Browsing by Autor "Adriana Bernal"

Now showing 1 - 5 of 5

Genome mining to elucidate antimicrobial and plant growth promoting potentials in Lactic acid bacteria
(Springer Science+Business Media, 2025) Christian Vargas; Lina Marcela Botero Rute; Edwin Rodríguez; Lorena Dávila; Camilo Racedo; Claudia Barrera; Adriana Bernal; Hugo Jiménez; Paola Zuluaga; Carolina González Almario
Abstract The pangenome of lactic acid bacteria (LAB) was constructed with five bacterial strains isolated from oat silage produced by smallholder farmers from a region in the highlands of the Colombian Andes. The goal of this work was to use genome mining to elucidate some potential mechanisms of action associated with plant growth promotion and biocontrol in LAB. Multiple genes were uncovered, including those associated with antibiosis and antimicrobial compound production, genes that induce plant defense and phytohormone activation. Additionally, genome sequencing suggested mechanisms for LAB to protect against abiotic and biotic stress. Furthermore, genes that may improve phosphorus availability and those that might stimulate root growth were present. We then tested some of these findings in vitro . For instance, the biocontrol activity of these strains was evaluated against the fungal pathogens Fusarium oxsyporum f. sp. cubense ( Foc R1 and Foc TR4) and the bacterial pathogen Ralstonia solanacearum ( Rs ). All tested strains showed the ability to significantly inhibit pathogen growth in vitro . The capability of LAB to grow at high concentrations of fusaric acid was demonstrated, suggesting that LAB might have detoxification mechanisms to compete with other microorganisms. Also, the ability of LAB to solubilize phosphate and produce IAA was demonstrated. These two properties might be involved in plant-growth promotion. Here we show that genomic sequencing can be an efficient tool to identify putative biocontrol or plant-growth promoting related sequences for genome mining.
Seborrheic dermatitis: predisposing factors and ITS2 secondary structure for<i>Malassezia</i>phylogenic analysis
(Oxford University Press, 2013) Yulien Amado; Anelvi Patiño-Uzcátegui; María Caridad Cepero de García; Javier F. Tabima; Adriana Motta; Martha Cárdenas; Adriana Bernal; Silvia Restrepo; Adriana Marcela Celis Ramírez
Seborrheic dermatitis (SD) is a chronic, widespread skin condition, which is considered a multifactorial disease influenced, in part, by Malassezia spp. opportunistic activities, as well as various endogenous and exogenous factors. Malassezia species are lipophilic, lipid-dependent yeasts that are members of the normal mycobiota of the human skin. Their isolation from SD lesions varies around the world and the study of the relationship among factors such as gender, age, immunosuppressive condition of the patient and SD development, can lead to a better understanding of this disease. To elucidate the association of age and gender with the development of SD and to precisely determine the Malassezia species involved in the disease, samples were obtained from 134 individuals, including individuals without lesions, human immunodeficiency virus positive patients, individuals with seborrheic dermatitis, and HIV patients with seborrheic dermatitis. Malassezia spp. were identified by phenotypic and genotypic methods and a phylogenetic analysis was performed using Bayesian inference. This study revealed that age and gender are not predisposing factors for SD development, and that the most frequent species of Malassezia related to SD development among the Colombian population is M. restricta. We also report the isolation of M. yamatoensis for the first time in Colombia, and propose an ITS2 secondary structure from Malassezia taxa that can be used for precise identification and to establish more robust phylogenetic relationships.
The Type VI Secretion System of Xanthomonas Phaseoli pv. Manihotis is Involved in Virulence and in vitro Motility
(Research Square (United States), 2020) Nathaly Andrea Montenegro Benavides; Alejandro Alvarez Borrero; Mario Luis Arrieta Ortiz; Luis M. Rodriguez‐R; David Octavio Botero Rozo; Javier Felipe Tabima R.; Luisa Fernanda Castiblanco Mosos; Cesar Trujillo Beltran; Silvia Restrepo; Adriana Bernal
Abstract Background: The type VI protein secretion system (T6SS) is important in diverse cellular processes in Gram-negative bacteria, including interactions with other bacteria and with eukaryotic hosts. In this study we analyze the evolution of the T6SS in the genus Xanthomonas and evaluate its importance of the T6SS for virulence and in vitro motility in Xanthomonas phaseoli pv. manihotis ( Xpm ), the causal agent of bacterial blight in cassava ( Manihot esculenta ). We delineate the organization of the T6SS gene clusters in Xanthomonas and then characterize proteins of this secretion system in Xpm strain CIO151. Results: We describe the presence of three different clusters in the genus Xanthomonas that vary in their organization and degree of synteny between species. Using a gene knockout mutagenesis, we also found that vgrG and hcp are required for maximal aggressiveness of Xpm on cassava plants while clpV is important for both motility and maximal aggressiveness. Conclusion: We characterized the T6SS in 15 different strains in Xanthomonas and our phylogenetic analyses suggest that the T6SS might have been acquired by a very ancient event of horizontal gene transfer and maintained through evolution, hinting at their importance for the adaptation of Xanthomonas to their hosts. Finally, we demonstrated that the T6SS of Xpm is functional, and significantly contributes to virulence and motility. This is the first experimental study that demonstrates the role of the T6SS in the Xpm -cassava interaction and the T6SS organization in the genus Xanthomonas .
