128 research outputs found

    VALORIZACIÓN DE SUBPRODUCTOS DE LA INDUSTRIA AGROALIMENTARIA COMO ANTIMICROBIANOS NATURALES FRENTE A MICROORGANISMOS PATÓGENOS MEDIANTE TECNOLOGÍAS NO TÉRMICAS DE CONSERVACIÓN

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    Tesis por compendioAgri-food industry generates, because of its production processes, high amount of by-products, which cause a negative impact both economically and environmentally. For this reason, nowadays, their revalorization is one of the main aims of European Union in support of sustainable development. This doctoral thesis is focused on the revalorization of by-products from the horticultural industry as natural antimicrobials, by themselves or combined with no-thermal technologies for food preservation, like Pulsed Electric Fields (PEF) or High Hydrostatic Pressure (HHP) against the main foodborne pathogens. Also, it pretends to evaluate the microbial resistance development against the subletal antimicrobial treatments under study and the possible virulence changes using C. elegans as a model organism. The agri-food by-products studied have shown an important antimicrobial effect against the main foodborne pathogens, also the ASE extracts and the infusions obtained therefrom, being S. Typhimurium the most sensitive microorganism. In addition, the combination of subletal treatments of PEF and HHP with by-product infusions has resulted in the emergence of synergies, which permit us to achieve the desirable levels of microbial inactivation (5 log cycles) in a minor period of time. The application of subletal antimicrobial treatments under study consecutively, has shown that it causes microbial resistance development in S. Typhimurium. However, C. elegans studies show that the development of microbial resistance not imply the increase of its virulence against a host organism. For all these reasons, we can conclude that the revalorization of agri-food by-products as natural antimicrobials is a viable alternative as an additional control measure to ensure the microbial food safety by themselves or combined with PEF or HHP treatments, due to their synergistic effect.La industria agroalimentaria genera, como resultado de sus procesos de producción, grandes cantidades de subproductos que suponen un impacto negativo a nivel económico y medioambiental. Es por ello que, en la actualidad, su revalorización es uno de los objetivos principales de la Unión Europea en apoyo al desarrollo sostenible. La presente tesis doctoral se centra en la revalorización de subproductos de la industria hortofructícola como antimicrobianos naturales en sí mismos o combinados con tecnologías no-térmicas de conservación de alimentos como los Pulsos Eléctricos de Alta Intensidad (PEF) o las Altas Presiones Hidrostáticas (HHP) frente a los microorganismos patógenos transmitidos por alimentos más importantes. Además, trata de evaluar el desarrollo de resistencias en los microorganismos a los tratamientos antimicrobianos subletales estudiados y sus posibles cambios de virulencia usando C. elegans como organismo modelo. Los subproductos hortofructícolas estudiados han demostrado un importante efecto antimicrobiano frente a los principales patógenos alimentarios, así como los extractos ASE y las infusiones obtenidas a partir de los mismos, siendo el microorganismo más sensible S. Typhimurium. Además, la aplicación de forma combinada de tratamientos subletales de PEF y HHP con infusiones de subproductos ha dado lugar a la aparición de sinergias que permiten alcanzar los niveles deseados de inactivación microbiana (5 ciclos logarítmicos) en un menor periodo de tiempo. La aplicación de los tratamientos antimicrobianos subletales estudiados de forma consecutiva se ha demostrado que da lugar a la generación de resistencia microbiana en S. Typhimurium. Sin embargo, los estudios con C. elegans ponen de manifiesto que el desarrollo de esta resistencia antimicrobiana no lleva consigo el aumento de su virulencia al infectar a un organismo hospedador. En base a todo lo anterior, podemos concluir que la revalorización de los subproductos de la industria hortofructícola como antimicrobianos naturales es una alternativa viable para su utilización como medida de control adicional de la seguridad microbiológica de productos alimenticios por sí mismos o en combinación con tratamientos de PEF o HHP, dado su efecto sinérgico.La industria agroalimentària genera, com a resultat dels seus processos de producció, grans quantitats de subproductes que suposen un impacte negatiu a nivell econòmic y mediambiental. És per això que, en la actualitat, la seua revalorització és un dels objectius principals de la Unió Europea en recolzament al desenvolupament sostenible. La present tesi doctoral es centra en la revalorització de subproductes de la industria hortofructícola com a antimicrobians naturals per sí mateixa o combinats amb tecnologies no-tèrmiques de conservació d'aliments com els Polsos Elèctrics d'Alta Intensitat (PEF) o les Altes Pressions Hidrostàtiques (HHP) front als microorganismes patògens transmesos per aliments més importants. A més, tracta d'avaluar el desenvolupament de resistències en els microorganismes als tractaments antimicrobians subletals estudiats i els seus possibles canvis de virulència utilitzant C. elegans com a organisme model. Els subproductes hortofructícoles estudiats han demostrat un important efecte antimicrobià front als principals patògens alimentaris, així com els extractes ASE i les infusions obtingudes a partir dels mateixos, sent el microorganisme més sensible S. Typhimurium. A més, l'aplicació de forma combinada de tractaments subletals de PEF i HHP amb infusions de subproductes ha donat lloc a l'aparició de sinèrgies que permeten aplegar als nivells desitjats d'inactivació microbiana (5 cicles logarítmics) en un menor període de temps. L'aplicació dels tractaments antimicrobians subletals estudiats de forma consecutiva s'ha demostrat que dona lloc a la generació de resistència microbiana en S. Typhimurium. No obstant això, els estudis amb C. elegans posen de manifest que el desenvolupament d'esta resistència antimicrobiana no du implícit l'augment de la seua virulència al infectar a un organisme hospedador. En base a tot lo anterior, podem concloure que la revalorització dels subproductes de la industria hortofructícola com a antimicrobians naturals és una alternativa viable per a la seua utilització com a mesura de control addicional de la seguretat microbiològica de productes alimentaris per sí mateixa o en combinació amb tractaments de PEF o HHP, donat el seu efecte sinèrgic.Sanz Puig, M. (2017). VALORIZACIÓN DE SUBPRODUCTOS DE LA INDUSTRIA AGROALIMENTARIA COMO ANTIMICROBIANOS NATURALES FRENTE A MICROORGANISMOS PATÓGENOS MEDIANTE TECNOLOGÍAS NO TÉRMICAS DE CONSERVACIÓN [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/90508TESISCompendi

