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Ítem Caracterización de los biomarcadores séricos del tamizaje combinado del primer trimestre para predicción de aneuploidías en mujeres embarazadas del Hospital San Juan de Dios entre enero 2017 y setiembre 2023(2023) González Calderón, Víctor; Loaiza Yee, Nancy PamelaJustificación y objetivos: Las anomalías cromosómicas son una causa importante de muerte perinatal y discapacidad en la infancia. Existen estrategias disponibles para su tamizaje con el objetivo de reducir la cantidad de procedimientos invasivos durante el embarazo, evitando su riesgo asociado y disminuyendo costos. Una de estas estrategias corresponde al tamizaje del primer trimestre, el cual permite un diagnóstico temprano de aneuploidías. La implementación de los marcadores bioquímicos del primer trimestre requiere establecer con precisión las semanas de embarazo y corregir los múltiplos de la mediana según las características propias de la población en estudio. La presente investigación tiene como objetivo caracterizar los múltiplos de la mediana de los biomarcadores séricos del tamizaje combinado de primer trimestre con el fin de valorar su desempeño diagnóstico en la población de mujeres embarazadas del Hospital San Juan de Dios a partir de resultados obtenidos en el periodo comprendido entre enero 2017 y setiembre 2023. Metodología: Se trata de un estudio observacional, retrospectivo, de tipo descriptivo, consiste en una recopilación de resultados de laboratorio en un período longitudinal. Resultados: Los MoM de la hCG-β de la población del Hospital San Juan de Dios en el período establecido presenta diferencia estadísticamente significativa con respecto a la población de referencia del PRISCA en las semanas 12 y 13 de gestación. Los MoM de la PAPP-A de la población del Hospital San Juan de Dios en el período establecido presenta diferencia estadísticamente significativa con respecto a la población de referencia del PRISCA únicamente en la semana 12 de gestación. Conclusiones: Se sugiere realizar la corrección de los múltiplos de mediana para la hCG-β de las pacientes en las semanas 12 y 13 de embarazo y para la PAPP-A de las pacientes en la semana 12 de embarazo utilizando la mediana propia calculada para el Hospital San Juan de Dios.Ítem Inhibitors and activators for myotoxic phospholipase A2-like toxins from snake venoms - a structural review(2024) Salvador, Guilherme Henrique Marchi; Cardoso, Fábio Florença; Lomonte, Bruno; Fontes, Marcos Roberto de MattosSnakebite envenomations result in acute and chronic physical and psychological health effects on their victims, leading to a substantial socio-economic burden in tropical and subtropical countries. Local necrosis is one of the serious effects caused by envenomation, primarily induced by snake venoms from the Viperidae family through the direct action of components collectively denominated as myotoxins, including the phopholipase A2-like (PLA2-like) toxins. Considering the limitations of antivenoms in preventing the rapid development of local tissue damage caused by envenomation, the use of small molecule therapeutics has been suggested as potential first-aid treatments or as adjuvants to antivenom therapy. In this review, we provide an overview of the structural interactions of molecules exhibiting inhibitory activity toward PLA2-like toxins. Additionally, we discuss the implications for the myotoxic mechanism of PLA2-like toxins and the molecules involved in their activation, highlighting key differences between activators and inhibitors. Finally, we integrate all these results to propose a classification of inhibitors into three different classes and five sub-classes. Taking into account the structural and affinity information, we compare the different inhibitors/ligands to gain a deeper understanding of the structural basis for the effective inhibition of PLA2-like toxins. By offering these insights, we aim to contribute to the search for new and efficient inhibitor molecules to complement and improve current therapy by conventional antivenoms.