Epidemiological study of Trichosporon asahii infections over the past 23 years

Real-time application of ITS and D1-D3 nanopore amplicon metagenomic sequencing in fungal infections: Enhancing fungal infection diagnostics

While fungal infections cause considerable morbidity and mortality, the performance of the current diagnostic tests for fungal infection is low. Even though fungal metagenomics or targeted next-generation sequencing have been investigated for various clinical samples, the real-time clinical utility of these methods still needs to be elucidated. In this study, we used internal transcribed spacer (ITS) and D1-D3 ribosomal DNA nanopore amplicon metagenomic sequencing to assess its utility in patients with fungal infections. Eighty-four samples from seventy-three patients were included and categorized into 'Fungal infection,' 'Fungal colonization,' and 'Fungal contamination' groups based on the judgement of infectious disease specialists. In the 'Fungal infection' group, forty-seven initial samples were obtained from forty-seven patients. Three fungal cases detected not by the sequencing but by conventional fungal assays were excluded from the analysis. In the remaining cases, the conventional fungal assay-negative/sequencing-positive group (n=11) and conventional fungal assay-positive/sequencing-positive group (n=33) were compared. Non-Candida and non-Aspergillus fungi infections were more frequent in the conventional-negative/sequencing-positive group (p-value = 0.031). We demonstrated the presence of rare human pathogens, such as Trichosporon asahii and Phycomyces blakesleeanus. In the 'Fungal infection' group and 'Fungal colonization' group, sequencing was faster than culturing (mean difference = 4.92 days, p-value < 0.001/ mean difference = 4.67, p-value <0.001). Compared to the conventional diagnostic methods including culture, nanopore amplicon sequencing showed a shorter turnaround time and a higher detection rate for uncommon fungal pathogens.

Fungemia due to opportunistic fungi in patients with cancer

BACKGROUND

Fungemia due to uncommon fungi and secondary to multiple risk factors has become an emergent health problem, particularly in oncology patients.

AIMS

This study shows the following data collected during an 11-year period in a tertiary care oncologic center from patients with fungemia: demographic data, clinical characteristics, and outcome.

METHODS

A retrospective study was performed at Instituto Nacional de Cancerología, a 135-bed referral cancer center in Mexico City, from July 2012 to June 2023. All episodes of non-Candida fungemia were included.

RESULTS

Sixteen cases with uncommon fungemia were found in the database, representing 0.3% from all the blood cultures positive during the study period, and 8.5% from all the fungi isolated. The most common pathogens identified in our series were Histoplasma capsulatum, Acremonium spp., Trichosporon asahii, and Saccharomyces cerevisiae. Eight patients had hematologic malignancies, and five had severe neutropenia. In eight cases fungemia was considered catheter-related, in four cases was classified as primary, and in the last four it was diagnosed as disseminated fungal diseases. Mortality at 30 days was 43.8%.

CONCLUSIONS

The improved diagnostic tools have led to a better diagnosis of uncommon fungal infections. More aggressive therapeutic approaches, particularly in patients with malignancies, would increase survival rates in these potentially fatal diseases.

Analysis of epidemiological and clinical aspects in cases of fungal osteomyelitis caused by non-Candida species

Osteomyelitis caused by non-Candida species is rare and often neglected, and current recommendations are based on primarily clinical experience and expert opinion. The objective of this study was to describe a case series of non-Candida fungal osteomyelitis. This retrospective study included 10 patients with non-Candida fungal osteomyelitis. Patients with osteomyelitis and microbiologically confirmed non-Candida species from bone fragment cultures were selected from the institution Infection Control Board database. Fusarium spp. were the most commonly isolated fungus from bone fragment cultures in five patients (50%). The majority did not present immunosuppression. The most common etiology was post-traumatic (n = 7, 70%), particularly open fractures. All patients were treated with antifungals associated with surgery. The antifungals used were itraconazole in five patients (50%), and voriconazole in another five patients (50%), with a median duration of antifungal therapy of four weeks (range: 3-25). There were no observed deaths within 30 days and one year. An antifungal approach combined with surgical treatment demonstrated favorable clinical outcomes, including low mortality rates and effective remission.

Universal digital high-resolution melting for the detection of pulmonary mold infections

Invasive mold infections (IMIs) are associated with high morbidity, particularly in immunocompromised patients, with mortality rates between 40% and 80%. Early initiation of appropriate antifungal therapy can substantially improve outcomes, yet early diagnosis remains difficult to establish and often requires multidisciplinary teams evaluating clinical and radiological findings plus supportive mycological findings. Universal digital high-resolution melting (U-dHRM) analysis may enable rapid and robust diagnoses of IMI. A universal fungal assay was developed for U-dHRM and used to generate a database of melt curve signatures for 19 clinically relevant fungal pathogens. A machine learning algorithm (ML) was trained to automatically classify these pathogen curves and detect novel melt curves. Performance was assessed on 73 clinical bronchoalveolar lavage samples from patients suspected of IMI. Novel curves were identified by micropipetting U-dHRM reactions and Sanger sequencing amplicons. U-dHRM achieved 97% overall fungal organism identification accuracy and a turnaround time of ~4 hrs. U-dHRM detected pathogenic molds (Aspergillus, Mucorales, Lomentospora, and Fusarium) in 73% of 30 samples classified as IMI, including mixed infections. Specificity was optimized by requiring the number of pathogenic mold curves detected in a sample to be >8 and a sample volume to be 1 mL, which resulted in 100% specificity in 21 at-risk patients without IMI. U-dHRM showed promise as a separate or combination diagnostic approach to standard mycological tests. U-dHRM's speed, ability to simultaneously identify and quantify clinically relevant mold pathogens in polymicrobial samples, and detect emerging opportunistic pathogens may aid treatment decisions, improving patient outcomes.

