324 research outputs found

    Pseudomonas aeruginosa and Staphylococcus aureus communication in biofilm infections: insights through network and database construction

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    AbstractThe polymicrobial nature of most infections is often characterized by complex biofilm communities, where pathogen interactions promote infection progression and severity. Quorum-sensing, the major regulator of virulence and inter-species communication, is a promising target for new anti-infective strategies. This study aimed at collecting and analysing experimental information on the molecular basis of Pseudomonas aeruginosa and Staphylococcus aureus interactions in biofilms. Data were systematically annotated from relevant full-text papers optimally retrieved from PubMed, reconstructed as networks and integrated with specialized databases to identify promising antimicrobial targets. Network analysis revealed key entities regulating P. aeruginosa/S. aureus interactions, for instance the PqsABCDE/PqsR quorum-sensing system, which affects S. aureus growth and biofilm formation. By identifying the most reported P. aeruginosa virulence factors affecting S. aureus, for example, HQNO and siderophores, a list of experimentally validated agents affecting those factors, ranging from synthetic drugs to natural plant extracts, was constructed. The complex experimental data on P. aeruginosa/S. aureus interactions were for the first time systematically organized and made publically available in the new Inter-Species CrossTalk Database (www.ceb.uminho.pt/ISCTD).This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit; the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte for the BioTecNorte operation (NORTE-01-0145-FEDER-000004); the COMPETE2020 and the FCT under the scope of the project POCI-01-0145-FEDER-029841; and the FCT under the scope of the PhD Grant of Andreia Patricia Magalhães [grant number SFRH/BD/132165/2017].info:eu-repo/semantics/publishedVersio

    Bacteria could help ectomycorrhizae establishment under climate variations

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    Rhizosphere microbiome is one of the main sources of plant protection against drought. Beneficial symbiotic microorganisms, such as ectomycorrhizal fungi (ECMF) and mycorrhiza helper bacteria (MHB), interact with each other for increasing or maintaining host plant fitness. This mutual support benefits all three partners and comprises a natural system for drought acclimation in plants. Cork oak (Quercus suber L.) tolerance to drought scenarios is widely known, but adaptation to climate changes has been a challenge for forest sustainability protection. In this work, ECMF and MHB communities from cork oak forests were cross-linked and correlated with climates. Cenococcum, Russula and Tuber were the most abundant ECMF capable of interacting with MHB (ECMF~MHB) genera in cork oak stands, while Bacillus, Burkholderia and Streptomyces were the most conspicuous MHB. Integrating all microbial data, two consortia Lactarius/Bacillaceae and Russula/Burkholderaceae have singled out but revealed a negative interaction with each other. Russula/Burkholderaceae might have an important role for cork oak forest sustainability in arid environments, which will be complemented by the lower drought adaptation of competitive Lactarius/Bacillaceae. These microbial consortia could play an essential role on cork oak forest resilience to upcoming climatic changes.This work was supported by FEDER funds through COMPETE (Programa Operacional Factores de Competitividade) and by national funds by FCT (Fundação para a Ciência e a Tecnologia) in the framework of the projects SuberControl (PTDC/ASP-SIL/28635/2017), BioISI (UIDB/04046/2020) and CIMO (UIDB/00690/2020).info:eu-repo/semantics/publishedVersio

    Meta-análise: estudo dos efeitos de programas de intervenção na prevenção de obesidade em crianças

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    A redução na prevalência de sobrepeso e obesidade são agora desafios prioritários para os pesquisadores em Epidemiologia e Saúde Pública. Diversas instituições médicas e científicas (American Heart Association, Center for Disease Control EUA, National Institutes of Health) demonstraram a sua grande preocupação com a diminuição dos níveis de actividade física em crianças e jovens, referindo que é de extrema importância, nessas idades, a adopção de um estilo de vida activo aliado a hábitos alimentares saudáveis. Objectivo: determinar o efeito de programas de intervenção sobre o IMC de crianças. Métodos: foram incluídas na análise 75 correlações (N=25432) de 54 estudos publicados em idioma Inglês e Português, pesquisados nas bases de dados eletrónicas: Pub Med MEDLINE, Web of Science (ISI); Lista de EBSCO; Latindex; SciELO.org e listas de referência ao artigo, datados do ano 2000 até 2011. Resultados: O effect size global foi de 0,095, embora seja estatisticamente significativo, revelou-se de baixa magnitude. O valor do effect size nos rapazes (r=0, 020) é ligeiramente inferior ao das raparigas (r=0,046), ainda assim, não são estatisticamente significativos (p=0,263). Existem diferenças significativas entre os programas realizados na escola e fora da escola (p=0,002). Nos programas com duração inferior a um ano r=0,056 e superiores a um ano r=0,133, ou seja, à medida que o tempo de intervenção aumenta o valor de effect size também aumenta. Conclusões: o presente estudo revelou que os programas de intervenção para prevenção da obesidade têm um efeito positivo, embora de baixa magnitude, no IMC das crianças e jovens. Os programas realizados fora da escola apresentam um efeito superior aos realizados na escola. Quando o programa tem uma duração superior a um ano, o tamanho do efeito da intervenção aumenta