Ítem Top-down proteomics of venoms from five Micrurus species from Costa Rica: Comparative composition of phospholipase A2-rich vs three-finger toxin-rich phenotypes(2024) Fernández Ulate, Julián; Chaves, Walter; Vargas Díaz, David; Petras, Daniel; Lomonte, BrunoCoralsnakes of the genus Micrurus include more than 80 species distributed in the American continent. They produce potent neurotoxic venoms acting at the neuromuscular junction and potentially leading to respiratory paralysis and death. The vast majority of proteins in coralsnake venoms belong to the three-finger toxin (3FTx) and the group I phospholipase A2 (PLA2) families. Previous studies using ‘bottom-up’ proteomic strategies have revealed a compositional dichotomy of toxin expression by which different Micrurus species display a predominance of either 3FTx or PLA2 proteins in their venoms, possibly linked to the phylogeographic structure of the genus radiation. ‘Top-down’ proteomics (TDP) allows the direct analysis of intact proteins in a high resolution mass spectrometer, circumventing the limitations of the ‘peptide-to-protein inference problem’ inherent to the bottom-up approach. Here, we analyzed the venoms of five out of the six Micrurus species that inhabit Costa Rica, by using a TDP approach. Results unveil venom proteoforms that are shared between these species, and provide additional insights into the variable compositional complexity of these venoms and relationships to their 3FTx/PLA2 dichotomy.Ítem Why are Latin American countries in the limbo of open-access scientific publications?(2024) Chavarría Vargas, Max; Lomonte, Bruno; Gutiérrez Gutiérrez, José María; Moreno Robles, Edgardo; Pérez Sánchez, Alice LorenaOpen Access (OA) model in scientific journals has brought about a range of benefits in terms of information accessibility. However, the high costs associated with Article Processing Charges (APCs) have posed a significant challenge for many scientists, leaving them in a ‘limbo’, where their ability to publish in reputable journals is contingent upon their financial capacity. Here, we intend to highlight the challenges faced by Latin American scientists that have arisen as a direct consequence of the implementation of the OA, specifically: (i) difficulties in disseminating our scientific work due to the impossibility of covering the high APCs imposed by journals, and (ii) the strong emergence and consolidation in our region of publishers with predatory practices. We urge the scientific community to establish policies that contribute to equity in OA models and to defend the right of Latin American scientists not only to read science freely but also to be read.Ítem Ciencias Ómicas y medicina de precisión aplicadas a la identificación bacteriana(2024) Castro Castrillo, Karol Vanessa; Segura Retana, Elvira EugeniaEn este trabajo se realizó una revisión de la literatura, para recopilar información sobre las aplicaciones de distintas estrategias de Ciencias Ómicas en la Medicina de Precisión; en aras de proporcionar a los profesionales de la salud una visión holística que promueva su instauración en la práctica clínica habitual. El término Medicina de Precisión se ha vuelto muy popular en los últimos años, impulsado por perspectivas científicas y políticas. A pesar de su popularidad, su significado exacto sigue sin estar claro. Lo cierto es que la Medicina de Precisión surgió como una crítica a la práctica médica convencional, caracterizada por emplear métodos simplificados de categorización; en los que todos los individuos que presentan un conglomerado de síntomas reciben un tratamiento similar sin tener en cuenta el dinamismo de los sistemas integradores del cuerpo humano. Estas falencias dieron paso a una ambición razonable, de formas más precisas de diagnóstico y tratamiento. De esta forma, el advenimiento de la Medicina de Precisión sugiere una visión centrada en el paciente cuyo objetivo es obtener la caracterización más detallada posible de las subpoblaciones; identificando singularidades genéticas y moleculares. Es por esta razón que la Medicina de Precisión se sirve de distintas herramientas basadas en Ciencias Ómicas para la ejecución de pruebas microbiológicas rápidas (en comparación con las técnicas estándar para la identificación de microorganismos) pues en combinación con prácticas como los Programas de Administración de Antimicrobianos (PROA) han demostrado la optimización de los resultados clínicos y económicos, incluida la disminución de la estancia hospitalaria, de los índices de morbimortalidad y de los costos de atención médica. En consonancia, una sección de esta tesis describe el surgimiento de antibióticos de precisión y el uso de técnicas como la monitorización terapéutica de fármacos, como alternativas para el abordaje de las infecciones sin dañar los microbiomas ni propiciar la resistencia a los antimicrobianos. Aunque el panorama es alentador; estos enfoques aún están en una etapa incipiente. Es imperativo la realización de investigaciones más exhaustivas pues existen desafíos notables y es fundamental abordar los retos que subyacen a la innovación.