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.

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.

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.

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.

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.

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.

Epidemiology and antifungal susceptibility analysis of Trichosporon asahii in urinary tract infection / 临床检验杂志

Objective To analyze the epidemiology,infection status,risk factors and microbiological characteristics of Trichosporon asahii in urinary tract infection for guidance of selecting the prompt and effective antifungal drugs in clinical therapy.Methods A total of 18 strains of Trichosporon asahii isolated from the patients with urinary tract infection were selected from 2013 to 2016.The isolation and identification of pathogenic bacteria,results of antimicrobial susceptibility test and clinical data were investigated by retrospective epidemiological survey.Results The 5 antifungal drugs,i.e.,5-fluorocytosine,amphotericin B,fluconazole,itraconazole and voriconazole,exhibited favorable antibacterial activity for the 18 strains of Trichosporon asahii with resistance rate of 0,5.6％,0,0 and 0 except itraconazole which showed only 50％ of sensitive rate.The risk factors of Trichosporon asahii infection in urinary system mainly included such as male,basic diseases (100％),long-term use of broad-spectrum antimicrobial agents (100％),indwelling catheter (83.3 ％),application of corticosteroids (50.0％) and immunosuppressive agents (38.9％) as well as a small proportion of granulocytopenia (5.6％).The 16 cases treated with fluconazole were improved,while the other 2 cases died following the treatment with itraconazole or voriconazole for reasons irrelevant to antifungal treatment.Conclusion Trichosporon asahii could cause urinary tract infections with high risk factors including basic diseases,long-term use of broad-spectrum antimicrobial agents,indwelling catheter,etc.The drug of top choice should be fluconazole.The key elements for successful treatment of Trichosporon asahii infection include early diagnosis of pathogens and correct selection of antifungal agents based on sensitivity and resistance tests of drugs.

The dynamic structure of Spitzenkörpers of Trichosporon asahii examined by the fluorescent probe FM4-64

Abstract The Spitzenkörper is a dynamic and specialized multicomponent cell complex present in the tips of hyphal cells. The amphiphilic styryl dye FM4-64 was found to be ideal for imaging the dynamic changes of the apical vesicle cluster within growing hyphal tips. It is widely used as a marker of endocytosis and to visualize vacuolar membranes. Here we performed uptake experiments using FM4-64 to study the dynamic of the Spitzenkörper in Trichosporon asahii. We observed that Spitzenkörpers were present at the tip of the budding site of the spore, blastospore, and the germ tube of T. asahii. We also found that Spitzenkörpers were present at the tip of the hyphae as well as the subapical regions. Cytochalasin D, an inhibitor of actin polymerization, leads to abnormal Spitzenkörper formation and loss of cell polarity.

Genotipo, sensibilidad a los antifúngicos y formación de biofilm de aislados de Trichosporon asahii recuperados de la orina de pacientes hospitalizados / Genotype, antifungal susceptibility, and biofilm formation of Trichosporon asahii isolated from the urine of hospitalized patients

En este estudio fueron analizadas mediante el cultivo muestras de orina de pacientes hospitalizados en la región centro-oeste de Brasil; los microorganismos aislados fueron identificados filogenéticamente como Trichosporon asahii. A través del análisis de máxima parsimonia de las secuencias de IGS1, fueron encontrados 3 genotipos que no habían sido descritos anteriormente. Las concentraciones inhibitorias mínimas frente a los 9 aislados identificados presentaron un rango de 0,06-1µg/ml en el caso de la anfotericina B, de 0,25-4µg/ml en el del fluconazol, y de 0,03-0,06µg/ml en el del itraconazol. Aproximadamente 6/9 de los aislados de T. asahii formaron biopelículas en la superficie de microplacas de poliestireno. Este trabajo documenta el aislamiento de T. asahii como agente causal de infeciones urinarias nosocomiales. Además, demuestra que la región IGS1 puede ser considerada una nueva herramienta epidemiológica para la genotipificación de los aislados de T. asahii. Los genotipos menos comunes encontrados en este estudio pueden estar relacionados con las características epidemiológicas locales

In this study, the culture analysis of urine samples from patients hospitalized in the Central-West region of Brazil was performed, and the isolated microorganisms were phylogenetically identified as Trichosporon asahii. Maximum parsimony analysis of the IGS1 sequences revealed three novel genotypes that have not been described. The minimum inhibitory concentrations of the nine isolates identified were in the range of 0.06­1µg/ml for amphotericin B, 0.25­4µg/ml for fluconazole, and 0.03­0.06µg/ml for itraconazole. Approximately 6/9 of the T. asahii isolates could form biofilms on the surface of polystyrene microplates. This study reports that the microorganisms isolated here as T. asahii are agents of nosocomial urinary tract infections. Furthermore, the IGS1 region can be considered a new epidemiological tool for genotyping T. asahii isolates. The least common genotypes reported in this study can be related to local epidemiological trends

