AGBA. BIOGEN

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Acceso abierto
A theranostic PSMA ligand for PET imaging and retargeting of T cells expressing the universal chimeric antigen receptor UniCAR
(Taylor & Francis Group, 2019-09-07) Arndt, Claudia; Feldmann, Anja; Koristka, Stefanie; Schäfer, Martin; Bergmann, Ralf; Mitwasi, Nicola; Berndt, Nicole; Bachmann, Dominik; Kegler, Alexandra; Schmitz, Marc; Puentes-Cala, Edinson; Soto, Javier-Andrés; Ehninger, Gerhard; Pietzsch, Jens; Liolios, Christos; Wunderlich, Gerd; Kotzerke, Jörg; Kopka, Klaus; Bachmann, Michael; Taylor & Francis Group
Chimeric antigen receptor (CAR) T cells have shown impressive therapeutic potential. Due to the lack of direct control mechanisms, therapy-related adverse reactions including cytokine release- and tumor lysis syndrome can even become life-threatening. In case of target antigen expression on non-malignant cells, CAR T cells can also attack healthy tissues. To overcome such side effects, we have established a modular CAR platform termed UniCAR: UniCAR T cells per se are inert as they recognize a peptide epitope (UniCAR epitope) that is not accessible on the surface of living cells. Bifunctional adapter molecules termed target modules (TM) can cross-link UniCAR T cells with target cells. In the absence of TMs, UniCAR T cells automatically turn off. Until now, all UniCAR TMs were constructed by fusion of the UniCAR epitope to an antibody domain. To open up the wide field of low-molecular-weight compounds for retargeting of UniCAR T cells to tumor cells, and to follow in parallel the progress of UniCAR T cell therapy by PET imaging we challenged the idea to convert a PET tracer into a UniCAR-TM. For proof of concept, we selected the clinically used PET tracer PSMA-11, which binds to the prostate-specific membrane antigen overexpressed in prostate carcinoma. Here we show that fusion of the UniCAR epitope to PSMA-11 results in a low-molecular-weight theranostic compound that can be used for both retargeting of UniCAR T cells to tumor cells, and for non-invasive PET imaging and thus represents a member of a novel class of theranostics.
Acceso abierto
Aceleración del proceso de compostaje de residuos post-cosecha (pulpa) del café con la aplicación de microorganismos nativos
(2010) Vásquez de Díaz, María Cristina; López, Andrea; Fuentes, Beatriz; Cote, Elva
Colombia, as a leading exporter of coffee smooth, in 2008 produced an average of 12 524 thousand bags of coffee, each 60 kg, of which 3 005 tones are coffee cherry, these large volumes produced post- harvest, are considered contaminants. These products can be used to produce organic fertilizer. The traditional composting process takes about 150 days because of that the decreasing time to 40 days, it is proposed. Isolation of microorganisms from a pre-enrichment in a basal medium cherry Saline (MBS) to obtain axenic cultures, were identified and tested for compatibility between the consortia to select strains tested. Four 4 biopiles were made with a weight of 175 kg each one and one control. They were inoculated by spraying with a concentration of 3 x 107 CFU/mL during 10, 20 and 30 days, with monitoring of physical parameters. They were isolated and identified 8 strains: Pseudomonas aeruginosa, Citrobacter koseri, Bacillus sp, Escherichia coli, Stenotrophomona maltophilia, Cromobacterium spp, Pseudomonas spp. The carbonnitrogen (C/N) ratio in the stack 1 (9.6 %), in the stack 2 (10 %), and the pile 4 (9.5 %) fulfilled the established values (< 20 %), showing maturity and sanitary quality with low levels of fecal coliform and total absence of Salmonella. The results in 40 days allowed a compost that meets the parameters established by the Colombian technical standard (5167 NTC, 2004).
