White Piedra Research Articles

Identificação de isolados de leveduras do gênero Trichosporon de infecções superficiais em pacientes do sexo masculino do Brasil Central: uma abordagem sobre a diversidade de infecções causadas por esse fungo basidiomiceto

Abstract The genus Trichosporon are currently recognized as opportunistic pathogens capable of causing superficial "white piedra" infections and potentially fatal invasive diseases (Trichosporonosis). In this work, determine the agent Trichosporon spp. isolated from the skin and appendages of a male population group in the Central-West region of Brazil. The isolates were analyzed by phenotypic, biochemical and molecular methods. Twenty-five strains of Trichosporon were isolated: T. asahii (18; 72%), followed by T. inkin (4; 16%) and T. faecale (3; 12%). Skin infections were the most affected (16; 64%) and the genitocrural region (13; 52%) was the most affected. The highest rate of isolation occurred between the ages of 21 and 30 years (9; 36%), with black men (African descent) (13; 52%) being the most affected by this type of superficial infection. After the advent of molecular techniques, more than 50 subspecies and about 16 different strains have been reported to cause human disease. In this series, three species of the genus Trichosporon of medical importance were highlighted, colonizing the genital and perigenital region of the studied population. For the identifications, classical phenotypic methods associated with genotypic identification were carried out, using molecular techniques based on the study of DNA; using sequence analysis of the DNA intergenic spacer region 1 (IGS1).

INVASIVE TRICHOSPORON INFECTION IN A SARS-COV-2 AND INFLUENZA COINFECTED PATIENT: A CASE REPORT

Trichosporon species can cause systemic or mucosal-associated or superficial infections, including white piedra, as well as invasive fungal infections. They can be an opportunistic cause of invasive infection, especially in patients with hematological malignancies and solid organ tumors or immunosuppressed transplant recipients. There has been an increase in invasive infections due to Trichosporon species in recent years. Treatment of patients with trichosporonosis poses a problem due to limited data regarding the antifungal agents used. In this article, we present a case that resulted in death as a result of invasive trichosporonosis infection that developed after a long stay in intensive care due to co-infection of COVID-19 and influenza.

P279 Invasive Trichosporonosis: an emerging blood stream fungal infection in immunocompromised patients

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PM Trichosporon is a genus of yeast-like fungi. It is perhaps most widely known as the cause of white piedra, a benign superficial mycosis seen in immunocompetent individuals in tropical and subtropical regions. However, the incidence of invasive trichosporonosis has increased in immunocompromised patients, most notably those with hematologic malignancies. Invasive infections due to Trichosporon species are considered rare so far, but during the past two decades, they have emerged as important opportunistic pathogens in immunocompromised individuals. All patients with blood culture positive for Trichosporon species from January 2020 to August 2020 at Woodlands Multispecialty Hospital, Kolkata, India were evaluated. In vitro susceptibility testing was performed using the reference broth micro-dilution method. Clinical co-relation was done with the positive culture report and patient's clinical condition to rule out colonization/contamination. A total of 7 patients were found to have blood culture positive for Trichosporon species among which five were true infections. Various predisposing factors previously reported to be associated with invasive trichosporonosis were also considered in the present study. All the cases were associated with either post radiotherapy/chemotherapy with renal failure requiring dialysis via hemodialysis catheter or use of central venous catheter or chemoport. Underlying malignancy was found in all patients. Susceptibility testing has been performed for 5-FC, amphotericin B, and Azoles. Azoles had good in vitro activity, whereas amphotericin B had higher MIC values. The all-cause mortality rate was 43%. Invasive Trichosporon infection is a rare, life-threatening infection in immunocompromised patients. Our study highlights the association of central venous catheter and hemodialysis catheter with Trichosporon fungemia and its high mortality. Therefore, strict infection control measures while handling these devices are recommended to prevent these infections. Species identification and susceptibility testing are to be attempted for all relevant clinical isolates in view of demonstrable resistance to certain antifungal drugs. Echinocandins are not effective in the treatment of trichosporon infection. Amphotericin B should also be avoided. Azoles, in particular, voriconazole is the drug of choice.

