Detección de enterotoxinas en especies Staphylococcus coagulasa negativos aislados de muestras de leche bovina

Tesis - Maestría en Salud Pública - Universidad Nacional de Córdoba. Facultad de Ciencias Médicas. Escuela de Salud Pública, 2018Due to the potential danger to the public health posed by staphylococcal thermostable enterotoxins in dairy products, the need arose to investigate the potential ability to produce these toxins by different coagulase negative Staphylococcus species (CNS) isolated in bovine milk. These bacteria, which are becoming increasingly involved in herd infections, produce several virulence factors, including enterotoxins, and biofilm forming, which contributes to their permanence in the dairy sector by hindering the action of sanitizing agents and disinfectants. Given that the correct identification of staphylococcal species is essential for effective diagnosis and treatment, this work had among its objectives the genotypic identification of the isolates by PCR-RFLP analysis of the gap gene. The comparison of this method and the technique considered as definitive proof of species identification based on protein profiles, MALDI-TOF MS, allowed the former to be considered reliable for the identification of species of CNS isolates with a 93.9% coincidence. Regarding the virulence factors of SCN, the presence of enterotoxin genes and the phenotypic capacity to form biofilm were investigated, in order to later determine the association between both. An important number of enterotoxin-producing strains was obtained (78.1%). Among the genes found, the gene was the most prevalent, present in forty-seven of the 96 strains (48.9%). Regarding the phenotypic capacity of biofilm formation, the majority (92.7%), eighty nine of the 96 isolates analyzed, showed this ability. It is interesting to note that 60.4% (58/96) were strong formers. The ability to produce biofilm by different species of SCN with the presence of enterotoxins genes, highlights the potential risk of persistence of these bacteria in the food processing environment. Since the staphylococcal toxins remain in the products even after the thermal process, the results obtained in this study value the importance of having strict hygiene programs that ensure milking practices and animal health, and in this way help preserve consumer's health.Ante el potencial peligro que representa para la salud pública la presencia de enterotoxinas estafilocócicas termoestables en productos lácteos, surgió la necesidad de investigar la potencial habilidad de producir estas toxinas por diferentes especies de Staphylococcus coagulasa negativos (SCN) aislados en leche bovina. Estas bacterias, que están adquiriendo cada vez mayor participación en las infecciones de los rebaños, producen varios factores de virulencia, entre ellos, enterotoxinas, y crecimiento en biofilm, lo cual contribuye a su permanencia en el sector productivo por dificultar la acción de agentes sanitizantes y desinfectantes. Dado que es esencial la correcta identificación de las especies estafilocócicas para un diagnóstico y tratamiento eficaz, este trabajo tuvo entre sus objetivos, la identificación genotípica de los aislamientos por análisis de PCR-RFLP del gen gap. La comparación de este método y la técnica considerada como prueba definitiva de identificación de especie basada en perfiles proteicos, MALDI-TOF MS, permitieron considerar al primero como confiable para la identificación de especie de los aislamientos de SCN con un 93,9% de coincidencia Sobre los factores de virulencia de SCN, se investigó, presencia de genes de enterotoxinas y capacidad fenotípica de formar biofilm, para luego determinar el grado de asociación entre ambas. Se obtuvo un importante número de cepas productoras de enterotoxinas (78,1%). Entre los genes encontrados, el gen sea fue el más prevalente, presente en cuarenta y siete de las 96 cepas (48,9%). En cuanto a la capacidad fenotípica de formación de biofilm, la mayoría (92,7%), ochenta y nueve de los 96 aislamientos analizados, presentaron esta habilidad. Es interesante destacar que el 60,4%, (58/96), resultaron fuertes formadores. La habilidad de producir biofilm por diferentes especies de SCN con presencia de genes para enterotoxinas remarca el riesgo potencial de la persistencia de estas bacterias en el ambiente de procesamiento de alimentos. Dado que las toxinas estafilocócicas permanecen en los productos aun luego del proceso térmico, los resultados obtenidos en este estudio valorizan la importancia de contar con estrictos programas de higiene que aseguren las prácticas de ordeño y la salud animal, y de este modo se ayude a preservar la salud del consumidor.2020-11-19Fil: Conesa, Agustín.Universidad Nacional de Villa María; ArgentinaFil: Conesa, Agustín. Consejo Nacional De Investigaciones Científicas y Técnicas. Centro Científico Tecnológico. Centro de Investigaciones y transferencia de Villa María; Argentin

Assessment of Streamflow from EURO-CORDEX Regional Climate Simulations in Semi-Arid Catchments Using the SWAT Model