Acceso abierto
Aislamiento de patógenos comunes asociados con enfermedad diarreica aguda en menores de 5 años, Bucaramanga, Colombia
(2009-08) Uribe Yepes, Marta Amparo; Rodríguez Villamizar, Laura Andrea; Gómez González, Yolanda Astrid; Olaya Gamboa, Lina Evelia; Rodríguez Santamaría, Sandra Milena
Introducción: La enfermedad diarreica aguda continúa siendo una de las primeras causas de morbilidad y mortalidad en menores de cinco años. El objetivo de este estudio fue determinar la prevalencia de los agentes patógenos comunes asociados con enfermedad diarreica aguda en niños menores de cinco años atendidos en los servicios de urgencias de instituciones de salud de Bucaramanga. Materiales y métodos: Estudio descriptivo transversal con recolección prospectiva. Las muestras se recolectaron aleatoriamente durante los turnos de mañana, tarde y noche; a cada muestra se le realizó diagnóstico para rotavirus, Salmonella spp, Shigella spp, parásitos y coccidias. Resultados: Se estudiaron 180 menores de cinco años con una mediana de edad de 12 meses. El 44,4% (IC 95% 37,1-52,0) de los episodios de diarrea fue causada por rotavirus. En el 8,9% (IC 95% 5,2-14,0) de los casos se encontró Blastocystis hominis, 7,8% (IC 95% 4,3-12,8) Giardia duodenalis, 7,8% (IC 95% 4,3-12,8) Salmonella spp, 5,0% (IC 95% 2,3-9,3) Entamoeba histolytica dispar, 2,8% (IC 95% 0,9-6,4) Shigella spp, 2,8% (IC 95% 0,9-6,4) Entamoeba histolytica mas Blastocystis hominis, 0,6% (IC 95% 0,0-3,1) Giardia duodenalis mas Entamoeba histolytica, y 0,6% (IC 95% 0,0-3,1) rotavirus mas Blastocystis hominis. En el 19,4% de los niños no se encontró ningún microorganismo por los métodos utilizados en el estudio. Conclusión: Rotavirus tiene un importante papel en el municipio de Bucaramanga como principal agente patógeno asilado asociado con enfermedad diarreica aguda en niños menores de cinco años. [Uribe Yepes MA, Rodríguez Villamizar LA, Gómez González YA, Olaya Gamboa LE, Rodríguez Santamaría SM. Aislamientos de patógenos comunes asociados con enfermedad diarreica aguda en menores de cinco años, Bucaramanga, Colombia.
Acceso abierto
Alteraciones tiroideas en diabetes mellitus tipo 2 - Thyroid alterations in type 2 diabetes mellitus
(Revista Latinoamericana de Hipersensible, 2019-10-01) Sierra-Castrillo, J.; Gómez Rave, Liz J.; Chacín-González, M.; Quintero, JR; Bermúdez Pirela, Valmore
Diabetes mellitus is one of the world’s leading non-communicable diseases. It leads to alterations in glucose metabolism due to the low availability of insulin or resistance to its action. Recent studies indicate that there is a relationship between diabetes mellitus and thyroid dysfunction, mediated by disturbances in the hypothalamus - pituitary - thyroid axis, and reduced deiodinase activity, synergism of mitogenic routes, increased inflammatory status, oxi-dative stress and insulin resistance. The most frequent alteration is subclinical hypothyroidism and it occurs more frequently in women, so it is suggested to periodically perform the thyroid profile to these patients. It is necessary that in clinical practice these implications are taken into account in order to provide timely treatment, improve complications such as cardiovascular disease and reduce morbidity and mortality rates.
