85 research outputs found

    Sensibility of the entomopathogenic fungus Metarhizium anisopliae (Metschnikoff) Sorokin to Pelargonium sidoides extract (EPs 7630®) assessed by conidia germination speed parameter

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    Pelargonium sidoides, known as umckaloabo, is a plant originally from South Africa and its extract is used in popular medicine. The fungus Metarhizium anisopliae, an important entomopathogen used in biological control of pests, is also employed as model for the evaluation of toxicity and compatibility of different products, considering, among other parameters, conidia germination speed. Therefore, this study aimed to evaluate the sensibility of M. anisopliae var. anisopliae in the presence of the extract of P. sidoides, at a concentration of 20.625 and 2.0625 mg/ml. During incubation at 28°C, samples were collected at 0, 6, 8, 10, 12 and 24 h and analyzed by light microscopy, with observation of 300 conidia, in triplicate, for both treatments and negative controls (in a completely randomized design). This study shows that the two concentrations of P. sidoides extract tested are capable of delaying the M. anisopliae conidia germination speed, in comparison to the controls, although the germination frequency has been restored after about 12 h of conidia incubations, with did not lack conidia viability, indicating no toxicity.Keywords: Model fungus; toxicity; vegetative development; viability

    Effect of polyethylene microplastics on activated sludge process Accumulation in the sludge and influence on the process and on biomass characteristics

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    [EN] According to previous research, it has been proved that wastewater treatment plants (WWTPs) can retain more than 90 % of the MPs contained in wastewater. However, a significant fraction of the MPs removed in WWTPs is retained in the sludge floc and this may lead to an environmental issue since biosolids can be used as fertilizers. The purpose of this research was to evaluate how the presence of polyethylene (PE) could interfere with the activated sludge performance. For this, a sequencing batch reactor (SBR) was continuously fed during 93 days with synthetic sewage and PE microbeads. It was observed that 98 +/- 2% of the total amount of MPs that entered SBR was accumulated in the activated sludge. Despite the high accumulation of MPs in the sludge, the depuration performance of the reactor was not compromised. However, the presence of MPs decreased the richness (Chao1) and abundance-based coverage estimators (ACE) and diversity (Shannon) of the bacterial community on day 93. Based on the analysis of the diversity indices and the relative abundances of microbial taxa, it was concluded that MPs had selective effects on activated sludge microbial community. However, MPs did not affect the abundance of nitrifying and denitrifying bacteria in the sludge.Authors thank the Spanish Ministry of Science, Innovation and Universities for the financial support (Reference of the project: RTI2018-096916-B-I00)Alvim, CB.; Castelluccio, S.; Ferrer-Polonio, E.; Bes-Piá, M.; Mendoza Roca, JA.; Fernández-Navarro, J.; Alonso Molina, JL.... (2021). Effect of polyethylene microplastics on activated sludge process Accumulation in the sludge and influence on the process and on biomass characteristics. Process Safety and Environmental Protection. 148:536-547. https://doi.org/10.1016/j.psep.2020.10.01453654714

    Alteración termoxidativa en un aceite de girasol utilizado en 75 frituras de patatas

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    The alteration of a sunflower oil used in 75 repeated deep fat frying of potatoes performed with addition of unused oil every 4-5 fryings with the aim to keep constant the proportion food/oil in 500 g / 3 liters, was evaluated by column and high performance size exclusion chromatographies. The polar components increased from 5.09 ± 0.21 (unused oil) to 19.11 ± 0,40 mg/100 mg oil mainly due to the formation of polymers and dimers of triacylglycerides, and to oxidized triacylglycerides. Oils, unused and from the 75 frying, were included at a rate of 15% on rat-diets. Dietary food intakes were similar, however body weight gain was a 22.3% lower in rat fed with the used oil-diet. Apparent digestibility ratios of fat and protein were similar in both groups of rats, however both. Alimentary and Protein Efficiency ratios decreased on the 75 frying oil fed rats.Se evalúa la alteración de un aceite de girasol utilizado en 75 frituras repetidas de patatas, efectuadas con adición de aceite sin usar cada 4-5 frituras con la finalidad de mantener constante la proporción alimento/aceite en 500 g / 3 litros, mediante cromatografías en columna y de alta eficacia por exclusión de tamaño de partícula. El contenido de los compuestos polares se incrementó de 5.09 ± 0.21 (aceite sin usar) a 19.11 ± 0.40 mg/100 mg de aceite, predominando los polímeros y dímeros de triacilglicéridos y los triacilglicéridos oxidados. Dichos aceites, sin usar y utilizado en 75 frituras, se incluyeron en la proporción del 15% en las dietas del lote basal y del lote fritura 75, respectivamente. La ingesta de ambas dietas fue similar, pero la ganancia de peso resultó ser un 22,3% menor en el lote fritura 75. Los coeficientes de digestibilidad aparente de grasa y proteína fueron similares en ambos lotes, pero la utilización nutritiva en términos de coeficientes de Eficacia Alimentaria y Proteica fue menor en el lote fritura 75

    A bicyclic α-iminophosphonate improves cognitive decline in 5xFAD murine model of neurodegeneration

