2,158 research outputs found

    Towards an integrated stratigraphy of the Gramame Formation (Maastrichtian), CIPASA quarry, Pernambuco-Paraíba Basin, NE Brazil

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    This study presents the integrated biostratigraphic (calcareous nannofossils and foraminifera), petrographic, geochemical and ichnological analyzes of the Gramame Formation (Maastrichtian) at the CIPASA Quarry section, in the Pernambuco-Paraíba Basin, northeastern Brazil. A high resolution calcareous nannofossil biostratigraphic study has been carried out, allowing to subdivide the studied section into three subzones of Maastrichtian age: CC25A, CC25B, and CC25C. Each biostratigraphic unit was further characterized by petrographic, geochemical and ichnological parameters. During the Maastrichtian the area was characterized by a dry and warm climate with low influx of terrigenous sediments. These conditions were fundamental to the widespread development of a carbonate ramp system in an outer neritic to bathyal setting, with deposition of alternating calcareous mudstones and argillaceous mudstones of the Gramame Formation. The Gramame Formation belongs to the transgressive system tract of second-order type, characteristic of a Passive Margin Sequence. The studied section consists of part of a third order deposicional cycle, which is arranged in a transgressive systems tract and a highstand systems tract. The lowstand systems tract was not characterized

    Analysis of intact prophages in genomes of paenibacillus larvae, an important pathogen for bees

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    Paenibacillus larvae is a highly contagious spore-forming bacteria, responsible for the American Foulbrood (AFB) disease, lethal to honeybee brood. Integrated in bacterial genomes, prophages are often able to provide new genes or to alter phenotypic characteristics of bacteria. The potential role of prophages in the performance of P. larvae has been studied. A total of 55 intact prophage genomes from 11 P. larvae strains were annotated and analysed. The main focus was to infer the influence of their genes with some type of virulence trait (e.g.: toxins), or functions such as antibiotic resistance, metabolic function, germination/sporulation or transporter of nutrients, which could improve bacterial fitness. We also aimed at understanding if specific traits were provided to a given genotype (ERIC I-V). A total of 67 putative genes with different functions were identified. Some were present in all genotypes, as for example, genes encoding phosphomannomutase, HicB and MazE antitoxins, while others were exclusive from a specific genotype. In ERIC I, were found genes encoding a DNA internalization protein or an enhancin-like toxin, in ERIC II, genes responsible for a SocA antitoxin or a DNA mismatch repair protein, in ERIC III, a gene for a lipid phosphatase, in ERIC IV, genes encoding proteins associated to ironsulfur uptake and nitrogen fixation and in ERIC V, genes for an aromatic acid exporter family protein, for an epsilon-toxin type B or for an epithelial and chitin-binding protein. Although several prophage-derived genes are closely linked to metabolic processes, only ERIC V strains appear to have a competitive advantage since prophages contained multiple genes that could contribute to a more aggressive infection. Despite the low representativeness on P. larvae strains diversity, we definitely contribute to leveraging studies in a subject with recent and short knowledge.info:eu-repo/semantics/publishedVersio

    Analysis of intact prophages in genomes of Paenibacillus larvae: An important pathogen for bees

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    The Supplementary materials for this article can be found online at: https://www.frontiersin.org/articles/10.3389/fmicb.2022.903861/full#supplementary-materialPaenibacillus larvae is the etiological agent of American Foulbrood (AFB), a highly contagious and worldwide spread bacterial disease that affects honeybee brood. In this study, all complete P. larvae genomes available on the NCBI database were analyzed in order to detect presence of prophages using the PHASTER software. A total of 55 intact prophages were identified in 11 P. larvae genomes (5.0±2.3 per genome) and were further investigated for the presence of genes encoding relevant traits related to P. larvae. A closer look at the prophage genomes revealed the presence of several putative genes such as metabolic and antimicrobial resistance genes, toxins or bacteriocins, potentially influencing host performance. Some of the coding DNA sequences (CDS) were present in all ERIC-genotypes, while others were only found in a specific genotype. While CDS encoding toxins and antitoxins such as HicB and MazE were found in prophages of all bacterial genotypes, others, from the same category, were provided by prophages particularly to ERIC I (enhancin-like toxin), ERIC II (antitoxin SocA) and ERIC V strains (subunit of Panton-Valentine leukocidin system (PVL) LukF-PV). This is the first in-depth analysis of P. larvae prophages. It provides better knowledge on their impact in the evolution of virulence and fitness of P. larvae, by discovering new features assigned by the viruses.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit. HR was supported by FCT through the grant SFRH/BD/128859/2017 and COVID/BD/151856/2021.info:eu-repo/semantics/publishedVersio

