Trichosporon isolation from human ungueal infections: Is there a pathogenic role?

Background: although dermatophytes are considered the major cause of onychomycosis,many reports have incriminated non-dermatophyte moulds and yeasts in the disease’s etiology. successive trichosporon isolation from onychomycosis has led to the genus being suspected as a nail primary pathogen. objective: to determine the prevalence of trichosporon isolation in onychomycosis patients who attended a mycology diagnostic service in rio de janeiro,brazil,between january 2003 and december 2006. the study also includes a worldwide review on trichosporon isolation prevalence in ungueal disease,emphasizing t. ovoides. methods: this retrospective study was conducted with the support of staff from the mycology laboratory at the dermatological service of rio de janeiro’s santa casa da misericórdia (mlds). results: mycological analysis provided positive results equaling 47/5036 (0.93%) for trichosporon spp.; obtained mainly as a single agent (72.35%),and from mixed cultures (27.65%; x2= 6.397; p= 0.018). the great majority belongs to the t. ovoides species (91.5%; n=43),obtained as a single isolate (74.41%; n= 32/43; x2 = 7.023; p= 0.014). conclusions: although t. ovoides is classically associated as an etiologic agent of white piedra,this study highlights its potential as a human nail disease pathogen. our study opens doors for future epidemiologic and virulence factors aimed at determining whether t. ovoides is an important causative agent of onychomycosis in brazil. © 2016 by anais brasileiros de dermatologia.