    Escherichia coli O157:H7 and Salmonella Typhimurium inactivation by the effect of mandarin, lemon, and orange by-products in reference medium and in oat-fruit juice mixed beverage

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    The antimicrobial capability of three water extracts of citrus peels was evaluated against Salmonella enterica serovar Typhimurium and Escherichia coli O157:H7 at various concentrations (0.5, 1, 5, 10%) and temperatures (5, 10, 22 °C) in a reference medium. The best of them was mandarin by-product, achieving a maximum inactivation level against S. Typhimurium (8 log10 cycles) with 5% at 5 °C. Also, this by-product had the highest total polyphenol content. Mandarin by-product showed a bactericidal effect in a food matrix also at 5 °C (≈2 log10 cycles). All results were adjusted to the Weibull model and the b values indicated that the higher concentration of mandarin, the greater the inactivation rate in reference medium, without significant differences between 5 and 10%. Similarly, in the food matrix, the inactivation rate of S. Typhimurium was higher when the mandarin by-product was added. Therefore, the mandarin by-product could be used as a control measure of S. Typhimurium in pasteurized products, which are stored under refrigeration.M. Sanz-Puig is grateful to the CSIC for providing a contract as a researcher working actively on the projects with reference IPT-2011-1724-060000 and AGL 2013–48993-C2-2-R, funded by the Ministry of Economy and Competitiveness and with FEDER funds. M.C. Pina-Pérez is grateful to the CSIC for providing a doctoral contract.Peer reviewe

