39 research outputs found
La construcción de la sociedad del buen vivir en tiempos de globalización (Tema Central)
Good living is more than a way of life of Andean peoples: it is a philosophy, a cosmovision and a form of resistance to the Western model, but they are not the only communities that find answers to daily and social problems and to the manifestations of nature in their millenary wisdom. On the other hand, globalization is the main tool of consumerism that demands unnecessary products, which require the irrational use of natural resources. Consumerism originates waste and squandering. In the throwaway culture, everything ends up in the trash: in the earth or in the oceans. Thus, globalization is at odds with good living, which has as its most important principle: the care of nature. This relationship between globalization and good living, can be redirected for a rapprochement between native cultures and a joint action in an attempt to improve the relationship of human beings with nature. It can also be the platform that makes viable the popular and solidarity economy of good living based on the fair exchange of products. Globalization can be a channel for common actions.El buen vivir es más que un modo de vida de pueblos andinos: es una filosofía, una cosmovisión y una forma de resistencia frente al modelo económico, social y cultural occidental, pero no son las únicas comunidades que encuentran en su sabiduría milenaria respuestas a los problemas cotidianos, sociales y a las manifestaciones de la naturaleza. A su vez, la globalización, al ser la herramienta principal del consumismo y, por ende, del derroche y del desperdicio, que se viabiliza a costa del uso irracional y abusivo de los recursos naturales, antagoniza con el buen vivir que propugna el cuidado de la naturaleza. Esa relación entre globalización y buen vivir que a primera vista resultaría imposible, puede ser reencauzada, en primer lugar, para un acercamiento entre las culturas originarias o no, con similares preocupaciones y objetivos, pero, sobre todo, para una acción conjunta en procura de mejorar y armonizar la relación del ser humano con la naturaleza. También puede ser útil para intercambiar saberes, conocimientos y productos. Puede ser además la plataforma que viabilice esa economía popular y solidaria propia del buen vivir. En suma, la globalización puede ser una ventana a la que se asomen todas las culturas para encauzar acciones comunes
¿Qué sistema tributario para el buen vivir?
El buen vivir, entendido como esa práctica milenaria de nuestros pueblos originarios, está llamado a cumplir un papel orientador de las políticas estatales, por mandato constitucional. Esta tesis busca establecer si las políticas y el sistema tributario en el Ecuador, están dirigidos al cumplimiento de esa filosofía o si, por el contrario, la ignoran. El estado de la situación con respecto de las políticas de protección y cuidado de la naturaleza desde el Estado no podía ser soslayado, porque nos permite identificar el grado de importancia que el pacto social concede a la interrelación ser humanonaturaleza, en forma concreta. A partir de allí, se busca establecer si las normas y principios constitucionales tributarios son idóneos para la consecución del buen vivir; y, en un contexto negativo, indagar sobre el tipo de sistema tributario que podría guardar más coherencia con el buen vivir. Parte importante de esta investigación es evidenciar el decisivo papel que en orden al cumplimiento de este objetivo pueden cumplir los gobiernos autónomos descentralizados y las herramientas que tienen a su alcance para esta finalidad. La relación entre sistema tributario y buen vivir es trascendental, pero ha sido poco valorada y dimensionada. De allí que la investigación se propone llamar la atención respecto de esta conexión estratégica para la construcción del buen vivir
ALTERNATIVE APPROACHES IN MOLECULAR CHARACTERIZATION OF FOODBORNE PATHOGENS: SHIGA TOXIN-PRODUCING Escherichia coli AND Salmonella SEROTYPES
Shiga toxin-producing E. coli (STEC) and Salmonella enterica subspecies enterica (S. enterica) are two major foodborne pathogens. They cause almost 1.5 million of cases of disease each year in the US. Due to their public health impact, development of new methods for their detection and identification are top priority. This research focused on identifying alternative molecular methods and markers for the identification of STEC and Salmonella.
First, a suspension array was developed to simultaneously identify the seven most prevalent STEC (O26, O45, O103, O111, O121, O145, and O157) in the US. The panel targeted genes wzx or wzy and Shigatoxin genes. Testing and optimization employed four to eleven isolates of each serotype in the panel. STEC fluorescence values were 30 to >270 times greater than those of negative controls, demonstrating the method's effectiveness for the molecular serotyping of STEC.
STEC strains (n=194) of 43 serotypes were examined for clustered regularly interspaced short palindromic repeats (CRISPR) arrays to study relatedness among serotypes. A subset of strains (n=81) was analyzed for cas and virulence genes to determine a possible relationship. CRISPR spacer content correlated well with serotypes, although some strains with different serogroup but the same H type shared identical arrays (O26:H11, O103:H11, and O111:H11). cas and virulence genes were not associated, but strains with greater probability of causing outbreaks and disease showed fewer spacers than those less likely to cause them (p<0.05). Therefore, CRISPR array content correlated well with STEC serotype, and CRISPR-cas systems were inversely related to strain virulence potential.
