Novel “nano-phage” interfaces for wireless biosensors

The prevention of food-borne illness has become a very important factor in public health. Meantime, the conventional microbiological detection techniques are time consuming, require proficiency and appropriate laboratory conditions. Recently, there has been an extensive work undertaken towards the development of diagnostic biosensor devices for on-site detection of biological threats that explore a diversity of transduction mechanisms and bio-recognition elements. In particular, the environmentally robust filamentous phages have been successfully used as an alternative to fragile antibodies in wireless biosensor system for real-time pathogen detection. However, when phages are used as interface, they can aggregate forming bundles of fibers that cannot cover completely the sensor’s interface leading to the decrease in sensor’s performance. In this work we developed novel wireless magnetoelastic biosensors with interface formed by biorecognition nanoparticles called “nano-phage”. “Nano-phage” comprises nanoparticles with diameter ~11 nm composed of self-assembled fusion major coat protein of landscape phages selected against the target analyte. For proof-of-concept, we investigated interfaces formed by three model phages selected from landscape libraries: streptavidin binders 7b1 and SAE10 and clone E2 highly specific and selective for S. typhimurium. Beside food borne pathogens, this new approach can be used to develop biosensors with increased performance for early detection of cancer diseases and other pathologies

Influence of Brazilian pine seed flour addition on rheological, chemical and sensory properties of gluten-free rice flour cakes.

O pinhão trata-se de uma semente sem glúten, produzida pelo pinheiro da espécie Araucaria angustifolia. Neste estudo, foram desenvolvidas misturas de bolo sem glúten, compostas por farinha de pinhão e farinha de arroz. As misturas de bolo foram produzidas conforme o modelo experimental Simplex Centroid, que definiu as proporções entre a farinha de arroz e a farinha de pinhão na variação de 50 a 100% e 0 a 50%, respectivamente. As misturas foram analisadas quanto à composição química, viscosidade aparente da pasta e distribuição de tamanho de partícula. Os bolos resultantes foram submetidos às análises de aceitação sensorial, textura volume específico e composição química. A farinha de pinhão demostrou ocorrência do pico de viscosidade ao aquecimento no valor de 1,761Pa.s contra 4,747Pa.s da amostra composta por 100% de farinha de arroz. A variação da firmeza dos bolos diminuiu com o aumento da porcentagem de farinha de pinhão. Em termos sensoriais, os bolos contendo entre 25 a 37,5% de farinha de pinhão apresentaram maior aceitação geral

Encapsulated bacteriophages in alginate-nanohydroxyapatite hydrogel as a novel delivery system to prevent orthopedic implant-associated infections

Supplementary data to this article can be found online at: https://doi.org/10.1016/j.nano.2019.102145.An innovative delivery system based on bacteriophages-loaded alginate-nanohydroxyapatite hydrogel was developed as a multifunctional approach for local tissue regeneration and infection prevention and control. Bacteriophages were efficiently encapsulated, without jeopardizing phage viability and functionality, nor affecting hydrogel morphology and chemical composition. Bacteriophage delivery occurred by swelling-disintegration-degradation process of the alginate structure and was influenced by environmental pH. Good tissue response was observed following the implantation of bacteriophages-loaded hydrogels, sustaining their biosafety profile. Bacteriophages-loaded hydrogels did not affect osteoblastic cells' proliferation and morphology. A strong osteogenic and mineralization response was promoted through the implantation of hydrogels system with nanohydroxyapatite. Lastly, bacteriophages-loaded hydrogel showed excellent antimicrobial activity inhibiting the attachment and colonization of multidrug-resistant E. faecalis surrounding and within femoral tissues. This new local delivery approach could be a promising approach to prevent and control bacterial contamination during implantation and bone integration.Funding: This work was supported by FEDER – Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020 – Operational Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, by Portuguese funds through FCT/MCTES in the framework of the project “institute for Research and Innovation in Health Sciences (POCI-01-0145-FEDER-007274), by Project Biotherapies (NORTE-01-0145-FEDER-000012) and by Joana Barrosʼ PhD grant (SFRH/BD/102148/2014). This work was also supported by Portuguese funds through FCT/MCTES (UID/QUI/50006/2019).info:eu-repo/semantics/publishedVersio