Ítem Differentiation of multiple fluorescent powders, powder transfer, and effect on mating in Aedes aegypti (Diptera: Culicidae)(2020-10-24) Rojas Araya, Diana; Alto, Barry W.; Cummings, Derek A. T.; Burkett Cadena, Nathan DanielFive different fluorescent powders (orange, yellow, green, blue, and violet) were tested on Aedes aegypti adults to evaluate the differentiation of multiple fluorescent powder colors applied externally in the same female mosquito, their effect on coupling time, copulation time, insemination success, mate choice, and the extent of transference of powders between marked and unmarked individuals, either during copulation or same-sex interactions. Marking with multiple powders was evaluated after applying different powders in the same female at different times and combinations. The comparative effect of powders on mating was explored using different cross-combinations of marked/unmarked couples. Transference of powders between marked/unmarked individuals after copulation was checked in mated individuals, and between same-sex interactions by allowing them to interact under crowded and uncrowded conditions. Identification of the colors included in multiple markings in the same individual was possible when exploring almost all combinations (exception: green–yellow). No important effect of powder marking between cross-combinations was found on coupling time (overall 95% CI (Confidence Interval) 37.6–49.6 min), copulation time (overall 95% CI 17–20 s), insemination success, nor their mate choice. Transferred powder after copulation activity, concentrated in genitalia, legs, and the tip of wings, occurred in >80% of females and 100% of males. Powder transference in legs and genitalia, between same-sex individuals, occurred only in males (ranged between 23–35%) under both density conditions. The lack of important effects of these powders on the studied aspects of Ae. aegypti provides information about their usefulness and limitations, which should be recognized for future applications and to avoid bias.Ítem Detection of fluorescent powders and their effect on survival and recapture of Aedes aegypti (Diptera: Culicidae)(2019-10-06) Rojas Araya, Diana; Alto, Barry W.; Burkett Cadena, Nathan Daniel; Cummings, Derek A. T.The use of insect markers, such as fluorescent powders, is a useful tool for studying ecological and epidemiological questions. Evaluating their effect on vectors of human disease agents, such as the invasive mosquito vector Aedes aegypti (Linnaeus), is crucial for their practical and reliable use, especially in parameters linked to the risk of disease transmission such as adult survival, dispersal, and host-seeking. Seven fluorescent powders (Hercules Radiant, DayGlo (DG), Risk Reactor (RR), and Angstrom Technologies), applied externally on cohorts of Ae. aegypti female mosquitoes, were tested to determine their impact on survival and recapture by baited mosquito traps, and their detectability after being exposed to controlled laboratory and semifield environments. There were no significant differences in survival among marked and unmarked females across all powders. Marked females were significantly less likely to be captured in baited traps relative to unmarked females, except for one of the DG powders. All females remained visibly marked on five parts of their body for 30 d (under both environments), except for one of the RR powders. The tested powders and application method are suitable for tracking mosquitoes throughout most of their lives under different environments, without significantly affecting their survival, but with potential impact on recapture by baited traps, possibly due to effects on senses or other physiological traits.Ítem Impacts of fluorescent powders on survival of different age cohorts, bloodfeeding success, and tethered flight speed of Aedes aegypti (Diptera: Culicidae) females(2020-04-10) Rojas Araya, Diana; Alto, Barry W.; Burkett Cadena, Nathan Daniel; Cummings, Derek A. T.Fluorescent powders are one of the most common external markers used to study mosquito behavior and ecology. For their reliable and practical use, it is important to evaluate their effect on biological parameters such as survival, blood-feeding, and mobility. We evaluated the effect of five different fluorescent powders (Day-Glo ® ECO Series) on the survival of different age cohorts, blood-feeding success, and tethered flight speed on Aedes aegypti (Linnaeus) adult females. For survival analysis, three cohorts (2–5, 6–9, and 10–13 days old) were marked and mortality was recorded until all died. To examine the effect of fluorescent powders on female response to blood-feeding, the proportions of unfed, partially fed, and fully engorged females, after being exposed to host blood under two different time sets (20 and 40 min.), were compared. Their impact on female tethered flight speed was evaluated recording