Invasive Trichosporonosis Research Articles

The Prevalence and Risk Factors of Trichosporonosis at King Abdulaziz University Hospital.

Fungal infections, especially those caused have emerged as a significant medical concern over the past three decades, particularly among immunocompromised patients. However, recent studies have highlighted the increasing prevalence of fungal infections resembling yeast other than Candida, such as trichosporonosis, especially among immunosuppressed individuals worldwide. Trichosporon has been identified as a significant contributor to superficial and invasive infections. Invasive trichosporonosis, primarily affecting immunocompromised patients, poses a significant threat with high mortality rates. The current study aimed to explore the clinical epidemiology of Trichosporon spp at King Abdulaziz University Hospital (KAUH) in Saudi Arabia. This retrospective study aimed to assess the clinical epidemiology of Trichosporon spp. infections in microbiology cultures obtained from KAUH in Saudi Arabia. The study analyzed data from patients over a five-year period, focusing on demographic, clinical, and microbiological characteristics. This study encompassed 21 participants, categorized into four distinct age groups. Moreover, this study indicated T. asahii as the predominant species isolated, accounting for 90.5% of infections, followed by T. mucoides (9.5%). ICU hospitalization, diabetes mellitus, taking immunosuppressive drugs, and antifungal drugs, and the use of invasive medical equipment were identified as prominent risk factors for trichosporonosis. Urinary tract infections were the most common clinical presentation, particularly among male and elderly patients. Mortality rates were high, especially among older individuals. This study contributes valuable epidemiological insights into trichosporonosis, highlighting the need for enhanced surveillance and preventive strategies in healthcare settings. Further research is warranted to optimize treatment approaches and infection control measures, ultimately reducing the burden of Trichosporon infections on patient outcomes.

Clinical and Microbiological Spectrum of Invasive Trichosporonosis at a Tertiary Care Institute: A Retrospective Observational Study

Introduction: Invasive trichosporonosis was considered rare in the past decades, but it has emerged as an opportunistic pathogen causing invasive infections in immunocompromised patients. It can colonise various parts of the body, and it is important to differentiate between colonisation and infection. Moreover, knowledge of the epidemiology and risk factors associated with the disease is limited. Its inherent resistance to echinocandins poses a therapeutic challenge in treating patients. If not treated appropriately, it may lead to disseminated infections. Aim: To understand the clinical and microbiological spectrum of infections caused by Trichosporon spp. Materials and Methods: This retrospective observational study was conducted in the Department of Microbiology at Nizam’s Institute of Medical Sciences, Hyderabad, Telangana, India for a peroid of one year period from January 2019 to December 2019. The study analysed demographic data such as age, sex, risk factors, clinical features, microbiological diagnosis, treatment, and patient outcomes related to invasive trichosporonosis from the case records. The final sample size was 14 cases. Samples were processed for both aerobic and fungal cultures. The samples were inoculated into Chromogenic agar plates (bioMeriux), 5% sheep blood agar plates (bioMeriux), and Sabouraud dextrose agar. The plates were incubated at 37°C for 48 hours. Culture identification was performed using the Vitek® 2 compact system with the yeast panel YST, and antifungal susceptibility was determined by Broth Microdilution (BMD). Descriptive statistics were used for analysis, and categorical data were described as frequencies with percentages. The data was entered into a Microsoft Excel sheet and analysed using Statistical Packages for the Social Sciences (SPSS) Version 20.0. Results: During the study period, there were 14 cases of invasive trichosporonosis. The predominant age group was 60-70 years. Risk factors included the administration of broad-spectrum antibiotics in 13 (92.8%) of patients, followed by prolonged Intensive Care Unit (ICU) stay in 8 (57.1%) of the patients. Trichosporon spp. were isolated from urine in 10 (71.4%) cases, blood in 2 (14.2%) cases, and tissue in 2 (14.2%) cases. Trichosporon asahii was the predominant species isolated in 12 (85.7%) patients. All isolates were sensitive to voriconazole and amphotericin B. Mortality was reported in 5 (35.7%) of the patients. Conclusion: In present study, Trichosporon spp. was predominantly isolated from urine in the majority of patients. The pathogen was isolated from patients with various risk factors. Hence, proper identification of the pathogen, understanding its clinical significance, and determining antifungal susceptibility would aid in the appropriate management of patients.

