Genes de proteínas-chave para a montagem e a função da estrutura de esporos bacterianos

Tese (doutorado)—Universidade de Brasília, Instituto de Ciências Biológicas, Departamento de Biologia Celular, Programa de Pós-Graduação em Biologia Microbiana, 2018.Muitas espécies da ordem Bacillales formam um tipo celular especializado denominado esporo, que é resistente a diversos tipos de estresses ambientais. Estudos utilizando Microscopia Eletrônica de Transmissão (TEM) revelaram que o esporo é composto por uma série de conchas concêntricas, que englobam o compartimento que abriga o DNA. A parte mais externa destas conchas varia significantemente em morfologia entre espécies, o que provavelmente reflete adaptações aos altamente diversos nichos em que esporos são encontrados. Para melhor caracterizar variações na ultraestrutura de esporos entre as diversas espécies, nos empregamos experimentos de TEM, manipulação genética e detecção de genes e proteínas in silico para analisar a diversidade de esporos do banco de dados NCBI e da Coleção de Bactérias aeróbias formadoras de endósporos (CBafes), que engloba, dentre outros, espécies dos gêneros Bacillus, Lysinibacillus, Paenibacillus, e Brevibacillus, isoladas do solo do Distrito Federal. Neste estudo, nós descobrimos que as estruturas destes esporos variam consideravelmente, como esperado. Observamos, entretanto, que embora estes isolados sejam novos representantes destas espécies, existem muitas similaridades estruturais entre estes e espécies bem descritas na literatura. Como, na maioria dos casos, as espécies analisadas pertencem a ramos da arvore filogenética muito negligenciados e pouco caracterizados, nossos dados fornecem evidências importantes acerca de quais características estruturais tendem a ser constantes dentro de um táxon e quais tendem a variar.Many species in the order Bacillales form a specialized cell type called a spore that is resistant to a range of environmental stresses. Transmission electron microscopy (TEM) reveals that the spore is comprised of a series of concentric shells, surrounding an interior compartment harbouring the spore DNA. The outermost of these shells varies considerably in morphology among species, likely reflecting adaptations to the highly diverse niches in which spores are found. To better characterize the variation in spore ultrastructure among diverse species, we used TEM, genetic manipulation and in silico gene and protein detections to analyse spores from a collection of spore-forming bacteria spanning, among others, the genera Bacillus, Lysinibacillus, Paenibacillus, and Brevibacillus, isolated from soil from central Brazil, Distrito federal (SDFstrains). In this study, we found that the structures of these spores varied widely, as expected. Interestingly, even though these isolates are novel strains of each species, they were structurally very similar to the known examples of each species in the literature. Because in most cases, the species we analysed are poorly characterized, our data provide important evidence regarding which structural features are likely to be constant within a taxon and which are likely to vary

Ultraestrutura e termorresistência de esporos e identificação de proteínas de bactérias aeróbias de solo do Distrito Federal

