Infección invasora por Trichosporon asahii en un niño con leucemia linfoblástica aguda

La enfermedad fúngica invasora (EFI) es una de las principales causas de morbimortalidad en los pacientes pediátricos inmunocom- prometidos. Los hongos que con mayor frecuencia causan EFI en este grupo de pacientes corresponden a especies de Candida y Aspergillus. Sin embargo, en los últimos años se ha descrito un aumento de patógenos no clásicos, tales como Fusarium, Scedosporium, Mucorales, Cryptococcus, Trichosporon, entre otros. Se presenta un caso de EFI por Trichosporon asahii en un preescolar con una leucemia linfo- blástica aguda en quimioterapia de inducción. Además, se presenta una revisión actualizada de la literatura especializada, con énfasis en la importancia del diagnóstico precoz y el tratamiento antifúngico específico.

Invasive fungal disease (IFD) is one of the leading causes of morbidity and death among immunosuppressed pediatric patients. The fungi that most frequently cause IFD in this group of patients correspond to Candida and Aspergillus species, however, in recent years an increase in non-classical pathogens, such as Fusarium, Scedosporium, Mucorales, Cryptococcus, Trichosporon, among others. A case of invasive fungal disease caused by Trichosporon asahii is presented in a preschool patient with acute lymphoblastic leukemia in induction stage. This review highlights the importance of active search for pathogens in immunosuppressed patients, and proposes a specific treatment.

Infección de vías urinarias a trichosporon asahii. A propósito de 2 casos / Urinary tract infection to trichosporon asahii. About 2 cases

Introducción: Las infecciones de las vías urinarias constituyen una de las patologías infecciosas más frecuentes tanto en la comunidad como en el ámbito hospitalario En el medio hospitalario se ha observado una alta frecuencia de infecciones asociadas a hongos oportunistas, en su mayoría corresponden a especies de Candida spp. Sin embargo, se aíslan otras especies como Trichosporon, donde predomina la especie asahii, en casos de pacientes inmunodeprimidos o con tratamiento previo de antibioticoterapia. Presentación de Casos Clínicos: Se presentan 2 casos donde se aisló en urocultivos Trichosporon asahii. En ambos casos los pacientes presentaron factores de riesgo y síntomas inespecíficos. Conclusión: La presencia de hongos de forma persistente en el tracto urinario es considerada clínicamente significativa. El tratamiento de la funguria debe basarse en el análisis del paciente, de su estado general y de sus factores de riesgo. Para el tratamiento, se observó que el efecto de los triazoles, fueron los más efectivos en el tratamiento de la infección por T. asahii.

Introduction: Urinary tract infections are one of the most frequent infectious pathologies both in the community and in the hospital setting. In the hospital environment, a high frequency of infections associated with opportunistic fungi has been observed, most of which correspond to species of Candida spp. However, other species such as Trichosporon are isolated, where the asahii species predominates (6,7). Presentation of Clinical Cases: Two cases are presented where Trichosporon asahii was isolated in urine cultures. In both cases, the patients presented risk factors and nonspecific symptoms. Conclusion: The persistent presence of fungi in the urinary tract is considered clinically significant (9,10). The treatment of funguria should be based on the analysis of the patient, his general condition and his risk factors (10). For treatment, it was observed that the effect of triazoles was the most effective in the treatment of T. asahii infection (8)

Spectrum of signs, symptoms, and treatment in amphotericin B杛esistant Trichosporon endophthalmitis: A series of ten cases of post朿ataract surgery cluster endophthalmitis