Acceso abierto
An oligo-His-tag of a targeting module does not influence its biodistribution and the retargeting capabilities of UniCAR T cells
(2019-07-29) Jureczek, Justyna; Bergmann, Ralf; Berndt, Nicole; Koristka, Stefanie; Kegler, Alexandra; Puentes-Cala, Edinson; Soto, Javier-Andrés; Arndt, Claudia; Bachmann, Michael; Feldmann, Anja
Recently, we established the controllable modular UniCAR platform technology to advance the efficacy and safety of CAR T cell therapy. The UniCAR system is composed of (i) target modules (TMs) and (ii) UniCAR armed T cells. TMs are bispecific molecules that are able to bind to the tumor cell surface and simultaneously to UniCAR T cells. For interaction with UniCAR T cells, TMs contain a peptide epitope sequence which is recognised by UniCAR T cells. So far, a series of TMs against a variety of tumor targets including against the prostate stem cell antigen (PSCA) were constructed and functionally characterised. In order to facilitate their purification all these TMs are expressed as recombinant proteins equipped with an oligo-His-tag. The aim of the here presented manuscript was to learn whether or not the oligo-His-tag of the TM influences the UniCAR system. For this purpose, we constructed TMs against PSCA equipped with or lacking an oligo-His-tag. Both TMs were compared side by side including for functionality and biodistribution. According to our data, an oligo-His-tag of a UniCAR TM has only little if any effect on its binding affinity, in vitro and in vivo killing capability and in vivo biodistribution.
Acceso abierto
Análisis de las mutaciones más frecuentes del gen BRCA1 (185delAG y 5382insC) en mujeres con cáncer de mama en Bucaramanga, Colombia
(2009-01) Sanabria, María Carolina; Muñoz, Gerardo; Vargas, Clara Inés
Introduction. Breast cancer is considered a worldwide public health problem, and, in Santander Province, Colombia, it is the first leading cause of morbidity and mortality by cancer in women. All cancers are considered genetic diseases, and mutations in BRCA (BReast CAncer) genes raises the risk for breast cancer by 60%-80%. The current study searched for the two most frequent BRCA1 mutations reported in the Breast Cancer Core Information database. Objective. The presence of specific mutations (185delAG, exon 2 and 5382insC, exon 20) was determined for the BRCA1 gene in women with familial/hereditary breast cancer. Materials and methods. The sample included 30 female patients using the oncology services in Bucaramanga, eastern Colombia; an informed consent, a questionnaire and a blood sample were obtained from each. The molecular analysis was done with PCR-Mismatch, to detect the insertion or eliminatation of a restriction site, and enzymatic digestion methods (HinfI or DdeI). Results. Two of the most frequent BRCA1 mutations in the international database were not found in the 30 patients studied. Conclusion. Additional mutation screening techniques are necessary involving the entire BRCA1 gene, are necessary in order to better characterize the molecular epidemiology of breast cancer in Bucaramanga, Santander, Colombia.
Acceso abierto
Asociación de los niveles de adiponectina y del factor de necrosis tumoral alfa con albuminuria en pacientes con diabetes tipo 2
(2017) Sierra Castrillo, Jhoalmis.; Gómez Rave, Liz J.
Type 2 Diabetes mellitus is a metabolic chronic disease, which if it is not properly controlled produces a progressive kidney damage causing diabetc nephropathy. It is also highly associated with a chronic infammatory state, related to adipocytokines (IL-6, TNF-α, leptn, adiponectn) secreton which are involved in metabolic homeostasis and crucial in both regulatng the atherogenic process as in insulin resistance. Objectve: To relate the behavior of adiponectn and TNF-α levels with albumi- nuria in patents with type 2 diabetes mellitus. Materials and methods: The research was based on a descriptve cross-sectonal model with a study populaton composed by patents admited to University Hospital Erasmo Meoz (Cucuta, Colombia). According to previously established selecton criteria, two analysis groups were conformed; patents diagnosed with type 2 diabetes mellitus and albuminuria >30 mg/L (n = 24), and a control group without the above conditons (n = 20). Results: The results revealed that there is a positve and statstcally signifcant correlaton between TNF-α concentraton and albuminuria (p <0.03). It was observed that between TNF-α and adiponectn levels there are no apparently correlaton (p> 0.05). Conclusions: although there are no signifcant diferences between adiponectn and TNF-α levels, TNF-α could be exploited as an early markers for kidney damage or help designing of progression estmators of injury in patents with diabetes type 2.
