|520-1||TRICHOSPORON OVOIDES ISOLATION FROM HUMAN UNGUEAL INFECTIONS: IS THERE A PATHOGENIC ROLE?|
|Autores:||Alba Regina de Magalhães (UFF - Universidade Federal Fluminense) ; Marília Martins Nishikawa (INCQS/ FIOCRUZ - Instituto Nacional de Controle de Qualidade em Saúde) ; Silvia Suzana Bona de Mondino (HUAP - UFF - Hospital Universitário Antônio Pedro) ; Elzarlinda Eurich Reis (SANTA CASA - Santa Casa de Misericórdia do Rio de Janeiro) ; Licínio Esmeraldo Silva (IME-UFF - Instituto de Matemática e Estatística) ; Andréa Regina de Souza Baptista (UFF - Universidade Federal Fluminense) |
Onychomycosis is characterized by nail thickening and distrophy, and may affect also the surrounding skin. The frequency of yeast isolation from onychomycosis increased in the last year which has been attributed to both local and systemic factors. Although dermatophytes are considered the major cause of onychomycosis, a great number of reports incriminate non-dermatophyte moulds and yeasts in this disease ethiology. A considerably important frequency of Trichosporon spp. isolation from onychomycosis led to the proposition of a role as a nail primary pathogen for this genus, other than a secondary colonizer. Six major human pathogens in the Trichosporon genus are implicated in both superficial and systemic disease: T. asahii, T. mucoides, T. ovoides, T. asteroides, T. cutaneum and T. inkin. The objective of the present work was to determine Trichosporon species prevalence from patients with clinical suspicion of onychomycosis attending a mycology diagnostic service in Rio de Janeiro, Southeast Brazil, from January 2003 to December 2006. Mycological analysis provided 47/5036 (0.93%) positive results for Trichosporon spp.; obtained mainly as a single agent (72.35%), and also from mixed cultures (27.65%; x2= 6.397; p= 0.018). The great majority belongs to the T. ovoides specie (91.5%; n=43), obtained as a single isolate (74.41%; n= 32/43; x2 = 7.023; p= 0.014). T. ovoides was also detected in mixed cultures from ungueal scrapping along with dermatophytes (two Trycophyton rubrum and one Trycophyton mentagrophytes; 3/43), yeast (four Candida spp.; 4/43) and moulds (two Fusarium spp. and two Scytalidium dimidiatum; 4/43). All fungi recovery from toenail resulted in the identification of the T. ovoides specie. The non identified species from the genus (n=4) were either isolated together with Candida spp. and T. mentagrophytes (one each) and also as the only fungi recovered. In the present study T. ovoides was the exclusive specie isolated from patients suffering from nail disease. Although T. ovoides is classically associated as one of the etiologic agents of white piedra, we were able to isolate this specie in a considerable frequency as a single microorganism from onychomycosis in patients living in Rio de Janeiro, Brazil. Therefore, our study highlights T. ovoides potential as a human nail disease pathogen. Our study open doors for future epidemiologic and virulence factors research aiming at determine whether T. ovoides is an important causative agent of onychomycosis in Brazil.
Palavras-chave: Brazil, Dermatomycosis, Onychomycosis, Trichosporonosis, Trichosporon ovoides