Author: Luz Adriana López Ramírez
"Sporotrichosis is an infection caused by members of the Sporothrix genus, and among them, Sporothrix schenckii is one of the etiological agents. Both, the disease and the causative agent have gained interest in the recent years, because of the report of epidemic outbreaks, and the description of the disease transmission from animals to human beings. Despite the relevance of S. schenckii in the clinical field, there are basic aspects of its biology poorly explored. So far, Agrobacterium tumefaciens-mediated transformation has been reported as an alternative for genetic manipulation of this fungal pathogen. Here, we report the optimization of the transformation method and used this to generate insertional mutants that express the green fluorescent protein in S. schenckii. We obtained five mutant strains that showed mitotic stability and expression of the reporter gene. The strains displayed normal cell wall composition, and a similar ability to interact ex vivo with human monocytes and monocyte-derived macrophages. Moreover, the virulence in larvae of Galleria mellonella was similar to that obtained with the wild-type control strains. These data indicate that these fluorescent mutants with normal ability to interact with the host could be used in bioimaging to track the host-Sporothrix interaction in vivo."
NANCY EDITH LOZOYA PEREZ J Sergio Casas Flores José Roberto Fogaça de Almeida JOSE ASCENCION MARTINEZ ALVAREZ Luz Adriana López Ramírez Grasielle Jannuzzi JOSE ELIAS TRUJILLO ESQUIVEL EINE ESTRADA MATA sandro almeida Bernardo Franco Leila Maria Lópes Bezerra HECTOR MANUEL MORA MONTES (2019)
"Background: Sporothrix schenckii is a neglected fungal pathogen for the human being and other mammals. In several fungal systems, Och1 is a Golgi alpha 1,6-mannosyltransferase with a key function in the synthesis of N-linked glycans; which are important elements during the host-fungus interplay. The role of OCH1 in fungal virulence seems to be species-specific, being an essential component for Candida albicans virulence and dispensable during the interaction of Aspergillus fumigatus with the host. Methods: Here, we silenced S. schenckii OCH1 and characterized the phenotype of the mutant strains. Results: The mutant strains did not show defects in the cell or colony morphology, the growth rate or the ability to undergo dimorphism; but the cell wall changed in both composition and exposure of inner components at the surface. When interacting with human monocytes, the silenced strains had a reduced ability to stimulate TNF alpha and IL-6 but stimulated higher levels of IL-10. The interaction with hitman macrophages was also altered, with reduced numbers of silenced cells phagocytosed. These strains showed virulence attenuation in both Galleria mellonella and in the mouse model of sporotrichosis. Nonetheless, the cytokine levels in infected organs did not vary significantly when compared with the wild-type strain. Conclusion: Our data demonstrate that OCH1 silencing affects different aspects of the S. schenckii-host interaction."
Cell wall Protein glycosylation Sporotrichosis Gene silencing Host-fungus interplay Mannosyltransferase MEDICINA Y CIENCIAS DE LA SALUD CIENCIAS MÉDICAS MEDICINA INTERNA ENFERMEDADES INFECCIOSAS ENFERMEDADES INFECCIOSAS