IMPORTANCE

Improvements in diagnostics for invasive mold infections are urgently needed. This work presents a new molecular detection approach that addresses technical and workflow challenges to provide fast pathogen detection, identification, and quantification that could inform treatment to improve patient outcomes.

Trichosporon asahii co-infection with Pneumocystis jiroveci in a renal transplant patient

Trichosporon asahii is considered an opportunistic pathogen, capable of causing superficial infections in humans and invasive deep-seated infections in immunocompromised hosts. Pneumocystis jirovecii can cause life-threatening pneumonia in immunosuppressed patients. Both Trichosporon and Pneumocystis jirovecii are highly lethal in immunocompromised individuals. Here we present a case of invasive Trichosporon asahii co-infection with Pneumocystis jiroveci in a renal transplant patient.

Photodynamic therapy successfully treats refractory onychomycosis caused by Trichosporon asahii: a case report

Onychomycosis, a fungal infection affecting the nail, is characterized by discoloration and thickening of the nail plate and is the most prevalent nail infection globally. We present a case of onychomycosis caused by Trichosporon asahii, a less common etiology. Notably, the patient was successfully treated with a non-traditional antibacterial approach, photodynamic therapy, which has been infrequently documented in the literature for such infections.

Erythematous ulcero-proliferative exophytic lesion in an oral squamous cell carcinoma patient- An unusual case of Trichosporonosis

ABSTRACT

The emergence of non-Candida yeast infections in humans has been increasingly recognized over the last decades. Trichosporon is the third most isolated non-candidal yeast in patients with an impaired immune system. We report a rare case of Trichosporon asahii causing erythematous oral lesion in a patient with squamous cell carcinoma. Our case highlights the occurrence of unusual yeast pathogens in patients with cancer with typical clinical presentations and warrants suspicion of fungal etiology to prevent misdiagnosis of trichosporonosis.

Genome-Wide Identification and Characterization of the Medium-Chain Dehydrogenase/Reductase Superfamily of Trichosporon asahii and Its Involvement in the Regulation of Fluconazole Resistance

The medium-chain dehydrogenase/reductase (MDR) superfamily contains many members that are widely present in organisms and play important roles in growth, metabolism, and stress resistance but have not been studied in Trichosporon asahii. In this study, bioinformatics and RNA sequencing methods were used to analyze the MDR superfamily of T. asahii and its regulatory effect on fluconazole resistance. A phylogenetic tree was constructed using Saccharomyces cerevisiae, Candida albicans, Cryptococcus neoformans, and T. asahii, and 73 MDRs were identified, all of which contained NADPH-binding motifs. T. asahii contained 20 MDRs that were unevenly distributed across six chromosomes. T. asahii MDRs (TaMDRs) had similar 3D structures but varied greatly in their genetic evolution at different phylum levels. RNA-seq and gene expression analyses revealed that the fluconazole-resistant T. asahii strain upregulates xylitol dehydrogenase, and downregulated alcohol dehydrogenase and sorbitol dehydrogenase concluded that the fluconazole-resistant T. asahii strain was less selective toward carbon sources and had higher adaptability to the environment. Overall, our study contributes to our understanding of TaMDRs, providing a basis for further analysis of the genes associated with drug resistance in T. asahii.

Effect of warm and humid days on the positivity rate of anti-Trichosporon asahii antibody test for the diagnosis of summer-type hypersensitivity pneumonitis

BACKGROUND

Summer-type hypersensitivity pneumonitis (SHP) has been reported to occur during warm and humid summer seasons in Japan; however, the effect of weather conditions on SHP remains unknown. Anti-Trichosporon asahii antibody (TaAb) test is highly specific and useful for the diagnosing SHP. Therefore, we aimed to investigate the impact of weather conditions on SHP by examining the relationship between the positivity rate of TaAb and warm and humid days.

METHODS

TaAb test data from June 2013 to June 2020 were obtained from major commercial laboratories to determine the number of samples and positivity rate of TaAb by prefecture. Using the Japan Meteorological Agency database, we counted the warm and humid days (maximum temperature ≥25 °C and average humidity ≥80 %) for each prefecture. Negative binomial regression was employed to examine the relationship between the positivity rate of TaAb and the number of warm and humid days per month.

