Navegando por Assunto "Microbiota"

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Acesso aberto (Open Access)
Análise de patógenos orais entre indivíduos portadores de câncer gástrico e indivíduos sem câncer
(Universidade Federal do Pará, 2021-06) OLIVEIRA, Gyselle Ribeiro de Carvalho; BURBANO, Rommel Mario Rodriguéz; http://lattes.cnpq.br/4362051219348099; https://orcid.org/0000-0002-4872-234X
The loss of teeth and lack of oral hygiene have been associated with the risk of developing gastric cancer in several populations evidenced in epidemiological studies. In this study, we quantitatively compared the proportion of oral pathogens in individuals with gastric cancer and individuals without cancer in a referral hospital in the city of Belém, Brazil. This study evaluated 192 patients with gastric cancer and 192 patients without cancer. Periodontal clinical examination was performed, and all individuals were submitted to the collection of salivary and dental biofilms. When comparing the median periodontal indexesin the gastric and cancer-free groups, it was statistically significant in the gastric cancer group compared to the probing depth of the periodontal pocket. Levels of bacterial DNA were observed in saliva and dental plaque, with a statistically significant difference between individuals with cancer and without neoplasia in all the bacteria surveyed. Significant relationships between biological agents and gastric cancer have been found in bacterial species that cause high rates of periodontal pathology and caries. The results suggest a different quantitative association in the presence of oral pathogens between individuals without cancer and patients with gastric cancer. As noted, it cannot be said that the bacteria present in the oral cavity increase the risk of gastric cancer or are aggravating factors of the disease. However, it is worth mentioning that, as it is part of the digestive system, the lack of care for the oral cavity can negatively affect the treatment of patients with gastric cancer.
Acesso aberto (Open Access)
Biodiversidade bacteriana durante a fermentação espontânea de frutos de açaí (Euterpe oleracea)
(Universidade Federal do Pará, 2015-06-22) MOURA, Fábio Gomes; ROGEZ, Hervé Louis Ghislain; http://lattes.cnpq.br/5202118426597590
Açai (Euterpe oleracea) fruits (AF) and a wide variety of products derived from this fruit are an example of success of a local and typically Brazilian product on the global market. The AF suffer spontaneous fermentation during postharvest due mainly to its high microbial load and the favourable intrinsic and extrinsic parameters. The biodiversity of microbial community in AF and their evolution between three geographical origins and two fermentation conditions were examined. Culture-independent methods based on 16S rRNA from fifteen samples revealed that Proteobacteria, Firmicutes, Actinobacteria, Bacteroidetes and Acidobacteria were the most abundant phyla. At genus level, were identified Massilia (taxon with more than 50 % of sequences remaining constant during the 30 h of fermentation), Pantoea (taxon with the highest increase during fermentation), Naxibacter, Enterobacter, Raoultella and Klebsiella, forming the carposphere bacterial microbiota of AF. Attributes related to plant growth promotion (siderophores) and others compounds e.g. poly-3-hydroxybutyrate (PHB) and violacein in response to stress conditions could improve the Massilia preponderance. Beta diversity showed that quality parameters of AF (pH, soluble solids, titratable acididy and lipids) and elemental analysis (C, N, H and C/N ratio) were unable to establish microbial patterns in AF. This research offers new insights and perspectives of the indigenous bacterial community composition on AF as a function of spontaneous fermentation during postharvest.
Acesso aberto (Open Access)
Impacto dos fatores antropogênicos e ambientais na dinâmica do microbioma e nas interações hospedeiro-patógeno em anfíbios
(Universidade Federal do Pará, 2025-04) MOSER, Camila Fernanda; BECKER, Guilherme; PELOSO, Pedro Luiz Vieira Del; http://lattes.cnpq.br/0963420424755544; https://orcid.org/0000-0003-0127-8293
Amphibians are among the most threatened vertebrates, with 41% of species at risk of extinction due to habitat loss, climate change, invasive species, and emerging diseases. A key factor influencing their health is the skin microbiota, a community of symbiotic microorganisms that contribute to immunity and disease resistance. However, this microbiome is highly sensitive to environmental disturbances, which can alter its composition and reduce its protective functions. One of the major threats to amphibians is chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd), a pathogen that disrupts skin integrity and weakens host defenses, leading to high mortality rates. This infection interacts with environmental stressors, including pollution and habitat degradation, increasing amphibian vulnerability. This thesis explores the composition and ecological drivers of amphibian skin microbiota, its interactions with Bd, and the effects of environmental disturbances. The results show that microbiome diversity varies across species, seasons, and environmental conditions. A case study on Bd dynamics across different species and environmental conditions demonstrated that infection prevalence and load were lower in warmer temperatures and in species with non-aquatic habits, suggesting that abiotic factors and host ecology significantly influence Bd susceptibility. Furthermore, seasonal variations in microbiota composition were observed, with microbial diversity generally decreasing in colder months. These seasonal shifts could be linked to changes in amphibian behavior and immune function, highlighting the need for long-term monitoring of microbiota-host-pathogen interactions. In conclusion, this thesis provides novel insights into the complex interactions between amphibian microbiota, environmental changes, and disease dynamics. Understanding how anthropogenic disturbances and seasonal variations shape microbiome diversity is essential for developing effective conservation strategies. Future research should focus on longterm monitoring of amphibian microbiomes, explore the role of larval-stage microbiota in pathogen resistance, and investigate microbiome-based interventions to support amphibian populations facing increasing environmental threats.