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

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

Emerging Nosocomial Trichosporon asahii in a Tertiary Hospital in Southern Saudi Arabia

Background: Trichosporon species are pathogenic yeasts that colonize diverse human body sites and cause superficial in addition to invasive trichosporonosis, especially in immunosuppressed patients. The disease is an emerging health-care problem, as it has shown a noticeable increase in recent years. The leading risk factors are antibiotic use, invasive medical equipment, and chemotherapy. Informed evidence on the disease and its causal agent is needed. Objective: Presentation of clinical cases caused by Trichosporon sp. and identification of isolates recovered from various specimens in Aseer Central Hospital setting. Materials and Methods: The study analyzed fungal cultures (n = 20) from different clinical specimens submitted on a routine basis from hospital wards for general microbiological investigation at Aseer Central Hospital, Abha, Saudi Arabia (2021–2023). Mycologically proven trichosporonosis cases were initially identified by desktop methods, automated Vitek 2, and confirmed by sequence analysis of the ribosomal targets, namely the large-subunit RNA gene (D1–D2 region) and internal transcribed spacers 1 and 2 (ITS1 and ITS2 regions), patients were treated with fluconazole, and treatment outcomes were recorded. Results: Clinical features and culture results confirmed trichosporonosis caused by Trichosporon asahii with different clinical presentations. The majority of the cases were urinary tract (44%), followed by skin (28%) and respiratory tract (12%). All trichosporonosis cases responded to fluconazole. The neighbor-joining phylogenetic tree based on the rRNA regions and ITS and comparative analysis using GenBank reference data showed the association of our strains to the reference T. asahii clade, closely related to T. faecale and T. insectorum but different from other species. Conclusions: The study offered accurate species identification of the Trichosporon isolates by routine phenotypic tests as well as sequence-based techniques. Urinary tract infections were the most common manifestation of the infection, followed by skin and then respiratory tract infections. The cases of trichosporonosis responded well to fluconazole treatment. T. asahii is possibly underreported and should be considered in routine diagnostic investigations, notably in nosocomial infections.

Fatal Invasive Trichosporonosis in a Patient with Advanced Retroviral Infection and Diffuse Large B Cell Lymphoma

Fatal Invasive Trichosporonosis in a Patient with Advanced Retroviral Infection and Diffuse Large B Cell Lymphoma

Antifungal Activity and Potential Action Mechanism of Allicin against Trichosporon asahii.

Trichosporon asahii is an emerging opportunistic pathogen that causes potentially fatal disseminated trichosporonosis. The global prevalence of coronavirus disease 2019 (COVID-19) poses an increasing fungal infection burden caused by T. asahii. Allicin is the main biologically active component with broad-spectrum antimicrobial activity in garlic. In this study, we performed an in-depth analysis of the antifungal characteristics of allicin against T. asahii based on physiological, cytological, and transcriptomic assessments. In vitro, allicin inhibited the growth of T. asahii planktonic cells and biofilm cells significantly. In vivo, allicin improved the mean survival time of mice with systemic trichosporonosis and reduced tissue fungal burden. Electron microscopy observations clearly demonstrated damage to T. asahii cell morphology and ultrastructure caused by allicin. Furthermore, allicin increased intracellular reactive oxygen species (ROS) accumulation, leading to oxidative stress damage in T. asahii cells. Transcriptome analysis showed that allicin treatment disturbed the biosynthesis of cell membrane and cell wall, glucose catabolism, and oxidative stress. The overexpression of multiple antioxidant enzymes and transporters may also place an additional burden on cells, causing them to collapse. Our findings shed new light on the potential of allicin as an alternative treatment strategy for trichosporonosis. IMPORTANCE Systemic infection caused by T. asahii has recently been recognized as an important cause of mortality in hospitalized COVID-19 patients. Invasive trichosporonosis remains a significant challenge for clinicians, due to the limited therapeutic options. The present work suggests that allicin holds great potential as a therapeutic candidate for T. asahii infection. Allicin demonstrated potent in vitro antifungal activity and potential in vivo protective effects. In addition, transcriptome sequencing provided valuable insights into the antifungal effects of allicin.