Finally, the CRISPR arrays of 221 S. enterica of 53 serotypes were analyzed to define their relationship. CRISPR-cas systems of 50 S. enterica serotype Bareilly (S. Bareilly) were analyzed to resolve intra-serotype variations. CRISPR arrays correlated well with serotypes, although some serotypes displayed more than one type of array (e.g. S. Bareilly). Additionally, CRISPR-cas system elements reflected S. Bareilly phylogeny, but the array content was not linked to food vehicle or isolate's geographical origin. In conclusion, CRISPR array are useful for designing molecular serotyping assays, but a range of strains should be included to account for variation in S. enterica
Occurrence and enumeration of Campylobacter spp. during the processing of Chilean broilers
<p>Abstract</p> <p>Background</p> <p>Thermotolerant <it>Campylobacter </it>is among the more prevalent bacterial pathogens that cause foodborne diseases. This study aimed at evaluating the occurrence of thermotolerant <it>Campylobacter </it>contamination in chicken carcasses and processing plant stations (chilling water, scalding water, defeathering machinery, evisceration machine, and transport crates) in two of the Chilean main slaughterhouses. In addition, the isolation rates of thermotolerant <it>Campylobacter </it>during evisceration and following chiller processing were compared.</p> <p>Results</p> <p>The overall slaughterhouse contamination with thermotolerant <it>Campylobacter </it>was 54%. Differences were evident when the results from each plant were compared (plant A and plant B was 72% and 36%, respectively). The sampling points with the greatest contamination rates in both plants were after evisceration (90% and 54%, for plants A and B respectively). The decrease of thermotolerant <it>Campylobacter </it>contamination after chilling was significant (2 and 1.6 logs for plant A and B respectively P < 0.05).</p> <p>Conclusion</p> <p>Our findings indicate that chilling process has a limited effect in the final products <it>Campylobacter </it>contamination because poultry enter the slaughter processing with high counts of contamination. This may represent a health risk to consumers, if proper cooking practices are not employed. The levels and frequencies of <it>Campylobacter </it>found during the processing of Chilean poultry appear to be similar to those reported elsewhere in the world.</p
Modelo familiar predominante en padres de familia de la catequesis parroquial
El presente trabajo es consecuencia de una investigación cuyo propósito es determinar las características del modelo familiar que más predomina en los padres de familia participantes de la Catequesis de una Parroquia Católica. Se trata de una investigación de enfoque cuantitativo, tipo descriptivo simple; cuyos resultados de la investigación reflejan que los encuestados mostraron características de los tres modelos de familia (economicista, sociológico y antropológico), con cierta tendencia a predominar el modelo antropológico en las concepciones referidas a las sub dimensiones: relaciones conyugales y relaciones sociales. 
Microbiological Quality and Presence of Foodborne Pathogens in Raw and Extruded Canine Diets and Canine Fecal Samples
Pet food can be a source of microbiological hazards that might affect companion animals and owners. Even though owners usually rely on conventional pet diets, such as extruded diets, new feeding practices, such as raw meat-based diets (RMBDs), have grown. RMBDs' benefits are still scientifically uncertain, while its risks have been documented. The use of canine RMBDs might increase the exposure to zoonotic pathogens, such as Salmonella spp., Listeria monocytogenes, Campylobacter spp., among others. Identifying pathogen prevalence in canine food and pets is required to contribute to public health measures. The aims of this study were: (1) to compare the microbiological quality of RMBDs and extruded diets (2) to identify and compare the prevalence of Salmonella spp., Campylobacter jejuni, and L. monocytogenes from raw and extruded canine diets and canine fecal samples, and (3) to characterize pet owners according to the diet chosen to be used on their pets, their motivations for using RMBDs, and their knowledge about benefits and risks related to this feeding practice. Conventional and molecular microbiological methods were used to identify pathogen presence from food and fecal samples, while pulsed-field gel electrophoresis (PFGE) was performed to evaluate the clonal relationship between isolates. Aerobic plate counts for RMBDs were higher than those detected for extruded diets. Salmonella spp. and L. monocytogenes were isolated from 35.7% (15/42) RMBDs, while Salmonella spp., C. jejuni, and L. monocytogenes from 33.3% (11/33) fecal samples from RMBD-fed dogs. From the RMBD samples positive to Salmonella spp., chicken was the main meat ingredient composing the diets. PFGE analysis confirmed a genetic association between Salmonella spp. isolates from fecal and raw food samples from the same household. We did not detect pathogens from extruded food samples or feces from extruded-fed dogs. Using a survey, we identified dog owners' unawareness and/or underestimation of risks related to RMBDs. We demonstrated that canine raw pet food might be a source of zoonotic foodborne pathogens that represent a health risk for both humans and pets. While clinical findings caused by the mentioned pathogens vary among pets, the zoonotic potential implies a significant concern
