Role of plant compounds in the modulation of the conjugative transfer of pRet42a

One of the most studied mechanisms involved in bacterial evolution and diversification is conjugative transfer (CT) of plasmids. Plasmids able to transfer by CT often encode beneficial traits for bacterial survival under specific environmental conditions. Rhizobium etli CFN42 is a Gram-negative bacterium of agricultural relevance due to its symbiotic association with Phaseolus vulgaris through the formation of Nitrogen-fixing nodules. The genome of R. etli CFN42 consists of one chromosome and six large plasmids. Among these, pRet42a has been identified as a conjugative plasmid. The expression of the transfer genes is regulated by a quorum sensing (QS) system that includes a traI gene, which encodes an acyl-homoserine lactone (AHL) synthase and two transcriptional regulators (TraR and CinR). Recently, we have shown that pRet42a can perform CT on the root surface and inside nodules. The aim of this work was to determine the role of plant-related compounds in the CT of pRet42a. We found that bean root exudates or root and nodule extracts induce the CT of pRet42a in the plant rhizosphere. One possibility is that these compounds are used as nutrients, allowing the bacteria to increase their growth rate and reach the population density leading to the activation of the QS system in a shorter time. We tested if P. vulgaris compounds could substitute the bacterial AHL synthesized by TraI, to activate the conjugation machinery. The results showed that the transfer of pRet42a in the presence of the plant is dependent on the bacterial QS system, which cannot be substituted by plant compounds. Additionally, individual compounds of the plant exudates were evaluated; among these, some increased and others decreased the CT. With these results, we suggest that the plant could participate at different levels to modulate the CT, and that some compounds could be activating genes in the conjugation machinery.Fil: Bañuelos Vazquez, Luis Alfredo. Universidad Nacional Autónoma de México; MéxicoFil: Castellani, Lucas Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Luchetti, Abril. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Romero, David. Universidad Nacional Autónoma de México; MéxicoFil: Torres Tejerizo, Gonzalo Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Brom, Susana. Universidad Nacional Autónoma de México; Méxic

Impactos del cambio climático sobre los rendimientos del arroz (Oryza sativa L.) en la Zona Llanos, Colombia

The effects of climate change on strategic sectors of local economies have become a priority for governments, scientists and academics in recent decades. In this sense, the objective of the present study was to estimate the relationship of dryland rice yields with climatic and economic variables. For this, the ordinary least squares method was applied, using a database corresponding to the period 1990 to 2016 of the rice producing area called Llanos in Colombia. Among the results it is highlighted that the maximum temperature has significant effects, while deficits or excess rainfall have a negative impact on rice yield. Likewise, cultural tasks such as preparing the land have adverse effects on rice yield, while the use of fertilizers positively affects them. Finally, it is concluded that the impacts of climate change on production yields will depend on the magnitude of the change in climate variables, as well as adaptation strategies that lead to the development of good agricultural practices and efficient use of resources.Los efectos del cambio climático sobre sectores estratégicos de las economías locales se han convertido en una prioridad de los gobiernos, científicos y académicos en las últimas décadas. En este sentido, el objetivo del presente estudio consistió en estimar la relación de los rendimientos del arroz secano con variables de tipo climáticas y económicas. Para esto, se aplicó el método de mínimos cuadrados ordinarios, utilizando una base de datos correspondiente al periodo 1990 a 2016 de la zona productora de arroz denominada Llanos en Colombia.  Entre los resultados se destaca que la temperatura máxima tiene efectos significativos, mientras que déficits o exceso de las precipitaciones tienen un impacto negativo en el rendimiento del arroz. Asimismo, labores culturales como la preparación del terreno presenta efectos adversos sobre el rendimiento del arroz, mientras que el uso de fertilizantes los afecta positivamente. Finalmente, se concluye que los impactos del cambio climático sobre los rendimientos de la producción dependerán de la magnitud del cambio de las variables climáticas, así como las estrategias de adaptación que conduzcan al desarrollo de buenas prácticas agrícolas y uso eficiente de los recursos

Relevance of Individual Data When Assessing the Gastrointestinal Nematode Infection Level, Nutritional and Productive Variables in a Tropical Farm Context: The Median Isn’t the Message

