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Tetrapods (amphibians, reptiles, birds, and mammals) are model systems for global biodiversity science, but continuing data gaps, limited data standardisation, and ongoing flux in taxonomic nomenclature constrain integrative research on this group and potentially cause biased inference. We combined and harmonised taxonomic, spatial, phylogenetic, and attribute data with phylogeny-based multiple imputation to provide a comprehensive data resource (TetrapodTraits 1.0.0) that includes values, predictions, and sources for body size, activity time, micro- and macrohabitat, ecosystem, threat status, biogeography, insularity, environmental preferences, and human influence, for all 33,281 tetrapod species covered in recent fully sampled phylogenies. We assess gaps and biases across taxa and space, finding that shared data missing in attribute values increased with taxon-level completeness and richness across clades. Prediction of missing attribute values using multiple imputation revealed substantial changes in estimated macroecological patterns. These results highlight biases incurred by nonrandom missingness and strategies to best address them. While there is an obvious need for further data collection and updates, our phylogeny-informed database of tetrapod traits can support a more comprehensive representation of tetrapod species and their attributes in ecology, evolution, and conservation research.
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Biodiversidade , Aves , Mamíferos , Filogenia , Répteis , Animais , Répteis/classificação , Anfíbios , Ecossistema , Viés , Humanos , Tamanho CorporalRESUMO
We propose a distributed rewiring model which starts with a planar graph embedded into the Euclidean space and then behaves as a distributed system, where each node is provided with a set of dynamic links. The proposed rewiring evolves through cycles, where nodes explore the network to identify possible shortcuts and rewire their dynamic links. The rewiring decisions are subject to Euclidean and geodesic distance constrains. The emerging networks were assessed through topological and robustness analyses. We found that the networks display a variety of characteristics observed in complex networks encompassing phenomena such as preferential attachment, the distinctive traits of small-world networks, the presence of community structures, and robustness against degradation process. We consider that our proposal can be applied in the design of those self-managed systems in which there is a limitation on communication resources that can be represented by the Euclidean distance and, however, the components themselves can deploy strategies to optimize the transport of information and develop tolerance before contingencies.
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PURPOSE: Ultrasound-guided percutaneous biopsy (USPB) of the native kidneys is the preferred diagnostic method for several nephrological conditions in both adult and pediatric populations. Conventionally, native kidney biopsies are conducted with patients in the prone position (PP). However, an alternative approach involving the supine oblique antero-lateral position (SALP) has been explored, particularly for individuals who are obese, elderly, or critically ill. METHODS: This study aimed to assess the feasibility and outcomes of USPB performed in SALP with a Free-Flank setting (FF-SALP) in pediatric patients (Group A) compared to adults (Group B). Data from kidney biopsies conducted between 2008 and 2021 were gathered. The study focused on the safety and the prevalence of biopsy samples containing a minimum of 10 glomeruli, histopathological yield in both groups. RESULTS: Complication rates were low in both groups (5.6% vs. 3.7%; p = 0.454), without major complications noted. The pediatric group achieved a significantly higher mean number of glomeruli per biopsy compared to the adult group (20.6 ± 12.3 vs. 15.7 ± 9.4; p < 0.001). However, when evaluating the minimum threshold of 10 glomeruli (76.3% vs. 68.5%; p = 0.072) and histopathologic yield (95.3% vs. 93.5%; p = 0.408), no differences were observed between groups. CONCLUSION: USPB of native kidneys in the FF-SALP position is a safe and effective method for tissue sampling in patients with parenchymal disease. It demonstrated comparable diagnostic yields and complication rates in the pediatric and adult populations, providing advantages in terms of airway management, making it particularly useful for pediatric patients that require general anesthesia.
