10(1): 22311, 2020 12 18.
Artigo em Inglês | MEDLINE | ID: mdl-33339839

RESUMO

In Brazil's Atlantic Forest (AF) biodiversity conservation is of key importance since the fungal pathogen Batrachochytrium dendrobatidis (Bd) has led to the rapid loss of amphibian populations here and worldwide. The impact of Bd on amphibians is determined by the host's immune system, of which the skin microbiome is a critical component. The richness and diversity of such cutaneous bacterial communities are known to be shaped by abiotic factors which thus may indirectly modulate host susceptibility to Bd. This study aimed to contribute to understanding the environment-host-pathogen interaction determining skin bacterial communities in 819 treefrogs (Anura: Hylidae and Phyllomedusidae) from 71 species sampled across the AF. We investigated whether abiotic factors influence the bacterial community richness and structure on the amphibian skin. We further tested for an association between skin bacterial community structure and Bd co-occurrence. Our data revealed that temperature, precipitation, and elevation consistently correlate with richness and diversity of the skin microbiome and also predict Bd infection status. Surprisingly, our data suggest a weak but significant positive correlation of Bd infection intensity and bacterial richness. We highlight the prospect of future experimental studies on the impact of changing environmental conditions associated with global change on environment-host-pathogen interactions in the AF.


Assuntos
Batrachochytrium/genética , Microbiota/genética , Micoses/microbiologia , Pele/microbiologia , Animais , Anuros/microbiologia , Batrachochytrium/patogenicidade , Biodiversidade , Brasil , Florestas , Interações entre Hospedeiro e Microrganismos/genética
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