Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

Pervasive gaps in Amazonian ecological research

Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

Comparative Expression of Genes in Dermatophytes during Interaction with the Host Environment and in Response to Antifungal Agents

Dermatófitos são um grupo de fungos intimamente relacionados, que tem a capacidade de invadir tecidos queratinizados como pele, cabelos e unhas de homens e outros animais causando dermatofitoses. Os agentes envolvidos nessas infecções pertencem aos gêneros Trichophyton, Microsporum ou Epidermophyton e, de acordo com seu habitat natural, são classificados em espécies geofílicas, zoofílicas ou antropofílicas. A maior incidência de dermatofitoses é causada pelo gênero Trichophyton, sendo T. rubrum a espécie mais prevalente em infecções de pele e unhas em humanos. Devido à severidade e longevidade destas infecções, e à resistência ao tratamento, o estudo de fatores envolvidos na interação patógeno-hospedeiro, na resistência dos dermatófitos a agentes antifúngicos e na manutenção do processo infeccioso são de grande relevância. Por análises morfológicas, fisiológicas e de expressão gênica, comparamos cinco dermatófitos cujos genomas foram sequenciados por iniciativa do Broad Institute, Microsporum canis, Trichophyton equinum, Trichophyton interdigitale, Trichophyton rubrum e Trichophyton tonsurans. Cultivos em queratina, mimetizando o processo infeccioso, foram utilizados para analisar o envolvimento dos dermatófitos na interação patógeno-hospedeiro e manutenção do processo infeccioso. Também expusemos as espécies a concentrações subinibitórias de agentes terapêuticos, de modo a verificar a resposta destes fungos a diferentes drogas. Observamos que o acúmulo de transcritos dos genes relacionados à virulência em dermatófitos avaliados durante o crescimento em queratina sugere que a maquinaria metabólica com atividade de formação da parede celular do fungo, metabolização do substrato e adesão ao hospedeiro ativa nos períodos iniciais de infecção. Contudo, um padrão de expressão correlacionado à similaridade das sequências genômicas não foi observado nas condições testadas. Também não se observa correlação direta entre o nicho preferencial dos dermatófitos e os níveis transcricionais em resposta à queratina de origem animal. Analisamos três genes envolvidos na resistência a múltiplas drogas (MDR) durante crescimento na presença de drogas com atividade antifúngica. Nossos dados sugerem que os genes MDR atuam sinergicamente em dermatófitos, e podem atuar de forma compensatória quando em presença de drogas antifúngicas, o que pode ser uma importante causa de falhas no tratamento. Nossos resultados fornecem evidências de que a expressão dos genes analisados não se correlaciona com as relações filogenéticas entre estes dermatófitos, visto que apesar da íntima relação entre o conteúdo genético e organização do genoma, os níveis transcricionais destes genes são diferentes entre as espécies. Assim, diferenças na adaptação a nichos específicos e a progressão da doença entre os dermatófitos podem ser explicadas por diferentes perfis de transcrição do gene.Dermatophytes are a group of closely related fungi, which have the ability to invade keratinized tissues, such as skin, hair, and nails of both human and animal hosts causing dermatophytosis. The agents involved in these infections belong to the genera Trichophyton, Microsporum or Epidermophyton and, according to their natural habitat, are classified as geophilic, zoophilic or anthropophilic species. The higher incidence of dermatophytosis is caused by the genera Trichophyton, being the specie T. rubrum the most prevalent causative of human skin and nail infections. Because of the severity and longevity of these infections and their resistance to treatment, the study of the factors involved in host-pathogen interaction, in resistance of dermatophytes to antifungal agents, and in maintenance of the infection is relevant. Through morphological, physiological and gene expression analysis we compared five dermatophytes, whose genomes were sequenced by initiative of the Broad Institute: Microsporum canis, Trichophyton equinum, Trichophyton interdigitale, T. rubrum and Trichophyton tonsurans. Growth in keratin, which mimetize the infectious process, was used to analyze the involvement of dermatophytes in host-pathogen interaction and maintenance of the infectious process. We also exposed the species to subinibitory concentrations of therapeutic agents to verify the response of these fungi to different drugs. We observed that the accumulation of transcripts of genes related to virulence in dermatophytes evaluated during growth in keratin, suggest that the metabolic machinery with activity on fungal cell wall formation, substrate metabolization, and host adhesion is activated in early stages of infection. However, an expression pattern correlating to genomic sequence similarity was not observed in the conditions tested. We also did not observe a direct correlation between the preferential niche of these dermatophytes and the transcriptional levels in response to the keratin from animal origin. We analyze three genes involved in multidrug resistance (MDR) during growth in the presence of drugs with antifungal activity. Our data suggest that MDR genes act synergistically in dermatophytes, and they may compensate for one another when challenged with antifungal drugs, which can be an important cause of therapeutic failure. We provide evidence that the expression of the analyzed genes does not correlate with the phylogeny of these dermatophytes since, in spite of the different species being highly related in gene content and genome organization, the transcription level of these genes is different among these species. Thus, differences in adaptation to a specific niche and disease progression among dermatophytes would be explained by different gene transcription profiles

Differential expression of multidrug-resistance genes in Trichophyton rubrum

Treatment of dermatophytosis is generally a long and challenging process, deeply affected by drug resistance owing to efflux-mediated activity. These drug-pumping mechanisms involve overexpression of transporter proteins with the ability to extrude a wide variety of structurally and functionally unrelated compounds. The ATP-binding cassette transporter and the major facilitator are the two largest superfamilies of transporters, expressed ubiquitously in all living organisms. Here, we examined the transcription modulation of both families of transporter genes in the dermatophyte Trichophyton rubrum upon challenge with sub-lethal doses of undecanoic acid or acriflavine. Data derived from RNA sequencing revealed transporters functioning in specific patterns according to the stressing condition, suggesting that each drug recruits specific physiological pathways. Synergistic transport activity may be acting to overcome drug toxicity, demonstrating that multidrug resistance transporters cooperate to induce drug resistance and fungal survival in an unpredictable manner

Evaluation of Paralytic Shellfish Toxins in Marine Oyster Farming and Microalgae in the Atlantic Amazon Evidences Safety but Highlights Potential Risks of Shellfish Poisoning

Marine phycotoxins are organic compounds synthesized by some species of microalgae, which accumulate in the tissues of filter-feeder organisms such as bivalve mollusks. These toxins can cause acute intoxication episodes in humans, a severe threat to aquaculture and fisheries. In the State of Pará, Brazil, oyster farming has community, artisanal and sustainable bases, using mangroves as cultivation environment and seed banks. In small-scale production, there are often no established methods of safeguarding the health of consumers elevating the potential risks of shellfish poisoning outbreaks. Our study evaluated the presence of phycotoxins in oysters cultivated in five municipalities in the region of the Atlantic Amazon (Pará, Brazil) assessing the quality of the final product. We further evaluated the microalgae, water quality, and the spatio-temporal variation of physicochemical factors in the same area. Diatoms dominated the microalgae composition, followed by dinoflagellates, some of which are reported to be potentially toxic and producers of paralytic shellfish toxins. For the first time, we describe the occurrence of the potentially toxic dinoflagellate Ostreopsis sp. in the Amazon region. Furthermore, for the first time, toxins were detected in oyster farming in the northeast of the State of Pará, namely GTX2,3, STX, and dc-STX nevertheless, with nontoxic values. The identified toxins represent a potential threat to shellfish consumers