their flight for 30 min. with a flight mill. Survival distributions between treatments were not significantly different within each cohort. Blood-feeding was not significantly different among marked or unmarked females at both times of blood exposure, with the exception of Signal Green-ECO 18 and Ultra Violet- ECO 20 (at 20 and 40 min.), in which a higher proportion of partially fed females was observed compared to control females. In relation to flight performance, no statistically significant difference in mean tethered flight speed (m/s), among marked and unmarked mosquito groups, was observed. Our results indicate that the tested powders and application method have few significant impacts on Ae. aegypti survival, blood-feeding success and flight performance, and are thus suitable for investigations of mosquito biology in the environment.Ítem Infection of eggs of Triatoma dimidiata (Hemiptera; Reduviidae) with Telenomus fariai (Hymenoptera: Scelionidae) in Alajuela, Costa Rica(2023) Rojas Araya, Diana; Troyo Rodríguez, Adriana; Camacho Leandro, Jacqueline; Calderón Arguedas, ÓlgerMicrohymenoptera of the species Telenomus fariai (Hymenoptera: Scelionidae) are recognized parasitoids of eggs of kissing bugs. These wasps constitute a potential modulator of populations of Triatoma dimidiata (Hemiptera: Reduviidae), the main vector of Chagas disease in Central America. This study describes the infection by Telenomus fariai in field-collected eggs of Triatoma dimidiata (Hemiptera: Reduviidae). The eggs were obtained in the peridomicile of a house in Tuetal Sur (Alajuela Province, Costa Rica). The wasp progeny, observed 24 h after receiving the eggs, consisted mainly of females (94.0%). The species confirmation was carried out by analysis of the male genitalia and DNA sequences corresponding to a fragment of the cytochrome c oxidase subunit 1 mitochondrial gene (COI). The identity of the wasp, based on analysis of sequences, places the local strain in proximity to specimens collected in Veracruz, Mexico. The characterization of strains of T. fariai could be useful for the identification of the best candidates to be employed in the biological control of T. dimidiata.Ítem Acknowledging extraordinary women in the history of medical entomology(2022-03-31) Troyo Rodríguez, Adriana; González Sequeira, María Paula; Aguirre Salazar, Mónica; Cambronero Ortíz, Ian; Chaves González, Luis Enrique; Mejías Alpízar, María José; Alvarado Molina, Kendall; Calderón Arguedas, Ólger; Rojas Araya, DianaThroughout history, women have been actively involved in the advancement of science, while struggling to overcome challenges to participate and a lack of recognition. Prior to 1950, most women were not included in the lists of “classical” descriptions of iconic scientific figures nor included in the most relevant historical accounts. Since the second half of the twentieth century, great efforts have been made to recognize the contributions of women to the advancement of science, especially since formal scientific careers have been dominated by men, with limited (or no) access to women. Despite these challenging social, political, and cultural contexts, many women have succeeded in making significant advancements, and their contributions are now being acknowledged. Such efforts have led to the publication of recent reviews and compilations on outstanding women in biological sciences. The field of medical entomology is inherently interdisciplinary, focusing on insects and other arthropods that affect human health, with input primarily from the biological and medical sciences and a strong public health perspective. Several reviews and book chapters describing the history of medical entomology have been published over the decades, but few women are mentioned in these publications, even though many women have contributed to this field. Much of the information on these women is currently scattered throughout the published literature and historical records on a wide range of topics, including activism, virology, vector control, and even acarology. Considering that there is no single available compilation of women contributors in the history of medical entomology, this review aims to provide a list of 22 women and their contributions to this field. The list includes women from diverse backgrounds, born in the late 1800s and before 1950, who directly impacted medical entomology in various ways and in different regions of the world. This compilation is far from exhaustive, but it aims to identify role models and examples of extraordinary women to motivate the evolving future of this field.