    Combined effect of high hydrostatic pressure (HHP) and antimicrobial from agro-industrial by-products against S. typhimurium

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    The inactivation potential of HHP treatment (200 MPa-2 min) was evaluated against Salmonella enterica serovar Typhimurium in cauliflower and mandarin by-product infusions at 37 and 10 °C. By-product infusions exerted a strong antimicrobial effect used alone, achieving 5 log cycles of bacterial reduction for cauliflower by-product infusion after 10 h and for mandarin by-product infusion after 80 h, at 37 °C. The HHP treatment caused only one log cycle of cellular damage, but when inoculated cauliflower or mandarin by-product infusions were subjected to HHP treatment the antimicrobial effect against S. Typhimurium was enhanced, achieving 5 log cycles of inactivation in 6 h at 37 °C in both cases. Inactivation curves were adjusted to the Weibull equation and the kinetic parameters (b and n) were obtained. When HHP treatment was combined with by-product infusions, the inactivation rates were greater than when either of the by-product infusions was added separately. In conclusion, a synergistic antimicrobial effect against S. Typhimurium appeared to take place when HHP treatment was combined with cauliflower or mandarin by-product infusion. These infusions could be considered as an additional microbial control measure to guarantee the food safety and food quality of pasteurized food products that are stored under refrigeration.M. Sanz-Puig is grateful to the CSIC for providing a contract as a researcher working actively on project AGL 2013–48993-C2-2-R. The present research work was funded by the Ministry of Economy and Competitiveness and with FEDER funds (AGL 2013-48993-C2-2-R).Peer reviewe

    ¿Cómo afectó la crisis económica de 2008 a los temas de investigación de los bancos centrales? El caso de los asociados y colaboradores del CEMLA

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    Central banks play a fundamental role in a country"s monetary policy. This study has a twofold objective: a) to analyse the contribution to academic research made by the associates and collaborating members of the Center for Latin American Monetary Studies (CEMLA) and b) to analyse the evolution of research topics in the economic literature over the without economic crisis and with crisis. Eighteen banks were subjected to bibliometric analysis covering the period 2000-2019. The results show that, although the number of publications is higher for the collaborating members, the growth rate over time is higher in the associates. Associates collaborate less with other institutions in the crisis period than collaborating members. The evolution of topics reveals important differences between the two groups.Los bancos centrales juegan un papel fundamental en la política monetaria de un país. Este estudio tiene un doble objetivo: a) analizar la contribución a la investigación académica realizada por los miembros asociados y colaboradores del Centro de Estudios Monetarios Latinoamericanos (CEMLA) y b) analizar la evolución de los temas de investigación en la literatura económica a lo largo del Períodos de precrisis y crisis. Dieciocho bancos fueron sometidos a análisis bibliométrico cubriendo el período 2000-2019. Los resultados muestran que, aunque el número de publicaciones es mayor para los miembros colaboradores, la tasa de crecimiento en el tiempo es mayor en los asociados. Los asociados colaboran menos con otras instituciones en periodo de crisis que los miembros colaboradores. La evolución de los temas revela diferencias importantes entre los dos grupos

    Use of Antimicrobials from Plants in Feed as a Control Measure for Pathogenic Microorganisms

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    Animal Feed has become an increasing critical component of the integrated food chain, in 2010 about 1000 mt of animal feed was produced globally and 150 mt in the EU27. The animal feed has an important impact in the human health. The farm or feedlot is the origin of microorganisms introduced onto carcasses during slaughter and dressing. It appears that changes in diet and management practices could precipitate increased shedding of pathogens. Additionally, antibiotics are used in animals, not only for treatment or prevent diseases, but also to promote growth. As a result of the use of antibiotics, food can contain antibiotic-resistant bacteria and resistance genes with important public health consequences. Although antibiotics are banned as growth promoters in the European Union and some other countries, this is not the case throughout the WHO European Region. Travel and the globalization of trade further increase the risk of spreading antibiotic-resistant bacteria.Peer reviewe

