The three-dimensional structure of DapE from Enterococcus faecium reveals new insights into DapE/ArgE subfamily ligand specificity.

DapE is a Zn2+-metallohydrolase recognized as a drug target for bacterial control. It is a homodimer that requires the exchange of interface strands by an induced fit essential for catalysis. Identifying novel anti-DapE agents requires greater structural details. Most of the characterized DapEs are from the Gram-negative group. Here, two high-resolution DapE crystal structures from Enterococcus faecium are presented for the first time with novel aspects. A loosened enzyme intermediate between the open and closed conformations is observed. Substrates may bind to loose state, subsequently it closes, where hydrolysis occurs, and finally, the change to the open state leads to the release of the products. Mutation of His352 suggests a role, along with His194, in the oxyanion stabilization in the mono-metalated Zn2+ isoform, while in the di-metalated isoform, the metal center 2 complements it function. An aromatic-π box potentially involved in the interaction of DapE with other proteins, and a peptide flip could determine the specificity in the Gram-positive ArgE/DapE group. Finally, details of two extra-catalytic cavities whose geometry changes depending on the conformational state of the enzyme are presented. These cavities could be a target for developing non-competitive agents that trap the enzyme in an inactive state.

In Vitro Evaluation of Anti-Rotaviral Activity and Intestinal Toxicity of a Phytotherapeutic Prototype of Achyrocline bogotensis (Kunth) DC.

Viruses represent the primary etiologic agents (70-80%) of acute diarrheal disease (ADD), and rotavirus (RV) is the most relevant one. Currently, four rotavirus vaccines are available. However, these vaccines do not protect against emerging viral strains or are not available in low-income countries. To date, there are no approved drugs available against rotavirus infection. In this study, we evaluated the in vitro anti-rotaviral activity and intestinal toxicity of a phytotherapeutic prototype obtained from Achyrocline bogotensis (Kunth) DC. (PPAb); medicinal plant that contains compounds that inhibit the rotavirus replication cycle. Virucidal and viral yield reduction effects exerted by the PPAb were evaluated by immunocytochemistry and flow cytometry. Furthermore, the toxic impact of the PPAb was evaluated in polarized human intestinal epithelial C2BBe1 cells in terms of cytotoxicity, loss of cytoplasmic membrane asymmetry, and DNA fragmentation by MTT and fluorometry. PPAb concentrations under 0.49 mg/mL exerted significant virucidal and viral yield reduction activities, and concentrations under 16 mg/mL neither reduced cell viability, produced DNA fragmentation, nor compromised the C2BBe1cell membrane stability after 24-h incubation. Based on these results, the evaluated phytotherapeutic prototype of Achyrocline bogotensis might be considered as a promising alternative to treat ADD caused by rotavirus.

Detection of Toxoplasma gondii in water for human consumption from water wells (jagüeyes) in the rural area of the municipality of Sincelejo / [Detección de Toxoplasma gondii en agua para el consumo humano proveniente de jagüeyes del área rural del municipio de Sincelejo].

Introduction: Toxoplasmosis is an orally-transmitted zoonosis that may appear after consuming food contaminated with any infective form of Toxoplasma gondii. Its transmission by water has been reported in several countries including Colombia. The rural population of Sincelejo could be at risk of contracting toxoplasmosis through this route given that they lack potable water. Objective: To evaluate T. gondii contamination in water for human consumption from water wells (jagüeyes) in the rural area of Sincelejo and establish its relationship with different social determinants of health in the study area. Materials and methods: Using nested PCR we evaluated 96 water samples obtained from 48 farms located in eight rural townships in Sincelejo. We took two samples in each farm: one of raw water from water wells and the other intended for direct consumption. We conducted a survey on each farm to collect information on the physical characteristics of dwellings, the presence of cats, and the availability and uses of water. Statistical relationships were evaluated through Fisher tests. Results: Of the 96 samples analyzed, 13 were contaminated with T. gondii (13.5%): Nine corresponded to raw water and four to water for direct consumption. No statistical association was found between the positive samples and the social determinants of health under evaluation (p>0.05). Conclusion: The rural population of Sincelejo could be at risk of contracting toxoplasmosis through the use and/or consumption of water from its water wells. The contamination of these water bodies by T. gondii may be influenced by unstudied social determinants.