RESULTS

A total of 79,211 samples and 7626 positive samples (9.6 %) were identified. We found that the number of warm and humid days, 1 or 2 months prior to testing for TaAb, was associated with the positivity rate of the test. An increase in the positivity rate by 1.6 % and 2.9 % was observed with every 1-day increase in warm and humid days 1 month and 2 months before the test, respectively.

CONCLUSIONS

Our TaAb analysis revealed a significant increase in TaAb positivity 1 or 2 months after periods of warm and humid days.

Update on therapeutic approaches for invasive fungal infections in adults

Invasive fungal infections are increasingly encountered with the expansion of iatrogenic immunosuppression, including not only solid organ and hematopoietic stem cell transplant recipients but also patients with malignancies or autoimmune diseases receiving immunomodulatory therapies, such as Bruton Tyrosine Kinase (BTK) inhibitor. Their attributable mortality remains elevated, part of which is a contribution from globally emerging resistance in both molds and yeasts. Because antifungal susceptibility test results are often unavailable or delayed, empiric and tailored antifungal approaches including choice of agent(s) and use of combination therapy are heterogeneous and often based on clinician experience with knowledge of host's net state of immunosuppression, prior antifungal exposure, antifungal side effects and interaction profile, clinical severity of disease including site(s) of infection and local resistance data. In this review, we aim to summarize previous recommendations and most recent literature on treatment of invasive mold and yeast infections in adults to guide optimal evidence-based therapeutic approaches. We review the recent data that support use of available antifungal agents, including the different triazoles that have now been studied in comparison to previously preferred agents. We discuss management of complex infections with specific emerging fungi such as Scedosporium spp., Fusarium spp., Trichosporon asahii, and Candida auris. We briefly explore newer antifungal agents or formulations that are now being investigated to overcome therapeutic pitfalls, including but not limited to olorofim, rezafungin, fosmanogepix, and encochleated Amphotericin B. We discuss the role of surgical resection or debridement, duration of treatment, follow-up modalities, and need for secondary prophylaxis, all of which remain challenging, especially in patients chronically immunocompromised or awaiting more immunosuppressive therapies.

Universal Digital High Resolution Melt for the detection of pulmonary mold infections

Background

Invasive mold infections (IMIs) such as aspergillosis, mucormycosis, fusariosis, and lomentosporiosis are associated with high morbidity and mortality, particularly in immunocompromised patients, with mortality rates as high as 40% to 80%. Outcomes could be substantially improved with early initiation of appropriate antifungal therapy, yet early diagnosis remains difficult to establish and often requires multidisciplinary teams evaluating clinical and radiological findings plus supportive mycological findings. Universal digital high resolution melting analysis (U-dHRM) may enable rapid and robust diagnosis of IMI. This technology aims to accomplish timely pathogen detection at the single genome level by conducting broad-based amplification of microbial barcoding genes in a digital polymerase chain reaction (dPCR) format, followed by high-resolution melting of the DNA amplicons in each digital reaction to generate organism-specific melt curve signatures that are identified by machine learning.

Methods

A universal fungal assay was developed for U-dHRM and used to generate a database of melt curve signatures for 19 clinically relevant fungal pathogens. A machine learning algorithm (ML) was trained to automatically classify these 19 fungal melt curves and detect novel melt curves. Performance was assessed on 73 clinical bronchoalveolar lavage (BAL) samples from patients suspected of IMI. Novel curves were identified by micropipetting U-dHRM reactions and Sanger sequencing amplicons.

Results

U-dHRM achieved an average of 97% fungal organism identification accuracy and a turn-around-time of 4hrs. Pathogenic molds (Aspergillus, Mucorales, Lomentospora and Fusarium) were detected by U-dHRM in 73% of BALF samples suspected of IMI. Mixtures of pathogenic molds were detected in 19%. U-dHRM demonstrated good sensitivity for IMI, as defined by current diagnostic criteria, when clinical findings were also considered.

Conclusions

U-dHRM showed promising performance as a separate or combination diagnostic approach to standard mycological tests. The speed of U-dHRM and its ability to simultaneously identify and quantify clinically relevant mold pathogens in polymicrobial samples as well as detect emerging opportunistic pathogens may provide information that could aid in treatment decisions and improve patient outcomes.

Genetic analysis of emerging fungal pathogens: Trichosporon asahii

Trichosporon asahii is an emerging opportunistic fungus that mainly causes fatal disseminated trichosporonosis, especially in immunocompromised patients. T. asahii infection has been reported in Thailand, but few studies of this fungus have been published. Therefore, this study investigated the genetic diversity of 51 clinical strains of T. asahii from urine samples in Thailand. We sequenced and characterized the beta-1-tubulin (TUB1), copper-exporting ATPase (ATP), phosphate carrier protein (PHCP), and topoisomerase-1 (TOP1) genes. In addition, intergenic spacer 1 (IGS1) sequences from our previous studies were investigated. The numbers of haplotypes were 3, 3, 2, 2, and 2 for IGS1, TUB1, ATP, PHCP, and TOP1, respectively. The results suggested a relatively low level of genetic diversity among the strains. The findings illustrated that IGS1, TUB1, ATP, PHCP, and TOP1 can be collectively used as an alternative molecular typing tool for investigating the population diversity and structure of T. asahii.