Acceso abierto
Biological activity of sacha inchi (Plukenetia volubilis linneo) and potential uses in human health. A review
(Food Technology and Biotechnology, 2021-07-13) Cárdenas Sierra, Denny-Miley; Gómez Rave, Lyz Jenny; Soto, Javier-Andres; Biogen
Sacha inchi (Plukenetia volubilis Linneo) is an ancestral plant originating in the Amazon jungle that has been adopted as a food source due to its high nutritional value, which has gradually been recognized to have potential benefits for human health. Diverse prospective studies have evaluated the effect of consuming components from the plant, derivatives from its seeds, leaves and shell on preventing the risk of cardiovascular disease, chronic inflammatory disease, dermatitis and controlling tumor proliferation, especially given its recognized high content of essential fatty acids, phenolic compounds and vitamin E, showing antioxidant, hypolipidemic, immunomodulation and emollient activity, as well as the capacity to remove heavy metals from aqueous solutions. This review offers a complete description of the existing information on the use and biological activity of P. volubilis L., based on its essential lipid components and evidenced on its use in the field of human health, in prevention, therapeutic and nutritional contexts, along with industrial uses, making it a promising bioresource.
Acceso abierto
Caracterizaci ón molecular de genes cry1, cry2, cry3 y cry4 en aislados de Bacillus thuringiensis y determinación de su actividad bioinsecticida en larvas de Aedes aegypti
(2013-02-20) Galvis Serrano, Nestor Fabián
Chemical insecticides can be toxic and cause environmental degradation. Therefore, biological control of insects represents an alternative of low ecological impact. Bacillus thuringiensis is a spore-forming Gram-positive bacterium that produces parasporal crystals of a proteic nature, formed by delta endotoxins that are toxic to a large number of insects and are biodegradable and innocuous to other species. In the present work 13 native strains of B. thuringiensis were isolated from soil samples and identified by selective methods and the BBL CRYSTAL method. In the molecular characterization utilizing specific primers for the identification of cry1, cry2, cry3 y cry4 genes, eight isolates presented the cry3 gene and two presented the cry2 gene. These two latter isolates were used in a bioassay on Aedes aegypti larvae to determine their toxic effect, showing that the preliminary toxicity essay of the BtUDES2 isolate presented a lethality of 56.67%. When determining the lethal concentration of this same isolate, an average lethal concentration of 11.4333ng·ml-1 and a total lethal concentration of 17.1542ng·ml-1 were found.
Acceso abierto
Caracterización molecular mediante REP-PCR de aislados nativos de bacillus thuringiensis, obtenidos de muestras de suelo
(2014) Galvis Serrano, Nestor Fabián; Moreno, Laura Yolima
Molecular characterization using rep-PCR of native isolates of Bacillus thuringiensis, obtained from soil samples. Bacillus thuringiensis is a Gram-positive bacteria forming spores, which produces parasporal crystals of a proteic nature, toxic against various orders of insects and biodegradable and harmless to other species. This research use the experimental model, allowing, through observation techniques, microbiological and biochemical identification of B. thuringiensisfrom soil samples from municipalities of Cúcuta, El Zulia, Los Patios, San Cayetano and Villa del Rosario, Norte de Santander, Colombia, and its subsequent characterization with molecular markers Bc-Rep and MB1. Microbiological and biochemical tests identified 10 isolates as B. thuringiensis; the results of phylogenetic analysis showed significant differences in the clusters obtained with Bc-Rep and MB1 markers. With Bc-Rep a low index of similarity (18%) was recorded, while with the marker MB1 a higher similarity index, 58%, was obtained. This work indicated a great genetic variability among isolates, showing that markers Bc-Rep and MB1 are highly effective to differentiate closely related strains, thus becoming a genetic tool of great value for studies of identification and diversity in B. thuringiensis.