34879 White piedra: An uncommon cause of pseudonits in Northeast Mexico

Introduction: White piedra is a rare superficial mycosis caused by the genus Trichosporon. Its prevalence is higher among tropical climates and predominantly affects children and women. Less than 17 cases have been described in Mexico, none of them in the Northeast region. We present the first case reported in this zone.

A Strange Umbilical Rash in a Newly Diagnosed HIV-Positive Man: A New Clinical Description of a Trichosporon Spp Dermatosis

Trichosporon is a basidiomycete yeast of tropical origin that is also opportunistic in the immunocompromised. It is characterized by irregular nodules attached to the hair called white piedra. Trichosporon spp has been reported as the 2 nd most common agent of disseminated, potentially fatal fungemia [1]. Nevertheless, no pure cutaneous manifestation had been reported. We report a single case of Trichosporon spp causing an umbilical papulonodular rash in a newly diagnosed HIV-positive subject.

Hair shaft disorders: a rare case series

<p class="abstract">The hair shaft is composed of multiple layers, which include the medulla, cortex and cuticle. Genetic disorders, diseases or environmental factors can lead to changes in the properties of these structures, resulting in fragility or alterations in hair shaft texture, appearance or manageability giving rise to various hair shaft disorders. Depending on the fragility of the hair the hair shaft disorders are divided into those with increased fragility and those without increased fragility. A clear detailed history and accompanying microscopic, trichoscopic evaluation help in establishing a diagnosis. In this case series we presented a series of seven hair disorders which included pili torti, trichorehexis nodosa, monelithrix, plica palonica, white piedra, trichoptilosis and Tay’s syndrome. Most of the hair shaft disorders have underlying metabolic disorders or genetic disorders that are left unnoticed and are commonly treated as alopecias which do not improve on treatment. Thereby creating a need of diagnosing these conditions appropriately. The treatment of hair shaft disorders depends on treating the underlying cause. In addition patients must be advised to reduce the traumatic effects on the hair like ironing, chemical treatments, curling.</p>

Molecular identification of yeasts from the order Trichosporonales causing superficial infections

BackgroundThe molecular reclassification of the order Trichosporonales placed the medically relevant Trichosporon species into three genera of the family Trichosporonaceae: Cutaneotrichosporon, Trichosporon, and Apiotrichum. From the clinical and epidemiological standpoint, it is important to identify any species of the family Trichosporonaceae because they present different antifungal susceptibility profiles. In Mexico, little is known about trichosporonosis etiology because the fungi are identified through phenotypic methods. AimsTo identify at a molecular level 12 yeast isolates morfologically compatible with Trichosporon, obtained from patients with superficial infections. MethodsThe yeast isolates were obtained from patients with white piedra, onychomycosis, and hand and foot dermatomycosis, and were identified morphologically and genotypically (sequencing of the IGS1 region and phylogenetic analysis using the Maximum Likelihood Method). The phylogenetic analysis included 40 yeast sequences from the order Trichosporonales and one from Cryptococcus neoformans as outgroup. ResultsBased on the molecular analysis, we identified three (25%) Trichosporon inkin isolates, two (16.7%) Trichosporon asteroides, two (16.7%) Cutaneotrichosporon mucoides, and one each (8.3%) of Trichosporon aquatile, Trichosporon asahii, Apiotrichum montevideense, Cutaneotrichosporon cutaneum, and Cutaneotrichosporon jirovecii. ConclusionsThe molecular characterization of the isolates showed a broad diversity of species within the order Trichosporonales, particularly among onychomycosis. It is essential to identify these yeasts at the species level to delve into their epidemiology.