The Type VI Secretion System of&nbsp;Xanthomonas&nbsp;phaseoli pv. manihotis&nbsp;is involved in virulence and&nbsp;in&nbsp;vitro&nbsp;motility
(Research Square (United States), 2020) Nathaly Andrea Montenegro Benavides; Alejandro Alvarez Borrero; Mario Luis Arrieta Ortiz; Luis M. Rodriguez‐R; David Octavio Botero Rozo; Javier Felipe Tabima R.; Luisa Fernanda Castiblanco Mosos; Cesar Trujillo Beltran; Silvia Restrepo; Adriana Bernal
Abstract Background: The type VI protein secretion system (T6SS) is important in diverse cellular processes in Gram-negative bacteria, including interactions with other bacteria and with eukaryotic hosts. In this study we analyze the evolution of the T6SS in the genus Xanthomonas and evaluate its importance of the T6SS for virulence and in vitro motility in Xanthomonas phaseoli pv. manihotis ( Xpm ), the causal agent of bacterial blight in cassava ( Manihot esculenta ). We delineate the organization of the T6SS gene clusters in Xanthomonas and then characterize proteins of this secretion system in Xpm strain CIO151. Results: We describe the presence of three different clusters in the genus Xanthomonas that vary in their organization and degree of synteny between species. Using a gene knockout strategy, we also found that vgrG and hcp are required for maximal aggressiveness of Xpm on cassava plants while clpV is important for both motility and maximal aggressiveness. Conclusion: We characterized the T6SS in 15 different strains in Xanthomonas and our phylogenetic analyses suggest that the T6SS might have been acquired by a very ancient event of horizontal gene transfer and maintained through evolution, hinting at their importance for the adaptation of Xanthomonas to their hosts. Finally, we demonstrated that the T6SS of Xpm is functional, and significantly contributes to virulence and motility. This is the first experimental study that demonstrates the role of the T6SS in the Xpm -cassava interaction and the T6SS organization in the genus Xanthomonas .
The Type VI Secretion System of&nbsp;Xanthomonas&nbsp;phaseoli pv. manihotis&nbsp;is involved in virulence and&nbsp;in&nbsp;vitro&nbsp;motility
(Research Square (United States), 2020) Nathaly Andrea Montenegro Benavides; Alejandro Alvarez Borrero; Mario Luis Arrieta Ortiz; Luis M. Rodriguez‐R; David Octavio Botero Rozo; Javier Felipe Tabima R.; Luisa Fernanda Castiblanco Mosos; Cesar Trujillo Beltran; Silvia Restrepo; Adriana Bernal
Abstract Background: The type VI protein secretion system (T6SS) is important in diverse cellular processes in Gram-negative bacteria, including interactions with other bacteria and with eukaryotic hosts. In this study we analyze the evolution of the T6SS in the genus Xanthomonas and evaluate its importance of the T6SS for virulence and in vitro motility in Xanthomonas phaseoli pv. manihotis ( Xpm ), the causal agent of bacterial blight in cassava ( Manihot esculenta ). We delineate the organization of the T6SS gene clusters in Xanthomonas and then characterize proteins of this secretion system in Xpm strain CIO151. Results: We describe the presence of three different clusters in the genus Xanthomonas that vary in their organization and degree of synteny between species. Using a gene knockout mutagenesis, we also found that vgrG and hcp are required for maximal aggressiveness of Xpm on cassava plants while clpV is important for both motility and maximal aggressiveness. Conclusion: We characterized the T6SS in 15 different strains in Xanthomonas and our phylogenetic analyses suggest that the T6SS might have been acquired by a very ancient event of horizontal gene transfer and maintained through evolution, hinting at their importance for the adaptation of Xanthomonas to their hosts. Finally, we demonstrated that the T6SS of Xpm is functional, and significantly contributes to virulence and motility. This is the first experimental study that demonstrates the role of the T6SS in the Xpm -cassava interaction and the T6SS organization in the genus Xanthomonas .