Purpose: The aim of this study was to present the signs, symptoms, management, and outcome of a series of cases of cluster endophthalmitis caused by a multi-drug resistant fungus, Trichosporon. Methods: This was a retrospective, non-randomized, consecutive interventional case series. Ten cases of postoperative endophthalmitis operated by a surgeon on three consecutive operation theater (OT) days presented 3�months after their surgery. All cases were microbiologically confirmed. The pathogen was found to be resistant to most antifungals, including amphotericin B. The cases had a latent period of around 45 days. Management of endophthalmitis included intravitreal injections, anterior chamber (AC) lavage, Pars Plana vitrectomy (PPV), posterior capsulotomy, IOL, and capsular bag removal. Multiple intravitreal injections were required due to recurrence of infections after initial improvement with voriconazole injections. Results: Structural integrity was maintained and infection-free status was achieved in all the eyes. The presenting vision ranged from 6/60 to PL (perception of light). Seven out of 10 had improvement in their final vision over the presenting vision. Final outcome of four patients had vision of 6/24 or better, 4 patients had vision in the range of 2/60 to 6/36 and 2 patients had PL. Conclusion: Trichosporon can cause devasting infections even in the immunocompetent, especially in association with implants and catheters. Triazoles form the mainstay of treatment of Trichosporon infection due to the high susceptibility of the organism in vitro. A regimen including voriconazole and amphotericin B may prove to be the most effective. This is the first report of an outbreak of cluster endophthalmitis caused by Trichosporon

A rare case of fatal sepsis caused by Trichosporon asahii in an immunocompetent chronic obstructive pulmonary disease patient

Trichosporon asahii is a yeast-like organism that is emerging as an important cause of invasive fungal infection in immunocompromised patients, especially in patients with cancer and neutropenia. Invasive infections due to T. asahii in immunocompetent patients are rarely reported. We describe a 62-year-old chronic obstructive pulmonary disease patient who contracted severe sepsis from T. asahii without any prior history of immunosuppression. He was successfully treated with voriconazole and was discharged from the hospital.

Disseminated mucocutaneous trichosporonosis in a patient with histiocytic sarcoma

Abstract Trichosporon asahii is the causal agent of trichosporonosis. Patients with immunosuppression or hematological malignancies are at higher risk of infection. Skin and mucosal involvement appear as fast-growing papulonodular lesions and necrotic ulcers. Internal organ dissemination is lethal. Therapeutic success depends on the underlying disease. Here, the authors present the first case of disseminated mucocutaneous trichosporonosis in a patient with a post-mortem diagnosis of histiocytic sarcoma, a rare and aggressive haematolymphoid neoplasm. Regretfully, death occurred despite treatment with liposomal amphotericin B and supportive measures, showcasing the fatality of both diseases.

Single cell oil production by a novel yeast Trichosporon mycotoxinivorans for complete and ecofriendly valorization of paddy straw

Background: Oleaginous yeasts can be grown on different carbon sources, including lignocellulosic hydrolysate containing a mixture of glucose and xylose. However, not all yeast strains can utilize both the sugars for lipogenesis. Therefore, in this study, efforts were made to isolate dual sugar-utilizing oleaginous yeasts from different sources. Results: A total of eleven isolates were obtained, which were screened for their ability to utilize various carbohydrates for lipogenesis. One promising yeast isolate Trichosporon mycotoxinivorans S2 was selected based on its capability to use a mixture of glucose and xylose and produce 44.86 ± 4.03% lipids, as well as its tolerance to fermentation inhibitors. In order to identify an inexpensive source of sugars, nondetoxified paddy straw hydrolysate (saccharified with cellulase), supplemented with 0.05% yeast extract, 0.18% peptone, and 0.04% MgSO4 was used for growth of the yeast, resulting in a yield of 5.17 g L−1 lipids with conversion productivity of 0.06 g L−1 h−1 . Optimization of the levels of yeast extract, peptone, and MgSO4 for maximizing lipid production using Box­Behnken design led to an increase in lipid yield by 41.59%. FAME analysis of single cell oil revealed oleic acid (30.84%), palmitic acid (18.28%), and stearic acid (17.64%) as the major fatty acids. Conclusion: The fatty acid profile illustrates the potential of T. mycotoxinivorans S2 to produce single cell oil as a feedstock for biodiesel. Therefore, the present study also indicated the potential of selected yeast to develop a zero-waste process for the complete valorization of paddy straw hydrolysate without detoxification

Trichosporon asahii ankle cavity effusion infection in a patient with severe aplastic anemia

