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ABSTRACT Mucormycosis is a rare life-threatening opportunistic infection, with rhinocerebral mucormycosis (ROCM) being the most common presentation. Trichosporon asahii is an emerging pathogen that often causes fatal infections in patients with underlying hematologic malignancies due to its high drug resistance. We report a rare case of concomitant rhinocerebral mucormycosis and T. asahii fungemia secondary to Pseudomonas aeruginosa sepsis in a patient with neutropenia and acute lymphoblastic leukemia. A boy aged one year and two months was diagnosed with B-cell acute lymphoblastic leukemia on January 10 and underwent three courses of regular chemotherapy. He experienced neutropenia for 154 days and was hospitalized for vomiting, diarrhea and fever for 3 days. The day after hospitalization, Pseudomonas aeruginosa was isolated by blood culture and ceftazidime/avibactam was administered. Extracorporeal Membrane Oxygenation (ECMO) was used to provide continuous extracorporeal respiration and circulation for the patient. On day 8, the patient developed T. asahii fungemia. On day 10, he presented with necrotizing skin caused by Rhizopus delemar. He was treated with liposomal amphotericin B for Rhizopus delemar and voriconazole for T. asahii infection. Unfortunately, his health deteriorated and he died on day 11 due to the rapid progression of the infection and multiple organ failure. The management and treatment of such a complex infection requires a multidisciplinary approach and close monitoring of the patient's condition. Therefore, it is imperative to continue to research and report rare cases such as this to further understand the complexities of mucormycosis and trichosporidiosis coinfection and improve patient outcomes.
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Background: patients with congenital cardiopathies are the main group at risk for infective endocarditis (IE) in the pediatric population. Fungal etiology is responsible for 2%-4% of all IEs, and the Trichosporon genus is an increasingly prevalent cause of infections in human beings. Case presentation: We describe a 9-year-old male with multiple surgical procedures to correct congenital cardiopathy defects, including insertion of RV-PA conduit, who was admitted due to suspicion of pneumonia and needed a surgical approach after being diagnosed with a mycotic pseudoaneurysm in the right ventricle's outflow tract, with dilation of the RV-PA conduit. The conduit was removed and antifungal treatment was started with Voriconazole after the agent was identified (T. asahii), with satisfactory therapeutic response. Approximately 4 years later, the patient was readmitted, presenting with intermittent fever, associated with nocturnal diaphoresis, dry cough, anxiety and chest pain. Vegetations consistent with T. asahii were evidenced in the RV-PA conduit, and a surgical approach was once again necessary. Discussion: diagnostic methods and treatment of T. asahii endocarditis aren't yet standardized, and recurrent surgical approaches are needed due to the inefficacy of antifungal treatment.
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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.
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Humanos , Masculino , Pré-Escolar , Leucemia-Linfoma Linfoblástico de Células Precursoras/complicações , Tricosporonose/complicações , Infecções Fúngicas Invasivas , Trichosporon/isolamento & purificação , Tricosporonose/diagnóstico , Tricosporonose/microbiologia , Tricosporonose/tratamento farmacológico , Antifúngicos/uso terapêuticoRESUMO
Yeast fungi of the genus Trichosporon spp. can colonize the gastrointestinal tract in humans. In recent decades, the pathogenic role of Trichosporon asahii has been increasingly acknowledged especially in the setting of neutropenic patients with hematological malignancies. However, non-neutropenic patients who are immunosuppressed for other reasons are also at risk of developing invasive forms of this mycosis. We present the case of a 62-year-old male, with a history of ulcerative colitis under immunosuppressive treatment and previous exposure to antibiotics for various bacterial infections, who was admitted to the emergency department with a mycotic aneurysm of the abdominal aorta and left common iliac secondary to T. asahii infection. A multidisciplinary approach of the case (both early medical and surgical interventions) allowed the patient's favorable outcome. The patient was followed for more than two years with no evidence of relapse. We postulate that the diagnosis of invasive Trichosporonosis should be considered in patients with inflammatory bowel disease (IBD) under immunosuppressive treatment and with prior exposure to antibiotics.