The Combined Effect of Cold and Copper Stresses on the Proliferation and Transcriptional Response of Listeria monocytogenes
Listeria monocytogenes is a foodborne pathogen that can cause severe disease in susceptible humans. This microorganism has the ability to adapt to hostile environmental conditions such as the low temperatures used by the food industry for controlling microorganisms. Bacteria are able to adjust their transcriptional response to adapt to stressful conditions in order to maintain cell homeostasis. Understanding the transcriptional response of L. monocytogenes to stressing conditions could be relevant to develop new strategies to control the pathogen. A possible alternative for controlling microorganisms in the food industry could be to use copper as an antimicrobial agent. The present study characterized three L. monocytogenes strains (List2-2, Apa13-2, and Al152-2A) adapted to low temperature and challenged with different copper concentrations. Similar MIC-Cu values were observed among studied strains, but growth kinetic parameters revealed that strain List2-2 was the least affected by the presence of copper at 8°C. This strain was selected for a global transcriptional response study after a 1 h exposition to 0.5 mM of CuSO4 × 5H2O at 8 and 37°C. The results showed that L. monocytogenes apparently decreases its metabolism in response to copper, and this reduction is greater at 8°C than at 37°C. The most affected metabolic pathways were carbohydrates, lipids and nucleotides synthesis. Finally, 15 genes were selected to evaluate the conservation of the transcriptional response in the other two strains. Results indicated that only genes related to copper homeostasis showed a high degree of conservation between the strains studied, suggesting that a low number of genes is implicated in the response to copper stress in L. monocytogenes. These results contribute to the understanding of the molecular mechanisms used by bacteria to overcome a combination of stresses. This study concluded that the application of copper in low concentrations in cold environments may help to control foodborne pathogens as L. monocytogenes in the industry
Probiotic Yeasts and Vibrio anguillarum Infection Modify the Microbiome of Zebrafish Larvae
The host microbiome plays an essential role in health and disease. Microbiome modification by pathogens or probiotics has been poorly explored especially in the case of probiotic yeasts. Next-generation sequencing currently provides the best tools for their characterization. Debaryomyces hansenii 97 (D. hansenii 97) and Yarrowia lipolytica 242 (Y. lipolytica 242) are yeasts that protect wildtype zebrafish (Danio rerio) larvae against a Vibrio anguillarum (V. anguillarum) infection, increasing their survival rate. We investigate the effect of these microorganisms on the microbiome and neutrophil response (inflammation) in zebrafish larvae line Tg(Bacmpx:GFP)i114. We postulated that preinoculation of larvae with yeasts would attenuate the intestinal neutrophil response and prevent modification of the larval microbiome induced by the pathogen. Microbiome study was performed by sequencing the V3-V4 region of the 16S rRNA gene and prediction of metabolic pathways by Piphillin in conventionally raised larvae. Survival and the neutrophil response were both evaluated in conventional and germ-free conditions. V. anguillarum infection resulted in higher neutrophil number in the intestinal area compared to non-infected larvae in both conditions. In germ-free conditions, infected larvae pre-inoculated with yeasts showed fewer neutrophil numbers than infected larvae. In both conditions, only D. hansenii 97 increased the survival of infected larvae. Beta diversity of the microbiota was modified by V. anguillarum and both yeasts, compared to non-inoculated larvae. At 3 days post-infection, V. anguillarum modified the relative abundance of 10 genera, and pre-inoculation with D. hansenii 97 and Y. lipolytica 242 prevented the modification of 5 and 6 of these genera, respectively. Both yeasts prevent the increase of Ensifer and Vogesella identified as negative predictors for larval survival (accounting for 40 and 27 of the variance, respectively). In addition, yeast pre-inoculation prevents changes in some metabolic pathways altered by V. anguillarum’s infection. These results suggest that both yeasts and V. anguillarum can shape the larval microbiota configuration in the early developmental stage of D. rerio. Moreover, modulation of key taxa or metabolic pathways of the larval microbiome by yeasts can be associated with the survival of infected larvae. This study contributes to the understanding of yeast–pathogen–microbiome interactions, although further studies are needed to elucidate the mechanisms involved
Robust estimation of bacterial cell count from optical density
Optical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data