Rationale: Trichosporon, an anamorphic fungus, proliferates under high humidity, causing serious opportunistic infections collectively called trichosporonosis. Among the Trichosporon species causing trichosporonosis are Trichosporon (T.) asahii, T. asteroides, T. cutaneum etc. Patient concerns: A 38-year-old Chinese male with severe aplastic anemia was admitted due to multiple joints pain, poor appetite, and right ankle swelling. One year earlier he had undergone allogeneic hematopoietic stem cell transplantation. Diagnosis: T. asahii infection and severe aplastic anemia. Interventions: Combined treatment of amphotericin B liposomes (55 mg/24 h) and voriconazole (200 mg/12 h) for 8 days. Outcomes: The symptoms of the patient's ankle were relieved and effusion cultures showed no T. asahii. Lessons: To the best of our knowledge, T. asahii ankle cavity effusion infections are rare. Trichosporon infections may be attributed to risk factors such as improper long-term use of antimicrobials for an underlying disease (e.g., anemia, hypoalbuminemia). Attention should be paid to prevent and control Trichosporon infections in order to avoid comorbidities.

Trichosporon asahii ankle cavity effusion infection in a patient with severe aplastic anemia

Rationale: Trichosporon, an anamorphic fungus, proliferates under high humidity, causing serious opportunistic infections collectively called trichosporonosis. Among the Trichosporon species causing trichosporonosis are Trichosporon (T.) asahii, T. asteroides, T. cutaneum etc. Patient concerns: A 38-year-old Chinese male with severe aplastic anemia was admitted due to multiple joints pain, poor appetite, and right ankle swelling. One year earlier he had undergone allogeneic hematopoietic stem cell transplantation. Diagnosis: T. asahii infection and severe aplastic anemia. Interventions: Combined treatment of amphotericin B liposomes (55 mg/24 h) and voriconazole (200 mg/12 h) for 8 days. Outcomes: The symptoms of the patient's ankle were relieved and effusion cultures showed no T. asahii. Lessons: To the best of our knowledge, T. asahii ankle cavity effusion infections are rare. Trichosporon infections may be attributed to risk factors such as improper long-term use of antimicrobials for an underlying disease (e.g., anemia, hypoalbuminemia). Attention should be paid to prevent and control Trichosporon infections in order to avoid comorbidities.

Trichosporon asahii fungaemia in an immunocompetent polytrauma patient who received multiple antibiotics

@#Trichosporon asahii is a yeast-like fungus that is emerging as an important cause of invasive infections in tertiary medical centres. A 58-year-old Chinese man with no known medical illnesses presented with liver lacerations and multiple fractures following an alleged 12-foot fall at a construction site. The gravity of his injuries and poor haemodynamic status necessitated an intensive care unit (ICU) admission, during which several febrile episodes were detected and multiple antibiotics were administered. After being in the ICU for at least two weeks, a urease-positive yeast was isolated from the patient’s blood. The yeast formed dry, fuzzy and wrinkled white colonies on Sabouraud dextrose agar following prolonged incubation, and produced blastoconidia, true hyphae, pseudohyphae and arthroconidia on slide culture. It was identified biochemically by the ID 32 C kit as T. asahii. The yeast had elevated minimal inhibitory concentration (MIC) values to fluconazole, amphotericin B, flucytosine and all echinocandins tested. In view of this, the patient was treated with voriconazole and was successfully transferred to the general medical ward.