Fungal Endocarditis: Pathophysiology, Epidemiology, Clinical Presentation, Diagnosis, and Management

Fungal endocarditis accounts for 1% to 3% of all infective endocarditis cases, is associated with high morbidity and mortality (>70%), and presents numerous challenges during clinical care. Candida spp. are the most common causes of fungal endocarditis, implicated in over 50% of cases, followed by Aspergillus and Histoplasma spp. Important risk factors for fungal endocarditis include prosthetic valves, prior heart surgery, and injection drug use. The signs and symptoms of fungal endocarditis are nonspecific, and a high degree of clinical suspicion coupled with the judicious use of diagnostic tests is required for diagnosis. In addition to microbiological diagnostics (e.g., blood culture for Candida spp. or galactomannan testing and PCR for Aspergillus spp.), echocardiography remains critical for evaluation of potential infective endocarditis, although radionuclide imaging modalities such as 18F-fluorodeoxyglucose positron emission tomography/computed tomography are increasingly being used. A multimodal treatment approach is necessary: surgery is usually required and should be accompanied by long-term systemic antifungal therapy, such as echinocandin therapy for Candida endocarditis or voriconazole therapy for Aspergillus endocarditis.

The Epidemiology and Clinical Characteristics of Fungemia in a Tertiary Hospital in Southern China: A 6-Year Retrospective Study

Knowledge of the epidemiology and clinical characteristics of fungemia in southern China is limited. We conducted a six-year retrospective descriptive study to analyze the epidemiological and clinical characteristics of fungemia at the largest tertiary hospital in Guangxi, southern China. Data were obtained from the laboratory registry of patients with fungemia between January 2014 and December 2019. Demographic characteristics, underlying medical conditions, and outcomes for each case were analyzed. A total of 455 patients with fungemia were identified. Unexpectedly, Talaromyces marneffei (T. marneffei) was the most frequently isolated agent causing fungemia in the region (149/475, 31.4%), and Candida albicans (C. albicans) was the most commonly isolated Candida spp. (100/475, 21.1%). We identified that more than 70% of talaromycosis fungemia developed in AIDS patients, whereas candidemia was most commonly associated with a history of recent surgery. Notably, the total mortality rate of fungemia and the mortality rate in patients with T. marneffei and Cryptococcus neoformans (C. neoformans) fungemia were significantly higher in HIV-uninfected patients than in HIV-infected patients. In conclusion, the clinical pattern of fungemia in Guangxi is different from that in previous studies. Our study may provide new guidance for the early diagnosis and prompt treatment of fungemia in similar geographic regions.

Mycotic aneurysms due to Trichosporon asahii in a patient with ulcerative colitis under immunosuppression

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.

Identification of Pathogenic and Opportunistic Yeasts in Pigeon Excreta by MALDI-TOF Mass Spectrometry and Their Prevalence in Chon Buri Province, Thailand

Pigeon excreta can cause environmental and public health issues, particularly in urban and public areas. They are reservoirs of several human pathogens including fungi, bacteria, and viruses. Epidemiological data of pathogenic and opportunistic yeasts in pigeon droppings in Chon Buri, one of the most reputable tourist cities of Thailand, are scarce. The present study aimed to identify yeasts in pigeon droppings by MALDI-TOF mass spectrometry, and to study their prevalence in Chon Buri, Thailand. A total of 200 pigeon fecal samples were collected randomly from all 11 districts of Chon Buri. A sum of 393 yeast-like colonies were isolated on Sabourand's dextrose agar and CHROMagar media. These isolates were further confirmed for their species by MALDI-TOF MS. Twenty-four yeast species belonging to 11 different genera were identified in pigeon fecal samples. Candida spp., predominantly C. krusei (14.32%), were the most prevalent yeast species. Other yeast species, including C. glabrata (12.73%), C. metapsilosis (11.93%), Lodderomyces elongisporus (10.87%), C. tropicalis (7.16%), C. albicans (5.83%), and Cryptococcus neoformans (4.77%) were identified. This study provides valuable epidemiological data and diversity of yeasts in pigeon droppings in Chon Buri, Thailand, and also supports the use of MALDI-TOF MS for yeast identification and epidemiological surveillance.

Promethazine inhibits efflux, enhances antifungal susceptibility and disrupts biofilm structure and functioning in Trichosporon

Trichosporon spp. are emerging opportunistic fungi associated with invasive infections, especially in patients with haematological malignancies. The present study investigated the in vitro inhibition of efflux pumps by promethazine (PMZ) as a strategy to control T. asahii and T. inkin. Planktonic cells were evaluated for antifungal susceptibility to PMZ, as well as inhibition of efflux. The effect of PMZ was also studied in Trichosporon biofilms. PMZ inhibited T. asahii and T. inkin planktonic cells at concentrations ranging from 32 to 256 μg ml^-1. Subinhibitory concentrations of PMZ inhibited efflux activity in Trichosporon. Biofilms were completely eradicated by PMZ. PMZ potentiated the action of antifungals, affected the morphology, changed the amount of carbohydrates and proteins and reduced the amount of persister cells inside biofilms. The results showed indirect evidences of the occurrence of efflux pumps in Trichosporon and opens a perspective for the use of this target in the control of trichosporonosis.