    Effects of intervention programs on child and adolescent BMI: a meta-analysis study

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    This meta-analysis study aims to assess the efficacy of school-based and after-school intervention programs on the BMIs of child and adolescents, addressing the correlation between some moderating variables. Methods: We analyzed 52 studies (N = 28,236) published between 2000-2011. Results: The overall effect size was 0.068 (P < .001), school (r = .069) and after-school intervention (r = .065). Programs conducted with children aged between 15-19 years were the most effective (r = .133). Interventions programs with boys and girls show better effect sizes (r = .110) than programs that included just girls (r = .073). There were no significant differences between the programs implemented in school and after-school (P = .770). The effect size was higher in interventions lasting 1 year (r = .095), with physical activity and nutritional education (r = .148), and that included 3-5 sessions of physical activity per week (r = .080). The effect size also increased as the level of parental involvement increased. Conclusions: Although of low magnitude (r = .068), the intervention programs had a positive effect in prevention and decreasing obesity in children. This effect seems to be higher in older children's, involving interventions with physical activity and nutritional education combined, with parent's participation and with 1-year duration. School or after-school interventions had a similar effect

    Structural equation modelling for predicting the relative contribution of each component in the metabolic syndrome status change

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    Understanding the factor weighting in the development of metabolic syndrome (MetS) may help to predict the progression for cardiovascular and metabolic diseases. Thus, the aim of this study was to develop a confirmatory model to describe and explain the direct and indirect effect of each component in MetS status change. A total of 3581 individuals diagnosed with MetS, aged 18–102 years, were selected between January 2019 and December 2020 from a community-representative sample of Portuguese adults in a north-eastern Portuguese region to test the model’s goodness of fit. A structural equation modelling (SEM) approach and a two-way ANOVA (age × body composition) were performed to compare the relative contribution of each MetS component using joint interim statement (JIS). Waist circumference (β = 0.189–0.373, p < 0.001), fasting glucose (β = 0.168–0.199, p < 0.001) and systolic blood pressure (β = 0.140–0.162, p < 0.001) had the highest direct effect on the change in MetS status in the overall population and concerning both sexes. Moreover, diastolic blood pressure (DBP), triglycerides (TG) and high-density lipoprotein cholesterol (HDL-c) had a low or non-significant effect. Additionally, an indirect effect was reported for age and body composition involving the change in MetS status. The findings may suggest that other components with higher specificity and sensitivity should be considered to empirically validate the harmonised definition of MetS. Current research provides the first multivariate model for predicting the relative contribution of each component in the MetS status change, specifically in Portuguese adults.This article is a result of the project “GreenHealth-Digital strategies in biological assets to improve well-being and promote green health” (Norte-01-0145-FEDER-000042), supported by North Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF). The authors also express acknowledgement all medical staff, patients and human resources of the two primary health care centers.info:eu-repo/semantics/publishedVersio

    Rainfall Erosivity: Gap-Filling Method Differences in the Brazilian Pantanal and Cerrado Biomes

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    To improve the use of soil and its conservation, precipitation data are necessary. With the Universal Soil Loss Equation (USLE), the study of historical precipitation series is a main factor, but in these series, there are gaps that need to be filled. This study had, as a basis, the methods of weighted likelihood, multiple regression, and weighted likelihood based on multiple regression to fill the gaps of the rainfall data for the rainfall gauges in the Brazilian biomes (Cerrado and Pantanal, municipalities of Campo Grande, Bandeirantes, Sidrolândia, Miranda, Fazenda Ponte, and Ribas do Rio Pardo). With this, it became possible to calculate the rainfall erosivity (R factor in the USLE). Therefore, the consistency of the filled rainfall data was analyzed by the double mass method. The value of the rainfall erosivity calculated varies from 2304.80 to 13562.10 MJ mm ha−1 h−1 year. With this data, it was possible to identify particular results that differed from the rainfall erosivity. Comparing all the gap-filling methods, numbers varying from 0–12% at the same rainfall gauge were obtained