Stigma Kills

Stigma Kills

JMM Profile: Trichosporon yeasts: from superficial pathogen to threat for haematological-neutropenic patients.

Trichosporon yeasts are classical agents of superficial mycoses, and they are ranked as the first to second predominant basidiomycetous yeast able to cause invasive infections. The clinical presentation of Trichosporon infections varies with the affected anatomical site, with fungaemia present in the majority of invasive trichosporonosis cases. Only a limited number of antifungal compounds can be used to treat Trichosporon infections. Azoles are the first choice due to their intrinsic resistance to echinocandins. Better laboratory methods and up-to-date databases of commercial platforms are required to improve identification, susceptibility testing and surveillance of this potentially threating infection.

P254 Clinical and microbiological spectrum of invasive trichosporonosis from a tertiary care institute in India

Poster session 2, September 22, 2022, 12:30 PM - 1:30 PMIntroductionTrichosporonosis has emerged as an opportunistic pathogen causing invasive infections in immunocompromised patients. Invasive trichosporonosis can involve most organs of the human body. Trichosporon species can colonize many parts of our body and hence it is important to differentiate between colonization and infection for appropriate management of the patients.ObjectiveTo understand the clinical and epidemiological features of infections caused by Trichosporon spp.MethodsAll patients with clinically significant isolation of Trichosporon spp from various samples during a period of one year from January 2019-December 2019 were included in the study.In the present retrospective study demographic data, risk factors, clinical features, microbiological data, treatment, and the outcome of patients with invasive trichosporonosis were analyzed.All the specimens were processed by standard mycological procedures. Identification and susceptibility were done by VITEK 2. The isolates were sent to NCCPF, PGIMER Chandigarh for identification by MALDI-TOF. As no clinical breakpoints for Trichosporon spp. have been established by CLSI and EUCAST, antifungal susceptibility results were interpreted as suggested by Lemes et al.ResultsThere were 14 cases of trichosporonosis during the study period. The predominant age group was 60-70 years and the male: female ratio is 6.5:1.The underlying condition of the patient at admission was accidental trauma in 4/14 (28.7%) chronic kidney disease in 2/14 (14.2%), hematological malignancy in 2/14 (14.2%), pneumonia in 1/14 (7.1%), retroviral disease in 1/14 (7.1%), acute febrile illness in 1/14 (7.1%). The risk factors for acquisition of infections with Trichosporon species in the 14 patients were administration of broad-spectrum antibiotics in 13 (92.8%), urinary catheterization in 11 (78.5%), central venous catheterization, and prolonged ICU stay in 8 (57.1%) each, previous antifungal therapy in 6 (42.8%). The other risk factors were chemotherapy, steroid usage, and neutropenia.The clinical presentations were urinary tract infections in 10/14 (71.4%) patients (9 were catheter-associated UTIs), fungemia in 2/14 (14.2%), and wound infections in 2/14 (14.2%) patients. Trichosporon asahii is the predominant species isolated in 12/14 (85.7%) patients. Other Trichosporon spp. isolated include T. inkin and T. dohaense. All the isolates were correctly identified by VITEK 2 except one which was identified as T. inkin in VITEK 2 and T. dohaense by MALDI-TOF.All the isolates were susceptible to voriconazole and amphotericin B. 9/14 (64.2%) of the isolates were susceptible to fluconazole. Trichosporon spp. is inherently resistant to echinocandins.A total of 7 patients (50%) were successfully treated with voriconazole for a period of 14 days with advice to follow up and discharged. In all, 5 patients (35.7%) died due to underlying diseases before treatment could be started.ConclusionUrinary tract infection, mostly CA-UTI was the commonest clinical presentation of Trichosporonosis in our study followed by bloodstream infection and wound infection. The commonest risk factor was prolonged broad-spectrum antibiotic therapy followed by urinary catheterization. The growth of Trichosporon spp. from various samples has to be interpreted with caution as the organism can also exist as a colonizer in different body sites. Voriconazole was effective in the treatment of trichosporonosis.

