Doctorado en Ciencias - Biología

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https://hdl.handle.net/1992/52128
Encuentre en acceso abierto la producción académica, investigativa y de creación del Doctorado en Ciencias - Biología de la Universidad de los Andes.

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Examinando Doctorado en Ciencias - Biología por Autor "Bernal Giraldo, Adriana Jimena"

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    PublicaciónAcceso abierto
    Elucidation of role of type three effectors from Xanthomonas axonopodis pv. manihotis
    (Universidad de los Andes, 2016) Medina Culma, César Augusto; Bernal Giraldo, Adriana Jimena
    El cultivo de la yuca es uno de los más importantes en los países tropicales, sin embargo este cultivo puede ser afectado por diversas enfermedades fúngicas, bacterianas y virales. El añublo bacteriano de la yuca (CBB por sus siglas en inglés) es considerada la enfermedad bacteriana más importante de la yuca. CBB puede generar importantes pérdidas en los cultivos bajo condiciones climáticas adecuadas. CBB es causado por Xanthomonas axonopodis pv. manihotis (Xam) una bacteria gram negativa la cual posee diferentes factores de virulencia. Los efectores tipo tres (T3Es por sus siglas en inglés) son los factores de virulencia más importantes en otras bacterias fitopatógenas. Este trabajo esta enfocado en determinar la importancia de los T3Es de Xam tomando diferentes aproximaciones. En la primera parte del trabajo se encontró el papel que juegan diferentes T3S en virulencia y en la inmunidad vegetal a través de la generación de cepas mutantes en los T3Es y mediante el uso de sistemas heterólogos que permiten identificar el papel de los T3Es en inmunidad vegetal...
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    PublicaciónRestringido
    Molecular mechanisms of microbial interaction and effects on host health related to acute hepatopancreatic necrosis disease in shrimp
    (Universidad de los Andes, 2021) Restrepo Cardona, Leda Carolina Amparo; Bayot, Bonny; Reyes Muñoz, Alejandro; Zambrano Eder, María Mercedes; Bernal Giraldo, Adriana Jimena
    Microbes play an important role in animal health, especially in aquatic organisms. The omics sciences have improved the understanding of pathogens that cause infectious diseases, not only because it helps to track them and acquire knowledge on their distribution, but it also allows the understanding of how they interact with other microorganisms. Aquatic environments are composed of thousands of bacterial species displaying complex interactions and where selective pressures award those capable of gaining new properties that enhance fitness. This thesis was developed based on the evaluation and implementation of new genomics and metagenomics approaches focused on epidemiological studies in aquatic species, to better understand how a specific aquatic pathogen develops its pathogenesis in situ, as well as the importance of interaction with other microorganisms associated with the host and the factors that control these activities. Furthermore, here I present a series of studies that integrated clinical microbiology, epidemiology, and genomics techniques to study bacterial pathogens that cause AHPND. The specific aims of this thesis were: 1) to investigate the genomic diversity, population structure, virulence potential, and phylogenetic relationships of two closely related Vibrio species, isolated from shrimp cultures that had mortality events caused by a bacterial disease in South America. 2) To investigate the gastric microbiome of shrimp during AHPND infection caused by Vibrio parahaemolyticus and determine probiotic strains that can promote host health, to define whether there are species-specific signatures in the metagenome that can be used to diagnose disease states in shrimp culture. 3) To characterize genetic variation between plasmids and chromosomes, important virulence factors, and phylogenomic relationships of virulent isolates of V. parahaemolyticus strains isolated from South America, along with strains distributed worldwide.
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    PublicaciónEmbargo
    Pathogenicity and resistance to antifungals-fungicides in Fusarium and Neocosmospora A One health approach
    (Universidad de los Andes, 2024-06-05) Sáenz Moncaleano, Valeri Andrea; Celis Ramírez, Adriana Marcela; Jiménez Alzate, María del Pilar; Bernal Giraldo, Adriana Jimena; Facultad de Ciencias::Grupo de Investigación Celular y Molecular de Microorganismos Patógenos (Cemop)
    The primary objective of this doctoral thesis was to determine the presence of Fusarium and Neocosmospora in humans, animals, and plants through a One Health approach. To achieve this, we conducted phenotypic and molecular studies on samples obtained from various environments and human strains in Colombia to identify Fusarium or Neocosmospora. Our research revealed that Neocosmospora keratoplastica and Neocosmospora falciformis are prevalent in samples collected from humans, animals, and the environment (soil and sand). Notably, we describe Sea Turtle Egg Fusariosis (STEF) in sea turtles in Colombia for the first time. Furthermore, to find differences in how Fusarium/Neocosmospora interacts with hosts, we employed a Galleria mellonella animal model. We inoculated the larvae with clinical, animal, and environmental samples to carry out this experiment. We observed similar effects on mortality when the larvae were exposed to 1.5x106 UCF / ml of inoculum and incubated in a maintained incubation at 25 ° C. Also, it was observed that human, animal, and environmental samples can induce mortality in larvae at 37°C. Moreover, we determined the in vitro susceptibility profile of 52 isolates towards antifungal and fungicides. Our findings confirmed high Minimum Inhibitory Concentrations (MICs) to itraconazole, posaconazole, propiconazole, tebuconazole, and difenoconazole. However, amphotericin B and voriconazole showed susceptibility in most of the isolates. Subsequently, we aimed to investigate the antifungal effectiveness of molecules involved in Protein Kinase signaling pathways against Fusarium/Neocosmospora clinical isolates (n=12). To do this, we performed an in vitro test using four different inhibitors: the Pkc1 inhibitor (NPC15437), the p38 MAPK inhibitor (SKF 86002), the human Hsp90-Cdc37 inhibitor (Celastrol), and the antiparasitic drug Miltefosine. Our results indicate that the PKC1 inhibitor (NPC15437) and Miltefosine have promising antifungal activity. Finally, we address the challenges of diagnosing fungal keratitis in clinical and microbiologic settings. This was achieved through a survey of healthcare workers and collaboration with ophthalmologists, clinical microbiologists, and biodesigners to perform the design drafts and initial sketches of a medical device for corneal scraping.