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BACKGROUND: Trichosporon asahii, an emerging fungal pathogen, has been frequently associated with invasive infections in critically ill patients. CASE REPORT: A 74-year-old male patient diagnosed with COVID-19 was admitted to an Intensive Care Unit (ICU). During hospitalization, the patient displayed episodes of bacteremia by Staphylococcus haemolyticus and a possible urinary tract infection by T. asahii. While the bacterial infection was successfully treated using broad-spectrum antibiotics, the fungal infection in the urinary tract was unsuccessfully treated with anidulafungin and persisted until the patient died. CONCLUSIONS: With the evolving COVID-19 pandemic, invasive fungal infections have been increasingly reported, mainly after taking immunosuppressant drugs associated with long-term broad-spectrum antibiotic therapy. Although Candida and Aspergillus are still the most prevalent invasive fungi, T. asahii and other agents have emerged in critically ill patients. Therefore, a proper surveillance and diagnosing any fungal infection are paramount, particularly in COVID-19 immunocompromised populations.
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COVID-19 , Micoses , Trichosporon , Tricosporonose , Infecções Urinárias , Idoso , Antifúngicos/uso terapêutico , Basidiomycota , Estado Terminal , Humanos , Masculino , Micoses/tratamento farmacológico , Micoses/microbiologia , Pandemias , Tricosporonose/diagnóstico , Tricosporonose/tratamento farmacológico , Tricosporonose/microbiologia , Infecções Urinárias/tratamento farmacológico , Infecções Urinárias/microbiologiaRESUMO
Melanin is one of the most studied virulence factors in pathogenic fungi. This pigment protects them from a series of both environmental and host stressors. Among basidiomycetes, Cryptococcus neoformans and Trichosporon asahii are known to produce melanin in the presence of phenolic precursors. Other species from the Trichosporonaceae family also produce this pigment, but the extent to this production among the clinically relevant species is unknown. For this reason, the aim of this study was to verify the production of melanin by different Trichosporonaceae species of clinical interest and to compare their pigments with the ones from C. neoformans and T. asahii, which are more prevalent in human infections. Melanin was produced in a minimal medium supplemented with 1 mM L-dihydroxyphenylalanine (L-DOPA). Pigment was evaluated using scanning electron microscopy, Zeta potential measurements, and energy-dispersive X-ray spectroscopy. It was found that, besides C. neoformans and T. asahii, Trichosporon japonicum, Apiotrichum montevideense, Trichosporon inkin, Trichosporon faecale, Cutaneotrichosporon debeurmannianum, and Cutaneotrichosporon arboriformis also produce melanin-like particles in the presence of L-DOPA. Melanin particles have negative charge and are smaller than original cells. Variations in color, fluorescence, and chemical composition was noticed between the studied strains. All melanins presented carbon, oxygen, sodium, and potassium in their composition. Melanins from the most pathogenic species also presented iron, zinc, and copper, which are important during parasitism. Biophysical properties of these melanins can confer to the Trichosporonaceae adaptive advantages to both parasitic and environmental conditions of fungal growth.
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Rhodotorula spp. and Trichosporon spp. are opportunistic pathogens, and although an association between these two species in the same infection appears to be uncommon, it has been reported. This is the first study that aimed to evaluate the pathogenesis of a co-infection by R. mucilaginosa and T. asahii, using a new in vivo model, the Zophobas morio larvae. Suspensions from planktonic and biofilm-recovered cells were injected in the larvae as in monospecies as mixed (a ratio of 1:1 for both agents of a of 105 inoculum). Individual and mixed biofilms of R. mucilaginosa and T. asahii were produced for 24 and 48 h, and they were partially characterized by crystal violet and reduction of tetrazolium salt. When evaluating the impact of the planktonic suspension in vivo we verified that the fungi in monoculture were more able to kill the larvae than those from planktonic mixed suspension. On the other hand, regarding biofilm-recovered cells, there was an increase in the death of larvae infected for mixed suspensions. Moreover, the death rate was more pronounced when the larvae were infected with 48 h biofilm-recovered cells than the 24 h ones. T. asahii was the best producer of total biomass, mainly in 48 h. The metabolic activity for both yeasts organized in biofilm maintained the same pattern between 24 and 48 h. The present study proves a synergistic interaction between R. mucilaginosa and T. asahii after an experience in a mixed biofilm. Our results suggest that both species were benefited from this interaction, acquiring a greater potential for virulence after passing through the biofilm and this ability was acquired by the cells released from the biofilm.