Acceso abierto
Caracterización molecular y detección de genes blaCTX-M grupos 1 y 9 en Klebsiella pneumoniae resistentes a ceftazidima, en un hospital de San José de Cúcuta, Colombia
(2019-06-01) Galvis S., Fabián; Moreno R., Laura
Background: The expression of CTX-M β-lactamases belonging to groups 1 and 9 in Klebsiella pneumoniae produces high levels of resistance to ceftazidime, and they have a wide distribution worldwide. Aim: To identify and characterize the blaCTX-M-Group1 and blaCTX-M-Group9 genes in K. pneumoniae isolates resistant to ceftazidime in a hospital in San José de Cúcuta, Colombia. Material and methods: Primers were designed for the identification of K. pneumoniae and blaCTX-M genes by PCR. Subsequently, the genetic relationship of these isolates was analyzed by REP-PCR. Results: A 38% of the 24 isolates identified by PCR as K. pneumoniae showed blaCTX-M-3. blaCTX-M-15 y blaCTX-M-32 genes (Group CTX-M-1) and 42% blaCTX-M14. blaCTX-M-24 y blaCTX-M-27 genes (Group CTX-M-9). The phylogenetic analysis grouped the K. pneumoniae isolates into 4 clusters, showing correlation in clusters I, II and IV, when comparing the genetic profiles with the type of sample and group of genes. Discussion: We found a similar frequency of blaCTX-M-Group 1 and blaCTX-M-Group 9 genes in isolates of K. pneumoniae resistant to ceftazidime. The correlation between the REP-PCR with the CTX-M groups and the type of sample revealed the presence of three clonal patterns.
Acceso abierto
Chroman-4-one hydrazones derivatives
(Medicinal Chemistry, Ernest Mario School of Pharmacy, Rutgers University, Piscataway, NJ, USA, 2019-09-29) Upegui, Yulieth; Ríos Ramírez, Yesmit-Karina; Quiñones, Wiston; Eccheverri, Fernando; Archbold, Rosendo; Murillo, Javier D.; Torres, Fernando; Escobar, Gustavo; Vélez, Iván D.; Robledo, Sara M.
Acceso abierto
Comparación de la PCR anidada y PCR convencional en el diagnóstico de Plasmodium Vivax y P. Falciparum
(2013) Galvis Serrano, Nestor Fabián; Carrillo Hernández, Marlen Yelitza; Quintero, Fabián A.
Malaria is diseases caused by Plasmodium sp., and in Colombia approximately 160,000 cases are annually registered, where 75% are produced by P. vivax and 24% for P. falciparum. The molecular diagnosis is performed by Nested PCR, is a general amplification followed by a specific, using two pairs of different primers. This study compared the sensitivity and specificity of nested PCR with the conventional PCR to identify P. vivax and P. falciparum in DNA from blood of patients. As samples were selected 18 patients were identified as positive by blood smear for malaria. At the DNA isolation protocols were used 3: Heidari, Chelex®100 and commercial kit from Promega. In the nested PCR and conventional primers were used to identify P. falciparum and P. vivax. The results of the amplifications obtained with conventional PCR were similar to those obtained with nested PCR, demonstrating that have the same specificity and sensitivity, which allows to conclude that the realization of the conventional PCR is sufficient for the diagnosis of P. vivax and P. falciparum, reducing time and costs in the identification. The PCR is the best method for the diagnosis of Malaria, which is more sensitive and specific compared with rapid testing and microscopic examination of drop thick, allowing the presence of the parasite in the early stages of the disease when the parasite load is minimal, and also gives the possibility of identifying cases of mixed infections.