Trichosporon asahii as an emerging panresistant agent of urinary tract infection: A case report

Objectives: Identification and determination of antifungal susceptibility of this yeast. Case Report: A 65 yrs. male patient k/c/o Diabetes and Hypertension since 5years was admitted with the complaints of decreased urine output and burning micturition since 15 days. After the relevant investigations he was clinically diagnosed with AKI on CKD. Materials and Methods: Urine sample was examined microscopically and Inoculated onto Blood agar, MacConkey agar and SDA and incubated overnight at 37?C. Growth was subjected to gram stain and further processed as per standard protocols conventionally. Isolate was identified by conventional and automation methods. Antifungal susceptibility was performed by Vitek2 system. Sample was collected for two more times and processed similarly to confirm pathogenicity. Results: Wet mount of urine showed many pus cells, yeast cells and fungal hyphae. On SDA cream colored, smooth colonies this later became dry folded. Gram stain of the isolate showed gram positive with lateral budding yeast cells, septate hyphae and rectangular arthrospores. Isolate identified as Trichosporon species conventionally and confirmed as T.asahii by MALDITOF. Antifungal susceptibility revealed multiresistance with preserved susceptibility to Voriconazole. All the three samples showed similar results. Patient was started on Voriconazole and showed improvement clinically. Discussion: T.asahii causes white piedra and onychomycosis in immunocompetent host and disseminated infection in immunocompromised host. Isolation of same yeast in three consecutive urine samples establishes T. asahii as an etiological agent of the infection in our patient. Conclusion: We need to have an increased awareness of disseminated infections due to Trichosporon species which is inherently resistant to AmphotericinB and Caspofungin. Such infections require early diagnosis and treatment for fast recovery of the patient. Keywords: Trichosporon, Asahii, Panresistant, Ur

Preparation and Evaluation of Silver Nanoparticles Embedded in Muntingia calabura Leaf Extract to Cure White Piedra

Trichosporon inkin is recognized as one of the vital causative organisms of white piedra in humans. Very few herbal treatments are available against white piedra. Muntingia calabura (MC) leaf extract and silver (Ag) nanoparticles are identified for their numerous therapeutic applications which is the main purpose of this research work. In this work, we synthesized, characterized, and studied the stability of Ag nanoparticles embedded in the aqueous extract of MC leaf. The antifungal and antioxidant activity of the Ag nanoparticles embedded MC leaf extract was examined using well diffusion method and 2, 2 diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay, respectively. Absorbance peak at 440 nm in UV-visible spectrum confirmed the reduction of silver ions to silver nanoparticles. Dynamic light scattering (DLS) zeta potential analyzer revealed the average particle size of the nanoparticles as 20 nm with the zeta potential of − 18.9 mV. Scanning electron microscope (SEM) analysis showed spherical nanoparticles with a particle size of 20 to 50 nm. Elemental analysis using energy-dispersive x-ray analysis (EDX) identified the presence of Ag. Fourier transforms infrared (FTIR) spectroscopy results predicted functional groups of MC leaf extract and Ag nanoparticles functionalized with MC extract explaining the interaction between them. The crystallinity of silver nanoparticles and particle size was identified using an x-ray diffractometer (XRD). Ag nanoparticles embedded in MC leaf extract exhibited good stability and possessed good antioxidant activity. The zone of inhibition inferred for the Ag nanoparticles embedded in MC leaf extract determined its antifungal activity against Trichosporon inkin. Hence, the developed Ag nanoparticles embedded in MC leaf extract can be used efficiently in any formulations formulated against Trichosporon inkin.

Combinatory Effect of ALA-PDT and Itraconazole Treatment for Trichosporon asahii.

