37 research outputs found
Ant-microbe metabolic integration supporting the nutrition of agricultural pest leaf-cutters
Actas do Colóquio organizado pelo IJC em 23 e 24 de Abril de 1998. Coordenação Prof. Doutor António Pinto Monteiro, Instituto Jurídico da Comunicação, Faculdade de Direito, Universidade de Coimbra.A adaptação dos direitos de autor aos desafios da Internet: do direito de copiar ao direito de acesso
Mensuração de externalidades econômicas oriundas das intoxicações exógenas por agrotóxicos em Mato Grosso.
Introdução: O agronegócio de Mato Grosso tem se destacado mundialmente como um dos maiores produtores de grãos e consumidor de agrotóxicos, fator que favorece as intoxicações, típica externalidade negativa. Objetivo: Descrever os aspectos epidemiológicos e mensurar a externalidade econômica oriunda das intoxicações por agrotóxicos relacionadas ao agronegócio.Materiais e métodos:Trata-se de um estudo descritivo, foram utilizados dados obtidos no SINAN, acerca das notificações das intoxicações exógenas por agrotóxicos agrícola,no período de 2015 a 2017, em Mato Grosso. Resultados: Foram registradas 242 notificações a maioria ocorreu na região Norte (44,62%) e nos municípios de Nova Mutum/Sinop/Sorriso (23,13%). Prevaleceu os casos em indivíduos do sexo masculino (84,71%), na faixa etária de 20 a 39 anos (57,85%) de raça parda (57,02%) e com escolaridade de 5a a 8a série incompleta (21,07%), 66,53% da exposição ocorreu no ambiente de trabalho, circunstância acidental (44,21%), destaque para a exposição aguda única (76,86%). As despesas oriundas da intoxicação exógena por agrotóxico agrícola foram de R$ 718,15 por indivíduo. Conclusão: O agronegócio tem contribuído positivamente com cerca de 50,5% do PIB do estado, porém gerado externalidades negativas, torna-se necessário, incentivar as ações de prevenção das intoxicações para garantir a saúde da população
Bacterial Communities in the Midgut of Ponerine Ants (Hymenoptera: Formicidae: Ponerinae)
Symbiotic microorganisms are directly related to the ecological success of host insects, influencing many aspects of their biology. The present study is the first to investigate the microbiota associated with ants of the subfamily Ponerinae and aims to identify the bacterial midgut communities of Dinoponera lucida, Pachycondyla curvinodis, Pachycondyla striata, Odontomachus brunneus and Odontomachus bauri. After dissecting the midguts of these ants, DNA was extracted, and the bacterial 16S rRNA gene was amplified via PCR using the universal primers pair 27F/1492R. The obtained PCR products were cloned and sequenced using an ABI 3500 automated sequencer. The sequences were grouped into operational taxonomic units (OTUs) based on a 97% similarity criterion using MOTHUR. The greatest species richness was observed in O. bauri, with 15 OTUs, followed by D. lucida with five OTUs, O. brunneus, with four OTUs, and P. curvinodis and P. striata, both with three OTUs. There were representatives of the phyla Actinobacteria, Proteobacteria, Tenericutes and Firmicutes, including the genera Bartonella, Mesoplasma, Mesorhizobium, Spiroplasma, Wolbachia and Serratia in the guts of the studied Ponerine ants. The low microbial diversity observed given the predatory trophic habits of the species studied suggests that there is selection for these microorganisms, predominantly preserving symbionts with functional roles that are able to colonize this environment. It is also valid to infer that the identified bacteria are predominant in the gut and exhibit mutualistic functions that are important for immunity, reproduction and nutrition; moreover, a subset may be parasites that have considerable impacts on the studied ants
Fungal communities in pressmud composting harbour beneficial and detrimental fungi for human welfare
Pressmud is a substrate derived from sugarcane juice filtrate, and around 26-40 kg of this residue are produced per ton of sugarcane. It is mainly used as fertilizer in crops, and its application in the field is often made without any prior treatment, but, in this research, it was studied for the risk this practice poses for human health. This research was stimulated by previous results indicating the presence of opportunistic pathogens in residues used in various composting systems and the extensive use of fresh pressmud in agriculture. Here, It was assessed the fungal diversity present in both fresh and composting pressmud using 454 pyrosequencing. In addition, heat-tolerant fungi