Successful treatment of Trichosporon mucoides infection with fluconazole in a heart and kidney transplant recipient

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.

Emerging fungal infections in solid organ transplant recipients: Guidelines of the American Society of Transplantation Infectious Diseases Community of Practice

These updated AST-IDCOP guidelines review the epidemiology, diagnosis, and management of emerging fungi after organ transplantation. Infections due to numerous generally innocuous fungi are increasingly recognized in solid organ transplant (SOT) recipients, comprising about 7%-10% of fungal infections in this setting. Such infections are collectively referred to as emerging fungal infections and include Mucormycetes, Fusarium, Scedosporium, and dematiaceous fungi among others. The causative organisms are diverse in their pathophysiology, uncommon in the clinical setting, have evolving nomenclature, and are often resistant to multiple commonly used antifungal agents. In recent years significant advances have been made in understanding of the epidemiology of these emerging fungal infections, with improved diagnosis and expanded treatment options. Still, treatment guidelines are generally informed by and limited to experience from cohorts of patients with hematological malignancies and/or solid and stem cell transplants. While multicenter randomized controlled trials are not feasible for these uncommon infections in SOT recipients, collaborative prospective studies can be valuable in providing information on the epidemiology, clinical manifestations, treatment strategies, and outcomes associated with the more commonly encountered infections.

Invasive Trichosporon Infection: a Systematic Review on a Re-emerging Fungal Pathogen

Objectives: This review aimed to better depict the clinical features and address the issue of therapeutic management of Trichosporon deep-seated infections.

Methods: We comprehensively reviewed the cases of invasive Trichosporon infection reported in the literature from 1994 (date of taxonomic modification) to 2015. Data from antifungal susceptibility testing (AST) studies were also analyzed.

Results: Two hundred and three cases were retained and split into four groups: homeopathy (n = 79), other immunodeficiency conditions (n = 41), miscellaneous (n = 58) and newborns (n = 25). Trichosporon asahii was the main causative species (46.7%) and may exhibit cross-resistance to different antifungal classes. The unfavorable outcome rate was at 44.3%. By multivariate analysis, breakthrough infection (OR 2.45) was associated with unfavorable outcome, whilst the use of an azole-based therapy improved the prognosis (OR 0.16). Voriconazole-based treatment was associated with favorable outcome in hematological patients (73.6 vs. 41.8%; p = 0.016). Compiled data from AST demonstrated that (i) T. asahii exhibits the highest MICs to amphotericin B and (ii) voriconazole has the best in vitro efficacy against clinical isolates of Trichosporon spp.

Conclusions:Trichosporon infection is not only restricted to hematological patients. Analysis of compiled data from AST and clinical outcome support the use of voriconazole as first line therapy.

Disseminated Trichosporon infection in a renal transplant recipient

Trichosporon species are basidiomycetous yeast-like anamorphic organisms (Basidiomycota, Hymenomycetes, Tremelloidae, Trichosporonales) that are widely distributed in nature. Trichosporon species colonize the skin and gastrointestinal tract of humans. We present a report of disseminated Trichosporon in a renal allograft recipient. Our patient satisfied the definitions of both "proven invasive trichosporonosis" and "probable pulmonary infection." Only 2 reports of disseminated Trichosporon infection in renal transplant recipients, to our knowledge, have been published.

A fatal case of Trichosporon asahii fungemia and pneumonia in a kidney transplant recipient during caspofungin treatment

Trichosporon asahii is an emerging opportunistic pathogen that is life-threatening particularly for immunosuppressed patients. Only a few studies have described Trichosporon infection in kidney transplant recipients. This study reports a 67-year-old male kidney transplant recipient who developed fatal fungemia and pneumonia caused by T. asahii during caspofungin treatment. Although funguria is benign, kidney transplant recipients are still at risk of T. asahii fungemia and invasive T. asahii infection even if they are under antifungal therapy, particularly echinocandins.

Fungemia due to Trichosporon mucoides in a diabetes mellitus patient: a rare case report

Trichosporon species are widely distributed in nature and can occasionally belong to the human microbiota. For many years, Trichosporon beigelii, the only species of this genus, was found as the aetiological agent of superficial skin infection called white piedra. However, many cases of invasive trichosporonosis caused by different newly delineated species of Trichosporon have been published in increasing numbers in recent past years, especially in immunocompromised persons. We report a rare case of fungemia due to Trichosporon mucoides in a diabetes mellitus patient, which will add to the emerging list of trichosporonosis infections.