Acceso abierto
Conocimiento, actitudes y prácticas frente al VIH/SIDA en estudiantes de bachillerato de Cúcuta, Norte de Santander, Colombia
(Archivos Venezolanos de Farmacologia y Terapeutica, 2019-01-02) Villafaña Angarita, Tatiana Maybeth; Sierra Leiva, Jahury-Estefanny; Parada, Holver-Smith; Soto, Javier-Andrés; Cárdenas Sierra, Denny-Miley
Objetivo. Determinar el nivel de conocimientos, actitudes y prácticas acerca del VIH y SIDA en adolescentes. Métodos. Estudio correlacional de campo en 318 estudiantes de 13-21 años de edad, de noveno-undécimo de bachillerato de dos Instituciones Educativas representativas de la ciudad de Cúcuta, mediante muestreo probabilístico. Se implementó instrumento CAP validado y ficha sociodemográfica, para análisis descriptivo y correlacional. Resultados. Se registró desconocimiento sobre transmisión, población susceptible y estabilidad de preservativos en 5-47% de los estudiantes, obteniéndose un nivel bajo para la dimensión conocimiento, en contraste con actitudes y prácticas adecuadas. Conclusiones. No se encontró asociación entre variables edad, sexo, estrato, tipo familiar o escolaridad con las dimensiones de los conocimientos, actitudes o prácticas, hallándose homogeneidad en la muestra, lo que la proyecta como un grupo modelo a contrastar en futuros estudios con otras poblaciones buscando identificar aspectos mejorables en torno a estrategias de prevención global de la pandemia.
Acceso abierto
Eect of the addition of Moringa Oleifera to fruit drinks on clinical parameters associated with iron deciency anaemia in schoolchildren
(2019, 2019-09-01) Martínez Marciales, Karen-Piedad; Soto, Javier-Andrés; Sierra Castrillo, Jhoalmis.; Olivieri Moncada, Jonathan-Gonzalo; Galeano Arias, Jaizul-Carolina; Gómez Rave, Lyz Jenny
Effect of the addition of Moringa oleifera to fruit drinks on clinical parameters associated with iron deficiency anaemia in schoolchildren. Worldwide, iron deficiency anaemia (IDA) is one the most significant nutritional maladies, especially in low and middle-income countries. This is mainly due to the associated morbidity, economic implications on the health system and the welfare state. One of the most prevalent causes of IDA in children is insufficient food intake, which has an obvious connection with the social environment. The main strategy in the management of this condition is counteracting such deficiency through the improvement of nutrition and family upbringing. Aiming to explore affordable, novel and straightforward approaches to treat this nutritional condition, we developed a descriptive study associated with the incorporation of Moringa oleifera in homemade fruit beverages delivered to 32 children from low-income families, in order to assess the evolution of IDA, evaluating specific clinical parameters such as red blood cells volume, as well as hemoglobin, ferritin and serum iron levels, within a two months lapse. At the end of this period, we observed a significant statistical rise in the levels of all the assessed parameters, finding about a 1.3-fold increase in hemoglobin and ferritin levels and in red blood cells volume; serum iron was 1.1 times higher. These findings are demonstrative of the wide spectrum of the medicinal features of Moringa and establish a promising and accessible strategy easy to incorporate into the diet of families of children suffering this pathology. ALAN, 2019; 69(1): 2-11.
