Cutaneotrichosporon (Trichosporon) debeurmannianum: A Rare Yeast Isolated from Blood and Urine Samples.

Cutaneotrichosporon (Trichosporon) debeurmannianum is a rarely isolated yeast from clinical samples. Nine isolates of this yeast were identified from clinical samples within a period of 3 years from June 2012 to May 2015. These isolates were from blood and urine samples sent to a clinical mycology laboratory of a tertiary care hospital in Assam, North East India. Clinically, the patients were diagnosed as septicemia and urinary tract infection. The age of the patients ranged from 2 to 50 years. Identification was made by sequencing the ITS region of ribosomal RNA gene. Antifungal susceptibility test by disk diffusion method (CLSI, M44-A) showed all the isolates to be sensitive to fluconazole and voriconazole. Vitek 2 compact commercial yeast identification system misidentified this yeast as Cryptococcus laurentii and low discrimination Cryptococcus laurentii/Trichosporon mucoides. This species was originally named as Trichosporon debeurmannianum. In 2015, this yeast has been included into new genera Cutaneotrichosporon based on an integrated phylogenetic classification of the Tremellomycetes. To the best of our knowledge, this is the first report of identification of this species from blood and urine samples of clinically suspected cases. We are reporting these isolates because of their rarity in clinical samples. The pathogenic potential and epidemiological relevance of this yeast remains to be seen.

A Trichosporonales genome tree based on 27 haploid and three evolutionarily conserved 'natural' hybrid genomes.

To construct a backbone tree consisting of basidiomycetous yeasts, draft genome sequences from 25 species of Trichosporonales (Tremellomycetes, Basidiomycota) were generated. In addition to the hybrid genomes of Trichosporon coremiiforme and Trichosporon ovoides that we described previously, we identified an interspecies hybrid genome in Cutaneotrichosporon mucoides (formerly Trichosporon mucoides). This hybrid genome had a gene retention rate of ~55%, and its closest haploid relative was Cutaneotrichosporon dermatis. After constructing the C. mucoides subgenomes, we generated a phylogenetic tree using genome data from the 27 haploid species and the subgenome data from the three hybrid genome species. It was a high-quality tree with 100% bootstrap support for all of the branches. The genome-based tree provided superior resolution compared with previous multi-gene analyses. Although our backbone tree does not include all Trichosporonales genera (e.g. Cryptotrichosporon), it will be valuable for future analyses of genome data. Interest in interspecies hybrid fungal genomes has recently increased because they may provide a basis for new technologies. The three Trichosporonales hybrid genomes described in this study are different from well-characterized hybrid genomes (e.g. those of Saccharomyces pastorianus and Saccharomyces bayanus) because these hybridization events probably occurred in the distant evolutionary past. Hence, they will be useful for studying genome stability following hybridization and speciation events. Copyright © 2017 John Wiley & Sons, Ltd.

Onychomycosis caused by Trichosporon mucoides.

A case of onychomycosis caused by Trichosporon mucoides in a man with diabetes is presented. The infection was characterized by a brown-black pigmentation of the nail plates and subungual hyperkeratosis of the first three toes of both feet. Onychogryphosis was also visible on the third left toe. Direct microscopic examinations revealed wide and septate hyphae and spores. Three cultures on Sabouraud-gentamicin-chloramphenicol 2 agar and chromID Candida agar produced white, creamy, and smooth colonies that were judged to be morphologically typical of T. mucoides. Microscopic examinations of the colonies showed arthroconidia and blastoconidia. The urease test was positive. A sugar assimilation test on yeast nitrogen base agar showed assimilation of galactitol, sorbitol, and arabinitol. Matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF) confirmed the diagnosis of T. mucoides infection. The patient was treated with topical urea and oral itraconazole. Three months later, a mild improvement was observed. The patient was subsequently lost to follow-up.

Oral colonization by yeasts in HIV-positive patients in Brazil / Colonização oral por leveduras em pacientes HIV-positivos no Brasil

INTRODUCTION: In HIV-infected patients, colonization of the oral cavity by potential pathogenic yeast may lead to development of systemic fungemia. We evaluated the prevalence of yeast in the oral cavity of Brazilian HIV-positive patients and verified whether or not the species characterized were enzymatically active. Furthermore, the species identified were tested for their susceptibility to antifungal treatment. METHODS: Patient saliva and oropharyngeal candidiasis samples were collected from 60 seropositive HIV patients and identified by the API20C system. Enzymatic activity was evaluated by the production of proteinase and phospholipase. Susceptibility to antifungal treatments were determined using the broth microdilution method. RESULTS: the most commonly isolated species were C. albicans (51.56 percent) followed by non-albicans Candida species (43.73 percent), Trichosporon mucoides (3.12 percent) and Kodamaea ohmeri (1.56 percent). Oral colonization by association of different species was observed in 42 percent of the patients. Enzymatic activity was verified in most of species isolated, except for C. glabrata, C. lusitaniae and C. guilliermondii. Resistance to Fluconazole and Amphotericin B was observed in isolates of C. albicans, C. glabrata, C. parapsilosis, C. krusei, and K. ohmeri. CONCLUSION: HIV-positive patients are orally colonized by single or multiple species of yeast that are occasionally resistant to Fluconazole or Amphotericin B.

INTRODUÇÃO: Em pacientes infectados pelo HIV, a colonização da cavidade bucal por leveduras patogênicas pode levar ao desenvolvimento de fungemias. No presente estudo, avaliamos a prevalência de leveduras na cavidade bucal de pacientes HIV-positivos e verificamos se as espécies isoladas foram enzimaticamente ativas. Além disso, as espécies identificadas foram testadas quanto à suscetibilidade a antifúngicos. MÉTODOS: Amostras de saliva e de candidose orofaríngea foram coletadas de 60 pacientes soropositivos para HIV e identificados pelo sistema API20C. A atividade enzimática foi avaliada pela produção de proteinase e fosfolipase. A suscetibilidade a antifúngicos foi determinada utilizando o método de microdiluição em caldo. RESULTADOS: As espécies mais comumente isoladas foram C. albicans (51,56 por cento), seguido por espécies de Candida não-albicans (43,73 por cento), Trichosporon mucoides (3,12 por cento) e Kodamaea ohmeri (1,56 por cento). A colonização bucal por associação de diferentes espécies foi observada em 42 por cento dos pacientes. A atividade enzimática foi verificada na maioria das espécies isoladas, com exceção de C. glabrata, C. lusitaniae e C. guilliermondii. Resistência ao fluconazol e anfotericina B foi observada em isolados de C. albicans, C. glabrata, C. parapsilosis, C. krusei, e K. ohmeri. CONCLUSÃO: Os pacientes HIV-positivos são colonizados por espécies únicas ou múltiplas de levedura que ocasionalmente são resistentes ao fluconazol ou anfotericina B.

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.