Dissertação (mestrado)—Universidade de Brasília, Programa de Pós-Graduação em Biologia Microbiana, Instituto de Ciências Biológicas, Departamento de Biologia Celular, Pós-Graduação em Biologia Microbiana, 2014.O solo é considerado o maior reservatório de bactérias aeróbias formadoras de endósporos (Bafes). Essas linhagens apresentam importância microbiológica e potencial biotecnológico em diversas áreas como a médica, agrícola, ecológica e de biodefesa. As Bafes estão distribuídas taxonomicamente dentro do filo Firmicutes, que abriga bactérias, em maioria, Gram positivas, com baixo conteúdo G+C e parede celular muito rígida. De um modo geral, o conhecimento atual sobre essas bactérias é limitado as espécies modelo, notadamente, o Bacillus subtilis, em adição aos B. cereus, B. thuringiensis e B. athracis. Estudos clássicos envolvendo esporos bacterianos investigados por microscopia eletrônica de transmissão revelaram a complexa ultraestrutura destas células. Essas características estruturais motivaram investigações para compreender como a estrutura é montada de modo a resultar no dispositivo celular mais resistente conhecido. Esses dados possibilitaram direcionar estudos evolutivos relacionados com as diferenças fenotípicas em um tipo celular supostamente preparado para resistir a estresses ubíquos, tanto de natureza física, quanto química. Durante este trabalho, o número de linhagens ambientais da Coleção de Bafes (CBafes) do Laboratório de Microbiologia/LaBafes da UnB foi ampliada em 125 linhagens e avaliada quanto a diversidade. Os esporos de dezenove linhagens de solo do DF (SDF) e a linhagem de Bacillus spp. FT9, também, parte do acervo, foram caracterizadas quanto à ultraestrutura, por microscopia eletrônica de transmissão e termorresistência, por calor úmido. Biomoléculas, como peptídeos e proteínas, produzidas durante o ciclo celular dessas linhagens também foram identificadas e analisadas quanto ao grau de pureza, por análises espectroscópicas e espectrometria de massa (MALDI-TOF). Os resultados obtidos, embora preliminares, reforçam a diversidade presente nas linhagens da CBafes, não somente dentro de uma visão taxonômica, como também quanto ao potencial de exploração biotecnológica e abertura para várias linhas de pesquisa.Soil is considered the greatest aerobic endospore-forming bacteria (Aefbs) reservoir. These lineages present microbiological importance and biotechnological potential in diverse fields such as medical, agricultural, ecological and biodefense. Aefbs are widely distributed within the phylum Firmicutes, which houses mainly Gram-positive bacteria, presenting low G+C content, and rigid cell wall. Generally, the current knowledge regarding these species is limited to some model lineages, notably, Bacillus subtilis in addition to B. cereus, B. thuringiensis, and B. anthracis. Classic studies involving bacterial spores investigated by transmission electron microscopy revealed the complex ultrastructure of these cells. These structural characteristics have motivated investigations to understand how this structure is assembled to result in the most resistant living cell ever known. These data impelled evolutionary studies related to phenotypic diversions in a cell type supposed to be prepared to resist to both physical and chemical ubiquitous stresses. During this work the number of environmental lineages within the Aefbs Collection (CBafes) from the Aefbs Laboratory’ (LaBafes UnB) was increased by 125 lineages and assayed for diversity. Spores from nineteen selected DF soil lineages (SDFs) and the Bacillus spp. lineage FT9 were further investigated regarding ultrastructure, by transmission electron microscopy and thermoresistance, by wet-heat. Biomolecules such as peptides and proteins produced during SDFs cell cycles were also identified and inspected concerning the degree of purity, by spectroscopy analysis and mass spectrometry (MALDI-TOF). Though preliminary, these results enhance the knowledge on the diversity presented by the SDF lineages both from a taxonomic view and regarding the biotechnological potential. Taken together these data represent a whole new research line in the spore-forming biology

The relationship between melatonin and sleep quality and its weight loss benefits

Melatonin is an endogenous substance easily found in the body. It is conceptualized as a hormone, derived from serotonin, synthesized by the pineal gland during the night period. As a hormone, melatonin has several functions, such as immunomodulation, antioxidant, anti-inflammatory, and antitumor, however its most compliant function is the control of the circadian rhythm, in addition to regularizing seasonality. Sleep is one of the primordial needs of the human being, after a period of physical and mental activities, it has a fundamental role to relax and re-establish the organism for a new cycle of activities. Thus, melatonin acts as a metabolism regulator influencing the quality of life, and its effectiveness in inducing sleep has led pharmaceutical companies to launch its synthetic version, widely sold as a supplement in some countries such as the United States and Europe. To analyze the importance of melatonin in the regulation of sleep, as well as to characterize its functions in the body that contribute to weight control. The work methodology consisted of a literature review, carried out through previously published research studies. Based on the literary subsidies that supported this research, it is concluded that the benefits achieved with the use of melatonin encompass the alignment of the sleep cycle and contribute to weight control, which may influence weight loss, as well as in other areas of the body