This research studies the effect of climate change on the hydrological behavior of two semi-arid basins. For this purpose, the Soil and Water Assessment Tool (SWAT) model was used with the simulation of two future climate change scenarios, one Representative Concentration Pathway moderate (RCP 4.5) and the other extreme (RCP 8.5). Three future periods were considered: close (2019–2040), medium (2041–2070), and distant (2071–2100). In addition, several climatic projections of the EURO-CORDEX model were selected, to which different bias correction methods were applied before incorporation into the SWAT model. The statistical indices for the monthly flow simulations showed a very good fit in the calibration and validation phases in the Upper Mula stream (NS = 0.79–0.87; PBIAS = −4.00–0.70%; RSR = 0.44–0.46) and the ephemeral Algeciras stream (NS = 0.78–0.82; PBIAS = −8.10–−8.20%; RSR = 0.4–0.42). Subsequently, the impact of climate change in both basins was evaluated by comparing future flows with those of the historical period. In the RCP 4.5 and RCP 8.5 scenarios, by the end of the 2071–2100 period, the flows of the Upper Mula stream and the ephemeral Algeciras stream will have decreased by between 46.3% and 52.4% and between 46.6% and 55.8%, respectively.ERDF/Spanish Ministry of Science, Innovation and Universities—State Research Agency/Project CGL2017-84625-C2-1-R (CCAMICEM)State Program for Research, Development and Innovation Focused on the Challenges of Societ

Multi-proxy survey of open-air surface scatters in drylands: Archaeological and physico-chemical characterisation of fossilised dunes in North Gujarat (India)

This research aims at improving our understanding of open-air archaeological surface scatters in drylands, their extension and the intensity of human activities during their occupation. To do so, the study of physico-chemical proxies is integrated to that of archaeological artefacts by means of systematic field survey combined with laboratory sedimentary analyses and a robust statistical approach. In most dry regions, archaeological survey has traditionally aimed at the collection of artefacts. When present, the study of physical and geochemical samples has been limited to excavated archaeological levels. In this work, we evaluate the archaeological significance of physico-chemical proxies from surface samples collected within and around four mid and late-Holocene surface scatters in North Gujarat, a semi-arid region located at the south-west margin of the Thar Desert in India. The four archaeological scatters are found on top of fossilised sand dunes. Archaeologically, they represent subsistence strategies based on hunting and gathering, agro-pastoralism, or a succession/mixture of the two. The four locations were systematically sampled across a linear transect. For each sampling unit, the archaeological materials were quantified and classified by means of a Linear Discriminant Analyses. Physio-chemical variables were ordinated in a PCA space and clustered through a Hierarchical Clustering. Results were displayed along the dune transect and integrated into a Correspondence Analysis. Significant differences are attested in the spatial distribution and content of Ca, P and grain size, allowing us to suggest a set of distinct cultural soilscapes that characterise the dunes of the study area: vertisols (agric horizons in interdunal lower slopes), aridisols (relict dune surfaces in the mid-slope), and anthrosols (top dune). The last show a strong correspondence with the presence of archaeological artefacts, and the different intensity of human footprint are discussed accordingly to potential past subsistence strategies and the intensity of human occupation. © 2016 Elsevier Ltd and INQUA.This research arises from collaboration between the MS University of Baroda and the IMF-CSIC (Spanish National Research Council) within the framework of the North Gujarat Archaeological Project (NoGAP) and the SimulPast Project CSD2010-00034). F.C.Conesa acknowledges worked on this paper with funding from the JAE-PreDoc program (CSIC and European Social Found). A. L. Balbo worked on this paper under the Juan de la Cierva Programme (MINECO JCI-2011-10734), and with a Research Fellowship from the Alexander von Humboldt Foundation/Stiftung.Peer reviewe

Les valls del Serpis: campanya de prospecció 2011

Troballes més importants de la campanya de 2011

Automated detection of archaeological mounds using machine-learning classification of multisensor and multitemporal satellite data.

This paper presents an innovative multisensor, multitemporal machine-learning approach using remote sensing big data for the detection of archaeological mounds in Cholistan (Pakistan). The Cholistan Desert presents one of the largest concentrations of Indus Civilization sites (from ca 3300 to 1500 BC). Cholistan has figured prominently in theories about changes in water availability, the rise and decline of the Indus Civilization, and the transformation of fertile monsoonal alluvial plains into an extremely arid margin. This paper implements a multisensor, multitemporal machine-learning approach for the remote detection of archaeological mounds. A classifier algorithm that employs a large-scale collection of synthetic-aperture radar and multispectral images has been implemented in Google Earth Engine, resulting in an accurate probability map for mound-like signatures across an area that covers ca 36,000 km2 The results show that the area presents many more archaeological mounds than previously recorded, extending south and east into the desert, which has major implications for understanding the archaeological significance of the region. The detection of small (30 ha) suggests that there were continuous shifts in settlement location. These shifts are likely to reflect responses to a dynamic and changing hydrological network and the influence of the progressive northward advance of the desert in a long-term process that culminated in the abandonment of much of the settled area during the Late Harappan period.ER