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

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

P084 Trichosporon osis awakening: molecular and antifungal susceptibility study on Trichosporonosis in North India and how antifungal stewardship can contribute in control

Poster session 1, September 21, 2022, 12:30 PM - 1:30 PM Background Trichosporon spp are yeast-like organisms belonging to class Basidiomycetes which are usually commensals. It can cause diseases ranging from superficial infection, commonly known as White Piedra, to disseminated infections (Trichosporonosis). Cases of invasive Trichosporonosis have increased worldwide. It has now become the second most common cause of fungemia after Candida spp, especially in immunocompromised individuals.MethodsWe conducted a hospital-based prospective chart review of six patients with nosocomial infections caused by Trichosporon spp. Demographic data, clinical history, comorbidities, and outcomes after treatment were collected. Samples were processed using conventional media, biochemicals, and confirmed using automated system, MALDI-TOF and VITEK-2ResultsA total of 8 patients developed UTIs and 4 developed disseminated bloodstream infections. All patients had associated co-morbidities. All patients had history of treatment with antimicrobials which were ineffective. In all, 8 patients were identified to be infected with T. asahii and 4 with T. mucoides. All patients showed improvement with azoles. We also encountered a case of breakthrough Trichosporonosis.ConclusionInvasive Trichosporonosis developed in patients with associated risk factors. Trichosporon spp presents diagnostic and therapeutic challenges. It is usually confused with disseminated candidiasis leading to incorrect treatment and increased risk of breakthrough Trichosporonosis. Prolonged undiagnosed infection can lead to disseminated infection. New triazoles have shown to be effective against Trichosporon spp.

Invasive Trichosporonosis in a Child Following Chemotherapy Induction

Trichosporonosis is an opportunistic fungal infection that commonly affects neutropenic, immunocompromised patients. We report a case of invasive trichosporonosis in a child with acute lymphoblastic leukemia following the induction of chemotherapeutic agents.

EQUAL Trichosporon Score 2022: an ECMM score to measure QUALity of the clinical management of invasive Trichosporon infections.

BackgroundInvasive infections due to Trichosporon spp. are life-threatening opportunistic fungal infections that require complex clinical management. Guidelines assist clinicians but can be challenging to comply with.ObjectivesTo develop a scoring tool to facilitate and quantify adherence to current guideline recommendations for invasive trichosporonosis.MethodsWe reviewed the current guideline for managing rare yeast infections (ECMM, ISHAM and ASM). The most important recommendations for diagnosis, treatment and follow-up were assembled and weighted according to their strength of recommendation and level of evidence. Additional items considered highly relevant for clinical management were also included.ResultsThe resulting EQUAL Trichosporon Score 2022 comprises 18 items, with a maximum score of 39 points. For diagnostics, seven or eight items, depending on whether organ involvement is present or not, apply, resulting in a maximum of 18 or 21 points. Recommendations on diagnostics include imaging, infectious diseases expert consultation, culture, microscopy, molecular techniques, histopathology, and susceptibility testing. For treatment, six recommendations with a maximum of ten points were identified, with two additional points for organ involvement and one point for second-line treatment in uncontrolled disease. Treatment recommendations include immediate initiation, source control, pharmacological treatment, therapeutic drug monitoring, treatment duration and surgical intervention. Follow-up comprises two items with five points maximum, covering follow-up blood cultures and imaging.ConclusionsThe EQUAL Trichosporon Score weighs and aggregates factors recommended for optimal management of Trichosporon infections. It provides a tool for antifungal stewardship as well as for measuring guideline adherence, but remains to be correlated with patient outcomes.

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.