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    I2 receptors (I2-IR) are widely distributed in the central nervous system. I2-IR ligands are associated with a neuroprotective effect but, as I2-IR structure remains unknown, the discovery of better and more selective ligands is necessary to understand the pharmacological and molecular implications of I2-IR. Recently, we described a new imidazoline-structure family which showed high affinity and selectivity for I2-IR. In vivo studies in mice indicated a neuroprotective role and revealed beneficial effects in behaviour and cognition with a murine model of neurodegeneration, senescence-accelerated prone mouse (SAMP8). Herein, we report a novel non-imidazoline-structure of bicyclic α-iminophosphonates family with high affinities for I2-IR. In vivo studies in 5X-FAD mice (a transgenic representative model of AD) and SAMP8 mice (a model of neurodegeneration linked to aging) showed an improvement in behaviour and cognition, a reduction of AD hallmarks and of neuroinflammation markers for the mice treated with the lead compound B06. After evaluating several pathways associated with neurodegeneration, we demonstrated that CaN pathway plays a critical role on the neuroprotective effects of I2-IR ligands on SAMP8 mice model. To rule out warnings of the novel family, we calculated DMPK and physicochemical properties for the novel bicyclic α-iminophosphonates. As well, we carried out drug metabolism, safety studies and in vivo pharmacokinetics for lead compound B06. In summary, we present a novel family of I2-IR ligands, its effectiveness in in vivo models and the possible neuroprotective molecular mechanism mediated by them. This highlights that the modulation of I2-IR by bicyclic α-iminophosphonates may open a new therapeutic venue for unmet neurodegenerative conditions

    Evaluation of Spatially Targeted Strategies to Control Non-Domiciliated Triatoma dimidiata Vector of Chagas Disease

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    Chagas disease is one of the most important parasitic diseases in Latin America. Since the 1980's, many national and international initiatives have contributed to eliminate vectors developing inside human domiciles. Today's challenge is to control vectors that are non-adapted to the human domicile, but still able to transmit the parasite through regular short stay in the houses. Here, we assess the potential of different control strategies applied in specific spatial patterns using a mathematical model that reproduces the dynamic of dispersion of such ‘non-domiciliated’ vectors within a village of the Yucatan Peninsula, Mexico. We show that no single strategy applied in the periphery of the village, where the insects are more abundant, provides satisfying protection to the whole village. However, combining the use of insect screens in houses at the periphery of the village (to simultaneously fight insects dispersing from the garden and the forest), and the cleaning of the peri-domicile areas of the centre of the village (where sylvatic insects are absent), would provide a cost-effective control. This type of spatially mixed strategy offers a promising way to reduce the cost associated with the repeated interventions required to control non-domiciliated vectors that permanently attempt to infest houses

    Single Dose Novel Salmonella Vaccine Enhances Resistance against Visceralizing L. major and L. donovani Infection in Susceptible BALB/c Mice

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    Visceral leishmaniasis is a major neglected tropical disease, with an estimated 500,000 new cases and more than 50,000 deaths attributable to this disease every year. Drug therapy is available but costly and resistance against several drug classes has evolved. Despite all efforts, no commercial, let alone affordable, vaccine is available to date. Thus, the development of cost effective, needle-independent vaccines is a high priority. Here, we have continued efforts to develop live vaccine carriers based on recombinant Salmonella. We used an in silico approach to select novel Leishmania parasite antigens from proteomic data sets, with selection criteria based on protein abundance, conservation across Leishmania species and low homology to host species. Five chosen antigens were differentially expressed on the surface or in the cytosol of Salmonella typhimurium SL3261. A two-step procedure was developed to select optimal Salmonella vaccine strains for each antigen, based on bacterial fitness and antigen expression levels. We show that vaccine strains of Salmonella expressing the novel Leishmania antigens LinJ08.1190 and LinJ23.0410 significantly reduced visceralisation of L. major and enhanced systemic resistance against L. donovani in susceptible BALB/c mice. The results show that Salmonella are valid vaccine carriers for inducing resistance against visceral leishmaniasis but that their use may not be suitable for all antigens

    Eco-bio-social determinants for house infestation by non-domiciliated Triatoma dimidiata in the Yucatan peninsula, Mexico

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    Background Chagas disease is a vector-borne disease of major importance in the Americas. Disease prevention is mostly limited to vector control. Integrated interventions targeting ecological, biological and social determinants of vector-borne diseases are increasingly used for improved control. Methodology/principal findings We investigated key factors associated with transient house infestation by T. dimidiata in rural villages in Yucatan, Mexico, using a mixed modeling approach based on initial null-hypothesis testing followed by multimodel inference and averaging on data from 308 houses from three villages. We found that the presence of dogs, chickens and potential refuges, such as rock piles, in the peridomicile as well as the proximity of houses to vegetation at the periphery of the village and to public light sources are major risk factors for infestation. These factors explain most of the intra-village variations in infestation. Conclusions/significance These results underline a process of infestation distinct from that of domiciliated triatomines and may be used for risk stratification of houses for both vector surveillance and control. Combined integrated vector interventions, informed by an Ecohealth perspective, should aim at targeting several of these factors to effectively reduce infestation and provide sustainable vector control
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