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Biópsia Guiada por Imagem , Rim , Posicionamento do Paciente , Ultrassonografia de Intervenção , Humanos , Criança , Masculino , Feminino , Ultrassonografia de Intervenção/métodos , Adulto , Biópsia Guiada por Imagem/métodos , Posicionamento do Paciente/métodos , Rim/patologia , Rim/diagnóstico por imagem , Adolescente , Decúbito Dorsal , Nefropatias/diagnóstico por imagem , Nefropatias/patologia , Pessoa de Meia-Idade , Idoso , Pré-Escolar , Estudos Retrospectivos , Estudos de ViabilidadeRESUMO
PURPOSE: Patients with post prostatectomy incontinence (PPI) seem to have different needs. Therefore, device post-operative readjustability may be a beneficial feature in PPI management, even though it lacks study support. The purpose of this study is to describe our surgical technique for male sling (MS) implantation, assess outcomes, and the impact of readjustability. METHODS: We performed a retrospective analysis of 89 consecutive patients who underwent PPI correction with MS Argus-T™ (Promedon, Córdoba, Argentina) from 2009 to 2021. The median follow-up was 48 months (12-120). Data were collected in a dedicated database. Perioperative variables were assessed. A descriptive statistical analysis was performed. Clinical and urodynamic variables were correlated with the need for readjustments and success. RESULTS: In this cohort, objective success was achieved in 80.5% of the patients (65.9% cured and 14.6% improved). A total of 85.4% of the patients met the criteria for subjective success (74.4% cured and 11% improved). For the subgroup of patients who received previous treatment for urethral stricture (US), 79% achieved objective success (63.2% cured, 15.8% improved), and 84.2% achieved subjective success (78.9% cured, 5.3% improved). For the subgroup of patients who received previous radiotherapy (RT) before sling surgery, 68.7% achieved objective success (37.5% cured, 31.2% improved), and 75% achieved subjective success (37.5% cured, 37.5% improved). Procedures for device readjustment were necessary for 27.7% of patients in the total study population. RT and previous US treatment were predictive factors for the need of readjustment, with rates of 66.7% and 61.1% (OR: 8.46; CI: 2.46-29.00; p = 0.001/OR: 6.41; CI: 2.05-20.03; p = 0.001, respectively). CONCLUSIONS: MS adjustability improved success rates, especially among irradiated patients and those with previous US. RT was an adverse predictor of total continence status even after readjustments.
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Prostatectomia , Slings Suburetrais , Humanos , Masculino , Estudos Retrospectivos , Idoso , Prostatectomia/métodos , Pessoa de Meia-Idade , Complicações Pós-Operatórias , Procedimentos Cirúrgicos Urológicos Masculinos/métodos , Desenho de Prótese , Incontinência Urinária/cirurgia , Ajuste de Prótese , Resultado do TratamentoRESUMO
Aquatic contaminants and infectious diseases are among the major drivers of global amphibian declines. However, the interaction of these factors is poorly explored and could better explain the amphibian crisis. We exposed males and females of the Brazilian Cururu Toad, Rhinella icterica, to an environmentally relevant concentration of the estrogen 17-alpha-ethinylestradiol (an emerging contaminant) and to the chytrid infection (Batrachochytrium dendrobatidis), in their combined and isolated forms, and the ecotoxicity was determined by multiple biomarkers: cutaneous, hematological, cardiac, hepatic, and gonadal analysis. Our results showed that Cururu toads had many physiological alterations in response to the chytrid infection, including the appearance of cutaneous Langerhans's cells, increased blood leukocytes, increased heart contraction force and tachycardia, increased hepatic melanomacrophage cells, which in turn led to gonadal atrophy. The estrogen, in turn, increased the susceptibility of the toads to the chytrid infection (higher Bd loads) and maximized the deleterious effects of the pathogen: reducing leukocytes, decreasing the contraction force, and causing greater tachycardia, increasing hepatic melanomacrophage cells, and leading to greater gonadal atrophy, which were more extreme in females. The exposure to estrogen also revealed important toxicodynamic pathways of this toxicant, as shown by the immunosuppression of exposed animals, and the induction of the first stages of feminization in males, which corroborates that the synthetic estrogen acts as an endocrine disruptor. Such an intricate relationship is unprecedented and reinforces the importance of studying the serious consequences that multiple environmental stressors can cause to aquatic populations.