Dysbiosis and obesity: implications of the gut microbiota

Introduction: Obesity has been considered a public health crisis, contributing as a risk factor for several important chronic diseases and even death. Considering this fact, it is noteworthy that there is a fundamental relationship between the intestine and health, and this organ is considered by modern medicine as our second brain in the concept of intestinal permeability. Within the evaluation of the food process, effective nutritional absorption can be altered due to imbalances, such as malabsorption, drug-nutrient interaction, changes in mucosal permeability, and, consequently, an imbalance in the gut microbiota. Dysbiosis is characterized by these negative changes that occur in the intestine. In this sense, the present systematic review study sought to answer: What influences can the microbiota composition have on the metabolic syndrome and obesity process? Objective: To elucidate the relationship between the presence of intestinal dysbiosis in the pathogenesis of obesity. Methods: This is a bibliographic review work where the MEDLINE, PubMed, and SciELO databases were consulted using the following descriptors: Human gut microbiota, obesity, dysbiosis. Results and Conclusion: Based on the literature that supports this theme, it was possible to observe that in the obese population there is an increase in bacteria of the genus Firmicutes and a decrease in the genus Bacteriodetes, with the blocking of factors and proteins that regulate the homeostasis of the absorption of lipids and fatty acids being observed thus being able to alter the energy metabolism leading to a greater accumulation of adipose tissue

Mediterranean diet in the treatment of metabolic syndrome: nutritional therapy and life perspective

Metabolic syndrome is the association of chronic diseases related to diet and physical activity. Also recognized as a complex entity that associates well-established cardiovascular risk factors, such as high blood pressure, hypercholesterolemia, and diabetes, among others, such as central fat deposition and insulin resistance. Currently, Metabolic Syndrome has gained worrisome dimensions within clinical practice, becoming one of the greatest challenges at the beginning of this century. In contrast, the Mediterranean diet recognized for its combination of tasty taste and nutritional benefits, in addition to its culture of the link between health and longevity, is a strategy in the treatment of the metabolic syndrome. Although there is no consensus on the most adequate nutritional strategy to treat Metabolic Syndrome (MS), in such a way that there is a reduction in cardiovascular risk, recent studies show the effectiveness of adopting healthy lifestyles capable of reversing this trend. To address the role of diet in MS treatment, with the main focus on the interaction of benefits of different nutritional interventions in MS remission, contributing to the integration of current evidence in the pre-existing context. In view of the studies carried out in this research, it was found that the Mediterranean diet has shown benefits in the secondary prevention of this syndrome, although the underlying mechanisms are not completely clear. In this sense, it is important to revitalize and apply this diet in the future in terms of preventive and therapeutic guidelines

Permeable gut syndrome, gluten, and autoimmune disease: an integrative review

oai:ojs2.ijn.zotarellifilhoscientificworks.com:article/4Introduction: Leaky Bowel Syndrome or intestinal permeability is a gastrointestinal condition that affects many people. A leaky gut is a trigger for many changes like food allergies and intolerances, autoimmune diseases, colitis, Crohn's and celiac disease, inflammatory diseases, depression, insulin resistance and even cancer have been linked. Objective: To analyze basic information for a better understanding of this topic, from the functioning of the gastrointestinal tract, as the diseases that are associated with it, how the immune system responds to these injuries, the quality, and importance of proteins, and the consequence of this disorder to the body human. Methods: Conducted an integrative literature review. The Pubmed, Google Scholar, and Scielo databases were consulted. Results: The intestine is naturally permeable to many small molecules, so it can absorb vital nutrients. Regulating intestinal permeability is one of the most basic functions of the cells that make up the intestinal wall. But one factor calls our attention, what is the role of gluten in the development of this disease and the worsening of symptoms? Insensitive people, gluten can cause cells to release zonulin, a protein that can break the tight junctions of intestinal tissue. Other factors—such as infections, toxins, stress, and age—can also cause these joints to come apart. Once strong joints break, you have a leaky gut. Gluten, therefore, is the number one cause of this process. A person with a leaky intestine tends to be highly allergic and intolerant to foods and substances, and may or may not manifest intestinal discomfort such as gas and bloating. Conclusion: Based on the literature that supports this theme, it is considered that gluten is a possible villain in the intestinal tract and is related to many autoimmune diseases. Furthermore, as an interventional measure, it is necessary to reduce some carbohydrate-rich foods and the maintenance of the body's balance with specific diets and physical activities