Ítem Mitochondrial and ribosomal markers in the identification of nematodes of clinical and veterinary importance(2024-02-20) Mejías Alpizar, María José; Porras Silesky, Catalina; Rodríguez Rodríguez, Esteban José; Quesada González, Joban Antonio; Alfaro Segura, María Paula; Robleto Quesada, Joby; Gutiérrez, Ricardo; Rojas Araya, Ana AliciaBackground: Nematodes of the Ascarididae, Ancylostomatidae and Onchocercidae families are parasites of human and veterinary importance causing infections with high prevalence worldwide. Molecular tools have significantly improved the diagnosis of these helminthiases, but the selection of genetic markers for PCR or metabarcoding purposes is often challenging because of the resolution these may show. Methods: Nuclear 18S rRNA, internal transcribed spacers 1 (ITS‑1) and 2 (ITS‑2), mitochondrial gene cytochrome oxidase 1 (cox1) and mitochondrial rRNA genes 12S and 16S loci were studied for 30 species of the mentioned families. Accordingly, their phylogenetic interspecies resolution, pairwise nucleotide p‑distances and sequence availability in GenBank were analyzed. Results: The 18S rRNA showed the least interspecies resolution since separate species of the Ascaris, Mansonella, Toxocara or Ancylostoma genus were intermixed in phylogenetic trees as opposed to the ITS‑1, ITS‑2, cox1, 12S and 16S loci. Moreover, pairwise nucleotide p‑distances were significantly different in the 18S compared to the other loci, with an average of 99.1 ± 0.1%, 99.8 ± 0.1% and 98.8 ± 0.9% for the Ascarididae, Ancylostomatidae and Onchocercidae families, respectively. However, ITS‑1 and ITS‑2 average pairwise nucleotide p‑distances in the three families ranged from 72.7% to 87.3%, and the cox1, 12S and 16S ranged from 86.4% to 90.4%. Additionally, 2491 cox1 sequences were retrieved from the 30 analyzed species in GenBank, whereas 212, 1082, 994, 428 and 143 sequences could be obtained from the 18S, ITS‑1, ITS‑2, 12S and 16S markers, respectively. Conclusions: The use of the cox1 gene is recommended because of the high interspecies resolution and the large number of sequences available in databases. Importantly, confirmation of the identity of an unknown specimen should always be complemented with the careful morphological examination of worms and the analysis of other markers used for specific parasitic groups.Ítem Evaluación del potencial de sensores fluorescentes análogos a esfingomielina para identificar interacciones quimioterapéuticas basadas en mecanismos autofágicos(2024-08) Mesén Porras, Susana; Mora Rodríguez, Rodrigo AntonioLa heterogeneidad tumoral conduce a la resistencia a la quimioterapia en el tratamiento del cáncer; así, los esfingolípidos tienen un rol fundamental en el destino celular y la señalización del estrés. En este proyecto de tesis, se analiza el metabolismo de los esfingolípidos y el flujo autofágico para estudiar las interacciones quimioterapéuticas en el modelo celular de cáncer de pulmón (A549) y de mama (MCF-7). Se utilizaron células cargadas con un análogo de esfingomielina fluorescente (BODIPY) y una sonda para rastrear el flujo autofágico (mCherry-EGFP-LC3B), con el fin de evaluar la citotoxicidad cuando las células se exponen a quimioterapia (epirrubicina, cisplatino y paclitaxel) junto con inhibidores de la vía de los esfingolípidos y moduladores de la autofagia. Las células de cáncer de mama MCF-7 no lograron mostrar internalización del análogo fluorescente, por lo que se determinó que los resultados restantes del proyecto se iban a generar únicamente basados en las células A549. El enfoque de modelo celular se basó en biosensores de esfingolípidos fluorescentes y un modelo matemático de mezclas Gaussianas (GMM) del perfil de heterogeneidad celular para mapear la influencia de la quimioterapia en la vía de los esfingolípidos e inferir posibles interacciones sinérgicas. Los resultados mostraron sinergias significativas, especialmente cuando se combina la quimioterapia epirrubicina con inductores de autofagia (rapamicina y torin), lo que reduce la viabilidad celular. El cisplatino, otro fármaco quimioterapéutico, también tuvo sinergia con un inhibidor de la ceramidasa. Por su parte, el agente anti-cáncer paclitaxel mostró principalmente efectos antagónicos. El modelo de mapeo planteado sugiere que la combinación de quimioterapias con inductores de autofagia aumenta la formación de vesículas, posiblemente relacionadas con la acumulación de ceramida, lo que desencadena la muerte celular. Sin embargo, el modelo in silico propuso la acumulación de ceramida en los autofagosomas, y el análisis cinético experimental proporcionó evidencia de colocalización de esfingolípidos en los autofagosomas. Es por lo anterior que, se requieren más estudios para identificar los esfingolípidos específicos que se acumulan en los autofagosomas. Estos hallazgos ofrecen información sobre estrategias potenciales para superar la resistencia a la quimioterapia dirigidos a la vía de los esfingolípidos.