Complementary and Alternative Therapies for Onychomycosis: A Systematic Review of the Clinical Evidence

INTRODUCTION

Onychomycosis is notoriously difficult to treat. While oral antifungals are the most efficacious treatment for onychomycosis, they are contraindicated in certain patient populations, and patients may desire lower risk and accessible alternatives to systemic agents. In this study, we examine the clinical evidence supporting the use of complementary and alternative therapies in the treatment of onychomycosis.

METHODS

PubMed, Embase, and Cochrane Library were searched for clinical trials, observational studies, and case reports/case series, examining the efficacy of a complementary or alternative therapy for the treatment of onychomycosis.

RESULTS

We identified 17 articles studying a complementary and alternative therapy for onychomycosis, including tea tree oil (n = 5), Ageratina pichinchensis (n = 3), Arthrospira maxima (n = 2), natural coniferous resin lacquer (n = 2), Vicks VapoRub® (n = 2), propolis extract (n = 2), and ozonized sunflower oil (n = 1).

CONCLUSION

Given the rise of antifungal resistance, complementary and alternative therapies should continue to be studied as adjunctive or alternative therapy for onychomycosis. While preliminary evidence exists for several complementary and alternative therapies in the treatment of onychomycosis, large-scale, randomized, placebo-controlled trials are needed prior to endorsing their use to patients.

Fungal Bloodstream Co-infection by Trichosporon asahii in a COVID-19 Critical Patient: Case Report and Literature Review

Opportunistic infections are serious complications in critically ill COVID-19 patients, especially co-infections with bacterial and fungal agents. Here we report a rare case of bloodstream co-infection by Trichosporon asahii, an emerging yeast, and Acinetobacterbaumannii, an opportunistic nosocomial pathogen, both multidrug resistant, in a tertiary hospital from southern Brazil. A review of the literature regarding similar cases is also included. Treatment with multiple antimicrobials failed, and the patient progressed to death four days after the diagnosis of bacteremia and fungemia.

Invasive Trichosporonosis in Neonates and Pediatric Patients with Malignancies or Hematologic Disorders

(1) Background: Trichosporon species have emerged as important opportunistic fungal pathogens, with Trichosporon asahii being the leading and most frequent cause of invasive disease. (2) Methods: We performed a global review focused on invasive trichosporonosis in neonates and pediatric patients with malignancies or hematologic disorders. We reviewed case reports and case series of trichosporonosis due to T. asahii published since 1994, the year of the revised taxonomic classification. (3) Results: Twenty-four cases of invasive trichosporonosis were identified in neonates with the presence of central venous catheter and use of broad-spectrum antibiotics recognized as the main predisposing factors. Thirty-two cases were identified in children with malignancies or hematologic disorders, predominantly with severe neutropenia. Trichosporon asahii was isolated from blood in 24/32 (75%) pediatric cases. Cutaneous involvement was frequently observed in invasive trichosporonosis. Micafungin was the most commonly used prophylactic agent (9/22; 41%). Ten patients receiving prophylactic echinocandins were identified with breakthrough infections. A favorable outcome was reported in 12/16 (75%) pediatric patients receiving targeted monotherapy with voriconazole or combined with liposomal amphotericin B. Overall mortality in neonates and children with malignancy was 67% and 60%, respectively. (4) Conclusions: Voriconazole is advocated for the treatment of invasive trichosporonosis given the intrinsic resistance to echinocandins and poor susceptibility to polyenes.

Immunosuppressed Patients with Clinically Diagnosed Invasive Fungal Infections: The Fungal Species Distribution, Antifungal Sensitivity and Associated Risk Factors in a Tertiary Hospital of Anhui Province

Objective

Since the nosocomial fungal infections increasingly emerge, we extensively investigated the fungal species stratification and antifungal sensitivity profiles, clinical characteristics and associated risk factors of immunosuppressed patients with clinically diagnosed invasive fungal infections (IFIs) in a tertiary hospital of Anhui province.

Methods

In total, 112 subjects with immunosuppressive state were enrolled from a comprehensive tertiary hospital in Central China between July 2019 and December 2021. Eight-one fungal isolates were clinically recovered by fungus-culturing approaches. The identifications were conducted through a mass spectrometry detecting platform. The susceptibilities to antifungals were tested using the broth micro-dilution method, and the possible antifungal azole-resistance mechanism in specific Candida species was availably explored by sequencing. Patient medical profiles were accessed via the digitized retrieval system of hospital, from which clinical outcomes and multiple risk factors for immunosuppressed patients with clinically diagnosed IFIs were explicitly documented for evaluation.

