Padronização da espectrometria de massa MALDI-TOF para identificação de cepas de Trichosporon spp. de importância médica / Standardization of MALDI-TOF mass spectrometry for identification of Trichosporon spp of medical relevance

O gênero Trichosporon é composto por leveduras artrosporadas do Filo Basidiomycota e é conhecido agente de infecção fúngica invasiva (IFI) em pacientes imunodeprimidos ou com outros fatores de risco. Em pacientes onco-hematológicos é a principal levedura responsável por IFI depois do gênero Candida. Entre as espécies responsáveis por infecções no homem encontram-se: T. asahii, T. inkin, T. mucoides, T. dermatis, T. jirovecii, T. ovoides, T. cutaneum, T. montevideense, T. domesticum, T. asteroides, T. coremiiforme, T. faecale, T. dohaense, T. lactis, T. japonicum. A tecnologia de identificação de fungos por espectrometria de massa (SM) MALDI-TOF ainda carece de padronização para identificação de fungos do gênero Trichosporon, mas a literatura mostra resultados encorajadores. O objetivo deste estudo é padronizar a técnica de espectrometria de massa MALDI-TOF para a identificação das espécies do gênero Trichosporon de importância médica. O estudo foi realizado em cooperação entre a Divisão de Laboratório Central do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo (DLC, HC-FMUSP), Instituto de Medicina Tropical da USP (IMT-USP), Instituto Adolfo Lutz (IAL) e Laboratoire de Parasitologie-Mycologie do Hospital Saint Antoine de Paris, vinculado ao grupo de pesquisa INSERM/UPMC UMR S945 "Immunité et Infection" Faculté de Medecine et Université Pierre et Marie Curie de Paris. Noventa e três cepas/isolados foram analisado(a)s, sendo dezenove cepas de referência adquiridas junto à coleção holandesa Centraalbureau Schimmelcultures (CBS), 19 isolados do HC-FMUSP e IAL, e 55 isolados de diferentes hospitais franceses. A identificação molecular foi realizada através do sequenciamento da região IGS1 do rDNA e foi considerada como método de referência. O protocolo de extração de proteínas foi estabelecido através da comparação do desempenho de três metodologias (Bruker®, Cassagne et al., Sendid et al.). Os espectros de massa foram obtidos no...

Trichosporon spp. are arthrospored yeasts from the Filum Basidiomycota that are known to produce invasive fungal infection (IFI) in patients with immunosupression or other risk factors. After Candida, Trichosporon is the second genus of yeasts responsible for IFI in patients with onco-hematological diseases. The most important species related to human infection are: T. asahii, T. inkin, T. mucoides, T. dermatis, T. jirovecii, T. ovoides, T. cutaneum, T. montevideense, T. domesticum, T. asteroides, T. coremiiforme, T. faecale, T. dohaense, T. lactis, T. japonicum. The technology of mass spectrometry (MS) for identification of Trichosporon species has not yet been standardized. However, preliminary promising results can be found in the literature. The objective of this study is to analyse and validate MS MALDI-TOF for the identification of Trichosporon species of medical relevance. This was a multicentric study with collaboration from the Central Laboratory Section from Clinics Hospital of the Medical School from the University of São Paulo (DLC-HCFMUSP), Tropical Medicine Institute from the University of São Paulo (IMT-USP), Instituto Adolfo Lutz (IAL) and Laboratoire de Parasitologie-Mycologie from the Hospital Saint Antoine of Paris and INSERM/UPMC UMR S945 "Immunité et Infection", Faculté de Medecine et Université Pierre et Marie Curie of Paris. Ninety three strains/isolates belonging to sixteen Trichosporon species were analysed. Nineteen were purchased from Centraalbureau Schimmelcultures (CBS) yeast collection, 19 belonged to HC-FMUSP and IAL collections, 55 belonged to different French collections. The reference identification method was the IGS1 rDNA sequencing. A protein extraction protocol was first established after comparing the performance of three different methodologies (Bruker(TM),...

Trichosporon species isolated from the perigenital region, urine and catheters of a Brazilian population

The present study aimed to 1) determine the colonization rates of medically important Trichosporon species on normal perigenital skin and 2) determine the isolation rates of Trichosporon spp. isolated from the urine and catheters of Brazilian patients hospitalized in the Intensive Care Unit (ICU). The overall colonization rate of Trichosporon spp. was 11.15 percent (112 isolates). The most common species isolated from normal perigenital skin was T. cutaneum (29.46 percent), followed by T. asteroides (20.53 percent), T. ovoides (15.17 percent), T. inkin (10.71 percent), T. mucoides (8.92 percent), and T. asahii (6.25 percent). From urine and catheters, T. asahii was the species most commonly isolated (76.5 percent; n =23), followed by T. inkin (16.6 percent; n = 5) and T. asteroides (6.6 percent; n = 2). In addition, the highest isolation rate occurred in subjects in the 71- to 80-year-old age range (36.7 percent; n= 11), followed by 61 to 70 (26.7 percent; n = 8), 51 to 60 (13.3 percent; n = 4), 31 to 40 (13.33 percent; n = 4), and 41 to 50 (10 percent; n =3). We concluded that 6 medically important species of the genus Trichosporon colonize the perigenital region in a normal population. The identification of these species is possible by means of classical methods but often requires repeated analyses repetitions due to difficulties in the assimilation process. In contrast, only 3 species of Trichosporon were isolated from urine and catheters.

