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

Búsqueda de genes de resistencia a arsénico en el metagenoma microbiano de la Sabana de Bogotá

El arsénico, como metaloide carcinogénico, de alto riesgo para la salud humana y el medio ambiente, ha incrementado su concentración en varios ecosistemas de la Sabana de Bogotá, especialmente en la cuenca media del Río Bogotá. La alta utilización de pesticidas en los terrenos hortícolas, así como la descarga de aguas de desecho industrial y doméstico han generado condiciones in situ de resistencia y adaptación microbiana a la presión de selección natural de varios contaminantes, metales pesados y metaloides. En este trabajo se realizó una búsqueda de genes involucrados en la resistencia a arsénico, presentes en las comunidades bacterianas endémicas de distintos ambientes de la Sabana de Bogotá, mediante un enfoque metagenómico. Se construyó una librería metagenómica de aproximadamente 50.000 clones a partir de muestras de suelos y sedimentos de la Sabana de Bogotá. Mediante un tamizaje que empleó arsenato como agente de selección, se logró la identificación de 11 clones de resistencia a altas concentraciones de arsénico y se identificaron genes reportados del operón ars, que están involucrados en la reducción de este metaloide.Abstract. Arsenic, as a human and environmental hazardous agent, has raised its concentration in many ecosystems of the Bogota Savannah, especially in the middle basin of the Bogota River. The constant utilization of pesticides in farmlands, together with the discharge of domestic and industrial sewage, has contributed to the generation of in situ processes of microbial resistance and adaptation to those contaminants, including heavy metals and metalloids. A search of arsenic resistance genes present in bacterial endemic communities of distinct ecosystems from the Bogota Savannah was conducted using a metagenomic approach. A soil and sediment based library of about 50.000 clones was performed. An arsenate based functional screening allowed the identification of 11 clones resistant to high arsenic concentrations. Its genomic sequences revealed known genes related to arsenic operon system ars which are involved in arsenic reduction processes.Maestrí

Sistematización del Laboratorio de Creación de la Obra Rojo Festival Brújula al Sur 2017.

La sistematización del laboratorio de creación de la obra Rojo recopila los detalles de la producción y proceso de creación de la obra Rojo en el marco del Festival Internacional Brújula al Sur 2017 del Teatro la Concha de la ciudad de Cali bajo la dirección de Johan Velandia. Además, logra revelar la importancia de contar historias locales a partir de los testimonios de los participantes, entre ellos el de Kevin Mauricio Latorre Valencia, estudiante invitado al proyecto y los documentos de desaparición forzada que existen en el distrito de Buenaventura.PregradoLICENCIADO(A) EN ARTE DRAMÁTIC

The Role of Fur in the Transcriptional and Iron Homeostatic Response of Enterococcus faecalis

The ferric uptake regulator (Fur) plays a major role in controlling the expression of iron homeostasis genes in bacterial organisms. In this work, we fully characterized the capacity of Fur to reconfigure the global transcriptional network and influence iron homeostasis in Enterococcus faecalis. The characterization of the Fur regulon from E. faecalis indicated that this protein (Fur) regulated the expression of genes involved in iron uptake systems, conferring to the system a high level of efficiency and specificity to respond under different iron exposure conditions. An RNAseq assay coupled with a systems biology approach allowed us to identify the first global transcriptional network activated by different iron treatments (excess and limited), with and without the presence of Fur. The results showed that changes in iron availability activated a complex network of transcriptional factors in E. faecalis, among them global regulators such as LysR, ArgR, GalRS, and local regulators, LexA and CopY, which were also stimulated by copper and zinc treatments. The deletion of Fur impacted the expression of genes encoding for ABC transporters, energy production and [Fe-S] proteins, which optimized detoxification and iron uptake under iron excess and limitation, respectively. Finally, considering the close relationship between iron homeostasis and pathogenesis, our data showed that the absence of Fur increased the internal concentration of iron in the bacterium and also affected its ability to produce biofilm. These results open new alternatives in the field of infection mechanisms of E. faecalis

Adopción de la tecnologías digitales en la industria pyme hamburguesera en Bogotá

La industria del e-commerce se encuentra en constante exploración, no solo por las tendencias a nivel global sino también por el constante incentivo de emprendedores de las diferentes industrias y el gobierno. A continuación, se expondrá un análisis de beneficios acerca de los factores con mayor incidencia en la implementación del comercio electrónico en la industria hamburguesera Pyme. La metodología a explorar se basa en la investigación de la literatura actual, el entendimiento de la industria acerca del concepto del comercio electrónico y el interés por parte de los empresarios en adoptarlo, logrando un entendimiento idóneo y certero acerca del momento actual de este método en la industria. Los resultados se adquirieron mediante una investigación cualitativa, la cual consistía en entrevistas cara a cara, adquiriendo puntos de vista tanto de expertos en e-commerce como de empresarios hamburgueseros pyme.Introducción. Revisión de la literatura. Metodología. Resultados. Propuesta. Conclusiones. Referencias. Anexos.Administrador de EmpresasPregrad