We evaluated the relationship between individual and herd GIN infection level, nutrition, production performance and anemia parameters in a tropical farm context. Fifty-four female goats were monitored to assess their body condition score (BCS, nutritional status indicator), live weight (LW) and LW gain (LWG, both used as production level indicators), FAMACHA© and hematocrit (HT, both used as anemia indicators). Goats browsed for 4 h in a tropical forest and received balanced feed and chopped grass. The eggs per gram of feces (EPG) indicated the GIN burden, with fecal samples obtained at 7:00 (AM) and 15:00 h (PM.) from each goat at six sampling points during the study. The variables and their relationship with GIN burdens were analyzed using Kruskall–Wallis, ANOVA and Friedman tests and Spearman correlations. The fecal samples obtained in the AM and PM can be equally representative of parasitic burdens (similar and highly correlated). However, the EPG of individual goats from periods of 30 days apart can be considered independent. The BCS and LWG varied between sampling times (p \u3c 0.05), whereas EPG, LW and HT did not (p \u3e 0.05). The GIN burden was negatively correlated with HT and BCS (−0.21, p = 0.01 for each one). The individual pattern of infection demonstrates the true impact of GINs on their hosts. Additionally, feeding and nutritional status may present important variations influencing the performance of the goats more than the impact of GINs under the farm conditions of the present study. However, GIN infection contributed to the variation in goat health and productivity in this tropical farm

Transfer of the symbiotic plasmid of rhizobium etli CFN42 to endophytic bacteria inside nodules

Conjugative transfer is one of the mechanisms allowing diversification and evolution ofbacteria. Rhizobium etli CFN42 is a bacterial strain whose habitat is the rhizosphere andis able to form nodules as a result of the nitrogen-fixing symbiotic relationship it mayestablish with the roots of Phaseolus vulgaris. R. etli CFN42 contains one chromosomeand six large plasmids (pRet42a ? pRet42f). Most of the genetic information involvedin the establishment of the symbiosis is localized on plasmid pRet42d, named asthe symbiotic plasmid (pSym). This plasmid is able to perform conjugation, usingpSym encoded transfer genes controlled by the RctA/RctB system. Another plasmidof CFN42, pRet42a, has been shown to perform conjugative transfer not only in vitro,but also on the surface of roots and inside nodules, using other rhizobia as recipients.In addition to the rhizobia involved in the formation of nodules, these structures havebeen shown to contain endophytic bacteria from different genera and species. Inthis work, we have explored the conjugative transfer of the pSym (pRet42d) fromR. etli CFN42 to endophytic bacteria as putative recipients, using as donor a CFN42derivative labeled with GFP in the pRet42d and RFP in the chromosome. We wereable to isolate some transconjugants, which inherit the GFP, but not the RFP marker.Some of them were identified, analyzed and evaluated for their ability to nodulate.We found transconjugants from genera such as Stenotrophomonas, Achromobacter,and Bacillus, among others. Although all the transconjugants carried the GFP marker,and nod, fix, and nif genes from pRet42d, not all were able to nodulate. Ultrastructuremicroscopy analysis showed some differences in the structure of the nodules of one ofthe transconjugants. A replicon of the size of pRet42d (371 Kb) could not be visualizedin the transconjugants, suggesting that the pSym or a segment of the plasmid isintegrated in the chromosome of the recipients. These findings strengthen the proposalthat nodules constitute a propitious environment for exchange of genetic informationamong bacteria, in addition to their function as structures where nitrogen fixation andassimilation takes placeFil: Bañuelos Vazquez, Luis Alfredo. Universidad Nacional Autónoma de México; MéxicoFil: Cazares, Daniel. Universidad Nacional Autónoma de México; MéxicoFil: Rodríguez, Susana. Universidad Nacional Autónoma de México; MéxicoFil: Cervantes De la Luz, Laura. Universidad Nacional Autónoma de México; MéxicoFil: Sánchez López, Rosana. Universidad Nacional Autónoma de México; MéxicoFil: Castellani, Lucas Gabriel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Torres Tejerizo, Gonzalo Arturo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata. Instituto de Biotecnología y Biología Molecular. Universidad Nacional de La Plata. Facultad de Ciencias Exactas. Instituto de Biotecnología y Biología Molecular; ArgentinaFil: Brom, Susana. Universidad Nacional Autónoma de México; Méxic

"HIV therapy adherence and outcomes in Peruvian military personnel over a 30-year period"

"Objectives: We aimed to describe the sociodemographic, clinical, and therapeutic characteristics of Peruvian military personnel diagnosed with HIV. Furthermore, we determined the frequency of highly active antiretroviral therapy (HAART) adherence, the complications and mortality. Methods: We retrospectively reviewed the medical records of patients diagnosed with HIV, confirmed by Western blot at a single institution from 1989-2020. Descriptive analyses were performed for all the variables using mean and standard deviation (SD) in the case of quantitative variables, and frequency and percentage for qualitative variables. Results:Ofthe 161 patients included, 95.7% were males and the mean age was 39.59 years (SD= 16.45 years). Most had college or higher education (67.7%) and were on active duty at diagnosis (77%). 35.4% had AIDS at diagnosis; 28.6% opportunistic infections; and 8.1% tuberculosis. The median follow-up was five years. 94.4% of the patients received HAART as the principal treatment; of these, 88.8% was adherent to treatment, and death was reported in 6.8%. There were no factors associated with adherence. Conclusions: Although the sociodemographic characteristics of Peruvian military personnel are similar to those of other countries, our findings suggest that Peruvian military personnel present higher adherence to HAART compared to previous studies in other military populations from South American countries. Further studies are recommended to assess specific factors attributed to these successful outcomes in the military personnelthat can be applied in other hospitals