Acceso abierto
Estudio piloto de la prevalencia de síndrome metabólico en estudiantes de la institución universitaria Colegio Mayor de Antioquia en Medellín y la Universidad de Santander. Cúcuta, Colombia
(Revista Latinoamericana de Hipertensión, 2019-03-01) Gómez Rave, Lyz Jenny; Sierra-Castrillo, Jhoalmis; Bermúdez Pirela, Valmore; Román Marín, Laura-Melisa; Rojas, Joselyn
Antecedentes: El síndrome metabólico (SM) es una condición que predispone al individuo al desarrollo de enfermedades cardiovasculares, diabetes mellitus tipo 2 y sus complicaciones. Debido a que su prevalencia se encuentra en aumento, se ha convertido en un problema de salud mundial que debe manejarse desde la prevención temprana y la promoción de hábitos saludables. Objetivo: Determinar la prevalencia de SM en un grupo de jóvenes universitarios de la Institución Universitaria Colegio Mayor de Antioquia y la Universidad de Santander. Diseño y método: la investigación es de tipo descriptivo y transversal con una muestra conformada por 80 estudiantes (16 hombres y 64 mujeres), entre los 17 y 32 años, aparentemente sanos. Utilizando la definición de la IDF para el SM, se midieron variables como circunferencia de cintura (CC), presión arterial sistólica y diastólica (PS, PD), glucosa en ayunas (GA), colesterol HDL (HDLc) y triglicéridos (TG). Para el análisis estadístico, la comparación entre grupos se realizó con la medida no paramétrica prueba U de Mann-Whitney, con un nivel de significaticancia p<0,005 y mediante el uso del programa estadístico SPSS versión 24. Resultados: se encontró una prevalencia de SM de 5 %, y en el análisis individual de sus componentes o factores de riesgo asociados se evidenció una mayor prevalencia para CC y GA elevada (38,89% en cada una), seguida de la disminución del HDLc (27,78%). Conclusiones: estos hallazgos concuerdan con estudios previos donde se estima que el SM está presente en adultos jóvenes de acuerdo con criterios de la IDF. A partir de esto se recomienda adoptar medidas institucionales que promuevan la actividad física y la alimentación saludable.
Acceso abierto
Identificación de Bacterias Diazotróficas Rizosféricas y Endófitas Asociadas a Lycopersicon Esculentum Mill en el Norte de Santander, Colombia
(2020-10-01) Moreno-Rozo, Laura Y.; Galvis-Serrano, Fabián; Biogen
Las bacterias diazotróficas pueden estimular el crecimiento del cultivo del tomate (Lycopersicon esculentum Mill.) mediante la síntesis de hormonas, fijación de N y producción de siderófo-ros, u otros procesos. Las bacterias diazotróficas predominantes en los agroecosistemas pueden ser biofertilizantes potenciales. El objetivo del estudio fue cuantificar y caracterizar la población de bacterias diazotróficas rizosféricas en muestras de suelo rizosféri-co (SR) y bacterias diazotróficas endófitas en muestras de raíces (R) y material foliar (MF), mediante pruebas fenotípicas y mole-culares. El estudio fue exploratorio y con un muestreo aleatorio, con 18 muestras SR, raíces (R) y MF de cultivos de tomate en seis fincas. Las diferencias en el número más probable (NMP) de bacterias diazotróficas no fueron significativas entre los sitios de las muestras de MF y R. La media de NFb mostró diferencias altamente significativas en Azotobacter sp. y Azospirillum sp. entre las muestras de SR, R y MF, con un NMP mayor y menor en SR y MF. Esto se relaciona con la caracterización fenotípica y bio-química de SR donde se identificaron 14 aislados como Azoto-bacter sp. y siete como Azospirillum sp. Los géneros Burkholderia y Gluconacetobacter no mostraron diferencias significativas en el número de aislados entre muestras de SR y R, pero sí respecto a MF, con la población celular menor. Las diferencias entre las fincas no fueron significativas en las variables del suelo relacio-nadas con la disimilitud de NMP. La caracterización molecular permitió identificar A. chroococcum, A. nigricans, A.vinelandii, A. brasilense, B. glumae y G. azotocaptans/G. johannae en muestras de SR; B. glumae, G. azotocaptans/G. johannae en muestras de R y G. azotocaptans/G. johannae en muestras de MF.