were isolated and surveyed for their enzymatic repertoire of biomass-degrading enzymes (cellulase, xylanase, laccase and polygalacturonase). A wide range of opportunistic pathogens was found among the most abundant taxa in the fresh pressmud, such as Lomentospora prolificans (43.13 %), Trichosporon sp. (10.07 %), Candida tropicalis (7.91 %), and Hormographiella aspergillata (8.19 %). This indicates that fresh pressmud might be a putative source of human pathogenic fungi, presenting a potential threat to human health if applied as fertilizer without any treatment. With regard to the heat-tolerant fungi found in this substrate, all the 110 isolates screened were able to produce at least one of the tested enzymes. The pressmud composting process not only effectively reduces the load of pathogenic fungi, but also creates an interesting environment for fungi able to produce thermostable hydrolytic and oxidative enzymes with biotechnological applications
Bactérias veiculadas por formigas em comunidade indígena
OBJETIVO: O objetivo da pesquisa foi identificar bactérias transportadas por formigas circulantes em uma comunidade indígena do Sul de Mato Grosso. MÉTODOS: A coleta dos insetos foi realizada na unidade básica de saúde e escola da aldeia. As formigas capturadas, foram inseridos em meio de cultura líquido para o pré-cultivo dos microrganismos. Em seguida uma alíquota da cultura foi semeada em ágar sangue e ágar Mueller Hinton visando a obtenção de cultura pura e estas então avaliadas quanto a classificação morfo-tintorial (Gram). As colônias de cocos Gram positivo foram submetidas a testes para a diferenciação de Staphylococcus e Streptococcus. Os bacilos Gram-negativos classificados quanto a fermentação de carboidratos. RESULTADOS: Foram isoladas 25 cepas de bactérias, sendo 24% de bacilos Gram positivos, 24% Staphylococcus coagulase negativo (24% S. saprophyticus e 12% S. epidermides), 16% Micrococcus sp e 24% bacilos Gram negativos (4% fermentadores e 20% não fermentadores). CONSIDERAÇÕES FINAIS: Os resultados obtidos mostram a ação vetorial de formigas no transporte patógenos, representando um risco potencial à saúde indígena
Fungal communities in pressmud composting harbour beneficial and detrimental fungi for human welfare
Pressmud is a substrate derived from sugarcane juice filtrate, and around 26-40 kg of this residue are produced per ton of sugarcane. It is mainly used as fertilizer in crops, and its application in the field is often made without any prior treatment, but, in this research, it was studied for the risk this practice poses for human health. This research was stimulated by previous results indicating the presence of opportunistic pathogens in residues used in various composting systems and the extensive use of fresh pressmud in agriculture. Here, It was assessed the fungal diversity present in both fresh and composting pressmud using 454 pyrosequencing. In addition, heat-tolerant fungi were isolated and surveyed for their enzymatic repertoire of biomass-degrading enzymes (cellulase, xylanase, laccase and polygalacturonase). A wide range of opportunistic pathogens was found among the most abundant taxa in the fresh pressmud, such as Lomentospora prolificans (43.13 %), Trichosporon sp. (10.07 %), Candida tropicalis (7.91 %), and Hormographiella aspergillata (8.19 %). This indicates that fresh pressmud might be a putative source of human pathogenic fungi, presenting a potential threat to human health if applied as fertilizer without any treatment. With regard to the heat-tolerant fungi found in this substrate, all the 110 isolates screened were able to produce at least one of the tested enzymes. The pressmud composting process not only effectively reduces the load of pathogenic fungi, but also creates an interesting environment for fungi able to produce thermostable hydrolytic and oxidative enzymes with biotechnological applications
Distribution and biological role of the oligopeptide-binding protein (OppA) in Xanthomonas species
In this study we investigated the prevalence of the oppA gene, encoding the oligopeptide binding protein (OppA) of the major bacterial oligopeptide uptake system (Opp), in different species of the genus Xanthomonas. The oppA gene was detected in two Xanthomonas axonopodis strains among eight tested Xanthomonas species. The generation of an isogenic oppA-knockout derivative of the Xac 306 strain, showed that the OppA protein neither plays a relevant role in oligopeptide uptake nor contributes to the infectivity and multiplication of the bacterial strain in leaves of sweet orange (Citrus sinensis) and Rangpur lime (Citrus limonia). Taken together these results suggest that the oppA gene has a recent evolutionary history in the genus and does not contribute in the physiology or pathogenesis of X. axonopodis