Contributions to the INIFAP technology transfer 35 years after its creation / Contribuições para a transferência de tecnologia INIFAP 35 anos após a sua criação

The main contributions that INIFAP has made in the transfer of technologies and knowledge, in support of the rural population of Mexico, are presented, the most outstanding models within the national and international scope that researchers have put into operation and their main results are detailed. Undoubtedly, the institutional contributions to the programs of the Ministry of Agriculture and Rural Development have marked a watershed between the traditional models or what "what occurred to him" to the researcher in contrast to the participatory and inclusive models to contribute to the substantial improvement of the productive processes, the family economy and for the agribusiness

Análisis de la eficiencia técnica de las empresas manufactureras en Villavicencio (Colombia)

The manufacturing sector is central for the economic development of a region given the technological progress it incorporates and the multiplier effect it has on other economic sector. This article aims to analyze the behavior of the technical efficiency of firms located in Villavicencio (Meta). In addition, the empirical approach allows comparing with other 9 capital cities in Colombia. This is a quantitative, non-experimental, longitudinal study and trend design that uses the non-parametric method of Data Envelopment Analysis (DEA) to estimate technical efficiencies using the Annual Manufacturing Survey carried out by the National Statistical Office (DANE). We identify three inputs: permanent staff salaries, intermediate consumption, and fixed assets; and as output the value of sales. Technical efficiency of Villavicencio businesses has grown in recent years, as result of adjustments in fixed assets and staff salaries, and their annual growth rate has been higher when compared to other cities. We conclude that the achievement of greater efficiency is linked to the flexibility of companies to adjust their factors to production levels.La industria es un sector central para el desarrollo económico de una región debido al progreso tecnológico que incorpora y el efecto multiplicador que tiene en la economía. Este artículo se propone analizar el comportamiento de la eficiencia técnica de las empresas manufactureras de la ciudad de Villavicencio (Meta) para realizar algunas aproximaciones teóricas y empíricas y comparaciones entre 9 ciudades colombianas. Este es un estudio cuantitativo, que utiliza el método no paramétrico de Análisis Envolvente de Datos (DEA) para estimar la eficiencia técnica a partir de las cifras de la Encuesta Anual Manufacturera que realiza el Departamento Administrativo Nacional de Estadística (DANE). Se toman tres inputs: salarios del personal permanente, consumo intermedio y activos fijos; y como output el valor de las ventas. Se encuentra que la eficiencia técnica de las empresas de Villavicencio ha crecido los últimos años, producto de ajustes en los activos fijos y los salarios del personal, y su tasa de crecimiento anual ha sido más alta que el de las 9 ciudades analizadas. Se concluye que la mayor eficiencia está vinculado a la flexibilidad de las empresas para ajustar sus factores a los niveles de producción

Antioxidant and antidiabetic activity and phytoconstituents of lichen extracts with temperate and polar distribution

The objective of this research was to characterize the chemical composition of ethanolic extracts of the lichen species Placopsis contortuplicata, Ochrolechia frigida, and Umbilicaria antarctica, their antioxidant activity, and enzymatic inhibition through in vitro and molecular docking analysis. In total phenol content, FRAP, ORAC, and DPPH assays, the extracts showed significant antioxidant activity, and in in vitro assays for the inhibition of pancreatic lipase, α-glucosidase, and α-amylase enzymes, together with in silico studies for the prediction of pharmacokinetic properties, toxicity risks, and intermolecular interactions of compounds, the extracts evidenced inhibitory potential. A total of 13 compounds were identified by UHPLC-ESI-QTOF-MS in P. contortuplicata, 18 compounds in O. frigida, and 12 compounds in U. antarctica. This study contributes to the knowledge of the pool of bioactive compounds present in lichens of temperate and polar distribution and biological characteristics that increase interest in the discovery of natural products that offer alternatives for treatment studies of diseases related to oxidative stress and metabolic syndrome

Genomic diversity of burkholderia pseudomalleiIsolates, Colombia

We report an analysis of the genomic diversity of isolates of Burkholderia pseudomallei, the cause of melioidosis, recovered in Colombia from routine surveillance during 2016–2017. B. pseudomallei appears genetically diverse, suggesting it is well established and has spread across the region