Invasive Trichosporonosis in Immunocompetent Patient, a Case Report and Review of Literature

Trichosporonosis is an uncommon fungal infection that affects immunocompromised patients and has a very poor prognosis. We present a case of a 23 years-old immunocompetent patient with a history of tuberculous lymph nodes. We observed the patient from admission until discharge from the hospital. There are several diagnostic and therapeutic difficulties. Clinical symptoms and radiological findings may vary according to the affected organ. Symptoms may reflect either superficial or deep infection. Diagnosis is based on microscopic study and culture of superficial specimen. In deep infections, identification of Trichosporon spp. depends on biochemical characteristics and cell morphology. Radiological imaging is most important to assess lesion extension. Several evolutions without treatment is recognized due to this disease and his complications. The patient died despite being on fluconazole treatment which confirms the reserved prognosis of the pathology reported in the literature. Several evolutions without treatment is recognized due to this disease and his complications. W. ithout treatment, the evolution occurs in more than 80% of cases towards death. Special attention should be paid to this pathology.

Specific microRNA/mRNA expression profiles and novel immune regulation mechanisms are induced in THP-1 macrophages by in vitro exposure to Trichosporon asahii.

Trichosporon asahii is considered the most prominent species associated with invasive trichosporonosis, but little is known about the pathogenesis of T.asahii infection in the host. MicroRNAs (miRNAs) are a class of noncoding endogenous small RNAs that play vital roles by manipulating immune responses against pathogenic microorganisms. Nevertheless, the exact functions of miRNAs in T.asahii infection are still unknown. To investigate the interactions involved in the miRNA immune response in THP-1 macrophages following in vitro exposure to T.asahii. We utilized next-generation sequencing to detect differentially expressed (DE) miRNAs and mRNAs in THP-1 cells after 24h of in vitro exposure to T.asahii. Real-time quantitative polymerase chain reaction (RT-qPCR) was used to verify the sequencing results. The miRNA-mRNA regulatory network was constructed with the DE miRNAs and DE mRNAs. We performed Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analysis of the predicted targeting mRNAs in the miRNA-mRNA network. A dual-luciferase reporter assay and enzyme-linked immunosorbent assay (ELISA) were utilized to demonstrate the reliability of the miR-342-3p/Dectin-1 pair. A total of 120 DE miRNAs and 588 DE mRNAs were identified after 24h of in vitro exposure to T.asahii. The miRNA-mRNA regulatory network was constructed with 39 DE miRNAs and 228 DE mRNAs. KEGG pathway analysis revealed that the up-regulated DE mRNAs in the complex interaction network were mainly involved in immune-related pathways. In addition, we verified the target relationship between miR-342-3p and Dectin-1 and found that miR-342-3p could promote the expression of TNF-α and IL-6 by negatively regulating Dectin-1. This study evaluated the expression profiles of miRNA/mRNA and revealed the immunological consequences of THP-1 macrophages in response to T.asahii exposure. Moreover, our data suggest that miR-342-3p can indirectly promote inflammatory responses and may be a potential therapeutic target against trichosporonosis.

751. Karius Cell-Free DNA Metagenomic Assay of Plasma Detects Pulmonary and Disseminated Trichosporon Infections in Patients with Hematological Malignancies

Background Trichosporon species are uncommon but emerging pathogens that cause life-threatening infections that are resistant to amphotericin B and echinocandins. Diagnosis of deeply invasive trichosporonosis is often elusive to conventional culture methods until locally advanced or disseminated disease has advanced.CT scans Pulmonary Trichosporonosis Lung Bx of Trichosporon detected by Karius Cell-Free DNA Metagenomic Assay of Plasma MethodsReview of cases of next-generation sequencing of microbial cell-free DNA from plasma using the Karius-based technology for establishing a diagnosis of invasive trichosporonosisResultsWe found that next-generation sequencing of microbial cell-free DNA from plasma using the Karius-based technology established a diagnosis in six pediatric and adult patients. The median age was 17 yrs (8-72 yrs) all patients had underlying acute leukemia myelogenous leukemia. Six patients had pulmonary nodules and two also had multiple cutaneous lesions with negative blood cultures. Biopsies of one pulmonary nodule and of two cutaneous lesions revealed yeast-like cells. Culture of cutaneous lesions in two patients grew Trichosporon sp. Karius assays performed on plasma and analyzed against a database of more than 300 species of fungi identified Trichosporon asahii in two cases, Trichosporon spp. in three, Trichosporon faecale in one. In all cases, the metagenomic results defined therapy for treatment of invasive trichosporonosis, which is based in antifungal triazoles. In one patient with pulmonary nodules, lung biopsy revealed mixed septate and non-septate hyphal elements that later grew Trichosporon asahii, Rhizomucor pusillus, and Candida parapsilosis, all of which were identified by Karius assay.ConclusionInvasive Trichosporon spp. are uncommon polyene and triazole-resistant pathogens that cause life-threatening invasive fungal disease resistant in immunocompromised patient with hematological malignancies; next-generation sequencing of fungal cell-free DNA by Karius-based technology identified all six cases of pulmonary and disseminated trichosporonosis, contributing to early detection and pathogen-directed antifungal therapy.DisclosuresAsim A. Ahmed, MD, Karius (Employee) Joshua Wolf, MBBS, PhD, FRACP, Karius inc (Grant/Research Support)