Introducción. La toxoplasmosis es una zoonosis que se transmite por vía oral al consumir alimentos contaminados con cualquier forma infectiva de Toxoplasma gondii. Su transmisión por agua ha sido documentada en varios países, incluido Colombia. Al no disponer de agua potable, la población rural de Sincelejo podría estar en riesgo de contraer toxoplasmosis por esta vía. Objetivo. Evaluar la contaminación por T. gondii del agua para consumo humano proveniente de jagüeyes de la zona rural de Sincelejo y establecer su relación con diferentes determinantes sociales de la salud en el área de estudio. Materiales y métodos. Mediante PCR anidada, se evaluaron 96 muestras de agua obtenidas en 48 fincas ubicadas en ocho corregimientos rurales de Sincelejo. En cada finca se obtuvieron dos muestras: una de agua cruda de jagüey y otra destinada al consumo directo. En cada finca se hizo una encuesta para recolectar información sobre características físicas de la vivienda, presencia de gatos, y disponibilidad de agua y sus usos. Las relaciones estadísticas se evaluaron con el test de Fisher. Resultados. De las 96 muestras analizadas, 13 resultaron contaminadas con T. gondii (13,5 %): nueve de agua cruda y cuatro de agua para el consumo directo. No se encontró asociación estadística entre las muestras positivas y los determinantes sociales de la salud evaluados (p>0,05). Conclusión. La población rural de Sincelejo podría estar en riesgo de contraer toxoplasmosis por el uso y consumo del agua proveniente de sus jagüeyes. La contaminación de estos cuerpos de agua por T. gondii puede estar influenciada por otros determinantes sociales de la salud no contemplados aquí.

In vitro antimicrobial activity of Caesalpinia coriaria (Jacq. ) Willd extracts on Streptococcus pyogenes and Candida albicans / Actividad antimicrobiana in vitro de extractos de Caesalpinia coriaria (Jacq. ) Willd sobre Streptococcus pyogenes y Candida albicans

Background: "Dividivi" Caesalpinia coriaria (Jacq.) Willd fruits are traditionally used by the Wayuú community in La Guajira (Colombia) to treat oral and skin cavity diseases caused by bacteria and fungi. Streptococcus pyogenes is a gram-positive cocci of group A (beta-hemolytic) that is the cause of pharyngeal disease, scarlet fever, cellulitis, erysipelas, or toxic shock-like syndrome. Alternatively, Candida albicans is a yeast-like fungus that is a normal flora of the digestive tract, vagina, or skin folds; it has been known to be the root cause of opportunistic diseases such as diaper rash, oral and esophagus thrush, or vulvovaginitis. Objective: This study evaluated the antimicrobial activity of methanolic and ethanolic extracts of C. coriaria (Jacq.) Willddry fruits on S. pyogenes ATCC 12384andC. albicans ATTC 14053. Method: C. coriaria extracts were obtained from the Soxhlet method using two solvents (methanol and ethanol 98%) prepared from pulverized fruits. A phytochemical test and an antimicrobial activity assay were performed using the obtained extracts and tested using S. pyogenes ATCC 12384 and C. albicans ATTC 14053 strains. Results: A phytochemical profile was performed, examining the presence of bioactive metabolites (tannins, alkaloids, glycosides, saponins, and anthraquinones) from each extract. Antimicrobial susceptibility tests showed that the ethanolic extract inhibited S. pyogenes ATCC 12384,causing inhibition halos of 14.1 ± 0.1 mm and a Minimum Inhibitory Concentration (MIC) of 172 mg/ml, and C. albicans test shows inhibition halos of 16.1 ± 0.2 mm and MIC of 212 mg/ml. Additionally, the methanolic extract inhibited S. pyogenes with inhibition halos of 15.2 ± 0.2 mm and MIC of 152 mg/ml; no inhibitory effect was observed on C. albicans.Conclusion: This study revealed that C. coriaria has an antimicrobial effect on the tested species opening the field of its possible use as a therapeutic agent

Introducción: Los frutos del "Dividivi" Caesalpinia coriaria (Jacq.) Willd son usados tradicionalmente por la comunidad indígena Wayuú en La Guajira (Colombia) para el tratamiento de enfermedades de la cavidad bucal y cutáneas ocasionadas por bacterias y hongos. Streptococcuspyogenes es un coco grampositivo del grupo A (beta-hemolítico) que es la causa de enfermedad faríngea, escarlatina, celulitis, erisipela o síndrome tipo shock tóxico. Candida albicans es un hongo levaduriforme que es flora normal del tracto digestivo, la vagina o los pliegues de la piel; se sabe que es la causa principal de enfermedades oportunistas como la dermatitis del pañal, aftas bucales y esofágicas, o vulvovaginitis. Objetivo: El objetivo de este estudio fue evaluar la actividad antimicrobiana de extractos metanólicos y etanólicos de frutos secos sobre microorganismos patógenos específicamente S. pyogenes ATCC 12384yC. albicansATTC 14053. Método: A partir de frutos polverizados de C. coriaria, usando el método Soxlet, se evaluaron dos solventes (metanol y etanol al 98%), los cuales, fueron usados para estudiar su actividad antimicrobiana evaluando su efecto en cepas de S. pyogenes ATCC 12384 y C. albicans ATTC 14053. Resultados: Mediante un perfil fitoquímico se determinó la presencia de grupos de metabolitos secundarios con compuestos bioactivos (taninos, alcaloides, glucósidos, saponinas, y antraquinonas). Las pruebas de sensibilidad antimicrobiana mostraron que el extracto etanólico tuvo un efecto inhibidor sobre S. pyogenesATCC 12384 con halos de inhibición de 14.1 ± 0.1 mm y una concentración mínima inhibitoria (CMI) de 172 mg/mL, y sobre C. albicans se presentaron halos de inhibición de 16.1 ± 0.2 mm y CMI de 212 mg/mL, mientras que el extracto metanólico tuvo un efecto inhibidor sobre S. pyogenes con halos de inhibición de 15.2 ± 0.2 mm y CMI de 152 mg/mL no se observó efecto inhibidor sobre C. albicans. Conclusión: Este estudio demostró que C. coriaria tiene efecto antimicrobiano en las especies evaluadas, abriendo un campo de investigación en la evaluación de su uso como agente terapéutico

