Virulence attributes and antifungal resistance of Trichosporon spp. isolates.

• Grant number: 13/07463-6
• Support Opportunities: Scholarships in Brazil - Post-Doctoral
• Effective date (Start): July 01, 2013
• Effective date (End): April 30, 2015
• Field of knowledge: Biological Sciences - Microbiology - Biology and Physiology of Microorganisms
• Principal Investigator: Gustavo Henrique Goldman
• Grantee: Marçal Mariné Mestres
• Host Institution: Faculdade de Ciências Farmacêuticas de Ribeirão Preto (FCFRP). Universidade de São Paulo (USP). Ribeirão Preto , SP, Brazil

Abstract

Virulence attributes and antifungal resistance of Trichosporon ssp. isolatesIntroduction:Trichosporon spp. are opportunistic yeasts that cause a wide range of infections, like superficial infections including white piedra, mucosa-associated, and systemic infections in immunocompromised patients. In recent years the number of patients with infections caused by Trichosporon species has increased and in those cases of systemic infections the prognosis for patients is very poor.Two of the most common species from the genus isolated in clinical settings are Trichosporon asahii and Trichosporon asteroides. T. asahii has commonly been associated to deep-seated infections that lead to fatal outcomes in clinical settings. T. asteroides has been associated to superficial infections, but also in rare occasions to disseminated ones.Traditional antifungal drugs such as Amphotericin B usually fail in the treatment of infections caused by members of the genus Trichosporon, including the species mentioned above.A better understanding of the virulence mechanisms and improving the current treatments against infections caused by these species is an urgent need. In order to develop more effective antifungal therapies, new in vitro and in vivo studies are required.The objectives of the proposed study include:- - The characterization of the morphological distribution of fungal elements such as blastoconidia, arthroconidia, pseudohyphae and hyphae, in different culture media and temperatures aiming to prepare the inocula for the other objectives described below, for three strains of T. ashii and three strains of T. asteroides, isolated from patients with invasive trichosporonosis.-- To establish a Galleria infection model in order to verify the virulence of those six Trichosporon strains.-- To develop an infection model with immunosupressed mice and describe the virulence of the above mentioned strains.-- To describe the antifungal susceptibility profile and test the efficacy of different antifungal treatments using the animal models developed, against those six strains of the genus Trichosporon.