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Quitridiomicetos , Micoses , Animais , Feminino , Masculino , Micoses/veterinária , Anfíbios , Bufonidae , Estrogênios , Taquicardia , AtrofiaRESUMO
The onset of global climate change has led to abnormal rainfall patterns, disrupting associations between wildlife and their symbiotic microorganisms. We monitored a population of pumpkin toadlets and their skin bacteria in the Brazilian Atlantic Forest during a drought. Given the recognized ability of some amphibian skin bacteria to inhibit the widespread fungal pathogen Batrachochytrium dendrobatidis (Bd), we investigated links between skin microbiome health, susceptibility to Bd and host mortality during a die-off event. We found that rainfall deficit was an indirect predictor of Bd loads through microbiome disruption, while its direct effect on Bd was weak. The microbiome was characterized by fewer putative Bd-inhibitory bacteria following the drought, which points to a one-month lagged effect of drought on the microbiome that may have increased toadlet susceptibility to Bd. Our study underscores the capacity of rainfall variability to disturb complex host-microbiome interactions and alter wildlife disease dynamics.
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Quitridiomicetos , Microbiota , Micoses , Animais , Secas , Micoses/veterinária , Anfíbios/microbiologia , Bactérias , Animais Selvagens , Pele/microbiologiaRESUMO
Anurans of the genus Brachycephalus are among the smallest vertebrates in the world, due to an extreme process of miniaturization. As an example of this process, Brachycephalus species show loss of fingers, loss of the eardrum and middle ear, bone fusions, and the presence of paravertebral plates and parotic plaque. However, no studies addressing the consequences of miniaturization on internal organs, such as the lungs and heart, are currently available. Thus, this study aimed to investigate if overall small body size has affected the cardiorespiratory system. We investigated, via dissections, individuals of four Brachycephaloidea species: Brachycephalus rotenbergae, B. pitanga, Eleutherodactylus johnstonei, and Ischnocnema parva. We observed that B. rotenbergae and B. pitanga present a reduction of the atrial septum and absence of the carotid body. On the other hand, despite being a member of the sister genus to Brachycephalus (both genera belong to the Brachycephalidae), individuals of Ischnocnema present a heart with a complete septum and carotid body; this is also observed in E. johnstonei (Eleutherodactylidae). We observed that B. rotenbergae and B. pitanga have thin skin with a one to two cell thick germ layer, and their lungs likely exhibit lower blood supply when compared to individuals of the E. johnstonei and I. parva species. Based on the observed structures, we suggest that in species of Brachycephalus, respiration is performed mainly through the skin, and their lungs may have a reduced respiratory function.
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Anuros , Coração , Humanos , AnimaisRESUMO
BACKGROUND: The objective of this study was to evaluate the novices' learning curves and proficiency level reached in laparoendoscopic single-site (LESS) surgery using three surgical training programs. MATERIAL AND METHODS: Participants were randomly divided into three groups, who trained in a specific practice regimen for 12 days using a laparoscopic box simulator and three tasks. Group A trained in three stages using conventional laparoscopic surgery (CLS) with straight instruments, and LESS with straight and articulating instruments for four days each. Group B trained in two stages in LESS with straight and articulating instruments for six days each. Group C trained only in LESS with articulating instruments exclusively for all 12 days. Performance was registered daily during the 12 days to evaluate the participants' progress. RESULTS: Pre- and post-training analysis of the three groups showed significant differences in performance, denoting the significant improvement in their LESS skills, with no difference between the groups. Group C reached a high level of technical competence with their specific training program in LESS, obtaining a lower asymptote and slow learning rate. CONCLUSION: Specific training programs in LESS settings using articulated instruments showed a slower learning rate than the other programs but better proficiency in the technique with the best surgical performance.