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

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

Epidemiology and Antifungal Susceptibility of Infections Caused by Trichosporon Species: An Emerging Non-Candida and Non-Cryptococcus Yeast Worldwide

AbstractIntroduction: Over the past four decades, there has been an increase in the number of fatal opportunistic invasive trichosporonosis cases especially in immunocompromised hosts. Objective: The objective of the study is to evaluate the epidemiological, clinical details and antifungal susceptibility pattern of the patients with Trichosporon infections. Materials and Methods: Twenty-four clinical isolates of Trichosporon species isolated from blood, samples, pleural fluid and nail were included in this study, over a period of 12 years (2005–2016) in a tertiary hospital in North India. The isolates were characterised phenotypically and few representative isolates were sequenced also. The minimum inhibitory concentration (MIC) was determined as per Clinical and Laboratory Standards Institute, 2012. Results:Trichosporon spp. from blood culture (57.78%), nail (37.5%) and pleural fluid (4.17%). On phenotypic tests, 79.16% of the isolates were Trichosporon asahii, followed by Trichosporon dermatis (8.33%), Trichosporon japonicum (4.17%), Trichosporon ovoides (4.17%) and Trichosporon mucoides (4.17%). The MIC range of Trichosporon species from invasive infections were fluconazole (0.06–256 μg/ml), amphotericin B (0.125–16 μg/ml), voriconazole (0.0616–8 μg/ml), posaconazole (0.0616–32 μg/ml) and caspofungin (8–32 μg/ml). The isolates from superficial infection were resistant to fluconazole (0.06–256 μg/ml) and itraconazole (0.125–32 μg/ml), all were susceptible to ketoconazole and while only two were resistant to voriconazole (0.25–4 μg/ml). Conclusion:T. asahii was the most common isolate. Disseminated trichosporonosis is being increasingly reported worldwide including India and represents a challenge for both diagnosis and species identification. Prognosis is limited, and antifungal regimens containing triazoles appear to be the best therapeutic approach. In addition, accurate identification, removal of central venous lines and voriconazole-based treatment along with control of underlying conditions were associated with favourable outcomes.

Rapid and Simple Detection of Trichosporon asahii by Optimized Colony PCR.

Trichosporon asahii is the major pathogen causing invasive trichosporonosis. Conventional methods of its detection are time-consuming or costly and often require complex DNA extraction and purification steps, which hinders rapid clinical diagnosis. In this study, we evaluated colony PCR, which directly uses colonies or trace clinical samples as the template for amplification, for rapid detection of T. asahii infection. Four methods, namely, direct colony, freeze-thaw, glass beads, and enzymolysis, were compared to select the best DNA extraction strategy. We subsequently designed and screened species-specific primers targeting the intergenic spacer 1 (IGS1) of the ribosomal DNA of T. asahii and used them to detect mock infection clinical samples. The species-specific colony PCR based on glass beads proved advantageous, with short procedure time (154.8 ± 0.6 min), good sensitivity (detection limit, 102 CFU/mL), and specificity for T. asahii, indicating that this method can be used for the rapid and simple identification of clinical samples of T. asahii infection.