Ítem Evaluación del espectro y propiedades neutralizantes del Varespladib hacia fosfolipasas A2 tóxicas de venenos ofídicos(2024) Bryan Quirós, Wendy; Lomonte, BrunoEl envenenamiento ofídico es un problema médico y de salud pública debido a su incidencia y al número de muertes que causa a nivel mundial. Las fosfolipasas A2 constituyen un porcentaje importante de los venenos de serpientes, y son las enzimas responsables de varios de los efectos en el organismo en el envenenamiento. A pesar de que se utilizan antivenenos eficientes, es necesario el desarrollo de nuevos tratamientos eficaces y económicos que logren disminuir los efectos del envenenamiento ofídico en el organismo. El Varespladib es un compuesto que ha mostrado características inhibitorias de las fosfolipasas A2 de los venenos de serpientes, y parece tener el potencial de ser desarrollado como un pretratamiento asequible ante el envenenamiento por mordeduras de serpiente. Con este estudio se buscó evaluar la capacidad del Varespladib para inhibir las actividades de fosfolipasas A2 representativas de los grupos I y II de venenos de serpientes, así como de sus correspondientes venenos completos. Para ello, se realizaron experimentos para determinar el efecto del Varespladib sobre la actividad enzimática, la citotoxicidad in vitro, y la miotoxicidad in vivo de cada una de estas toxinas y venenos completos. Los resultados mostraron una inhibición significativa de la toxicidad, apoyando el concepto de que el Varespladib pueda llegar a utilizarse como un tratamiento complementario eficaz que disminuya los efectos del envenenamiento ofídico causado por diversas especies de serpientes.Ítem Alteraciones del sistema nervioso central asociadas con desmielinización y estrés oxidativo inducidos por la toxina épsilon de clostridium perfringens(2024) Madrigal Gamboa, Verónica; Flores Díaz, MariettaLa toxina épsilon (ETX) es una neurotoxina formadora de poros producida por Clostridium perfringens toxinotipos B y D, un bacilo anaeróbico, grampositivo y formador de esporas. La ETX es considerada la tercera toxina bacteriana más potente. Esta toxina provoca enteritis severa en terneros, potrillos, corderos y lechones jóvenes, así como enterotoxemia en ovejas y cabras y ocasionalmente en bovinos. Los efectos inducidos por la ETX en el sistema nervioso central (SNC) de ovinos han sido ampliamente estudiados y recientemente se ha sugerido su participación en la etiología de la esclerosis múltiple (EM) en humanos, enfermedad caracterizada por la desmielinización a nivel del SNC y las consecuentes disfunciones motoras. El objetivo de este trabajo fue caracterizar el mecanismo de la citotoxicidad inducida por la ETX en células “Madin-Darby canine kidney” (MDCK), así como los cambios en la actividad motora y la desmielinización generados por esta toxina en un modelo murino. En células MDCK se determinó que la citotoxicidad está mediada por la generación de especies reactivas de oxígeno (ROS) y es prevenible con el uso de antioxidantes. Además, se encontró que el daño oxidativo inducido por la toxina en células MDCK se relaciona con la activación de óxido nítrico sintasa (NOS), la mieloperoxidasa (MPO), la vía de las ERK y la fosforilación oxidativa a nivel de mitocondria. Por análisis inmunohistoquímicos se observó que la expresión de la proteína básica de mielina (MBP) disminuye levemente en el árbol de la vida del cerebelo de ratones expuestos a dos dosis de las proteínas secretadas por C. perfringens toxinotipo D. Además, un análisis de Western Blot demostró desmielinización en cerebro y cerebelo de animales tratados con las proteínas secretadas. Finalmente, se realizaron pruebas de comportamiento y se determinó que la toxina induce cambios significativos en la actividad motora al aplicar dos dosis subletales. Estos resultados aportan información novedosa del mecanismo de acción de la ETX, lo cual puede llevar a futuras investigaciones que relacionen y ayuden a esclarecer el papel de la ETX en la patogénesis de la EM.