Results

Candida species predominated in clinically diagnosed IFIs of immunosuppressed patients (accounting for 88.88%), followed by Trichosporon and Aspergillus species (6.17% and 4.94%, respectively). The source types of specimen were primarily comprised of urine (41.98%), respiratory samples (33.33%) and peripheral blood (9.88%). Frequently isolated Candida and Trichosporon species exhibited a high level of in vitro sensitivity for amphotericin B and 5-fluorocytosine, whereas a substantial portion of Candida species including C. glabrata, C. parapsilosis complex and C. tropicalis, and Trichosporon species showed lowered sensitivity patterns toward itraconazole, fluconazole and voriconazole at different levels. Specifically, gene mutations of ERG11 were identified in azole-resistant C. tropicalis. Distinct risk factors were analyzed to be highly associated with the clinically diagnosed IFI incidence, mainly including hospitalization duration, surgical procedures, immunosuppressive treatments, underlying diseases and other conditions.

Conclusion

Candida, Trichosporon and Aspergillus species were the top three pathogenic fungal agents causing clinically diagnosed IFIs in immunosuppressed patients. The attenuated sensitivity to azoles in Candida and Trichosporon species needs close surveillance, and ERG11 polymorphism might contribute to azole resistance in specific Candida species. Multiple featured risk factors for immunosuppressed patients developing clinically diagnosed IFIs require further consideration during clinical practice.

A 71-Year-Old Man From Ecuador With a History of Type 2 Diabetes Mellitus and Severe COVID-19 Pneumonia and Lung Cavitation Associated With Triple Infection With Trichosporon Asahii, Klebsiella Pneumoniae, and Pseudomonas Aeruginosa

Unvaccinated patients with comorbidities that impair the immune function, such as type 2 diabetes mellitus, are more likely to develop severe COVID-19. The COVID-19-associated acute respiratory distress syndrome has raised new concerns in intensive care units globally owing to the presence of secondary fungal infections. We report the case of a 71-year-old man from Ecuador with a history of type 2 diabetes mellitus, severe COVID-19 pneumonia, and lung cavitation associated with triple infections with Trichosporon asahii, Klebsiella pneumoniae, and Pseudomonas aeruginosa. The patient with a history of high blood pressure and type 2 diabetes was admitted to our hospital from a private care center with a diagnosis of COVID-19-associated acute respiratory distress syndrome. On arrival, the patient presented with signs of hypoxemic respiratory failure. During his stay at another hospital, he had received tocilizumab and corticosteroid therapy. Therefore, intubation was performed and mechanical ventilation was initiated. The patient developed a septic shock and renal failure with a glomerular filtration rate of 27.5 mL/min/1.73 m2; therefore, two hemodiafiltration sessions were started. The bronchoalveolar lavage revealed erythematous lesions in the bronchial tree and abundant purulent secretions and erosions in the bronchial mucosa, with a cavitary lesion in the right bronchial tree. The bronchoalveolar lavage samples were used to isolate Trichosporon asahii, Klebsiella pneumoniae, and Pseudomonas aeruginosa carbapenemase class A. Matrix-assisted laser desorption/ionization–time of flight (MALDI-TOF) Biotyper mass spectrometry and polymerase chain reaction (PCR) molecular identification were performed. This case report suggested that patients with severe COVID-19 pneumonia, with or without comorbidities, are more susceptible to opportunistic infections.

Trichosporon asahii Urinary Tract Infection in a Patient with Severe COVID-19

Trichosporon asahii is a yeast-like basidiomycete that is an emerging opportunistic infection in immunocompromised patients. Urinary tract infections due to T. asahii are rarely reported in the literature and typically seen only in immunocompromised patients. In addition to being immunocompromised, critically ill COVID-19 patients often have prolonged exposure to antibiotics, corticosteroids, and Foley catheters, which further increases their susceptibility to infection with T. asahii. There are limited case reports documenting successful treatment of T. asahii among hospitalized patients, particularly among COVID-19 patients, in the literature. Therefore, it is important that successful treatment regimens be reported. Here, we report a case of T. asahii urinary tract infection successfully treated with fluconazole and voriconazole in a 73-year-old male recovering from COVID-19. Urinary tract infections with T. asahii should be considered in persistently febrile COVID-19 patients with fungal urinary tract infections since prompt recognition and treatment can reduce the risk of disseminated disease and early mortality.

Complicated Trichosporon asahii mastoiditis in immunocompetent child

Background

Trichosporon asahii is an opportunistic fungus that causes infections in immunosuppressed patients. It is rarely seen in children and immunocompetent hosts. The mortality rates are still high despite early treatment with proper antifungal drugs. Trichosporon asahii mastoiditis in an immunocompetent child makes this case challenging.

Case presentation

This report presents a case of Trichosporon asahii mastoiditis which was complicated by transverse sinus thrombosis, in an otherwise healthy 21-month-old girl, and successfully treated with voriconazole. Trichosporon asahii was isolated, in three different occasions, from ear discharge of an immunocompetent healthy child, who presented with prolonged history of fever and received appropriate dosages of multiple types of antimicrobials as an outpatient but without improvement. After 48 h of starting the Voriconzole; post auricular swelling and ear discharge improved significantly.

Conclusion

A high index of clinical and microbiological suspicion is needed for optimal diagnosis of Trichosporon infection. Trichosporon asahii can also cause infection in immunocompetent individual even without previous history of hospitalization or intervention. We emphasize the importance of early pediatric infectious evaluation and intervention.