Bronquiolitis respiratoria y neumonía descamativa asociada a fungemia por trichosporon asahii en inmunocompetente: a propósito de un caso / Respiratory bronchiolitis and desquamative interstitial pneumonia associated with fungemia by trichosporon asahii in immunocompetent: a case report / Bronquiolite respiratória e pneumonia intersticial desquamativa associada a fungômia por trichosporon asahii em imuno-componente: um relato de caso

Trichosporon asahii es un hongo patógeno emergente reportado en la literatura médica principalmente en pacientes inmunocomprometidos. No obstante, el presente caso es inusual debido a que se trata de un paciente adulto joven inmunocompetente que presentó fungemia por T. asahii y al mismo tiempo desarrolló insuficiencia respiratoria aguda por bronquiolitis respiratoria y neumonía descamativa, la cual resolvió posterior al tratamiento antimicótico instaurado, soporte ventilatorio y vigilancia en Unidad de Cuidado Intesivo (UCI).

Trichosporon asahii is an emerging fungal pathogen reported in the medical literature mainly in immunologically compromised patients. However, this case is unusual because is a young immunocompetent patient who developed fungemia by T. asahii simultaneously with acute respiratory failure, respiratory bronchiolitis and desquamative interstitial pneumonia, who responded satisfactorily to ventilatory support and antifungal therapy.

Trichosporon asahii é um patógeno fúngico emergente relatado na literatura médica principalmente em pacientes imunologicamente comprometidos. No entanto, este caso é incomum porque é um jovem imunocompetente que desenvolveu fungemia por T. asahii simultaneamente com insuficiência respiratória aguda, bronquiolite respiratória e pneumonia intersticial descamativa, que responderam satisfatoriamente ao suporte ventilatório e à terapia antifúngica.

Differential diagnosis in bloodstream infection with Trichosporon asahii and Geotrichum capitatum / 中国感染控制杂志

Objective To provide reference for establishing diagnosis and differential diagnosis methods of rare yeast-like fungal bloodstream infection for clinical microbiology laboratory.Methods Trichosporon asahii (T.asa-hii)and Geotrichum capitatum (G.capitatum)bloodstream infection was diagnosed and differentially diagnosed through clinical data analysis,morphological examination,biochemical reactions,and molecular biology technology. Results Two types of yeast-like fungal bloodstream infections in case 1 and case 2 both occurred in leukemia agranulocytosis phase after chemotherapy,such infections were serious and highly similar.The cultivated colonies on blood agar plates of case 1 and case 2 were performed gram stain and microscopic examination.Hyphae,arthro-spores and microconidia were visible in the former,thickness of hyphae branches and length of arthrospores were different,most presented rectangular and barrel shape;the latter can be seen hyphae with transparent septum bro-ken up into arthrospores,presented rectangular shape,did not produce blastoconidia.Identification with API 20C AUX showed that they were T.asahii and G.capitatum.The PCR product sequences were compared with NCBI, suggesting that T.asahii and G.capitatum were at sexual stage.Conclusion Comprehensive application of a varie-ty of technical methods is helpful for improving the diagnosis accuracy of bloodstream infection with yeast-like fungi, identifying Trichosporon and Geotrichum to the species level may help physicians to understand such rare fungal in-fection,choose antifungal agents rationally,and improve clinical prognosis.

Rare severe mycotic infections in children receiving empirical caspofungin treatment for febrile neutropenia

ABSTRACTEmpirical antifungal therapy is most often given to patients with leukemia. However breakthrough fungal infections under antifungal therapy are not uncommon. Four children, with hematologic malignant disease developed mycotic breakthrough infections while on empirical caspofungin treatment for a median of 14 (range 11-19) days. Trichosporon asahii was detected in the blood culture of two patients and Geotrichum capitatum in the other two (one patient also had positive cerebrospinal fluid culture). Because the patients' clinical situation worsened, voriconazole was empirically added for two patients three and five days before the agent was detected. The first sterile blood culture was obtained 3-7 days of voriconazole treatment. All patients reached clear cultures but one patient died. One patient with central nervous system infection with G. capitatum had severe neurological sequelae. Very severe fungal infections can occur during empirical caspofungin therapy. Therefore, patients should be followed closely.

A Case of Trichosporon asahii Fungemia with Urinary Tract Infection as a Primary Focus / 대한임상미생물학회지

Since the report of disseminated trichosporonosis in 1970s, several cases of infection by various Trichosporon species in different clinical patients were published. We've isolated a strain of T. asahii from not only blood but also urine. We report 71 year-old male patient with Trichosporon asahii fungemia, who had renal stones. It was identified as T. asahii using conventional method and also confirmed by 18S rRNA gene sequencing. The patient was discharged without any complication, in which case only antibiotic agent was used without any antifungal one.

A Case of Disseminated Trichosporon asahii Infection in an Immunocompromised Patient / 대한피부과학회지

No abstract available.