Ítem Highly abundant bacteria in the gut of Triatoma dimidiata (Hemiptera: Reduviidae) can inhibit the growth of Trypanosoma cruzi (Kinetoplastea: Trypanosomatidae)(2024) Cambronero Heinrichs, Juan Carlos; Rojas Gätjens, Diego; Baizán Rojas, Mónica; Alvarado Ocampo, Johan; Rojas Jiménez, Keilor Osvaldo; Loaiza Montoya, Randall; Chavarría Vargas, Max; Calderón Arguedas, Ólger; Troyo Rodríguez, AdrianaChagas disease, caused by the protozoan Trypanosoma cruzi, is a zoonosis primarily found in rural areas of Latin America. It is considered a neglected tropical disease, and Triatoma dimidiata is the main vector of the parasite in Central America. Despite efforts, Chagas disease continues to be a public health concern, and vector control remains a primary tool to reduce transmission. In this study, we tested the hypothesis that highly abundant bacteria in the gut of T. dimidiata inhibit the growth of T. cruzi. To achieve this, bacterial diversity in the gut of T. dimidiata specimens from Costa Rica was characterized by metabarcoding of the 16S rRNA, microbial isolation was performed, and the effect of freeze-dried supernatants of the isolates on T. cruzi was investigated. Metabarcoding showed that the most abundant genera in the gut were Corynebacterium, Tsukamurella, Brevibacterium, and Staphylococcus. Barcoding and sequences comparison confirmed that 8 of the 30 most abundant amplicon sequence variants (ASVs) were isolated, and 2 of them showed an inhibitory effect on the growth of T. cruzi epimastigotes. These bacteria correspond to isolates of Tsukamurella and Brevibacterium, which were respectively the second and sixth most abundant ASVs in the gut of T. dimidiata. Notably, only the isolate of Brevibacterium showed a significant difference in growth inhibition against epimastigotes of both T. cruzi strains tested. These findings suggest that the gut microbiota of T. dimidiata may play an active role in modulating parasite development.Ítem Futuro de la terapia y el diagnóstico con vesículas extracelulares(2024) Alvarado Ocampo, Johan; Abrahams Sandí, Elizabeth; Retana Moreira, LissetteLas vesículas extracelulares son nanoparticulas secretadas por células procariotas y eucariotas, con funciones variadas que van desde la comunicación intercelular hasta la modulación de la respuesta inmune. La investigación en este tema se enfocó inicialmente en el aislamiento, identificación y caracterización, para luego abarcar los mecanismos fisiológicos en los que se ven involucradas. Más recientemente, la investigación, particularmente centrada en exosomas, ha permitido abrir campo a novedosas hipótesis sobre su utilidad en inmunoterapia y como marcadores biológicos. Esta revisión explora aspectos básicos sobre la biogénesis y la composición de los exosomas, así como su uso en diagnóstico y tratamiento, a partir del conocimiento generado sobre su aislamiento y purificación, distribución de cargos específicos y su relación con la respuesta inmune. Los hallazgos sobre su aplicabilidad en procesos cancerosos son promisorios; sin embargo, existe toda una ventana de posibilidades para investigar esta plataforma molecular como potenciales vacunas acelulares y marcadores de pronóstico, diagnóstico y alerta, tanto en cáncer como en patologías causadas por agentes infecciosos.Ítem Overview of extracellular vesicles in pathogens with special focus on human extracellular protozoan parasites(2024) Alvarado Ocampo, Johan; Abrahams Sandí, Elizabeth; Retana Moreira, LissetteExtracellular vesicles (EVs) are lipid-bilayered membrane-delimited particles secreted by almost any cell type, involved in different functions according to the cell of origin and its state. From these, cell to cell communication, pathogen-host interactions and modulation of the immune response have been widely studied. Moreover, these vesicles could be employed for diagnostic and therapeutic purposes, including infections produced by pathogens of diverse types; regarding parasites, the secretion, characterisation, and roles of EVs have been studied in particular cases. Moreover, the heterogeneity of EVs presents challenges at every stage of studies, which motivates research in this area. In this review, we summarise some aspects related to the secretion and roles of EVs from several groups of pathogens, with special focus on the most recent research regarding EVs secreted by extracellular protozoan parasites.Ítem Comparative in vitro and in silico analysis of the ability of basic Asp49 phospholipase A2 and Lys49-phospholipase A2-like myotoxins from Bothrops diporus venom to inhibit the metastatic potential of murine mammary tumor cells and endothelial cell tubulogenesis(2024) Sasovsky, Daniela Jaqueline; Angelina, Emilio; Leiva de Vila, Laura Cristina Ana; Bal de Kier Joffé, Elisa Dora; Lomonte, Bruno; Bustillo, SoledadSnake venoms are a complex mixture of proteins and polypeptides that represent a valuable source of potential molecular tools for understanding physiological processes for the development of new drugs. In this study two major PLA2s, named PLA2-I (Asp49) and PLA2-II (Lys49), isolated from the venom of Bothrops diporus from Northeastern Argentina, have shown