Bloodstream infections due to Trichosporon species in paediatric patients: Results from the first national study from Turkey

BACKGROUND

Invasive Trichosporon infections are rarely seen opportunistic fungal infections in children and mainly affect immunocompromised patients. This multicenter retrospective study has rewieved the characteristics, risk factors, treatment modalities and outcomes of bloodstream infections caused by Trichosporon species in children diagnosed over the past ten years in Turkey.

METHODS

The study was performed with the participation of 12 of 55 hospitals invited from Turkey. In each center, the patients with bloodstream infections caused by Trichosporon spp. between January 2010 and December 2020 were retrospectively ascertained and the results were reported to the study coordinator by means of a simple case report. Data were collected on patient demographics, underlying condition(s), treatment of.infections caused by Trichosporon spp, and 7 and 30- day mortality rates.

RESULTS

A total of 28 cases with fungemia caused by Trichosporon spp. were included in the study. The most common underlying disease was paediatric cancers (39.3%). T. asahii infections were detected in 78.5 % (n=22) of patients. A various spectrum of antifungal treatment regimens were used including intravenous amphotericin B monotherapy in 35.7%, intravenous amphotericin B and voriconazole combination in 32.1% and intravenous voriconazole monotherapy in 28.6% of the patients. The overall mortality rate was 28.5 %. The mortality rates were 12.5% in the voricanozole, 30% in the amphotericin B and 33.3% in combined voriconazole -amphotericin B arms CONCLUSIONS: Invasive Trichosporon infections with an important impact of patients quality of life are almost related to underlying diseases with an overall mortality rate of 28.5%. Voriconazole was found to be associated with lower mortality rates when compared with other treatment regimens.

Management of Invasive Infections due to a Rare Arthroconidial Yeast, Saprochaete capitata, in Two Patients with Acute Hematological Malignancies

Saprochaete capitata is an arthroconidial yeast, found principally in the environment, even if it belongs also to the normal microbial flora that colonize human subjects. This yeast is increasingly associated with invasive infections in hematological patients, in particular in those affected by acute leukemia. An important risk factor that predisposes to this infection is the profound neutropenia present in such immunocompromised patients. Saprochaete spp. were found resistant to both echinocandins and fluconazole so the treatment is often difficult. Here, we report two cases of sepsis in two patients with acute leukemia. All of them had fatal events, due to the worsening of their clinical condition. An early diagnosis and appropriate management of these pathogens is important in consideration of the poor prognosis associated to these fungal invasive infections.

Fatal fungemia by biofilm-producing Trichosporon asahii in a liver transplant candidate

Acute-on-chronic liver failure (ACLF) is often associated with a dismal outcome. Infections might preclude access to liver transplantation (LT) for these patients, further reducing their chance of survival. We report the case of a patient with ACLF who died before LT for biofilm-producing Trichosporon asahii fungemia. The patient early started antifungal therapy with anidulafungin, but T. asahii was not susceptible to echinocandins, delaying the start of active antifungal therapy. Although rare, invasive infections by Trichosporon spp. are associated with high mortality rates due to low antimicrobial susceptibility and production of biofilms on indwelling devices. Early diagnosis and treatment are crucial to reduce mortality and enhance patient survival.

All You Need To Know and More about the Diagnosis and Management of Rare Yeast Infections

Invasive infections with emerging yeasts such as Geotrichum, Saprochaete/Magnusiomyces, Trichosporon, and other species are associated with high morbidity and mortality rates. Due to the rarity and heterogeneity of these yeasts, medical mycology has lacked guidance in critical areas affecting patient management. Now, physicians and life scientists from multiple disciplines and all world regions have united their expertise to create the "Global guideline for the diagnosis and management of rare yeast infections: an initiative of the European Confederation of Medical Mycology in cooperation with the International Society for Human and Animal Mycology and the American Society for Microbiology." Recommendations are stratified for high- and low-resource settings and are therefore applicable worldwide. The advantages and disadvantages of various diagnostic methods and treatment options are outlined. This guideline reflects the current best-practice management for invasive rare yeast infections in a range of settings, with the intent of establishing a global standard of care for laboratorians and clinicians alike.

Trichosporon asahii fungemia and COVID-19 co-infection: An emerging fungal pathogen; case report and review of the literature

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Trichosporon asahii fungemia is an emerging invasive pathogen in critically ill Coronavirus disease 2019 patients.

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Judicious use of immunosuppressant medications is advisable in critically ill Coronavirus disease 2019.

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Periodically fungal surveillance program is recommended in critically ill COVID-19 patients.

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Voriconazole is the first option of therapy for Trichosporon asahii infection.

With the evolving COVID-19 pandemic, increasing concerns about invasive fungal infections have been reported particularly with the use of potent immunosuppressant medications to treat the immunological storms in patients with severe COVID-19 illnesses. Trichosporon asahii (T. asahii) is an emerging highly resistant pathogen with considerable mortality particularly in critically ill patients and immunocompromised individuals. We describe a case of a 58-year-old patient who developed T. asahii fungemia after using immunosuppressant agents for his severe COVID-19 related cytokines release syndrome. Pseudohyphae, arthroconidia, and lateral blastoconidia were seen in the stain, and later confirmed to be T. asahii. Voriconazole successfully treated this multi-drug-resistant fungal infection. The clinical presentation, assessment, and management are reviewed to raise awareness of the circumstances leading to coinfection with this emerging resistant yeast.