Trichosporiosis is an opportunistic infection that includes superficial infections, white piedra, hypersensitivity pneumonitis, and invasive trichosporonosis. The effect of antifungal agents against these infections is largely weakened by drug resistance and biofilms-related virulence. Photodynamic therapy (PDT) is a new therapeutic approach developed not only to combat cancerous lesions but also to treat infectious diseases such as fungal infections. However, there are few studies on the antimicrobial mechanism of 5-aminolevulinic acid PDT (ALA-PDT) in treating Trichosporon. In this work, we explored the possibility of combining ALA-PDT with an antifungal agent to enhance the therapeutic efficacy of Trichosporon asahii (T. asahii) in a clinical setting and in vitro. The biofilms of T. asahii were constructed by a 96-well plate-based method in vitro. The planktonic and adherent T. asahii were exposed to different concentrations of photosensitizers and different light doses. After PDT treatment, counting colony-forming units and tetrazolium (XTT) reduction assay were used to estimate the antifungal efficacy. The minimal inhibitory concentration of itraconazole before and after PDT treatment was determined by the broth dilution method, and XTT viability assay was used to detect and evaluate the synergistic potential of ALA-PDT and itraconazole combinations in inhibiting biofilms. Scanning electron microscopy (SEM) was performed to assess the disruption of biofilms. Using combination therapy, we have successfully treated a patient who had a T. asahii skin infection. Further in vitro studies showed that the antifungal effect of ALA-PDT on planktonic and adherent T. asahii was dependent on the concentration of ALA and light dosages used. We also found that the sensitivity of both planktonic and biofilm cells to itraconazole were increased after ALA-PDT. Synergistic effect were observed for biofilms in ALA-PDT and itraconazole-combined treatment. The disruption of biofilms was confirmed by SEM, suggesting that ALA-PDT effectively damaged the biofilms and the destruction was further enhanced by ALA-PDT combination of antifungal agents. In conclusion, these data suggest that ALA-PDT could be an alternative strategy for controlling infections caused by Trichosporon. The combination therapy of ALA-PDT with itraconazole could result in increased elimination of planktonic cells and biofilms compared with single therapy. All these findings indicate that it could be a promising treatment against trichosporonosis. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

Efficacy of topical vs combined oral and topical antifungals in white piedra of the scalp.

Topical antifungals are the most commonly used therapy in white piedra of the scalp. However, persistence and relapse of infection still pose a significant challenge. Systemic antifungals have been recommended to enhance the therapeutic response. To compare the efficacy of topical antifungal alone versus combined topical and oral antifungals in the treatment of white piedra of the scalp. Sixty patients with white piedra of the scalp were divided into 3 groups, each containing 20 patients. Group A received topical clotrimazole, group B received combined topical clotrimazole and oral itraconazole, and group C received combined topical clotrimazole and oral terbinafine. The treatment was continued until clearance of infection was confirmed by dermoscopic and mycological examination. Positive responders were followed up for 3months after treatment. All the patients achieved complete clearance of infection. The median treatment time in group B was significantly shorter than group A (P<.001) and group C (P<.001), respectively. In addition, the median treatment time in group C was significantly shorter than group A (P=.002). No recurrence of infection was noted during follow-up period. The three modalities were effective in the treatment of white piedra of the scalp. The most rapid response was observed with the combined use of topical and oral azoles.

White Piedra, a Rare Superficial Mycosis: an Update

White piedra (WP) is a rare superficial mycosis that has been poorly described in the literature. This review aims to summarize our current understanding of Trichosporon spp. infection and WP. Trichosporon spp. are part of the human skin microbiome. The mechanism of hair shaft infection and nodule ultrastructure has been identified. Trichoscopy is an important diagnostic tool. Besides the classical WP signs, atypical presentations and concomitant diseases have also been described. Combination of systemic and topical antifungals is more effective than topical therapy alone. Most cases of WP have occurred in Latin America. High humidity, curly, and long hair are predisposing factors for scalp WP in females. Genital WP is more frequently reported in men. There is a paucity of studies describing the pathophysiology. Therapeutic recommendations are limited to small case series. Species identification is strongly encouraged for further basic and clinical research.

Hemorrhagic Necrotizing Pneumonia Caused by Trichosporon asahii Suspected by Distinctive Histology in Tissue