Endocardite fúngica por trichosporon Asahii: relato de um caso raro em imunocompetentes / Fungal endocarditis due to trichosporon Asahii: a rare case report in immunocompetent subject

Relatar o caso de um paciente com múltiplas trocas valvares aórticas, imunocompetente, com diagnóstico de endocardite fúngica por T. asahii. Relato do caso: Homem, 63 anos, com história de febre reumática e quatro trocas da valva aórtica que evoluiu com sintomas de insuficiência cardíaca aguda e febre. Não foi encontrada nenhuma evidência de imunossupressão. Os exames laboratoriais demonstraram anemia e plaquetopenia leves, com leucograma normal e elevação de lactato desidrogenase e proteína C reativa. O ecocardiograma revelou insuficiência aórtica importante e múltiplas vegetações na valva aórtica. T. asahii foi isolado em duas hemoculturas, sendo iniciada a administração de anfotericina B. O paciente necessitou de cirurgia de emergência para nova troca valvar por deterioração clínica. Em decorrência de complicações intraoperatórias, evoluiu para óbito. Discussão: O diagnóstico e o tratamento da endocardite por T. asahii não estão bem estabelecidos na literatura. Os antifúngicos disponíveis atualmente são triazóis e anfotericina B, com evidências que sugerem superioridade dos triazóis, mas a cirurgia é necessária por ineficácia desses fármacos isoladamente. Conclusões: Faltam dados sobre o tratamento medicamentoso mais eficaz e seguro para a endocardite por T. asahii. Neste caso, as trocas valvares prévias agregaram dificuldade técnica ao novo procedimento, que resultou em evolução desfavorável. Não há dados de literatura sobre o momento ideal para troca valvar em pacientes com múltiplas trocas valvares prévias

To present the case report of an immunocompetent patient with multiple aortic valve replacements, diagnosed with fungal endocarditis due to T. asahii. Case report: A 63-year-old male patient with a history of rheumatic fever and four aortic valve replacements, who progressed with symptoms of acute heart failure and fever. No evidence of immunosuppression was found. Laboratory tests detected mild anemia and thrombocytopenia, with normal leukogram and elevated lactate dehydrogenase and C-reactive protein levels. The echocardiogram revealed severe aortic insufficiency and multiple aortic valve vegetations. T. asahii was isolated in two blood cultures, and administration of amphotericin B was initiated. The patient required emergency surgery for a further valve replacement due to clinical deterioration. The patient later died as a result of intraoperative complications. Discussion: Diagnosis and treatment of T. asahii endocarditis are not well established in the literature. The currently available antifungals are triazoles and amphotericin B, with evidence suggesting superiority of the former, but surgery is required because of the ineffectiveness of these drugs alone. Conclusions: There is insufficient data on the safest and most effective pharmaceutical treatment for T. asahii endocarditis. In this case, the previous valve replacements added technical difficulty to the new procedure, which resulted in an unfavorable outcome. There is no data in the literature on the optimal timing for valve replacement in patients with multiple prior replacements

A Case of Fungemia with Co-isolation of Candida parapsilosis and Trichosporon asahii Confirmed by MALDI-TOF MS and D2 rRNA Sequencing

Fungi are a major cause of human infections with diverse clinical manifestations. The incidence of fungal infections has increased over time, particularly in patients who have risk factors such as neutropenia, immune suppression, an intravascular catheter, parenteral nutrition, a prosthetic device, and prior broad spectrum antibiotic therapy. Here, we present an unusual case of co-infection by 2 distinct fungi, Candida parapsilosis and Trichosporon asahii, isolated from a patient who did not have any known risk factors initially, except active pulmonary tuberculosis. Despite the negative conversion of sputum acid-fast bacilli (AFB) culture test after treatment, clinical symptoms were refractory to therapy. The patient developed symptoms suggesting septic shock, and 2 distinct colonies were isolated from a blood specimen, which were identified as C. parapsilosis and T. asahii by MALDI-TOF and rRNA sequencing. Fever and hypotension were relieved after anti-fungal agent injection, and pulmonary lesions identified by imaging also improved.

