Modernización del Sistema Aduanero y su vinculación con la sociedad civil

Informe de investigación--Universidad de Costa Rica, Vicerrectoría de Acción Social, Trabajo Comunal Universitario. 2012. Para mayor información puede escribir a [email protected] documento es una guía a los agroexportadores para que conozcan información general sobre los formularios exigidos en el tema de exportación, tales como modernización del sistema aduanero costarricense, notificaciones previas, el compendio de leyes en materia aduanera, la inscripción como importador, entre otras. La información del presente documento se complementa con las presentaciones adjuntas en este fichero.Universidad de Costa RicaUCR::Vicerrectoría de Acción Social::Trabajo Comunal Universitario (TCU

Optimización de temperatura de anillamiento de PCR multiplex para la detección de Listeria monocytogenes

Listeria monocytogenes is an opportunistic intracellular pathogen that has become one of the most important causes of foodborne infections worldwide. Due to the importance of L. monocytogenes in public health many protocols for the identification and typing of this organism have been described, but for the most part they are very complex and long lasting. For this reason, a multiplex PCR was developed for the rapid and sensitive detection of this bacterium in different types of samples. The objective of the present study was to optimize the multiplex PCR technique for the identification of L. monocytogenes. Different annealing temperatures were tested to determine which has the highest specificity, avoiding nonspecific amplifications. Amplifications were obtained at 57 ° C and lower temperatures. It is concluded that the best temperature for tm is 57 ° C.Listeria monocytogenes es un patógeno intracelular oportunista que se ha convertido en una de las causas más importante de infecciones transmitidas por alimentos en todo el mundo. Debido a la importancia de L. monocytogenes en la salud pública se han descrito muchos protocolos para la identificación y tipificación de este organismo, pero en su mayoría son muy complejos y de larga duración. Por esta razón, se desarrolló un PCR multiplex, para la detección rápida y sensible de esta bacteria en diferentes tipos de muestras. El objetivo del presente estudio fue optimizar la técnica de PCR multiplex para la identificación de L. monocytogenes. Se probaron distintas temperaturas de anillamiento para determinar cuál presenta mayor especificidad, evitando las amplificaciones inespecíficas. Se obtuvo amplificaciones a 57°C y temperaturas menores. Se concluye que la mejor temperatura para tm es la de 57°C

Optimización de temperatura de anillamiento de PCR multiplex para la detección de Listeria monocytogenes

Listeria monocytogenes is an opportunistic intracellular pathogen. It is one of the most important causes of foodborne infections worldwide. Due to the importance of L. monocytogenes in public health many protocols for the identification and typing of this organism have been described, but most of them are very complex and long lasting. For this reason, a multiplex PCR was developed for the rapid and sensitive detection of this bacterium in different types of samples. The objective of the present study was to optimize the multiplex PCR technique for the identification of L. monocytogenes. Different annealing temperatures were tested to determine which has the highest specificity, avoiding nonspecific amplifications. Amplifications were obtained at 57 ° C and lower temperatures. It is concluded that the best temperature for tm is 57 ° CListeria monocytogenes es un patógeno intracelular oportunista que se ha convertido en una de las causas más importantes de infecciones transmitidas por alimentos en todo el mundo. Debido a la relevancia de L. monocytogenes en la salud pública se han descrito muchos protocolos para la identificación y tipificación de este organismo, pero en su mayoría son muy complejos y de larga duración. Por esta razón, se desarrolló un PCR multiplex, para la detección rápida y sensible de esta bacteria en diferentes tipos de muestras. El objetivo del presente estudio fue optimizar la técnica de PCR multiplex para la identificación de L. monocytogenes. Se probaron distintas temperaturas de anillamiento para determinar cuál presentaba mayor especificidad, evitando las amplificaciones inespecíficas. Se obtuvo amplificaciones a 57°C y temperaturas menores. Se concluye que la mejor temperatura para tm es la de 57°C

Proyectos relacionados con diversidad, ecología, desplazamiento, virulencia y potencial biotecnológico de cepas de Listeria spp. aisladas en Costa Rica a partir de muestras alimentarias, clínicas y ambientales