Disseminated Trichosporon asahii infection presenting as eosinophilia in an immunocompetent patient: A case report

Trichosporon are naturally found in external environments and are a part of the normal flora of the human skin, respiratory tract, and gastrointestinal tract. Disseminated Trichosporon infection occurs sporadically in patients with immunodeficiency, and is mainly manifested as blood, urine, catheter, and thorax/peritoneum infections, rarely as lymphatic, liver and spleen infections. Elevated blood eosinophil granulocyte from Trichosporon infection have rarely been reported. Here, we report a rare Case of eosinophilia associated with lymphatic and liver and spleen infections due to Trichosporon asahii in an immunocompetent patient. No reports of eosinophilia from Trichosporon infections other than lung, to our knowledge, have been published.

Recent developments in less known and multi-resistant fungal opportunists

Fungal infections have increased in recent years due to host factors, such as oncohaematological and transplant-related disorders, immunosuppressive therapy, and AIDS. Additionally, molecular and proteomic facilities have become available to identify previously unrecognizable opportunists. For these reasons, reports on less-known and recalcitrant mycoses, such as those caused by black fungi, hyaline filamentous fungi, coelomycetes, Mucorales, and non-Candida yeasts have emerged. In this review, novel taxonomy in these groups, which often are multi-resistant to one or several classes of antifungals, is discussed. Clinical presentations, diagnosis and current treatment of some major groups are summarised.

Summer-type hypersensitivity pneumonitis in a share house for foreigners in Japan

Summer-type hypersensitivity pneumonitis commonly occurs in Japan during the warm and humid season, when the causative Trichosporon asahii flourish. The assessment of anti-T. asahii antibodies in patients with hypersensitivity pneumonitis without any obvious causative antigen may be useful even outside Japan.

Production of Secreted Carbohydrates that Present Immunologic Similarities with the Cryptococcus Glucuronoxylomannan by Members of the Trichosporonaceae Family: A Comparative Study Among Species of Clinical Interest

Glucuronoxylomannan (GXM) participates in several immunoregulatory mechanisms, which makes it an important Cryptococcus virulence factor that is essential for the disease. Trichosporon asahii and Trichosporon mucoides share with Cryptococcus species the ability to produce GXM. To check whether other opportunistic species in the Trichosporonaceae family produce GXM-like polysaccharides, extracts from 28 strains were produced from solid cultures and their carbohydrate content evaluated by the sulfuric acid / phenol method. Moreover, extracts were assessed for cryptococcal GXM cross-reactivity through latex agglutination and lateral flow assay methods. Cryptococcus neoformans and Saccharomyces cerevisiae were used as positive and negative controls, respectively. In addition to T. asahii, the species Trichosporon inkin, Apiotrichum montevideense, Trichosporon japonicum, Trichosporon faecale, Trichosporon ovoides, Cutaneotrichosporon debeurmannianum, and Cutaneotrichosporon arboriformis are also producers of a polysaccharide immunologically similar to the GXM produced by human pathogenic Cryptococcus species. The carbohydrate concentration of the extracts presented a positive correlation with the GXM contents determined by titration of both methodologies. These results add several species to the list of fungal pathogens that produce glycans of the GXM type and bring information about the origin of potential false-positive results on immunological tests for diagnosis of cryptococcosis based on GXM detection.

Ebselen and diphenyl diselenide against fungal pathogens: A systematic review

Fungal infections are one of the most prevalent diseases in the world and there is a lack of new antifungal drug development for these diseases. We conducted a systematic review of the literature regarding the in vitro antifungal activity of the organoselenium compounds ebselen (Eb) and diphenyl diselenide [(PhSe)2]. A systematic review was carried out based on the search for articles with data concerning Minimal Inhibitory Concentration (MIC) values, indexed in international databases and published until August 2020. A total of 2337 articles were found, and, according to the inclusion and exclusion criteria used, 22 articles were included in the study. Inhibitory activity against 96% (200/208) and 95% (312/328) of the pathogenic fungi tested was described for Eb and [(PhSe)2], respectively. Including in these 536 fungal isolates tested, organoselenium activity was highlighted against Candida spp., Cryptococcus ssp., Trichosporon spp., Aspergillus spp., Fusarium spp., Pythium spp., and Sporothrix spp., with MIC values lower than 64 μg/mL. In conclusion, Eb and [(PhSe)2] have a broad spectrum of in vitro inhibitory antifungal activity. These data added with other pharmacological properties of these organoselenium compounds suggest that both compounds are potential future antifungal drugs. Whether MICs toward the upper end of the ranges described here are compatible with efficacious therapy, and whether they may achieve such end as a result of the favorable non-antimicrobial effects of selenium on the host, requires more in vivo testing.