Detección de Toxoplasma gondii en agua para el consumo humano proveniente de jagüeyes del área rural del municipio de Sincelejo / Detection of Toxoplasma gondii in water for human consumption from water wells (jagüeyes) in the rural area of the municipality of Sincelejo

Resumen | Introducción. La toxoplasmosis es una zoonosis que se transmite por vía oral al consumir alimentos contaminados con cualquier forma infectiva de Toxoplasma gondii. Su transmisión por agua ha sido documentada en varios países, incluido Colombia. Al no disponer de agua potable, la población rural de Sincelejo podría estar en riesgo de contraer toxoplasmosis por esta vía. Objetivo. Evaluar la contaminación por T. gondii del agua para consumo humano proveniente de jagüeyes de la zona rural de Sincelejo y establecer su relación con diferentes determinantes sociales de la salud en el área de estudio. Materiales y métodos. Mediante PCR anidada, se evaluaron 96 muestras de agua obtenidas en 48 fincas ubicadas en ocho corregimientos rurales de Sincelejo. En cada finca se obtuvieron dos muestras: una de agua cruda de jagüey y otra destinada al consumo directo. En cada finca se hizo una encuesta para recolectar información sobre características físicas de la vivienda, presencia de gatos, y disponibilidad de agua y sus usos. Las relaciones estadísticas se evaluaron con el test de Fisher. Resultados. De las 96 muestras analizadas, 13 resultaron contaminadas con T. gondii(13,5 %): nueve de agua cruda y cuatro de agua para el consumo directo. No se encontró asociación estadística entre las muestras positivas y los determinantes sociales de la salud evaluados (p>0,05). Conclusión. La población rural de Sincelejo podría estar en riesgo de contraer toxoplasmosis por el uso y consumo del agua proveniente de sus jagüeyes. La contaminación de estos cuerpos de agua por T. gondii puede estar influenciada por otros determinantes sociales de la salud no contemplados aquí.

Abstract | Introduction:Toxoplasmosis is an orally-transmitted zoonosis that may appear after consuming food contaminated with any infective form of Toxoplasma gondii. Its transmission by water has been reported in several countries including Colombia. The rural population of Sincelejo could be at risk of contracting toxoplasmosis through this route given that they lack potable water. Objective: To evaluate T. gondii contamination in water for human consumption from water wells (jagüeyes) in the rural area of Sincelejo and establish its relationship with different social determinants of health in the study area. Materials and methods: Using nested PCR we evaluated 96 water samples obtained from 48 farms located in eight rural townships in Sincelejo. We took two samples in each farm: one of raw water from water wells and the other intended for direct consumption. We conducted a survey on each farm to collect information on the physical characteristics of dwellings, the presence of cats, and the availability and uses of water. Statistical relationships were evaluated through Fisher tests. Results: Of the 96 samples analyzed, 13 were contaminated with T. gondii (13.5%): Nine corresponded to raw water and four to water for direct consumption. No statistical association was found between the positive samples and the social determinants of health under evaluation (p>0.05). Conclusion: The rural population of Sincelejo could be at risk of contracting toxoplasmosis through the use and/or consumption of water from its water wells. The contamination of these water bodies by T. gondii may be influenced by unstudied social determinants.

Simultaneous transcriptome analysis of oil palm clones and Phytophthora palmivora reveals oil palm defense strategies.