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Coinfecção , Rhodotorula , Trichosporon , Antifúngicos , Biofilmes , HumanosRESUMO
OBJECTIVES: To investigate the occurrence of Trichosporon asahii fungemia among critically ill COVID-19 patients. METHODS: From 1 July to 30 September 2020, cases of T asahii fungemia (TAF) in a Brazilian COVID-19 referral centre were investigated. The epidemiology and clinical courses were detailed, along with a mycological investigation that included molecular species identification, haplotype diversity analysis and antifungal susceptibility testing. RESULTS: Five critically ill COVID-19 patients developed TAF in the period. All five patients had common risk conditions for TAF: central venous catheter at fungemia, previous exposure to broad-spectrum antibiotics, prior echinocandin therapy and previous prolonged corticosteroid therapy. The average time of intensive care unit hospitalisation previous to the TAF episode was 23 days. All but one patient had voriconazole therapy, and TAF 30-day mortality was 80%. The five T asahii strains from the COVID-19 patients belonged to 4 different haplotypes, mitigating the possibility of skin origin and cross-transmission linking the 5 reported episodes. The antifungal susceptibility testing revealed low minimal inhibitory concentrations for azole derivatives. CONCLUSIONS: Judicious prescription of antibiotics, corticosteroids and antifungals needs to be discussed in critically ill COVID-19 patients to prevent infections by hard-to-treat fungi like T asahii.
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Corticosteroides/administração & dosagem , Antifúngicos/administração & dosagem , Basidiomycota/isolamento & purificação , COVID-19/complicações , Superinfecção/complicações , Tricosporonose/complicações , Corticosteroides/farmacologia , Idoso , Antifúngicos/farmacologia , Basidiomycota/classificação , Basidiomycota/efeitos dos fármacos , Basidiomycota/genética , Brasil/epidemiologia , COVID-19/epidemiologia , Candidemia/complicações , Feminino , Fungemia/complicações , Haplótipos , Humanos , Masculino , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Filogenia , Fatores de Risco , Superinfecção/epidemiologia , Tricosporonose/epidemiologiaRESUMO
Trichosporon asahii is an opportunistic fungal pathogen that can cause severe infections with high mortality rates. Azole derivatives are the best-targeted therapy for T. asahii invasive infections, but azole-resistant isolates have been reported. To investigate peculiarities in the antifungal susceptibility profile (ASP) of T. asahii clinical isolates, we analyzed the genotype distribution, isolation sources, and ASP of 284 strains collected from 1997 to 2019 in different Brazilian medical centers. Species identification and genotype characterization were performed by analysis of the intergenic spacer (IGS1) region of the ribosomal DNA (rDNA). Antifungal susceptibility testing (AST) for amphotericin B and azoles was with the CLSI M27, 4th edition, microdilution broth method. Trends in the ASP of Brazilian T. asahii isolates were investigated using epidemiological cutoff values. Five different genotypes were found among the 284 isolates tested (G1, 76%; G3, 10%; G4, 3%; G5, 7%; and G7, 4%). The isolates were collected mainly from urine (55%) and blood/catheter tip samples (25%) where G1 was the most frequent genotype found (P < 0.05). The G7 isolates exhibited the highest MIC90 values for azoles compared to those for the other genotypes (P < 0.05). Genotype 7 isolates also contributed to the increasing rates of voriconazole non-wild-type isolates found in recent years (P = 0.02). No significant differences were found among the AST results generated by isolates cultured from different anatomical sites. Monitoring T. asahii genotype distributions and antifungal susceptibility profiles is warranted to prevent the spread of azole-resistant isolates.