    Antimicrobial resistance three ways: healthcare crisis, major concepts, and the relevance of biofilms

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    Worldwide, infections are resuming their role as highly effective killing diseases, as current treatments are failing to respond to the growing problem that is antimicrobial resistance (AMR). The social and economical burden of AMR seems ever rising, with health- and research-related organizations rushing to collaborate on a worldwide scale to find effective solutions. Resistant bacteria are spreading even in first-world nations, being found not only in healthcare-related settings, but also in food and in the environment. In this mini-review, the impact of AMR in healthcare systems and the major bacteria behind it are highlighted. Ecological aspects of AMR evolution and the complexity of its molecular mechanisms are explained. Major concepts, such as intrinsic, acquired, and adaptive resistance, as well as tolerance and heteroresistance, are also clarified. More importantly, the problematic of biofilms and their role in AMR, namely its main resistance and tolerance mechanisms, is elucidated. Finally, some of the most promising anti-biofilm strategies being investigated are reviewed. Much is still to be done regarding the study of AMR and the discovery of new anti-biofilm strategies. Gladly, considerable research on this topic is generated every day and increasingly concerted actions are being engaged globally to try and tackle this problem.This work was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684) and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. The authors also acknowledge COMPETE2020 and FCT for the project POCI-01-0145-FEDER-029841, and FCT for the PhD Grants of Andreia Magalhães [grant number SFRH/BD/132165/2017] and Tânia Grainha [grant number SFRH/BD/136544/2018].info:eu-repo/semantics/publishedVersio

    Magnetogels based on iron oxide nanoparticles and peptide hydrogels containing Naproxen and/or RGD

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    In this work, iron oxide nanoparticles, with diameters around 12 nm, were synthesized by coprecipitation method in aqueous solution. These nanoparticles exhibit a superparamagnetic behavior, with a coercive field of 9.7 Oe and a blocking temperature of 118 K. The nanoparticles were successfully incorporated in peptide-based hydrogels containing naproxen (Npx) and/or RGD. The ability of these magnetogels to act as drug nanocarriers is being investigated, aiming at developing multifunctional therapeutic nanosystems.info:eu-repo/semantics/publishedVersio

    The Extremophile Endolithella mcmurdoensis gen. et sp. nov. (Trebouxiophyceae, Chlorellaceae), a new Chlorella-like Endolithic alga from Antarctica

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    The McMurdo Dry Valleys constitute the largest ice-free region of Antarctica and one of the most extreme deserts on Earth. Despite the low temperatures, dry and poor soils and katabatic winds, some microbes are able to take advantage of endolithic microenvironments, inhabiting the pore spaces of soil and constituting photosynthesis-based communities. We isolated a green microalga, Endolithella mcmurdoensis gen. et sp. nov, from an endolithic sandstone sample collected in the McMurdo Dry Valleys (Victoria Land, East Antarctica) during the K020 expedition, in January 2013. The single non-axenic isolate (E. mcmurdoensis LEGE Z-009) exhibits cup-shaped chloroplasts, electron-dense bodies, and polyphosphate granules but our analysis did not reveal any diagnostic morphological characters. On the basis of phylogenetic analysis of the 18S rRNA (SSU) gene, the isolate was found to represent a new genus within the family Chlorellaceae.We are sincerely grateful to Antarctica New Zealand for providing logistics support during K020 event. This campaign was conducted as part of the New Zealand Terrestrial Antarctic Biocomplexity Survey (nzTABS) through awards (UOWX0710 and UOWX1401) from the New Zealand Foundation for Research and Technology (FRST), Antarctica New Zealand, and the New Zealand Ministry of Business, Innovation and Employment to SCC. The work was also supported by the Portuguese Science and Technology Foundation (FCT) through grants UID/Multi/04423/2019 to CIIMAR, IF/01358/2014 and PTDC/MAR-BIO/2818/2012 to PNL, PTDC/CTA-AMB/30997/2017 to CM, and PhD scholarships to AR (SFRH/BD/140567/2018).info:eu-repo/semantics/publishedVersio
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