Abstract Trichosporon spp. are yeast-like organisms most often responsible for superficial skin infections (white piedra) and may transiently colonize the respiratory tract. Trichosporon asahii can be an opportunistic pathogen, causing invasive disease and sometimes disseminated infections, usually in immunocompromised patients. They are the third most commonly isolated yeast species in clinical settings. They cause hemorrhagic and necrotizing bronchopneumonia due to vascular invasion; mycotic emboli are identified within hemorrhagic infarcts. Distinctive pleomorphic budding yeasts, true hyphae, and arthroconidia stain weakly with silver stain in tissue. A 53-year-old HIV-negative male with PMH of schizophrenia and intravenous drug abuse presented with shortness of breath and chest pain. Patient was admitted to the MICU for acute respiratory distress likely secondary to pneumonia. Chest CT scan revealed multiple ill-defined opacities in the lung periphery. The patient had neutrophilic leukocytosis and positive blood culture for methicillin-resistant Staphylococcus aureus and Candida glabrata. Broad-spectrum antibiotics and antifungal drugs (fluconazole, voriconazole, amphotericin B, micafungin) were started. Two weeks later, wedge lung biopsy revealed necrotizing pneumonia with abscess formation and pleomorphic budding yeast-like cells, measuring 3 to 6 microns in diameter; septated hyphae; and arthroconidia. Culture of a bronchial washing was confirmed to be T asahii by matrix-assisted laser desorption/ionization time of flight (MALDI-TOF). Unfortunately, the patient died and partial autopsy of his lungs showed the same pathogen. Invasive respiratory infections caused by T asahii have increased in frequency over the last two decades. Distinctive histology in tissue (pleomorphic yeasts, septated hyphae, and arthroconidia) can suggest the diagnosis, confirmed with MALDI-TOF. Risk factors for invasion include prior antibiotic therapy, central catheterization, malignancy (often hematologic), and intensive care unit admission. Thirty-day all-cause mortality has been reported to be 42% and has been linked to resistance to amphotericin B and echinocandins.

Piedra Branca por Trichosporon ovoides no Sudeste do Brasil: Relato e Breve Revisão da Literatura

A raridade desta entidade e a exuberância destes casos de piedra branca, associada à documentação completa (incluindo a identificação da espécie) motivaram este relato. Mãe e filha apresentando nódulos diminutos, em torno de 1 a 2 mmde diâmetro, coloração branco-amarelada na haste dos cabelos, há cerca de 6 meses. Assintomáticas. O clima quente e húmido e o hábito do uso de cremes recondicionadores podem ter sido fatores determinantes da infecção. A análise dos fios ao microscópio óptico, a cultura e o microcultivo e a espectrometria de massas (MALDI-TOF/MS) concluíram o diagnóstico de piedra branca por Trichosporon ovoides. O tratamento de escolha foi o corte dos cabelos associado a champô de cetoconazol 2%.

Trichoscopy in the Differential Diagnosis of Pseudonits

Aim: The purpose of the study was to describe the trichoscopic features of pseudonits and to assess the usefulness of trichoscopy in their differential diagnosis. Methods: A retrospective study was performed on those patients seen for the suspicion of head or pubic lice and who underwent trichoscopy with polarized light at ×10 magnification for a more accurate diagnosis. Forty-two patients (28 males/14 females, mean age: 34.5 years, range: 7–59) were evaluated. Results: In 30 cases, trichoscopy confirmed the suspicion of head (24 cases) or pubic (6 cases) lice, whereas in 12 cases it allowed for a final diagnosis of seborrheic dermatitis (5 cases), hair casts (3 cases), trichobacteriosis (2 cases), white piedra (1 case), and trichorrhexis nodosa (1 case), by showing different types of pseudonits. Conclusion: Hair examination using trichoscopy in routine clinical practice may provide useful information for the correct diagnosis, ranging from common head and pubic lice infestations to rarer shaft abnormalities. Differentiating pseudonits from nits is essential to make the correct diagnosis in order to prevent unnecessary treatment, anxiety, and/or embarrassment.

Trichosporon inkin meningitis in Northeast Brazil: first case report and review of the literature

BackgroundTrichosporon species may colonize the skin, respiratory tract and gastrointestinal tract of human beings. The yeast is recognized as etiological agent of white piedra, a superficial mycosis. Nevertheless, immunocompromised hosts may develop invasive Trichosporonosis. Central nervous system trichosporonosis is a very rare clinical manifestation. In fact, only a few cases have been published in the literature and none of them was caused by Trichosporon inkin.Case presentationHere we report the first clinical case of meningoencephalitis due to this species in a female previously healthy patient under corticosteroids and antibiotics therapy for several months. She was submitted to an invasive procedure to remove a left sided acoustic neuroma and further developed a cerebrospinal fistula. After some days of the procedure, she presented a predominantly and intensive occipital holocranial headache, followed by vomiting, hyporexia, weight loss, asthenia, irritability, difficulty to concentrate and rotator vertigo. The patient further developed a cerebrospinal fistula in the occipital region and was submitted to a surgical correction. After several months of clinical interventions, she was diagnosed with CNS Trichosporonosis, after Magnetic Resonance Imaging and positive microbiological cultures obtained within two different occasions (2 weeks apart). Despite the antifungal therapy with Amphotericin B and Voriconazole, the patient did not survive.ConclusionsDespite CNS Fungal infections are mostly due to Cryptococcus spp., other emergent yeasts, such as T. inkin may be considered as a likely etiological agent. This is the first case report of CNS Trichosporonosis, where species identification was performed with rDNA sequencing.