Gravitational Lorentz Force and the Description of the Gravitational Interaction

In the context of a gauge theory for the translation group, we have obtained, for a spinless particle, a gravitational analog of the Lorentz force. Then, we have shown that this force equation can be rewritten in terms of magnitudes related to either the teleparallel or the riemannian structures induced in spacetime by the presence of the gravitational field. In the first case, it gives a force equation, with torsion playing the role of force. In the second, it gives the usual geodesic equation of General Relativity. The main conclusion is that scalar matter is able to feel anyone of the above spacetime geometries, the teleparallel and the metric ones. Furthermore, both descriptions are found to be completely equivalent in the sense that they give the same physical trajectory for a spinless particle in a gravitational field.Comment: Equations (44)-(47) correcte

Bacteriophage-receptor binding proteins for multiplex detection of Staphylococcus and Enterococcus in blood

Health care-associated infections (HCAIs) affect hundreds of millions of patients, representing a significant burden for public health. They are usually associated to multidrug resistant bacteria, which increases their incidence and severity. Bloodstream infections (BSIs) are among the most frequent and life-threatening HCAIs, with Enterococcus and Staphylococcus among the most common isolated pathogens. The correct and fast identification of the etiological agents is crucial for clinical decision-making, allowing to rapidly select the appropriate antimicrobial and to prevent from overuse and misuse of antibiotics and the consequent increase in antimicrobial resistance. Conventional culture methods are still the gold standard to identify these pathogens, however are time-consuming and may lead to erroneous diagnosis, which compromises an efficient treatment. (Bacterio)phage receptor binding proteins (RBPs) are the structures responsible for the high specificity conferred to phages against bacteria and thus are very attractive biorecognition elements with high potential for specific detection and identification of pathogens. Taking into account all these facts, we have designed and developed a new, fast, accurate, reliable and unskilled diagnostic method based on newly identified phage RBPs and spectrofluorometric techniques that allows the multiplex detection of Enterococcus and Staphylococcus in blood samples in less than 1.5 hours after an enrichment step.This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the project “Phages‐on‐chip” PTDC/BTM‐SAL/32442/2017 (POCI‐01‐0145‐FEDER‐032442) and the strategic funding of UIDB/04469/2020 unit 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. Catarina Nogueira, Ana Brandão and Susana Costa were supported by the FCT grants PD/BD/143037/2018, SFRH/BD/133193/2017 and SFRH/BD/130098/2017, respectively. We would also like to acknowledge Professor Hermínia de Lencastre, Doctor Carina Almeida and Doctor Nuno Cerca for gently providing some of the strains used in this study. We acknowledge Professor Paulo Freitas for providing some of the infrastructures to perform the experiments.info:eu-repo/semantics/publishedVersio

European Sea Bass (Dicentrarchus labrax) immune status and disease resistance are impaired by arginine dietary supplementation