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Laparoscopia , Treinamento por Simulação , Humanos , Curva de Aprendizado , Competência Clínica , Laparoscopia/métodos , Treinamento por Simulação/métodosRESUMO
Global change is predicted to induce shifts in anuran acoustic behavior, which can be studied through passive acoustic monitoring (PAM). Understanding changes in calling behavior requires automatic identification of anuran species, which is challenging due to the particular characteristics of neotropical soundscapes. In this paper, we introduce a large-scale multi-species dataset of anuran amphibians calls recorded by PAM, that comprises 27 hours of expert annotations for 42 different species from two Brazilian biomes. We provide open access to the dataset, including the raw recordings, experimental setup code, and a benchmark with a baseline model of the fine-grained categorization problem. Additionally, we highlight the challenges of the dataset to encourage machine learning researchers to solve the problem of anuran call identification towards conservation policy. All our experiments and resources have been made available at https://soundclim.github.io/anuraweb/ .
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Anuros , Vocalização Animal , Animais , Acústica , EcossistemaRESUMO
Background: Animal communication consists of signal production and perception, which are crucial for social interactions. The main form used by anurans is auditory communication, in most cases produced as advertisement calls. Furthermore, sound perception happens mainly through an external tympanic membrane, and plays an important role in social behavior. In this study, we evaluated the influence of body and tympanic membrane sizes on call frequency across the phylogeny of anurans. Methods: We use data on snout-vent length, tympanic membrane diameter, and dominant frequency of the advertisement call from the literature and from natural history museum collections. We mapped these traits across the anuran phylogeny and tested different models of diversification. Our final dataset includes data on body size, tympanic membrane size, and call dominant frequency of 735 anuran species. Results: The best explanatory model includes body and tympanum size with no interaction term. Although our results show that call frequency is strongly constrained by body and tympanum size, we identify five evolutionary shifts in allometry from that ancestral constraint. We relate these evolutionary shifts to the background noise experienced by populations. Body size is important for myriad ecological interactions and tympanum size is strongly associated with female call frequency preferences. Thus, allometric escape in frog calls might arise through environmental selection such as breeding in fast flowing or soundscape competition, as well as sexual selection linked to tympanum size.
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Evolução Biológica , Audição , Animais , Feminino , Filogenia , Anuros , PercepçãoRESUMO
By altering the abundance, diversity, and distribution of species-and their pathogens-globalization may inadvertently select for more virulent pathogens. In Brazil's Atlantic Forest, a hotspot of amphibian biodiversity, the global amphibian trade has facilitated the co-occurrence of previously isolated enzootic and panzootic lineages of the pathogenic amphibian-chytrid (Batrachochytrium dendrobatidis, 'Bd') and generated new virulent recombinant genotypes ('hybrids'). Epidemiological data indicate that amphibian declines are most severe in hybrid zones, suggesting that coinfections are causing more severe infections or selecting for higher virulence. We investigated how coinfections involving these genotypes shapes virulence and transmission. Overall, coinfection favored the more virulent and competitively superior panzootic genotype, despite dampening its transmission potential and overall virulence. However, for the least virulent and least competitive genotype, coinfection increased both overall virulence and transmission. Thus, by integrating experimental and epidemiological data, our results provide mechanistic insight into how globalization can select for, and propel, the emergence of introduced hypervirulent lineages, such as the globally distributed panzootic lineage of Bd.