    API480: features towards therapy in honeybee hives

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    American foulbrood disease (AFB) is a devastating bacterial disease affecting honeybees. It is caused by Paenibacillus larvae, a worldwide-distributed spore forming Gram-positive bacterium which spread easily across apiaries producing highly resistant spores. When AFB symptoms are found the burning of contaminated hives is mandatory causing serious economic losses [1]. Bacteriophages (phages) are being considered valuable solutions to the control of this infection [2-5]. So far, 48 Siphoviridae P. larvae phages sequences are known and most encode integration genes suggesting a temperate lifestyle. All of these 48 phages seem to have a common evolutionary ancestor showing an overall common structure. Their genomes were grouped into four clusters (with Fern, Harrison, Vegas and Halcyone as representative phages) and one singleton (phage Lily) [6].Project APILYSE,PTDC/CVT-EPI/4008/2014-POCI-01-0145-FEDER-016598,-funded by FEDER through COMPETE2020-Programa Operacional Competitividade e Internacionalização(POCI) and the Portuguese Foundation for Science and Technology(FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTec Norte operation(NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020-Programa Operacional Regional do Norte.The work was also supported by CEB-UM that provided the laboratorial facilities to perform this research. HR was supported by FCT through the grant SFRH/BD/128859/2017. MB and RL were supported by KULeuven through a GOAgrant[3E140356]info:eu-repo/semantics/publishedVersio

    In Vitro Effect of Local Anesthetics on Candida albicans Germ Tube Formation

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    Objective: This study was planned to clarify the in vitro effect of lidocaine and bupivacaine on germ tube formation by Candida albicans isolates from cases of clinical vaginal candidiasis

    Insulin glycation by methylglyoxal results in native-like aggregation and inhibition of fibril formation

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    <p>Abstract</p> <p>Background</p> <p>Insulin is a hormone that regulates blood glucose homeostasis and is a central protein in a medical condition termed insulin injection amyloidosis. It is intimately associated with glycaemia and is vulnerable to glycation by glucose and other highly reactive carbonyls like methylglyoxal, especially in diabetic conditions. Protein glycation is involved in structure and stability changes that impair protein functionality, and is associated with several human diseases, such as diabetes and neurodegenerative diseases like Alzheimer's disease, Parkinson's disease and Familiar Amyloidotic Polyneuropathy. In the present work, methylglyoxal was investigated for their effects on the structure, stability and fibril formation of insulin.</p> <p>Results</p> <p>Methylglyoxal was found to induce the formation of insulin native-like aggregates and reduce protein fibrillation by blocking the formation of the seeding <it>nuclei</it>. Equilibrium-unfolding experiments using chaotropic agents showed that glycated insulin has a small conformational stability and a weaker dependence on denaturant concentration (smaller m-value). Our observations suggest that methylglyoxal modification of insulin leads to a less compact and less stable structure that may be associated to an increased protein dynamics.</p> <p>Conclusions</p> <p>We propose that higher dynamics in glycated insulin could prevent the formation of the rigid cross-β core structure found in amyloid fibrils, thereby contributing to the reduction in the ability to form fibrils and to the population of different aggregation pathways like the formation of native-like aggregates.</p

    3D printed functional cookies fortified with Arthrospira platensis: Evaluation of its antioxidant potential and physical-chemical characterization

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    In the last few decades, consumers' growing attention to the close relationship between health and nutrition is emerging as a new trend, mostly regarding the incorporation of natural ingredients into food. Among those ingredients, microalgae are considered as innovative and promising compounds, rich in valuable nutrients and bioactive molecules. In the present work, 3D printed cookies were fortified with the microalga Arthrospira platensis aiming at developing a new functional food with antioxidant properties. A. platensis antioxidants were recovered using ultrasound-assisted extraction in hydroalcoholic solutions. Ethanol/water and biomass/solvent ratios were optimised through a Design of Experiments (DOE) approach, using the antioxidant activity (ORAC and ABTS) and total phenolic content (TPC) as response variables. The highest ORAC, ABTS and TPC values were observed in the extract obtained with 0% ethanol and 2.0% biomass; thus, this extract was chosen to be incorporated into a printable cookie dough. Three different incorporation approaches were followed: (1) dried biomass, (2) freeze-dried antioxidant extract and (3) antioxidant extract encapsulated into alginate microbeads to enhance the stability to heat, light, and oxygen during baking and further storage. All dough formulations presented shape fidelity with the 3D model. The cookies had aw values low enough to be microbiologically stable, and the texture remained constant after 30 days of storage. Moreover, the extract encapsulation promoted an improvement in the ORAC value and colour stability when compared to all other formulations, revealing the potential of A. platensis for the development of a functional 3D food-ink.This work was funded by the European Union INTERREG Atlantic Area Programme and the European Regional Development Fund (ERDF) through the project “Enhance Microalgae: High added-value industrial opportunities for microalgae in the Atlantic Area” (Ref. EAPA_338/2016).info:eu-repo/semantics/publishedVersio
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