cytotoxic effects on LM3 murine mammary tumor cells, with PLA2-II-like exhibiting a stronger effect compared to PLA2-I. At sub-cytotoxic levels, both PLA2s inhibited adhesion, migration, and invasion of these adenocarcinoma cells. Moreover, these toxins hindered tubulogenesis in endothelial cells, implicating a potential role in inhibiting tumor angiogenesis. All these inhibitory effects were more pronounced for the catalytically-inactive toxin. Additionally, in silico studies strongly suggest that this PLA2-II-like myotoxin could effectively block fibronectin binding to the integrin receptor, offering a dual advantage over PLA2-I in interacting with the αVβ3 integrin. In conclusion, this study reports for the first time, integrating both in vitro and in silico approaches, a comparative analysis of the antimetastatic and antiangiogenic potential effects of two isoforms, an Asp49 PLA2-I and a Lys49 PLA2-II-like, both isolated from Bothrops diporus venom.Ítem Mandibular gland proteomics of the Mexican alligator lizard, Abronia graminea, and the red-lipped arboreal alligator lizard, Abronia lythrochila(2024-08-02) Calvete Chornet, Juan José; Lomonte, Bruno; Tena Garcés, Jordi; Zollweg, Michael; Dietrich, MebsA useful approach to deepen our knowledge about the origin and evolution of venom systems in Reptilia has been exploring the vast biodiversity of this clade of vertebrates in search of orally produced proteins with toxic actions, as well as their corresponding delivery systems. The occurrence of toxins in anguimorph lizards has been demonstrated experimentally or inferred from reports of the toxic effects of the oral secretions of taxa within the Varanidae and Helodermatidae families. In the present study, we have focused on two alligator lizards of the Anguidae family, the Mexican alligator lizard, Abronia graminea, and the red-lipped arboreal alligator lizard, A. lythrochila. In addition, the fine morphology of teeth of the latter species is described. The presence of a conserved set of proteins, including B-type natriuretic peptides, cysteine-rich secretory proteins, group III phospholipase A2, and kallikrein, in submandibular gland extracts was demonstrated for both Abronia species. These proteins belong to toxin families found in oral gland secretions of venomous reptile species. This finding, along with previous demonstration of toxin-producing taxa in both paleo- and neoanguimorpha clades, provides further support for the existence of a handful of conserved toxin families in oral secretions across the 100+ million years of Anguimorpha cladogenesis.Ítem How bioaugmentation for pesticide removal influences the microbial community in biologically active sand filters(2024-07-27) Pickering, Laura; Castro Gutiérrez, Víctor Manuel; Holden, Barrie; Haley, John; Jarvis, Peter; Campo Moreno, Pablo; Hassard, FrancisRemoving pesticides from biological drinking water filters is challenging due to the difficulty in activating pesticide-degrading bacteria within the filters. Bioaugmented bacteria can alter the filter's microbiome, affecting its performance either positively or negatively, depending on the bacteria used and their interaction with native microbes. We demonstrate that adding specific bacteria strains can effectively remove recalcitrant pesticides, like metaldehyde, yielding compliance to regulatory standards for an extended period. Our experiments revealed that the Sphingobium CMET-H strain was particularly effective, consistently reducing metaldehyde concentrations to levels within regulatory compliance, significantly outperforming Acinetobacter calcoaceticus E1. This success is attributed to the superior acclimation and distribution of the Sphingobium strain within the filter bed, facilitating more efficient interactions with and degradation of the pesticide, even when present at lower population densities compared to Acinetobacter calcoaceticus E1. Furthermore, our study demonstrates that the addition of pesticide-degrading strains significantly impacts the filter's microbiome at various depths, despite these strains making up less than 1% of the total microbial community. The sequence in which these bacteria are introduced influences the system's ability to degrade pesticides effectively. This research shows the potential of carefully selected and dosed bioaugmented bacteria to improve the pesticide removal capabilities of water filtration systems, while also highlighting the dynamics between bioaugmented and native microbial communities. Further investigation into optimizing bioaugmentation strategies is suggested to enhance the resilience and efficiency of drinking water treatment systems against pesticide contamination.