Acceso abierto
Identificación y caracterización molecular de aislados de Burkholderia glumae, agente causante del añublo bacterial en el cultivo de arroz
(2015) Galvis Serrano, Nestor Fabián; Carrillo Hernández, Marlen Yelitza
El objetivo de este trabajo fue implementar la identificación especifica de Burkholderia glumae por PCR convencional; y conocer sus características genéticas, a partir de plantas de arroz con evidencia de pudrición. Burkholderia glumae es el agente causal del añublo bacterial de la panícula del arroz, con una alta incidencia ocasionando considerables pérdidas en la producción de los cultivos en Colombia. Debido a que su identificación es difícil, se requiere de un sistema de evaluación que permita determinar de manera rápida y precisa este patógeno. Se obtuvo 64 aislados, de los cuales 41 fueron identificados por Reacción en Cadena de la Polimerasa (PCR) como Burkholderia glumae. La caracterización molecular con los marcadores MB1 y BOX-PCR mostraron variabilidad genética en la mayoría de los aislados, pero permitieron el agrupamiento de acuerdo a su origen geográfico. La gran diversidad genética encontrada refleja el alto grado de variabilidad existente dentro de los individuos de esta especie.
Acceso abierto
Identification of Cry1 genes in Bacillus thuringiensis isolates and their toxic effect against Milax gagates , plague in lettuce ( Lactuca sativa )
(2018-05) Galvis Serrano, Nestor Fabián; Moreno, Laura Yolima
Milax gagates constituye una de las principales plagas en el cultivo de lechuga causando considerables pérdidas económicas. El control con molusquicidas elimina total o parcialmente la plaga, pero genera un impacto negativo en el ambiente por su alta toxicidad. El manejo biológico también permite el control de la plaga, pero de manera específica e inocua para el ambiente. Por ello, el objetivo de este trabajo fue evaluar el efecto tóxico de Bacillus thuringiensis, con genes Cry1, contra M. gagates mediante la elaboración de un bioensayo. Se tomaron 75 muestras de suelo de varios municipios del Norte de Santander, Colombia, de donde se obtuvieron 58 colonias aisladas de B. thuringiensis con características similares. De estas colonias, cinco evidenciaron la presencia de genes Cry1, y fueron las empleadas en los bioensayos junto con el control B. thuringiensis var. Kurstaki. Los tratamientos presentaron letalidad ante M. gagates de entre 90 y 100 % a una concentración de 500 μg∙mL-1. La CL99 calculada sugiere el uso de 820 μg∙mL-1 del biopreparado para obtener 100 % de letalidad con cualquiera de los cinco aislados estudiados.
Acceso abierto
Immunological Memory to Zika Virus in a University Community in Colombia, South America
(2020-05-29) Cárdenas Sierra, Denny-Miley; Jaimes, Miguel A.; Vega, Leidy D.; Oliveros, Nicolas L.; Soto, Javier-Andrés; Chía, Claudia R.; Osorio, Jorge E.; Ciuoderis, Karl A.
Zika virus appeared in South America in 2015, generating alarm worldwide as it causes microcephaly and autoimmunity. This study aims to determine the serological footprint of the incoming epidemic in a student community and to characterize the memory functional cell response during post convalescence. In a cross-sectional study, Zika-specific IgG using LIA immunoassay was found in 328 university students (CI=95%), while in the second phase, the functional cellular memory response for IFN-γ and IL-2 was quantified using post-stimulus ELISpot with inactivated virus, starting with individuals seropositive for Zika and control individuals (seropositive only for Dengue and seronegative for Zika-Dengue). Depending on the antigen used, memory humoral response (IgG) against Zika Virus was observed in >60% of the population; seropositivity for NS1 was 21.1% higher than E antigen with high intensity. The analysis of cell functionality in 22 individuals seropositive for Zika virus revealed either IFN-γ+ or IL-2+ cells in 86.3% of cases (Th1 profile), presenting multifunctionality in 50% (11 individuals), 64% of which presented> 6 SFC/104 PBMCs (>600 SFC/106 PBMC), reflecting memory circulating cells. A good agreement (Kappa= 0.754) was observed between the coexistence of both cellular and humoral responses but not in their intensity.

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