Traveling through the transcriptome and volatilome to understand Malassezia host-bacteria interactions

Malassezia is a lipid-dependent yeast inhabiting human and animal skin, representing about 80% of mycobiota. Although Malassezia is considered commensal, it has been associated with skin diseases that affect the general population. The mechanisms by which these yeasts get this pathogenic role are unknown. Malassezia species exhibit a wide lipid metabolic diversity, enhancing their adaptation processes to the host. However, the involvement of these dynamic processes in the host, and the beginning of the transition from beneficial to pathogenic remain unclear. Likewise, the function of secondary metabolites like volatile compounds in interactional processes with the host and resident or transitory microbiota is undefined. Previous studies about other microorganisms suggest these compounds could also be involved in biological interactions. On the other hand, the yeast and host approach to global gene expression when interacting has yet to be reported. Moreover, Malassezia lipid composition could be involved in the pathogenic processes. This research aims to answer the following question through a metabolomic and transcriptomic approach: What is the effect of the Malassezia metabolism (differential gene expression and volatile compounds production) in its interaction with the host and other bacteria? This question would be solved by implementing a keratinocyte in vitro model supplemented with lipids and infected with M. globosa, followed by a transcriptome analysis throughout RNAseq. Additionally, the determination of the volatile profile for Malassezia spp. was performed by Headspace-solid phase microextraction (HS-SPME) and gas chromatography coupled mass spectrometry (GC-MS) to separate and characterize the volatile compounds. After this, we assessed the interaction processes between volatile compounds and Staphylococcus aureus as a microorganism model from microbiota.

• Autores: Ríos Navarro, Andrea
• Tipo de recurso: Doctoral thesis
• Fecha de publicación: 2024
• Institución: Universidad de los Andes
• Repositorio: Séneca: repositorio Uniandes
• Idioma: eng
• OAI Identifier: oai:repositorio.uniandes.edu.co:1992/74378
• Acceso en línea: https://hdl.handle.net/1992/74378
• Palabra clave: Malassezia; Volatile organic compounds; Transcriptomic; Lipid metabolism; Biological interactions; Biología
• Rights: embargoedAccess
• License: https://repositorio.uniandes.edu.co/static/pdf/aceptacion_uso_es.pdf