    Effect of pulsed electric fields (PEF) combined with natural antimicrobial by-products against S. typhimurium

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    The effect against Salmonella enterica serovar Typhimurium of PEF treatment combined with cauliflower and mandarin by-product infusions at several concentrations (0, 1, 5, and 10% (w/v)) was evaluated at various incubation temperatures (10, 22, and 37 °C). The possible synergistic antimicrobial action of the combined process of Pulsed Electric Field (PEF) technology followed by exposure to the by-product infusions and the occurrence of sublethal cellular damage were also studied. Antimicrobial kinetics of by-product infusions alone or following PEF treatment were fitted to a Weibull model. Both mandarin and cauliflower by-product infusions showed a maximum antimicrobial effect against S. Typhimurium after 10 h at 37 °C when the microorganism was exposed to 10% of by-product infusion, achieving reductions of initial bacterial load up to undetectable levels. The effect of the PEF treatment (20 kV–900 μs) caused a reduction of 4 log cycles of the initial cell population (108 cfu/mL) of S. Typhimurium and 1 log cycle (90%) of cellular damage. Moreover, when the PEF pre-treated S. Typhimurium population was subjected to subsequent incubation in the presence of both by-product [10%] infusions, the microbial inactivation was faster, achieving a reduction of the initial bacterial load (4 log10 cycles) up to undetectable levels in 2 h. The kinetic values of the Weibull model were obtained. The higher the concentration of by-product infusion, temperature, and PEF treatment applied, the greater the kinetic parameter “b” values, which are related to the microbial inactivation rate. Therefore, the addition of cauliflower and mandarin by-product infusions could be a good additional control measure contributing to ensure bacterial counts below recommended limits in pasteurized PEF products during their storage at refrigeration temperatures.M. Sanz-Puig is grateful to the CSIC for providing a contract as a researcher working actively on project AGL 2013-48993-C2-2-R. The present research work was funded by the Ministry of Economy and Competitiveness through project AGL 2013-48993-C2-2-R and with FEDER funds. We are also grateful to INDULLEIDA, S.A. and TRASA, S.L. for providing the by-products that we worked with. Authors acknowledge L. Santos-Carvalho Erasmus Placement scholarship, and L.M. Cunha acknowledges support from the European Union (FEDER funds) and National Funds (FCT/MEC, Fundação para a Ciência e Tecnologia and Ministerio da Educação e Ciência) under the Partnership Agreements PT2020 UID/QUI/50006/2013–POCI/01/0145/FEDER/007265 (LAQV) and UID/AGR/04033/2013–POCI/01/0145/FEDER/006958 (CITAB).Peer reviewe

    Decline in fertility induced by economic recession in Spain

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    OBJECTIVE: To describe trends in fertility in Spain before (pre-recession; 1998-2008) and during (recession period; 2009-2013) the economic crisis of 2008, taking into account women's age and regional unemployment in 2010. METHOD: The study consisted of a panel design including cross-sectional ecological data for the 17 regions of Spain. We describe fertility trends in Spain in two time periods, pre-recession (1998-2008) and recession (2009-2013). We used a cross-sectional, ecological study of Spanish-born women to calculate changes in fertility rates for each period using a linear regression model adjusted for year, period, and interaction between them. RESULTS: We found that compared to the pre-recession period, the fertility rate in Spain generally decreased during the economic recession. However, in some regions, such as the Canary Islands, this decrease began before the onset of the recession, while in other regions, such as the Basque country, the fertility rate continued to grow until 2011. The effects of the recession on the fertility rate are clearly observed in women aged 30-34 years. CONCLUSIONS: The current economic recession has disrupted the positive trend in fertility that began at the start of this century. Since Spain already had very low fertility rates, the further decline caused by the economic recession could jeopardize the sustainability of welfare-state systems

    How Did the 2008 Economic Crisis Affect Central Banks’ Research Topics? The Case of CEMLA Associates and Collaborating Members