The benefits of glutamine in the treatment of patients with cancer

The subject of this study is the benefits of immunonutrition or immunomodulation, based on the concept that malnutrition impairs immune function. It is a therapeutic approach in an artificial form of food with the function of rebuilding cells for the immune response, which involves specific amino acids such as arginine, glutamine, and fiber. In this sense, it is intended to deal specifically with glutamine, which is a “conditionally essential” amino acid, as its concentration in plasma can decrease by up to 50% during stress, causing a deficiency condition. In the treatment of cancer patients, glutamine constitutes an immunomodulatory nutrient, being a fundamental substrate for the cells of the immune system, stimulating the multiplication of lymphocytes, the differentiation of B cells, the production of interleukin 1, and the phagocytosis of macrophages. The high use of glutamine by lymphocytes and macrophages suggests that the provision of this amino acid is of paramount importance for the functioning of these cells and also for the proper functioning of the immune response. Important in viral infections and in combating tumor cells, Natural Killer (NK) cells are dependent on adequate glutamine stores for their proliferation. It also exerts a local immunostimulating effect, increasing intestinal T cells, and is a precursor of an important intracellular antioxidant, glutathione. This is bibliographical research, of a qualitative nature, carried out through specialized scientific articles on the chosen topic

Untreated or ammoniated cotton gin trash in the ensiling of elephant grass reduces silage quality

This study examined the inclusion of untreated or urea-ammoniated CGT on the chemical composition, pH, gas, and effluent losses, dry matter recovery (DMR), and aerobic stability of elephantgrass silage. The experiment was laid out in a randomized design with a 3 × 3 factorial arrangement represented by three levels of inclusion of CGT during ensiling (0, 5, or 10%) and three levels of ammoniation of CGT with urea before ensiling (0, 4 or 8% for 28 days), using four replications. Data were subjected to analysis of variance and Tukey's test, considering a 5% significance level. The pH and DM, NDIN, ADIN, NDF and ADF contents of the silages increased (p < 0.05) with the inclusion of CGT, regardless of ammoniation. The lowest (p < 0.05) effluent loss was achieved using 10% of CGT ammoniated with 8% urea. In contrast, the elephantgrass silage exhibited the lowest (p < 0.05) gas loss and the greatest (p < 0.05) DMR. The inclusion of CGT compromised the aerobic stability of the silage. Therefore, the inclusion of CGT – either untreated or ammoniated – in the ensiling of elephantgrass is not recommended

Perfil epidemiológico da febre maculosa na região sudeste do Brasil no período de 2012-2022

Introdução: A febre maculosa é uma doença infecciosa causada pela bactéria Rickettsia rickettsii, transmitida aos humanos através da picada de carrapato. Ela pode apresentar sintomas como febre alta, dores de cabeça intensas, dores musculares, fadiga extrema, náuseas e vômitos, erupção cutânea, conjuntivite, sensibilidade à luz, icterícia e hemorragias. No Brasil, o vetor mais importante é o Amblyomma cajennense. Objetivo: Discutir as notificações de casos confirmados, os critérios diagnósticos utilizados, a evolução da doença e o ambiente de infecção, correlacionando com grupos demográficos distintos da região Sudeste do Brasil entre 2012 e 2022. Metodologia: A metodologia consistiu na coleta de dados do SINAN/DATASUS para analisar a febre maculosa associando a artigos relevantes sobre o tema. Foram incluídos estudos epidemiológicos sobre Febre Maculosa publicados entre 2015 e 2023, abrangendo o perfil na região Sudeste do Brasil e em outras regiões do país. Artigos com enfoque em pesquisa de cepas e epidemiologia em animais foram excluídos para garantir a homogeneidade dos dados analisados, que abordaram variáveis como faixa etária, sexo, raça, critério de confirmação e evolução. Resultados: Observou-se taxa de letalidade de 48,6% e uma concentração de óbitos no estado de São Paulo, com o principal meio de diagnóstico sendo exames laboratoriais. Conclusão: Os achados alcançados ajudam a conscientizar os profissionais da saúde sobre a importância de integrar informações clínicas, epidemiológicas e laboratoriais, o que torna mais fácil identificar a doença e iniciar o tratamento de forma precoce