Catheter-Related Trichosporon asahii Bloodstream Infection in a Neutropenic Patient with Myelodysplastic Syndrome

Because primary antifungal prophylaxis is widely used for immunocompromised hosts, the incidences of unusual fungal infections have increased. Trichosporon asahii has emerged as an important life-threatening opportunistic systemic pathogen because of the increased use of cytotoxic or immunosuppressant agents, along with high mortality rates. Here, we describe a case of catheter-related T. asahii bloodstream infection with multiple septic skin nodules in both the arms and legs of the patient who was in the neutropenic period after allogeneic stem cell transplantation for myelodysplastic syndrome treated with prophylactic ciprofloxacin and itraconazole. We successfully treated her with intravenous voriconazole for more than a month without any complications. Clinicians should consider breakthrough Trichosporon infections when clinical progress in an immunocompromised patient with unexplained infection signs and symptoms does not improve despite proper treatment with antibiotics or various antifungal agents. In addition, voriconazole can be a good treatment choice for achieving better treatment results and prognosis.

Catheter-Related Trichosporon asahii Bloodstream Infection in a Neutropenic Patient with Myelodysplastic Syndrome

Because primary antifungal prophylaxis is widely used for immunocompromised hosts, the incidences of unusual fungal infections have increased. Trichosporon asahii has emerged as an important life-threatening opportunistic systemic pathogen because of the increased use of cytotoxic or immunosuppressant agents, along with high mortality rates. Here, we describe a case of catheter-related T. asahii bloodstream infection with multiple septic skin nodules in both the arms and legs of the patient who was in the neutropenic period after allogeneic stem cell transplantation for myelodysplastic syndrome treated with prophylactic ciprofloxacin and itraconazole. We successfully treated her with intravenous voriconazole for more than a month without any complications. Clinicians should consider breakthrough Trichosporon infections when clinical progress in an immunocompromised patient with unexplained infection signs and symptoms does not improve despite proper treatment with antibiotics or various antifungal agents. In addition, voriconazole can be a good treatment choice for achieving better treatment results and prognosis.

Current knowledge on Trichosporon spp / 中华检验医学杂志

In recent years , with the increasing of immunocompromised patients , Trichosporon spp. has become a more and more significant clinical opportunistic pathogen .Medical staff should enhance the clinical awareness to this pathogen . In this paper , the classification , virulence factor and pathogenic mechanism, infections, diagnostic methods of laboratory , antifungal susceptibility and treatment of Trichosporon spp. were reviewed systematically . Trichosporon asahii is the major pathogen of invasive infections.Biofilm formation and enzyme production will promote its ability to escape from antifungal drugs and host immune responses .Matrix assisted laser desorption ionization time of flight mass spectrometry has the advantages of accurate , fast and low cost for identification of Trichosporon spp., and zoles is the first-line treatment for invasive infections .

Sepsis secundaria a infección urinaria asociada a sonda vesical por Trichosporon asahii en una unidad pediátrica de quemados: reporte de 2 casos / Trichosporon asahii sepsis associated with urinary catheter in a pediatric burn unit: 2 case reports

Trichosporon asahii es un hongo ubicuo que se ha aislado como parte de la microbiota humana. Recientemente, se ha visto una emergencia de este patógeno en infecciones tanto localizadas como sistémicas. En unidades de cuidados intensivos pediátricos para quemados, existen escasos reportes de infecciones del tracto urinario por este microorganismo. Se describen 2 pacientes pediátricos con internación prolongada por quemaduras extensas y múltiples tratamientos antibióticos previos. Ambos presentaron sepsis por infección del tracto urinario asociada a sonda vesical por Trichosporon asahii. En ambos pacientes, se realizó el recambio de la sonda vesical y tratamiento con voriconazol por 10 días, con buena evolución. En los casos presentados, debido a la ausencia de otros aislamientos microbiológicos y a la buena respuesta al tratamiento antifúngico junto con el recambio de la sonda vesical, se asumió al Trichosporon asahii como el probable agente causal de la sepsis.

Trichosporon asahii is a ubiquitous fungus that has been isolated as part of human microbiota. There has been an emergence of this pathogen in recent years, causing superficial and deep seated infections. There are scarce reports of urinary tract infections in pediatric intensive care burn units caused by this agent. We describe the cases of 2 pediatric patients with prolonged hospitalization due to severe burns that had received several antibiotic courses for previous infections. Both presented sepsis secondary to catheter related urinary tract infection by Trichosporon asahii. Both patients underwent urinary catheter replacement and were treated effectively with voriconazole for 10 days. In the cases presented, sepsis was assumed to be due to Trichosporon asahii since no other microorganism was identified and the patients showed favorable outcome with the prescribed treatment with voriconazole and replacement of the urinary catheter.