Infectious diseases and fish feeds management are probably the major expenses in the aquaculture business. Hence, it is a priority to define sustainable strategies which simultaneously avoid therapeutic procedures and reinforce fish immunity. Currently, one preferred approach is the use of immunostimulants which can be supplemented to the fish diets. Arginine is a versatile amino acid with important mechanisms closely related to the immune response. Aiming at finding out how arginine affects the innate immune status or improve disease resistance of European seabass (Dicentrarchus labrax) against vibriosis, fish were fed two arginine-supplemented diets (1% and 2% arginine supplementation). A third diet meeting arginine requirement level for seabass served as control diet. Following 15 or 29 days of feeding, fish were sampled for blood, spleen and gut to assess cell-mediated immune parameters and immune-related gene expression. At the same time, fish from each dietary group were challenged against Vibrio anguillarum and survival was monitored. Cell-mediated immune parameters such as the extracellular superoxide and nitric oxide decreased in fish fed arginine-supplemented diets. Interleukins and immune-cell marker transcripts were down-regulated by the highest supplementation level. Disease resistance data were in accordance with a generally depressed immune status, with increased susceptibility to vibriosis in fish fed arginine supplemented diets. Altogether, these results suggest a general inhibitory effect of arginine on the immune defences and disease resistance of European seabass. Still, further research will certainly clarify arginine immunomodulation pathways thereby allowing the validation of its potential as a prophylactic strategy.European Union's Seventh Framework Programme AQUAEXCEL (Aquaculture Infrastructures for Excellence in European Fish Research) [262336]; AQUAIMPROV [NORTE-07-0124-FEDER-000038]; North Portugal Regional Operational Programme (ON. 2 - O Novo Norte) , under the National Strategic Reference Framework, through the European Regional Development Fund; North Portugal Regional Operational Programme (ON. 2 - O Novo Norte), under the National Strategic Reference Framework through the COMPETE - Operational Competitiveness Programme; Fundacao para a Ciencia e Tecnologia; Fundacao para a Ciencia e Tecnologia [SFRH/BD/89457/2012, SFRH/BPD/77210/2011]; Generalitat Valenciana through the project REVIDPAQUA [ISIC/2012/003]; [PEst-C/MAR/LA0015/2013]; [UID/Multi/04423/2013]info:eu-repo/semantics/publishedVersio

The CgHaa1-regulon mediates response and tolerance to acetic acid stress in the human pathogen Candida glabrata

To thrive in the acidic vaginal tract C. glabrata has to cope with high concentrations of acetic acid. The mechanisms underlying C. glabrata tolerance to acetic acid at low pH remain largely uncharacterized. In this work it is demonstrated the essential role of the CgHaa1 transcription factor (encoded by ORF CAGL0L09339g) in the response and tolerance of C. glabrata to acetic acid. Transcriptomic analysis showed that CgHaa1 regulates, directly or indirectly, the expression of about 75% of the genes activated under acetic acid stress. CgHaa1-activated targets are involved in multiple physiological functions including membrane transport, metabolism of carbohydrates and amino acids, regulation of the activity of the plasma membrane H+-ATPase and adhesion. Under acetic acid stress CgHaa1 increased the activity and the expression of the CgPma1 proton pump and contributed to increased colonization of vaginal epithelial cells by C. glabrata. CgHAA1, CgTPO3 and CgHSP30, two identified CgHaa1-activated targets, are herein demonstrated to be determinants of C. glabrata tolerance to acetic acid. The protective effect of CgTpo3 and of CgHaa1 was linked to a role of these proteins in reducing the accumulation of acetic acid inside C. glabrata cells. In response to acetic acid stress, marked differences were found in the regulons controlled by CgHaa1 and by its S. cerevisiae ScHaa1 ortholog, demonstrating a clear divergent evolution of the two regulatory networks. The results gathered in this study significantly advance the understanding of the molecular mechanisms underlying the success of C. glabrata as a vaginal colonizer.Cristoph Schueller (University of Natural Resources and Life Sciences, Austria) and Ken Haynes (University of Exeter, UK) are acknowledged for sharing strains. Funding received by the Institute for Bioengineering and Biosciences from the Portuguese Foundation for Science and Technology (FCT) (UID/BIO/04565/2013) and from Programa Operacional Regional de Lisboa 2020 (project no. 007317)is acknowledged. FCT is also acknowledged for funding the Centre of Biological Engineering through contracts FCOMP-01-0124-FEDER020243 and PTDC/EBB-EBI/120495/2010. Science Foundation Ireland and the Wellcome Trust are acknowledged for funding G.B