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    Central banks play a fundamental role in a country’s monetary policy. This study has a twofold objective: a) to analyse the contribution to academic research made by the associates and collaborating members of the Center for Latin American Monetary Studies (CEMLA) and b) to analyse the evolution of research topics in the economic literature over the pre-crisis and crisis periods. Eighteen banks were subjected to bibliometric analysis covering the period 2000-2019. The results show that, although the number of publications is higher for the collaborating members, the growth rate over time is higher in the associates. Associates collaborate less with other institutions in the crisis period than collaborating members. The evolution of topics reveals important differences between the two groups

    Desarrollo y validación preliminar del instrumento HSQoL-24 para evaluar calidad de vida en pacientes con hidradenitis supurativa

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    Introducción y objetivos: La hidradenitis supurativa (HS) es una enfermedad inflamatoria crónica de la piel que influencia negativamente la calidad de vida. En la actualidad no existen escalas en español que la evalúen. El objetivo del presente estudio fue desarrollar y validar un cuestionario específico para evaluar la calidad de vida en pacientes con HS. Material y métodos: Se desarrolló un estudio multicéntrico en España entre 2016 y 2017 para elaborar un cuestionario. Para ello se consideró tanto el marco conceptual como el conocimiento de la situación del paciente mediante la revisión de la bibliografía, reuniones de profesionales de diferentes áreas y entrevistas con pacientes. El cuestionario resultante se pasó a un grupo de 30 pacientes con 30 ± 10 días de intervalo entre uno y otro. Resultados: El análisis de fiabilidad muestra una buena consistencia interna y reproductibilidad con puntuación alfa de Cronbach de 0, 920 (test) y 0, 917 (retest) y coeficiente de correlación intraclase con DLQI y Skindex-29 de 0, 698 IC 95% (0, 456-0, 844) y 0, 900 IC 95% (0, 801-0, 951) respectivamente. Se establecieron puntos de corte para su uso y se comprobó que el instrumento es sensible al cambio. Conclusiones: El cuestionario HSQoL-24 es la primera prueba autoadministrada específica para evaluar la calidad de vida en HS en español. Sencillo de usar y puntuar por los profesionales. Este estudio demuestra que el instrumento es fiable, válido y sensible al cambio, pendiente de realizar estudio confirmatorio con una muestra mayor con 100 pacientes con HS. Introduction and objectives: Hidradenitis suppurativa (HS) is a chronic inflammatory disease of the skin with a negative impact on quality of life. Up to now, there are no disease specific instruments in Spanish to assess quality of life in HS. The objective of this study was to develop and validate a questionnaire to evaluate the quality of life in patients with HS. Material and methods: A multicentre study was carried out in Spain between 2016 and 2017 to develop the questionnaire. Both the conceptual framework and understanding of the patient''s situation were considered through a review of the literature, consensus of professionals from different related health areas, and in-depth interviews with patients. The resulting questionnaire was passed to a group of 30 patients with 30±10 days of interval between both assessments. Results: The reliability analysis shows a good internal consistency and reproducibility with Cronbach''s alpha score of 0.920 (test) and 0.917 (retest) and intraclass correlation coefficient with DLQI and Skindex-29 of 0.698 IC 95% (0.456-0.844) and 0.900 IC 95% (0.801-0.951) respectively. Cut-off points were established for its use and the instrument was found to be sensitive to change. Conclusions: The HSQoL-24 is the first disease-specific self-administered instrument to assess quality of life in patients with HS in Spanish. It is user friendly, and easy to score. This study shows that the instrument is reliable, valid and sensitive to change, pending confirmatory study with a larger sample of 100 patients with HS

    Interlaboratory analytical validation of a Next-generation sequencing strategy for clonotypic assessment and minimal residual disease monitoring in multiple myeloma