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Coinfecção , Humanos , Coinfecção/epidemiologia , Biodiversidade , Florestas , Genótipo , Virulência/genéticaRESUMO
OBJECTIVE: This study aimed to analyze the evidence and controversies about the use of vaginal energy-based devices (laser and radiofrequency) for treatment of genitourinary syndrome of menopause, recurrent urinary tract infection, urinary incontinence, and genital prolapse through a literature review. METHODS: A search of literature databases (PubMed, Medline) was performed for publications in December 2022. Keywords included genitourinary syndrome of menopause, vaginal laxity, vaginal/vulvovaginal atrophy, urinary tract infection, urgency incontinence, frequency, urgency, stress urinary incontinence, genital prolapses AND energy-based devices, AND vaginal laser, AND vaginal radiofrequency, AND CO2 laser, AND Er:YAG laser. Publications in English from the last 7 years were reviewed and selected by the authors. RESULTS: The literature regarding vaginal energy-based devices in the treatment of urogynecological conditions is primarily limited to prospective case series with small numbers and short-term follow-up. Most of these studies showed favorable results, improvement of symptoms with low risk, or no mention of serious adverse events. Consensus statement documents from major medical societies suggest caution in recommending these therapies in clinical practice until more relevant data from well-designed studies become available. CONCLUSION: The potential of the vaginal laser and radiofrequency as a therapeutic arsenal for the evaluated urogynecological conditions is great, but qualified research must be done to prove their efficacy and long-term safety, define application protocols, and recommend the use of these technologies in clinical practice.
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Lasers de Estado Sólido , Incontinência Urinária por Estresse , Doenças Vaginais , Feminino , Humanos , Menopausa , Doenças Vaginais/terapia , Vagina/cirurgia , Incontinência Urinária por Estresse/cirurgia , Lasers de Estado Sólido/uso terapêuticoRESUMO
Prostate cancer (PCa) is the second most common malignant tumor in men in Brazil and worldwide. Although positron emission tomography (PET) prostate-specific membrane antigen (PSMA) has been used for over 10 years and several studies have been published regarding its superior performance in PCa primary staging and other scenarios, the management decision is often still based on conventional imaging information. A retrospective analysis was performed in 35 patients with PCa in the primary staging scenario with conventional exams as well as with PET PSMA. The findings of our study showed changes on the staging classification and significant impact on the therapeutic choice. PET PSMA is a dependable imaging exam and has already proved its worth and superiority when compared with conventional methods to evaluate PCa patients in primary staging and biochemical relapse, in addition to other potential roles. Prospective studies are needed to assess the outcome of patients whose management was guided by PSMA.
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Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Neoplasias da Próstata , Masculino , Humanos , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Estudos Retrospectivos , Recidiva Local de Neoplasia/diagnóstico por imagem , Recidiva Local de Neoplasia/patologia , Tomografia por Emissão de Pósitrons/métodos , Neoplasias da Próstata/patologia , Estadiamento de Neoplasias , Radioisótopos de GálioRESUMO
BACKGROUND: Prostate cancer (PCa) is the most common malignant tumor in males and conventional imaging does not provide accurate primary staging. Prostate-specific membrane antigen (PSMA) positron emission tomography (PET) presents superior performance and strongly affects therapeutic choice. OBJECTIVE: The aim of this study was to evaluate the impact of PSMA PET, compared with conventional imaging methods, on the therapeutic approach in primary staging scenarios in patients with PCa treated at the Brazilian National Public Health System. METHODS: Overall, 35 patients diagnosed with PCa were evaluated using PSMA after conventional staging imaging with multiparametric magnetic resonance (MMR) and/or total abdominal computed tomography (CT) scan and bone scintigraphy (BS). The PCa extension identified by PET was compared with conventional imaging; staging changes and the management impact were then determined. PET comparison with conventional imaging, staging, and decision-making changes was analyzed using descriptive statistics. RESULTS: PET revealed local disease (LD) in 15 (42.9%) patients, seminal vesicle invasion (SVI) in 5 (14.3%) patients, pelvic nodal impairment (PNI) in 7 (20%) patients, pelvic and distant nodes in 3 (8.6%) patients, pelvic nodes and bone metastasis in 4 (11.4%) patients, and pelvic and distant nodes and bone metastasis in 1 (2.8%) patient. Staging changes were observed in 60% of patients, with downstaging predominance (76.2%). Volume increase was identified in 11 (31.4%) patients (only 4 related to upstaging, 36.4%). The board changed management decisions for 60% of the patients. The main limitations of this study were the sample size and its retrospective nature. CONCLUSIONS: PSMA findings changed the management decisions in more than half of the patients, which made the majority eligible for locoregional treatment and avoided unnecessary procedures in the systemic disease scenario.