Emergence of Trichosporon mycotoxinivorans (Apiotrichum mycotoxinivorans) invasive infections in Latin America

We report the first two cases of Trichosporon mycotoxinivorans infections in Latin America. We also conducted a literature review and a microbiological investigation, including that of clinical and environmental isolates. A 30-year-old man with chronic renal failure had disseminated infection after dialysis and a 15-year-old boy with cystic fibrosis (CF) had pulmonary exacerbations with positive respiratory samples. A review of the relevant literature revealed that deep-seated infections were related to immunosuppression or invasive devices, while most of the CF patients showed a decline in lung function after positive cultures. Phylogenetic analyses revealed three distinct circulating genotypes. MALDI-TOF mass spectrometry analysis showed similar spectral profiles and correctly identified all strains/isolates. Biofilm production was documented in a bloodstream isolate and biofilm-producing cells showed high minimum inhibitory concentrations against antifungals.

Piedra blanca en pacientes de centros dermatológicos de Pereira / Report of cases of white stone in patients of dermatological centers from Pereira

La piedra blanca es una micosis superficial crónica y asintomática poco frecuente del pelo causada por Trichosporon spp. (T. asahii, T. cutaneum o T. beigelii, T. inkin y T. mucoides), caracterizada por presentar nódulos blandos, blanquecinos, adheridos a los tallos pilosos, preferentemente del cuero cabelludo, axilas, cejas, pestañas y con menor frecuencia, en la barba, el bigote, el pubis y el perineo. Suele aparecer con mayor frecuencia en población de climas templados y tropicales. En los tres casos reportados se tomó muestra de los cabellos con los nódulos sospechosos, se le realizaron pruebas diagnósticas que permitieron confirmar la presencia de estructuras levaduriformes compatibles con Trichosporon spp. La sospecha de pediculosis es el motivo de consulta de los pacientes con piedra blanca, confundiendo los nódulos con liendres; por consiguiente es importante que el médico tenga claro las enfermedades micóticas con las cuales se debe hacer el diagnóstico diferencial para poder orientar y establecer el adecuado tratamiento para el paciente

The white stone is a rare, superficial, chronic and asymptomatic mycosis of the hair caused by Trichosporon spp. (T asahii, T. cutaneum or T. beigelli, T. inkin, and T. mucoid), which is characterized by the presence of white soft nodules, adhered to the hair shafts, preferably the scalp, armpits, eyebrows, eyelashes, and less frequently, in the beard, moustache, pubic area and perineum. It usually appears with greater frequency in areas of temperate and tropical climates. In the three reported cases, the sample of hair was taken from suspect hair, and then a series of diagnostic tests were performed to allow the confirmation of the presence of yeast shaped structures compatible with Trichosporon spp. Often, a possible pediculosis was the main reason of consultation of the patients who suffer white stone, and it can be confused with nodules of nits. Therefore, it is important that the physician has a better understanding of the fungal diseases that will be part of the differential diagnosis in order to guide and establish a proper treatment for the patients

Oxidative Stress, Chromium-Resistance and Uptake by Fungi: Isolated from Industrial Wastewater