Barreras en la interrupción voluntaria del embarazo en Colombia

La consecución y reconocimiento de derechos fundamentales, hacen parte de esa evolución histórica de la humanidad, todo estos avances apoyados en principios como la autodeterminación, la dignidad humana y del libre desarrollo de la personalidad, entre otros; en Colombia la Corte Constitucional a través de la sentencia T-355 de 2006 marca el rumbo histórico de la despenalización del aborto y otorga a las mujeres ese derecho fundamental de decidir voluntariamente sobre la interrupción de su embarazo cuando se esté frente a causales que objetivamente se han establecido. Mediante la dogmática jurídica se analizó la sentencia en cita, al igual que las normas que han permitido su implementación, materialización y los derechos involucrados; así mismo se identificaron los diferentes pronunciamientos que con posterioridad se dieron en la Corte Constitucional y que llegaron a su conocimiento por la revisión a las que fueron sometidas; mostrándose el panorama que ha tenido este tema, y donde se pone en evidencia los obstáculos y barreras impositivas e injustificadas que se han presentado en cuanto a la efectivización de este derecho fundamental.The achievement and recognition of fundamental rights are part of that historical evolution of humanity, all these advances supported by principles such as self-determination, human dignity and the free development of the personality, among others; In Colombia, the Constitutional Court, through ruling T-355 of 2006, marks the historical course of the decriminalization of abortion and grants women that fundamental right to voluntarily decide on the interruption of their pregnancy when faced with causes that objectively have established. Through legal dogmatic, the judgment in question was analyzed, as well as the norms that have allowed its implementation, materialization and the rights involved; Likewise, the different pronouncements that were subsequently given in the Constitutional Court and that came to their attention due to the review to which they were submitted were identified; showing the panorama that this issue has had, and where the obstacles and tax and unjustified barriers that have arisen in terms of the realization of this fundamental right are highlightedIntroducción. -- Tema de investigación y planteamiento del problema. -- pregunta de investigación. -- Justificación. -- Justificación. -- Objetivos de la investigación. -- Objetivo general. -- Objetivos específicos. -- Metodología. -- Marco referencial. -- Marco Teórico. -- Marco histórico. – Marco jurídico. -- Postulados internacionales. -- Postulados nacionales. -- Marco conceptual. -- De la objeción de conciencia. -- Conceptos del ministerio de salud. -- Conceptos de la fiscalía general de la nación. -- Conceptos superintendencia de salud. -- Resultados. -- Conclusiones. -- Referencias bibliográficas

Simultaneous genetic engineering and culture media manipulation improve rh-EPO productivity through lactate re-metabolization on CHO cell culture

Please click Additional Files below to see the full abstract

Comparative EST transcript profiling of peach fruits under different post-harvest conditions reveals candidate genes associated with peach fruit quality

<p>Abstract</p> <p>Background</p> <p>Cold storage is used to inhibit peach fruit ripening during shipment to distant markets. However, this cold storage can negatively affect the quality of the fruit when it is ripened, resulting in disorders such as wooliness, browning or leathering. In order to understand the individual and combined biological effects that factors such as cold storage and ripening have on the fruit and fruit quality, we have taken a comparative EST transcript profiling approach to identify genes that are differentially expressed in response to these factors.</p> <p>Results</p> <p>We sequenced 50,625 Expressed Sequence Tags (ESTs) from peach mesocarp <it>(Prunus persica </it>O'Henry variety) stored at four different postharvest conditions. A total of 10,830 Unigenes (4,169 contigs and 6,661 singletons) were formed by assembling these ESTs. Additionally, a collection of 614 full-length and 1,109 putative full-length cDNA clones within flanking loxP recombination sites was created.</p> <p>Statistically analyzing the EST population, we have identified genes that are differentially expressed during ripening, in response to cold storage or the combined effects of cold storage and ripening. Pair-wise comparisons revealed 197 contigs with at least one significant difference in transcript abundance between at least two conditions. Gene expression profile analyses revealed that the contigs may be classified into 13 different clusters of gene expression patterns. These clusters include groups of contigs that increase or decrease transcript abundance during ripening, in response to cold or ripening plus cold.</p> <p>Conclusion</p> <p>These analyses have enabled us to statistically identify novel genes and gene clusters that are differentially expressed in response to post-harvest factors such as long-term cold storage, ripening or a combination of these two factors. These differentially expressed genes reveal the complex biological processes that are associated with these factors, as well as a large number of putative gene families that may participate differentially in these processes. In particular, these analyzes suggest that woolly fruits lack the increased boost of metabolic processes necessary for ripening. Additionally, these results suggest that the mitochondria and plastids play a major role in these processes. The EST sequences and full-length cDNA clones developed in this work, combined with the large population of differentially expressed genes may serve as useful tools and markers that will enable the scientific community to better define the molecular processes that affect fruit quality in response to post-harvest conditions and the organelles that participate in these processes.</p