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Antígenos de Superfície , Carcinoma , Glutamato Carboxipeptidase II , Neoplasias da Próstata , Humanos , Masculino , Brasil/epidemiologia , Carcinoma/diagnóstico por imagem , Carcinoma/patologia , Carcinoma/terapia , Radioisótopos de Gálio , Estadiamento de Neoplasias , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada/métodos , Próstata/patologia , Neoplasias da Próstata/diagnóstico por imagem , Neoplasias da Próstata/terapia , Neoplasias da Próstata/patologia , Saúde Pública , Estudos RetrospectivosRESUMO
INTRODUCTION AND HYPOTHESIS: The objective was to characterize the impact of the COVID-19 pandemic on the surgical treatment of female stress urinary incontinence (FSUI) in Brazil. METHODS: This study was conducted with population-based data from the Brazilian public health system database. We obtained data on the number of surgical procedures for FSUI in 2019 (before the coronavirus disease [COVID-19] pandemic), 2020, and 2021 (during the pandemic) in each of the 27 Brazilian states. We included official Brazilian Institute of Geography and Statistics (IBGE) data on the population, Human Development Index (HDI), and annual per capita income of each state. RESULTS: A total of 6,718 surgical procedures for FSUI were performed in the Brazilian public health system in 2019. The number of procedures was reduced by 56.2% in 2020, and an additional reduction of 7.2% was seen in 2021. The distribution of procedures by state showed important differences, ranging from 4.4 procedures/1,000,000 inhabitants in Paraíba and Sergipe to 67.6 procedures/1,000,000 inhabitants in Paraná (p<0.01) in 2019. The number of surgical procedures was higher in states with a higher HDI (p=0.0001) and per capita income (p=0.042). The decrease in the number of surgical procedures affected the whole country and its rate did not correlate with HDI (p=0.289) or per capita income (p=0.598). CONCLUSION: The impact of the COVID-19 pandemic on the surgical treatment of FSUI in Brazil was significant in 2020 and persisted in 2021. Access to surgical treatment of FSUI varied according to geographic region, HDI, and per capita income, even before COVID-19.
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COVID-19 , Slings Suburetrais , Incontinência Urinária por Estresse , Feminino , Humanos , Incontinência Urinária por Estresse/epidemiologia , Incontinência Urinária por Estresse/cirurgia , Brasil/epidemiologia , Pandemias , Saúde Pública , COVID-19/epidemiologia , Procedimentos Cirúrgicos Urológicos/métodosRESUMO
SUMMARY OBJECTIVE: This study aimed to analyze the evidence and controversies about the use of vaginal energy-based devices (laser and radiofrequency) for treatment of genitourinary syndrome of menopause, recurrent urinary tract infection, urinary incontinence, and genital prolapse through a literature review. METHODS: A search of literature databases (PubMed, Medline) was performed for publications in December 2022. Keywords included genitourinary syndrome of menopause, vaginal laxity, vaginal/vulvovaginal atrophy, urinary tract infection, urgency incontinence, frequency, urgency, stress urinary incontinence, genital prolapses AND energy-based devices, AND vaginal laser, AND vaginal radiofrequency, AND CO2 laser, AND Er:YAG laser. Publications in English from the last 7 years were reviewed and selected by the authors. RESULTS: The literature regarding vaginal energy-based devices in the treatment of urogynecological conditions is primarily limited to prospective case series with small numbers and short-term follow-up. Most of these studies showed favorable results, improvement of symptoms with low risk, or no mention of serious adverse events. Consensus statement documents from major medical societies suggest caution in recommending these therapies in clinical practice until more relevant data from well-designed studies become available. CONCLUSION: The potential of the vaginal laser and radiofrequency as a therapeutic arsenal for the evaluated urogynecological conditions is great, but qualified research must be done to prove their efficacy and long-term safety, define application protocols, and recommend the use of these technologies in clinical practice.