Expressed sequence tags from Atta laevigata and identification of candidate genes for the control of pest leaf-cutting ants
<p>Abstract</p> <p>Background</p> <p>Leafcutters are the highest evolved within Neotropical ants in the tribe Attini and model systems for studying caste formation, labor division and symbiosis with microorganisms. Some species of leafcutters are agricultural pests controlled by chemicals which affect other animals and accumulate in the environment. Aiming to provide genetic basis for the study of leafcutters and for the development of more specific and environmentally friendly methods for the control of pest leafcutters, we generated expressed sequence tag data from <it>Atta laevigata</it>, one of the pest ants with broad geographic distribution in South America.</p> <p>Results</p> <p>The analysis of the expressed sequence tags allowed us to characterize 2,006 unique sequences in <it>Atta laevigata</it>. Sixteen of these genes had a high number of transcripts and are likely positively selected for high level of gene expression, being responsible for three basic biological functions: energy conservation through redox reactions in mitochondria; cytoskeleton and muscle structuring; regulation of gene expression and metabolism. Based on leafcutters lifestyle and reports of genes involved in key processes of other social insects, we identified 146 sequences potential targets for controlling pest leafcutters. The targets are responsible for antixenobiosis, development and longevity, immunity, resistance to pathogens, pheromone function, cell signaling, behavior, polysaccharide metabolism and arginine kynase activity.</p> <p>Conclusion</p> <p>The generation and analysis of expressed sequence tags from <it>Atta laevigata </it>have provided important genetic basis for future studies on the biology of leaf-cutting ants and may contribute to the development of a more specific and environmentally friendly method for the control of agricultural pest leafcutters.</p
Development and validation of protocols for automated annotation of ORESTES sequences of Eimeria spp. of domestic fowl.
A coccidiose aviária é uma doença entérica causada por protozoários parasitas do gênero Eimeria. Visando uma maior compreensão dos mecanismos moleculares envolvidos na regulação do ciclo de vida dos parasitas, foram geradas 15.000 seqüências expressas (ORESTES) para cada uma das três espécies mais importantes: E. tenella, E. maxima e E. acervulina. O presente trabalho consistiu no desenvolvimento de componentes de anotação automática de seqüências para o sistema EGene, plataforma previamente desenvolvida pelo nosso grupo (Durham et al. Bioinformatics 21: 2812-2813, 2005) para a construção de processamentos encadeados (pipelines). Estes componentes foram utilizados para a construção de pipelines de anotação automática de seqüências-consenso obtidas a partir da montagem dos ORESTES de Eimeria spp. A anotação consistiu na identificação dos genes e atribuição da função dos respectivos produtos protéicos, baseando-se em um conjunto de evidências. As seqüências também foram classificadas e quantificadas utilizando-se um vocabulário controlado de termos de ontologia gênica (GO).Avian coccidiosis is an enteric disease caused by protozoan parasites of the genus Eimeria. Aiming at obtaining a better understanding of the molecular mechanisms that regulate the life cycle of the parasites, our group generated 15,000 expressed sequences (ORESTES) for each one of the three most important species: E. tenella, E. maxima and E. acervulina. In the present work, we report the development of a set of components for the automated sequence annotation through EGene, a platform for pipeline construction previously described by our group (Durham et al. Bioinformatics 21: 2812-2813, 2005). These components were used to construct pipelines for the automated annotation of assembled sequences of ORESTES of Eimeria spp. The annotation process consisted in the identification of genes and the corresponding protein function based on a set of evidences. The sequences were also mapped and quantified using a controlled vocabulary of gene ontology (GO) terms