Quality and fruit colour change in Verna lemon

While most of lemon cultivars in the northern hemisphere are harvested in autumn-winter, Verna, an autochthonous Spanish cultivar, is harvested later (February to August), supplying the European market when lemons are in short supply, a market that is also served by imports from the southern hemisphere, mainly Argentina and South Africa. The aim of this study was to determine the temperature at which degreening begins naturally in Verna lemon, noting the evolution of colorimetric parameter a and comparing the same with the equivalent measurements made in Eureka lemon, the most widely cultivated lemon worldwide. The influence of solar radiation on the colorimetric parameters was studied, and then the influence of the minimum temperatures on the change from green to yellow, using the data collected over five growing seasons, was also assessed. The results confirmed the relation between net solar radiation and degreening in Verna, a process that begins when net solar radiation reaches a value of between 2 and 4 MJ/m2.day and when the mean temperature of the 14 days prior to sampling is8.8 ºC or when the daily mean temperature reaches5.5 ºC on two consecutive days. The information obtained will enable growers to predict the colour changes that will occur in the field and potential growers to ascertain whether a given geographical zone is suitable for the crop in question.

Study of the use-wear and application of non-destructive chemical analysis on a macro-tool from the Hort de Cortés-Volcán del Faro site (Cullera, València)

Los macroútiles han sido habitualmente marginados de los estudios, debido al peso que ha tenido la industria lítica tallada para la observación de los cambios y continuidades cronológicos y culturales. Sin embargo, estos elementos aparecen en yacimientos arqueológicos asociados a diferentes contextos geográficos y cronológicos, lo cual les confiere un valor como marcadores de la adaptación y de la evolución técnica desarrollada por los grupos humanos. En este trabajo se presentan los resultados del análisis detallado de un objeto procedente del yacimiento de Hort de Cortés-Volcán del Faro (València), asociado a niveles gravetienses. La singularidad de su morfología, de la materia prima y la presencia de huellas de uso apreciables a nivel macroscópico motivaron la aplicación de diferentes metodologías de estudio sobre la pieza para su comprensión. El análisis de las huellas de uso apunta a que esta roca carbonatada fue utilizada en actividades asociadas con el tratamiento de la piel. La diferenciación de dos grupos de huellas de uso ha determinado la distinción de dos tareas desarrolladas con el objeto. La presencia de residuos que se pueden correlacionar con el uso de la pieza se ha evaluado aplicando una aproximación multianalítica y no destructiva. Además, se han aplicado técnicas de espectroscopía atómica y molecular junto con estadística multivariante, con el objetivo de identificar la potencial fuente de materia prima. El interés de este estudio reside en la combinación de aproximaciones para el estudio de un macroútil. Todo ello ha permitido ampliar la limitada información que se tiene sobre este tipo de materiales, y abrir el debate sobre el conocimiento del nivel tecnológico alcanzado por los grupos humanos.Macro-lithic tools have usually been marginalised from studies, due to the importance that the flaked lithic industry has had for the observation of chronological and cultural changes and continuities. However, these elements appear in archaeological sites associated with different geographical and chronological contexts, which gives them value as markers of the adaptation and technical evolution developed by human groups. This paper presents the results of the detailed analysis of an object from the site of Hort de Cortés-Volcán del Faro (València), associated with Gravettian levels. The singularity of its morphology, the raw material and the presence of use-wear appreciable at a macroscopic level, motivated the application of different methodologies of study on the piece in order to understand it. The analysis of the use-wear suggests that this carbonate rock was used in activities associated with the treatment of the leather. The differentiation of two different groups of use-wear has determined the distinction of two different tasks carried out on the object. The presence of residues that can be correlated with the use of the piece has been evaluated by applying a multi-analytical and non-destructive approach. In addition, atomic and molecular spectroscopy techniques together with multivariate statistics have been applied in order to identify the potential source of raw material. The interest of this study lies in the combination of approaches to the study of a macro-lithic tool. All of this has allowed us to expand the limited information we have on this type of material, and to open the debate on the knowledge of the technological level reached by human groups.Este proyecto se ha llevado a cabo gracias a la Consellería de Educación, Cultura y Deporte de la Generalitat Valenciana, a través de los proyectos: «Smartphone y química analítica verde» (PROMETEO 2019-056) y «The Great Deglaciation: climate change and social dynamics in the Late Palaeolithic and Mesolithic period in the Iberian Mediterranean region» (Prometeo 2022, CIPROM/2021-036). Gianni Gallello agradece el apoyo económico de la ayuda Beatriz Galindo (2018) financiada por el Ministerio de Ciencia e Innovación y el Ministerio de Universidades de España (Proyecto BEAGAL18/00110: «Desarrollo de métodos analíticos aplicados a la arqueología» y al Ministerio de Ciencia e Innovación de España por la financiación del proyecto EvolMED «Evolutionary cultural patterns in the contexts of the neolithisation process in the Western Mediterranean» (PID2021-127731NB-C21)