ABSTRACT Trichosporon asahii and Rhodotorula mucilaginosa isolated from wastewater effluents were identified as chromium-resistant yeasts. Cr(VI) concentrations at 8 mM and 6 mM were inhibitory for R. mucilaginosa and T. asahii. Remarkably elevated GSH (69.88 ± 10.01) and GSSG (11.24 ± 0.96) was observed under metal stress in T. asahii as compared to R. mucilaginosa GSH (18.95 ± 3.19) and GSSG (3.7 ± 2.74) mM g-1 8 level. Statistical analysis revealed significantly higher GSH/GSSG ratio in both strains. NPSH (29.84 ± 0.54) level in T. asahii was much higher than in R. mucilaginosa (6.05 ± 0.24). Chromate reductase (ChR) was assayed and its activity was optimum at 50°C (pH 6) in T. asahii while R. mucilaginosa showed higher activity at 30°C (pH 7). Activity of both ChRs was enhanced in the presence of Mg, Na, Co and Ca but strongly inhibited by Hg cations. Cr(VI) uptake capabilities were ranged between 43-97% in R. mucilaginosa and 35-88% in T. asahii. One dimensional electrophoresis revealed enriched bands of cysteine rich metallothioneins suggesting some differential proteins could be overexpressed under Cr(VI) stress.

Differences in expression of Ras1, Rac1 and Rho1 genes between yeast and hyphal phases of Trichosporon asahii / 中华皮肤科杂志

Objective To investigate differences in the expression of Ras 1,Rac1 and Rho1 genes between yeast and hyphal phases of Trichosporon asahii (T.asahii),and to explore their roles in the formation of hyphae.Methods The yeast phase and hyphal phase of T.asahii were cultured and served as yeast phase group and hyphal phase group respectively.Total RNA was extracted from the 2 groups,and real -time fluorescence-based quantitative PCR (RT-PCR) was performed to measure the mRNA expression of Ras1,Rac1 and Rho1.Results The hyphal formation rate was significantly lower in the yeast phase group than in the hyphal phase group (0.40％ ± 0.53％ vs.99.33％ ± 0.57％,t =13.93,P ＜ 0.05).When the mRNA expression of Ras1,Rac1 and Rho1 in the yeast phase group was all set as 1,that in the hyphal phase group was 25.17 ± 10.99,16.81 ± 7.80,42.61 ± 18.50,respectively,with significant differences between the two groups in the three parameters (t =3.81,3.51,3.90,respectively,all P ＜ 0.05).Conclusion Ras1,Rac1 and Rho1 genes may participate in the regulation of hyphal formation in T.asahii.

Expression of the ERG11 gene in fluconazole-resistant Trichosporon asahii / 中华皮肤科杂志

Objective To investigate the role of the ERG11 gene in the drug resistance of Trichosporon asahii (T.asahii), and to explore the relationship between the gene expression and drug concentrations. Methods Stable fluconazole-resistant strains of T.asahii were induced in vitro following exposure to a series of concentrations of fluconazole. Fluconazole-sensitive and-resistant strains of T.asahii were separately cultured in the medium containing fluconazole at concentrations of 0, 0.25, 0.5, 1, 2, 4, 8, 16, 32 and 64 μg/ml. Real-time quantitative PCR was performed to determine the mRNA expression of ERG11 gene. Results In fluconazole-free medium, the fluconazole-resistant strain of T.asahii showed significantly increased mRNA expression of the ERG11 gene compared with the fluconazole-sensitive strain (7.542 ± 5.311 vs. 1.014 ± 0.012, t=3.002, P=0.03). Additionally, the mRNA expression of ERG11 gene was also significantly higher in the fluconazole-resistant strains than the fluconazole-sensitive strains in the culture medium containing fluconazole at different concentrations of 0.25 (9.183 ± 3.226 vs. 3.281 ± 2.068), 0.5(13.657 ± 5.428 vs. 3.459 ± 1.923), 1(15.292 ± 7.007 vs. 3.242 ± 2.530), 2(13.720 ± 8.550 vs. 3.651 ± 0.728), 4(13.949 ± 2.960 vs. 3.969 ± 1.924)and 8(13.123 ± 6.429 vs. 3.824 ± 1.875)μg/ml(all P<0.05). However, no significant correlation was observed between the mRNA expression of ERG11 gene and fluconazole concentrations(fluconazole-resistant strains: rs = 0.229, P = 0.096; fluconazole-sensitive strains:rs=0.166, P=0.357). Conclusion Overexpression of ERG11 gene is associated with fluconazole resistance in T.asahii, but there is no correlation between the mRNA expression of ERG11 gene and fluconazole concentrations.