The genus Listeria is composed of more than 15 species, which can be isolated from different environments, including vegetation, soil, water and animals. L. monocytogenes has been studied worldwide as a model of intracellular pathogenesis, which has allowed deciphering important information on the behavior of the pathogen, such as the response to intracellular antibiotic activity, transcription of genes during intracellular life and development of in vivo models for the study of infections. Costa Rica is one of the most biologically rich nations in the world, being of interest for studies of genetic diversity in organisms. Therefore, most studies conducted in the country focus on the isolation of Listeria spp. to determine the presence or absence of the microorganism in samples of interest, being the foodstuffs the most analyzed. The little genetic information on these bacteria, led researchers from the Biotechnology Research Center of TEC, together with national and international collaborators, to carry out the first study on the genetic diversity of Listeria spp. in Costa Rica. Since then the research projects in Listeria spp. that have been developed at the CIB have a scientific scope that allow the understanding of the bacteria present in our environment, their pathogenic potential, traceability, contamination control and biotechnological potential. Likewise, it is intended to maintain and strengthen important national and international collaborations with a view to forming a network oriented to research applied to the sector of food infections in the country.El género Listeria está compuesto por más de 15 especies, que pueden ser aisladas de diferentes ambientes, incluyendo vegetación, suelo, agua y animales. L. monocytogenes ha sido mundialmente estudiada como un modelo de patogénesis intracelular, lo cual ha permitido descifrar información importante sobre el comportamiento del patógeno, como es el caso de la respuesta a la actividad antibiótica intracelular, transcripción de genes durante la vida intracelular y desarrollo de modelos in vivo para el estudio de infecciones. Costa Rica es una de las naciones del mundo más ricas biológicamente siendo de interés para estudios de diversidad genética en organismos. Por lo tanto, la mayoría de los estudios realizados en el país se centran en el aislamiento de Listeria spp. para determinar la presencia o ausencia del microorganismo en muestras de interés, siendo las alimenticias las más analizadas. La poca información genética sobre estas bacterias llevó a que investigadores del Centro de Investigación en Biotecnología del TEC, junto con colaboradores nacionales e internacionales, realizarán el primer estudio sobre la diversidad genética de Listeria spp. en Costa Rica. Desde entonces los proyectos de investigación en Listeria spp. que se han desarrollado actualmente en el CIB tienen un alcance científico que permiten la comprensión de las bacterias presentes en nuestro ambiente, su potencial patogénico, trazabilidad, control de contaminación y potencial biotecnológico. Asimismo, se pretende mantener y fortalecer las colaboraciones importantes tanto nacionales como internacionales con miras a formar una red orientada a la investigación aplicada al sector de las infecciones alimentarias del país

Looking for the Best Fit of a Function over Circadian Rhythm Data

Circadian rhythm regulates many biological processes. In plants, it controls the expression of genes related to growth and development. Recently, the usage of digital image analysis allows monitoring the circadian rhythm in plants, since the circadian rhythm can be observed by the movement of the leaves of a plant during the day. This is important because it can be used as a growth marker to select plants in plant breeding processes and to conduct fundamental science on this topic. In this work, a new algorithm is proposed to classify sets of coordinates to indicate if they show a circadian rhythm movement. Most algorithms take a set of coordinates and produce plots of the circadian movement, however, some databases have sets of coordinates that must be classified before the movement plots. This research presents an algorithm that determines if a set corresponds to a circadian rhythm movement using statistical analysis of polynomial regressions. Results showed that the proposed algorithm is significantly better compared with a Lagrange interpolation and with a fixed degree approaches. The obtained results suggest that using statistical information from the polynomial regressions can improve results in a classification task of circadian rhythm data.UCR::Vicerrectoría de Investigación::Unidades de Investigación::Ciencias Agroalimentarias::Centro para Investigaciones en Granos y Semillas (CIGRAS)UCR::Sedes Regionales::Sede del Atlántic

Physicochemical and Microbial Properties of Dairy Barn Soils: A Case Study in Costa Rican Farm-Associated Soils Harboring the Foodborne Pathogen <i>Listeria monocytogenes</i>

Animal farming activities can influence soil properties that contribute to the survival of foodborne pathogens like the ubiquitous Listeria monocytogenes. However, the presence of this pathogen in farm-associated soils in Costa Rica has not been studied, which might provide new insights regarding the environmental conditions associated with the establishment of this pathogen. In this work, we correlated the presence of L. monocytogenes with the soil physicochemical properties and bacterial community structure of soils associated with livestock activities, including a dairy barn floor (DB) and a slaughterhouse holding pen (SH). A cropland (CL) was included as an example of soil not associated with animal farming practices. We characterized the presence pattern of L. monocytogenes via culture-dependent and culture-independent techniques (i.e., metabarcoding based on 16S rRNA gene sequencing) and conducted a determination of physical, elemental and chemical parameters with Fourier-transform infrared spectroscopy (FT-IR) to statistically determine the soil properties that correlate with L. monocytogenes’ presence in the soil. L. monocytogenes was isolated from DB samples and SH but not from CL. Subsequently, 16S rRNA gene-based metabarcoding showed that the presence of L. monocytogenes was positively correlated with higher bacterial diversity, while physicochemical analyses revealed that the total hydrogen and nitrogen contents of soil organic matter, pH, and electrical conductivity were the main drivers of L. monocytogenes’ presence. Moreover, a CL sample fertilized with animal-derived products showed DB-like physicochemical properties matching conditions in favor of L. monocytogenes’ presence. Hence, our work emphasizes the significance of soil as a primary source for the widespread dissemination of pathogens, particularly underscoring the necessity for improved agricultural practices to prevent cross-contamination with L. monocytogenes. Additionally, we highlight the importance of further understanding the biotic and abiotic factors in facilitating the establishment of L. monocytogenes.</i