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Trichosporon , Tricosporonose , Antifúngicos/farmacologia , Basidiomycota , Brasil , DNA Fúngico , Análise de Dados , Genótipo , Humanos , Testes de Sensibilidade Microbiana , Trichosporon/genética , Tricosporonose/tratamento farmacológicoRESUMO
INTRODUCTION: Cases of invasive Trichosporon infections have increasingly emerged; it is now the second leading cause of yeast bloodstream infections after Candida spp., particularly in the immunosuppressed population, where it often causes breakthrough fungemia with high mortality. METHODS: We present a case report of a breakthrough Trichosporon asahii infection in a patient with acute myeloid leukemia and review all of the cases of breakthrough Trichosporon spp. infections published in the literature to date. RESULTS: We extracted 68 cases of breakthrough Trichosporon spp. infections, wherein 95.5% patients had hematological malignancy, 61.8% of them occurred in the presence of echinocandins, 22% of triazoles, 13.2% of amphotericin and 3% of other combinations of antifungals. The most prevalent manifestation was fungemia (94%); 82.8% of these were associated with the presence of a central venous catheter. The overall mortality was 68.7%; the patients who survived recovered from the neutropenic event. CONCLUSIONS: Invasive trichosporonosis is an acute fatal condition that occurs in immunosuppressed patients, usually under antifungal selective pressure. Typically, neutropenia and its underlying diseases are associated with adverse outcomes.
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Leucemia Mieloide Aguda/complicações , Trichosporon/isolamento & purificação , Tricosporonose , Voriconazol/uso terapêutico , Adulto , Anfotericina B/uso terapêutico , Antifúngicos/uso terapêutico , Cateteres Venosos Centrais/efeitos adversos , Equinocandinas/uso terapêutico , Fungemia/patologia , Neoplasias Hematológicas/complicações , Humanos , Hospedeiro Imunocomprometido , Masculino , Pessoa de Meia-Idade , Mortalidade , Neutropenia/complicações , Triazóis/uso terapêutico , Tricosporonose/complicações , Tricosporonose/tratamento farmacológico , Tricosporonose/patologiaRESUMO
Trichosporon asahii has recently been recognized as an emergent fungal pathogen able to cause invasive infections in neutropenic cancer patients as well as in critically ill patients submitted to invasive medical procedures and broad-spectrum antibiotic therapy. T. asahii is the main pathogen associated with invasive trichosporonosis worldwide. Treatment of patients with invasive trichosporonosis remains a controversial issue, but triazoles are mentioned by most authors as the best first-line antifungal therapy. There is mounting evidence supporting the claim that fluconazole (FLC) resistance in T. asahii is emerging worldwide. Since 2000, 15 publications involving large collections of T. asahii isolates described non-wild type isolates for FLC and/or voriconazole. However, very few papers have addressed the epidemiology and molecular mechanism of antifungal resistance in Trichosporon spp. Data available suggest that continuous exposure to azoles can induce mutations in the ERG11 gene, resulting in resistance to this class of antifungal drugs. A recent report characterizing T. asahii azole-resistant strains found several genes differentially expressed and highly mutated, including genes related to the Target of Rapamycin (TOR) pathway, indicating that evolutionary modifications on this pathway induced by FLC stress may be involved in developing azole resistance. Finally, we provided new data suggesting that hyperactive efflux pumps may play a role as drug transporters in FLC resistant T. asahii strains.
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Antifúngicos/uso terapêutico , Triazóis/uso terapêutico , Trichosporon/efeitos dos fármacos , Tricosporonose/tratamento farmacológico , HumanosRESUMO
Trichosporon spp. have been increasingly recognized as an important pathogen of invasive and disseminated infections in immunocompromised patients. These species are prone to form biofilms in medical devices such as catheters and prosthesis, which are associated with antifungal resistance and therapeutic failure. Therefore, new antifungals with a broader anti-biofilm activity need to be discovered. In the present study we evaluate the inhibitory potential of sodium butyrate (NaBut) - a histone deacetylase inhibitor that can alter chromatin conformation - against planktonic and sessile cells of T. asahii and T. inkin. Minimum inhibitory concentration (MIC) of NaBut against planktonic cells was evaluated by microdilution and morphological changes were analyzed by optical microscopy on malt agar supplemented with NaBut. Biofilms were evaluated during adhesion, development and after maturation for metabolic activity and biomass, as well as regarding ultrastructure by scanning electron microscopy and confocal laser scanning microscopy. NaBut inhibited the growth of planktonic cells by 50% at 60â¯mM or 120â¯mM (pâ¯<â¯0.05) and also reduced filamentation of Trichosporon spp. NaBut reduced adhesion of Trichosporon cells by 45% (10xMIC) on average (pâ¯<â¯0.05). During biofilm development, NatBut (10xMIC) reduced metabolic activity and biomass up to 63% and 81%, respectively (pâ¯<â¯0.05). Mature biofilms were affected by NaBut (10xMIC), showing reduction of metabolic activity and biomass of approximately 48% and 77%, respectively (pâ¯<â¯0.05). Ultrastructure analysis showed that NaBut (MIC and 10xMIC) was able to disassemble mature biofilms. The present study describes the antifungal and anti-biofilm potential of NaBut against these opportunist emerging fungi.