Antifungal susceptibility profile of trichosporon isolates: correlation between CLSI and etest methodologies

The aim of the present study was to evaluate the antifungal susceptibility profile of Trichosporon species isolated from different sources employing the Clinical and Laboratory Standards Institute (CLSI) method and E-test method. Thirty-four isolates of Trichosporon spp. and six CBS reference samples were tested for their susceptibility to Amphotericin B, 5-flucytosine, Fluconazole, Itraconazole, Voriconazole and Terbinafine. All species showed high Minimun Inhibitory Concentrations (MIC) for Itraconazole and susceptibility to Fluconazole, The comparison among the results obtained by the CLSI method and E-test revealed larger discrepancies among 5-flucytosine and Itraconazole. The present work provides epidemiological data that could influence therapeutic choices. Furthermore, the comparison between different methodologies could help to analyze results obtained by different laboratories.

An outbreak of scalp white piedra in a Brazilian children day care / Surto de piedra branca afetando os cabelos do couro cabeludo de crianças em creche brasileira

White piedra is a superficial mycosis caused by Trichosporon spp. that affects the hair shaft of any part of the body. It is presented an outbreak of scalp white piedra seen in 5.8 percent of the children frequenting a day care in Northeastern of São Paulo State, Brazil. Mycological exam and culture identified T. cutaneum in all five cases, and scanning electron microscopy of nodules around hair shaft infected by Trichosporon spp. is demonstrated comparing them with those of black piedra and with nits of Pediculous capitis.

Piedra branca caracteriza-se por ser micose superficial, causada por Trichosporon spp., que compromete a haste dos pelos de qualquer região do corpo. Um surto de piedra branca, afetando os cabelos do couro cabeludo, foi registrado em 5,8 por cento das crianças que freqüentavam uma creche na região nordeste do estado de São Paulo. Exame micológico direto e cultura identificaram T. cutaneum nas cinco crianças afetadas. Enfatiza-se a utilização da microscopia eletrônica de varredura, que mostrou nódulos circundando a haste dos cabelos infectada por Trichosporon spp., comparando-os com nódulos de Piedra nigra e com lêndeas de Pediculus capitis.

Trichosporon mucoides infección en paciente inmunocompetente / Trichosporon mucoides infection in an immunocompetent host

Mujer de 40 a±os, con historia de un mes de evolución de necrosis progresiva del lecho ungueal del cuarto dedo de la mano derecha, con dolor intenso y destrucción de la placa ungueal. Sin antecedentes patológicos, ni traumßticos. En la biopsia se observaron estructuras micóticas y en los cultivos para hongos se obtuvo crecimiento de Trichosporon mucoides, confirmado mediante pruebas bioquímicas. Se inició fluconazol y se obtuvo resolución del cuadro. Estos hongos son habitantes normales del suelo y se caracterizan por la presencia de hifas verdaderas, pseudohifas, artroconidias y blastoconidas. T. mucoides puede comportarse como un patógeno oportunista que produce infecciones graves en huéspedes inmunocomprometidos. Se conocen casos aislados de T. mucoides como agente causal de onicomicosis pero ninguno con la severidad del caso que aquí se presenta.

A forty-year-old woman, hairdresser, presented a month history of progressive necrosis of the left fourth finger nailbed, accompanied by intense pain, without pathological antecedents and no trauma. Histologic examination showed extensive surface necrosis with abundant cell detritus and erythrocytes, within the necrotic tissue displacing the collagen. There were hyaline, birrefringent structures compatible with arthroconidia Tissue culture for aerobic as well as anaerobic bacteria and mycobacteria were negative. In tissue culture for fungus grew Trichosporon mucoides. A fluconazole therapy was initiated with 400 mg per week dosage, with clinical improvement. This fungus also normal soil inhabitant, is characterized by the presence of true hyphae, other members of the genus have pseudohyphae, arthroconidia y blastoconidia. T. mucoides can also be an opportunistic pathogen producing potentially fatal systemic infections in immunocompromised hosts. Cases of onychomycoses with this fungus as causative organism have been reported, but their symptomatology has not been as severe as in this case.