Fungal diseases in children and adolescents in a referral centre in Bogota, Colombia.

A cross-sectional descriptive study was conducted at a dermatology referral centre in Bogotá, to estimate the frequencies and aetiologies of mycoses in the population under 18years of age attending the medical mycology laboratory over a 13-year period (2000-2012). A total of 1337 samples from 1221 patients were evaluated, involving direct examination and culture for 1279 samples, direct examination alone for 50 and culture alone for 8. During the study period, dermatophytosis was diagnosed via culture in 537 cases (40.1%). The most common aetiological agents were Trichophytonrubrum (235 cases), Microsporumcanis (177), Trichophytonmentagrophytes (74) and Microsporumgypseum (22). Pityriasis versicolor was found in 31 cases (5.1%), Candida spp. were found in 17 cases, and non-dermatophyte moulds were confirmed by a second sample in 6 cases (3 cases involving Fusarium spp., 2 Neoscytalidiumdimidiatum and 1 Acremonium spp.). In addition, white piedra was diagnosed in 4 cases (0.7%), and tinea nigra in 2 cases (0.3%). Regarding subcutaneous mycoses, 14 cases of sporotrichosis were identified. The results from this study confirm the predominance of dermatophytosis in the paediatric population. T.rubrum and M.canis were the main aetiological agents. We found a few cases of onychomycosis by non-dermatophyte moulds. Sporotrichosis was the only subcutaneous mycosis diagnosed during the study period.

White piedra, black piedra, tinea versicolor, and tinea nigra: contribution to the diagnosis of superficial mycosis.

Superficial mycoses are fungal infections restricted to the stratum corneum and to the hair shafts, with no penetration in the epidermis; they are: white piedra, black piedra, tinea versicolor, and tinea nigra. This study presents images of mycological tests performed in the laboratory, as well as exams performed at the authors office, in order to improve the dermatologist's knowledge about the diagnosis of these dermatoses, which are common in many countries.

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

BACKGROUNDAlthough 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.OBJECTIVETo 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.METHODSThis 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).RESULTSMycological 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).CONCLUSIONSAlthough 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.

Experimental white piedra: a robust approach to ultrastructural analysis, scanning electron microscopy and etiological discoveries

White piedra is a fungal infection characterized by nodules comprised of Trichosporon species and restricted to the extrafollicular portion of the hair shaft. The diagnosis is based on clinical and mycological characteristics, and must be confirmed with a precise identification of the etiological agent. This research aimed to develop an in vitro infection model of white piedra and analyze its morphological and ultra-structural aspects. In the process, hair infection was induced using eight isolates of the genus Trichosporon maintained in the Culture Collection Micoteca URM. The ITS and IGS1 regions were sequenced for taxonomic confirmation. Scanning Electron Microscope (SEM) was performed at the Strategic Center for Northeast Technologies (CETENE). The scanning electron microscope was equipped with an Energy Dispersion Spectrometer (EDS). The Trichosporon isolates were identified as Trichosporon asahii (6) and Trichosporon montevideense (2) by internal transcript spacer (ITS) region and intergenic spacer 1 region (IGS1) sequencing. All eight strains were used to induce the in vitro hair infection, and nodules formed after the incubation period. Temperature variations and high humidity were not observed to be related to the development of this hair disease. The main chemical constituents detected in the nodules were carbon, nitrogen and oxygen, as well as a low level of sulfur. The absence of calcium, combined with the low level of sulfur, might explain the soft nature of the white piedra nodules. This study demonstrated that several Trichosporon species may be responsible for causing white piedra.