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Infectious diseases are one of the main threats to biodiversity. The fungus Batrachochytrium dendrobatidis (Bd) is associated with several amphibian losses around the globe, and environmental conditions may dictate the success of pathogen spread. The Brazilian Amazon has been considered climatically unsuitable for chytrid fungus, but additional information on Bd dynamics in this ecoregion is still lacking. We sampled 462 amphibians (449 anurans, 4 caudatans and 9 caecilians), representing 57 species from the Brazilian Amazon, and quantified Bd infections using qPCR. We tested whether abiotic variables predicted the risk of Bd infections, and tested for relationships between biotic variables and Bd. Finally, we experimentally tested the effects of Bd strains CLFT 156 and CLFT 102 (from the southern and northern Atlantic Forest, respectively) on Atelopus manauensis. We detected higher Bd prevalence than those previously reported for the Brazilian Amazon, and positive individuals in all 3 orders of amphibians sampled. Both biotic and abiotic predictors were related to prevalence, and no variable explained infection load. Moreover, we detected higher Bd prevalence in forested than open areas, while the host's reproductive biology was not a factor. We detected higher mortality in the experimental group infected with CLFT 156, probably because this strain was isolated from a region characterized by discrepant climatic conditions (latitudinally more distant) when compared with the host's sampling site in Amazon. The lowland Brazilian Amazon is still underexplored and future studies targeting all amphibian orders are essential to better understand Bd infection dynamics in this region.
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Quitridiomicetos , Micoses , Animais , Anfíbios/microbiologia , Anuros/microbiologia , Biodiversidade , Micoses/epidemiologia , Micoses/veterinária , Micoses/microbiologiaRESUMO
Microbial diversity positively influences community resilience of the host microbiome. However, extinction risk factors such as habitat specialization, narrow environmental tolerances, and exposure to anthropogenic disturbance may homogenize host-associated microbial communities critical for stress responses including disease defense. In a dataset containing 43 threatened and 90 non-threatened amphibian species across two biodiversity hotspots (Brazil's Atlantic Forest and Madagascar), we found that threatened host species carried lower skin bacterial diversity, after accounting for key environmental and host factors. The consistency of our findings across continents suggests the broad scale at which low bacteriome diversity may compromise pathogen defenses in species already burdened with the threat of extinction.
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Widespread introduced species can be leveraged to investigate the genetic, ecological and adaptive processes underlying rapid evolution and range expansion, particularly the contributions of genetic diversity to adaptation. Rhinella marina, the cane toad, has been a focus of invasion biology for decades in Australia. However, their introduction history in North America is less clear. Here, we investigated the roles of introduction history and genetic diversity in establishment success of cane toads across their introduced range. We used reduced representation sequencing (ddRAD) to obtain 34,000 SNPs from 247 toads in native (French Guiana, Guyana, Ecuador, Panama, Texas) and introduced (Bermuda, southern Florida, northern Florida, Hawai'i, Puerto Rico) populations. Unlike all other cane toad introductions, we found that Florida populations were more closely related to native Central American lineages (R. horribilis), than to native Southern American lineages (R. marina). Furthermore, we found high levels of diversity and population structure in the native range, corroborating suggestions that R. marina is a species complex. We also found that introduced populations exhibit only slightly lower genetic diversity than native populations. Together with demographic analyses, this indicates founding populations of toads in Florida were larger than previously reported. Lastly, within R. marina, only one of 245 putatively adaptive SNPs showed fixed differences between native and introduced ranges, suggesting that putative selection in these introduced populations is based upon existing genetic variation. Our findings highlight the importance of genetic sequencing in understanding biological introductions and hint at the role of standing genetic variation in range expansion.