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Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Ácido Butírico/farmacologia , Trichosporon/efeitos dos fármacos , Adesão Celular/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Microscopia , Microscopia Confocal , Microscopia Eletrônica de Varredura , Trichosporon/citologia , Trichosporon/crescimento & desenvolvimentoRESUMO
BACKGROUND: Trichosporon asahii is a yeast-like fungus that has recently gained importance as a cause of opportunistic systemic infections. The pathogenicity and virulence factors of T. asahii remain largely unknown. Because of the association between invasive infections and the use of catheters and related devices, the ability of the microorganism to adhere and form biofilms may play an important role in the pathogenicity during a trichosporonosis. AIMS: The aim of this study is to identify an association between biofilm formation by T. asahii isolates and their genotype and/or clinical source. METHODS: The biofilm production of 49 T. asahii strains isolated from Mexican patients was measured using the crystal violet stain method, and a comparison made with different adhesion phase incubation times. Antifungal susceptibility testing was performed using a modified CLSI protocol coupled with the quantification of the viable cells with the XTT reduction method. RESULTS: All the T. asahii isolates assayed were able to produce biofilm in vitro, with an intraspecific variability being observed. Overall, increased biofilm production was found when extending the adhesion phase incubation time from 2 to 4h. No association could be established between the biofilm-producing phenotype and either the genotype or clinical source. Higher antifungal resistance to amphotericin B and fluconazole was linked to increased biofilm production by T. asahii. CONCLUSIONS: All clinical isolates tested were able to produce biofilm. No association could be established between biofilm formation and genotype or clinical source.
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Trichosporon/efeitos dos fármacos , Tricosporonose/microbiologia , Adolescente , Adulto , Idoso , Anfotericina B/farmacologia , Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Criança , Pré-Escolar , Farmacorresistência Fúngica , Feminino , Fluconazol/farmacologia , Humanos , Lactente , Masculino , México , Pessoa de Meia-Idade , Trichosporon/isolamento & purificação , Trichosporon/fisiologia , Adulto JovemRESUMO
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.
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Humanos , Masculino , Pré-Escolar , Infecções Urinárias/etiologia , Sepse/etiologia , Infecções Relacionadas a Cateter/etiologia , Tricosporonose/etiologia , Cateteres Urinários/efeitos adversos , Unidades de Queimados , Queimaduras/complicaçõesRESUMO
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.
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.
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Infecções Relacionadas a Cateter/etiologia , Sepse/etiologia , Tricosporonose/etiologia , Cateteres Urinários/efeitos adversos , Infecções Urinárias/etiologia , Unidades de Queimados , Queimaduras/complicações , Pré-Escolar , Humanos , MasculinoRESUMO
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.
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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
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Humanos , Masculino , Feminino , Infecções Urinárias/microbiologia , Trichosporon/isolamento & purificação , Trichosporon/classificação , Testes de Sensibilidade Microbiana/métodos , Urina/microbiologia , Tricosporonose/epidemiologia , Perfil GenéticoRESUMO
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.
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Corantes Fluorescentes/análise , Hifas/citologia , Organelas/metabolismo , Compostos de Piridínio/análise , Compostos de Amônio Quaternário/análise , Coloração e Rotulagem/métodos , Trichosporon/citologia , Trichosporon/crescimento & desenvolvimento , Hifas/crescimento & desenvolvimento , Microscopia de FluorescênciaRESUMO
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 0.06-1 µg/ml for amphotericin B, 0.25-4 µg/ml for fluconazole, and 0.03-0.06 µg/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.
Assuntos
Antifúngicos/farmacologia , Biofilmes , Trichosporon/efeitos dos fármacos , Trichosporon/fisiologia , Infecção Hospitalar/microbiologia , Genótipo , Hospitalização , Humanos , Testes de Sensibilidade Microbiana , Trichosporon/genética , Trichosporon/isolamento & purificação , Infecções Urinárias/microbiologia , Urina/microbiologiaRESUMO
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.