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    [Context]: Minimal residual disease (MRD) is a major prognostic factor in multiple myeloma, although validated technologies are limited. [Objective]: To standardize the performance of the LymphoTrack next-generation sequencing (NGS) assays (Invivoscribe), targeting clonal immunoglobulin rearrangements, in order to reproduce the detection of tumor clonotypes and MRD quantitation in myeloma. [Design]: The quantification ability of the assay was evaluated through serial dilution experiments. Paired samples from 101 patients were tested by LymphoTrack, using Sanger sequencing and EuroFlow's next-generation flow (NGF) assay as validated references for diagnostic and follow-up evaluation, respectively. MRD studies using LymphoTrack were performed in parallel at 2 laboratories to evaluate reproducibility. [Results]: Sensitivity was set as 1.3 tumor cells per total number of input cells. Clonality was confirmed in 99% and 100% of cases with Sanger and NGS, respectively, showing great concordance (97.9%), although several samples had minor discordances in the nucleotide sequence of rearrangements. Parallel NGS was performed in 82 follow-up cases, achieving a median sensitivity of 0.001%, while for NGF, median sensitivity was 0.0002%. Reproducibility of LymphoTrack-based MRD studies (85.4%) and correlation with NGF (R2 > 0.800) were high. Bland-Altman tests showed highly significant levels of agreement between flow and sequencing. [Conclusions]: Taken together, we have shown that LymphoTrack is a suitable strategy for clonality detection and MRD evaluation, with results comparable to gold standard procedures. Multiple myeloma (MM) is a plasma-cell dyscrasia characterized by the accumulation of plasma cells in the bone marrow that produces an excess of clonal immunoglobulins (M-protein or monoclonal component).1 New treatment approaches have increased the number of patients achieving complete response (CR),2–5 progressively improving progression-free and overall survival rates in the last 10 years.6–11 Nonetheless, the presence of low levels of drug-resistant cells (known as minimal residual disease, MRD)12–14 that remain undetected by conventional serologic and morphologic methods explains frequent relapses with this disease, which is still considered an incurable illness.Minimal residual disease is currently considered one of the most informative prognostic parameters, since those patients with undetectable disease have shown prolonged survival rates as compared with MRD-positive patients,15–17 and this difference is still significant even when patients achieving only stringent complete response (sCR) are taken into account.18 The International Myeloma Working Group (IMWG) defined MRD positivity as the persistence of clonal malignant plasma cells assessed with a sensitivity of at least 10−5 (1 malignant cell per hundred thousand normal cells)19 ; therefore, MRD should be monitored with only highly sensitive methods. To date, 3 different approaches have been tested for MRD monitoring in hematologic malignancies: immunophenotypic (multiparametric flow cytometry [MFC]),20 molecular (quantitative polymerase chain reaction [PCR], next-generation sequencing [NGS], digital PCR),21–23 and imaging tools (positron emission tomography–computed tomography; magnetic resonance imaging).24,25 However, in MM standardization has been achieved only for MFC26 and NGS.27,28 As a result, the IMWG recommended the use of highly sensitive, standardized flow and sequencing approaches,19 including EuroFlow's next-generation flow (NGF)29 and Adaptive Biotechnologies' ClonoSEQ solutions (Adaptive Biotechnologies, Seattle, Washington). NGF is a 2-tube, 8-color flow assay that allows the simultaneous analysis of 10 million cells, providing a sensitivity of around 2·10−6.This work was partially supported by the Instituto de Salud Carlos III (ISCIII), Spanish Ministry of Economy and Competitiveness PI15/01956, CIBERONC-CB16/12/00233, and “Una manera de hacer Europa” (Innocampus; CEI-2010-1-0010). García-Álvarez, Prieto-Conde, and Jiménez were supported by the Fundación Española de Hematología y Hemoterapia (FEHH, cofunded by Fundación Cris in the latter case), Medina by the European Social Fund through the University of Salamanca and the ISCIII (FI19/00320), and Sarasquete by the ISCIII (CPII18/00028). All Spanish funding is cosponsored by the European Union FEDER program
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