Phytophthora palmivora is an oomycete that causes oil palm bud rot disease. To understand the molecular mechanisms of this disease, palm clones with contrasting responses (Ortet 34, resistant and Ortet 57, susceptible) were inoculated with P. palmivora, and RNAseq gene expression analysis was performed. The transcriptome was obtained by sequencing using Illumina HiSeq2500 technology during the asymptomatic phase (24, 72 and 120 hours postinfection, hpi). A simultaneous analysis of differentially expressed gene (DEG) profiles in palm and P. palmivora was carried out. Additionally, Gene Ontology (GO) and gene network analysis revealed differences in the transcriptional profile of the two ortets, where a high specificity of the pathogen to colonize the susceptible ortet was found. The transcriptional analysis provided an overview of the genes involved in the recognition and signaling of this pathosystem, where different transcription factors, phytohormones, proteins associated with cell wall hardening and nitrogen metabolism contribute to the resistance of oil palm to P. palmivora. This research provides a description of the molecular response of oil palm to P. palmivora, thus becoming an important source of molecular markers for the study of genotypes resistant to bud rot disease.

Detección de Toxoplasma gondii por amplificación del gen B1 en carnes de consumo humano / Toxoplasma gondii detection by gene B1 amplification in meat human consumption

Objetivo: Determinar la frecuencia de formas parasitarias de Toxoplasma gondii (T. gondii) en diferentes tipos de carne de consumo humano comercializadas en Sincelejo-Sucre, mediante la amplificación del gen B1 por la técnica de reacción en cadena de la polimerasa (PCR). Materiales y métodos: Se realizó un estudio descriptivo que determinó la infección por Toxoplasma gondii , en 120 muestras de carnes de consumo humano, obtenidas en 2 tipos de expendios del municipio de Sincelejo. De cada sector se tomaron 60 muestras distribuidas así: 20 muestras de carne de res, 20 muestras de carne de cerdo y 20 muestras de carne de pollo. Estas muestras fueron sometidas a una extracción de ADN mediante el método de altas concentraciones de sales y a una PCR anidada para amplificar una región específica del material genómico de T. gondii correspondiente al gen B1. Resultados: Se detectó ADN de Toxoplasma gondii en el 32% de las carnes analizadas. Dentro de este porcentaje se encontraron en proporciones similares, formas parasitarias de T. gondii en carne de pollo (35%), cerdo (32,5%) y res (27,5%), por lo cual no se observó diferencia estadística al realizar el análisis por tipo de carne. Así mismo se encontró una frecuencia de formas parasitarias de T. gondii de 36,6% en las muestras recolectadas en el mercado público y 26,7% en las muestras recolectadas en los supermercados de cadena. Conclusiones: Esta investigación demuestra la alta frecuencia de formas parasitarias de T. gondii en diferentes tipos de carne de consumo humano comercializados en el municipio de Sincelejo, e indica un elevado riesgo de infección por el parásito en la población.

Objective: To determine the frequency of infection by Toxoplasma gondii in different types of meat that is sold for human consumption in Sincelejo-Sucre, by PCR for B1 gene amplification. Materials and methods: A total of 120 samples of meat for human consumption were obtained at 2 types of outlets (municipality public market and retail chain stores) in the city of Sincelejo. At each store, 60 samples of 3 different species were obtained: 20 beef samples, 20 pork samples and 20 chicken samples. These samples were submitted to DNA extraction procedures for tissues and to nested PCR to amplify B1 specific genomic region of T. gondii. Results: Toxoplasma gondii DNA was detected in 32% of the analyzed meat. There were a slight higher frequency (36,6%) in samples collected at the municipality public market compared to retailed chain stores (26,7%) without statistical significance. The frequency of infection was similar between animal species: chicken (35%), pork (32,5%) and beef (27,5%). Conclusions: This work demonstrates a high frequency of T. gondii infection in different types of meat sold for human consumption in the town of Sincelejo, suggesting a high risk of infection by the parasite in the population.

Production cost analysis and use of pesticides in the transgenic and conventional corn crop [Zea mays (L.)] in the valley of San Juan, Tolima.

A survey of 10 producers of conventional corn (Hybrids PAC 105 and Maximus) and 10 producers of transgenic corn (Pioneer Hybrid 30T17) was carried out in the municipality of Valle de San Juan in the territorial division of Tolima (Colombia), in order to analyze the differences in production costs and environmental impacts of these two agricultural technologies.  The environmental impacts were determined by calculating the field "Environmental Index Quotient" (EIQ). In the production cost analysis, a difference of 15% was found in benefit of the transgenic technology. The structure of costs of the transgenic technology was benefited by the reduced use of pesticides (insecticides and herbicides). In regards to production, the transgenic technology showed a greater yield, 5.22 ton/ha in comparison to 4.25 ton/ha the conventional technology, thus a 22% difference in yield. Finally, the EIQ calculation showed quantitative differences of 196.12 for the conventional technology (EIQ insecticides 165.14 + EIQ herbicides 30.98), while the transgenic technology was of 4.24 (EIQ insecticides 0 + EIQ herbicides 4.24). These results show a minor environmental impact when using the transgenic technology in comparison to the conventional technology, in regards to the use of insecticides and herbicides in a temporal, spatial and genotypical context analysis. :