Invasive Trichosporon infection in solid organ transplant patients: a report of two cases identified using IGS1 ribosomal DNA sequencing and a review of the literature

Trichosporon species are rare etiologic agents of invasive fungal infection in solid organ transplant (SOT) recipients. We report 2 well-documented cases of Trichosporon inkin invasive infection in SOT patients. We also conducted a detailed literature review of Trichosporon species infections in this susceptible population. We gathered a total of 13 cases of Trichosporon species infections. Any type of organ transplantation can be complicated by Trichosporon infection. Bloodstream infections and disseminated infections were the most common clinical presentations. Liver recipients with bloodstream or disseminated infections had poor prognoses. Although the most common species was formerly called Trichosporon beigelii, this species name should no longer be used because of the changes in the taxonomy of this genus resulting from the advent of molecular approaches, which were also used to identify the strains isolated from our patients. Antifungal susceptibility testing highlights the possibility of multidrug resistance. Indeed, Trichosporon has to be considered in cases of breakthrough infection or treatment failure under echinocandins or amphotericin therapy. Voriconazole seems to be the best treatment option.

Emerging fungal infections in solid organ transplant recipients

The most important emerging and rare fungal pathogens in solid organ transplant recipients are the Zygomycetes, Scedosporium, Fusarium, and the dark molds. Factors affecting the emergence of these fungi include the combination of intensive immunosuppressive regimens with increasingly widespread use of long-term azole antifungal therapy; employment of aggressive diagnostic approaches (eg, sampling of bronchoalveolar lavage fluid); and changes in patients' interactions with the environment. This article reviews the epidemiology, microbiology, and clinical impact of emerging fungal infections in solid organ transplant recipients, and provides up-to-date recommendations on their treatment.

Disseminated Trichosporon mycotoxinivorans, Aspergillus fumigatus, and Scedosporium apiospermum coinfection after lung and liver transplantation in a cystic fibrosis patient

Trichosporon mycotoxinivorans is a novel pathogen recently found in cystic fibrosis patients. We report the first case of a disseminated fatal infection with T. mycotoxinivorans associated with invasive Aspergillus fumigatus and Scedosporium apiospermum infection after lung and liver transplantation in a cystic fibrosis patient.

Epidemiology of invasive mycoses in North America

The incidence of invasive mycoses is increasing, especially among patients who are immunocompromised or hospitalized with serious underlying diseases. Such infections may be broken into two broad categories: opportunistic and endemic. The most important agents of the opportunistic mycoses are Candida spp., Cryptococcus neoformans, Pneumocystis jirovecii, and Aspergillus spp. (although the list of potential pathogens is ever expanding); while the most commonly encountered endemic mycoses are due to Histoplasma capsulatum, Coccidioides immitis/posadasii, and Blastomyces dermatitidis. This review discusses the epidemiologic profiles of these invasive mycoses in North America, as well as risk factors for infection, and the pathogens' antifungal susceptibility.

Identification of Trichosporon spp. strains by sequencing D1/D2 region and sub-typing by sequencing ribosomal intergenic spacer region of ribosomal DNA

To re-identify and further group 25 isolates of Trichosporon spp. identified morphologically previously, sequences of D1/D2 region of large subunit (LSU) of ribosomal DNA (rDNA) of 25 tested strains for identification and those of ribosomal intergenic space 1 (IGS1) region of 11 strains for subgrouping were detected. The identifications of tested strains were changed except 6 strains. According to the alignment of the IGS1 region, 6 T. asahii isolates tested fell into 4 groups and 5 T. faecale isolates into 3 groups. Polymorphism of 2 T. japonicum isolates was found in 10 positions. With the alignments obtained in this research compared with the relative GenBank entries, it was found that T. asahii, T. faecale and T. japonicum species were divided into 7, 3 and 2 subtypes respectively. Morphological and biophysical methods are not sufficient for Trichosporon spp. identification. Sequencing becomes necessary for Trichosporon diagnosis. There is obvious diversity within a species.

Molecular identification and susceptibility of Trichosporon species isolated from clinical specimens in Qatar: isolation of Trichosporon dohaense Taj-Aldeen, Meis & Boekhout sp. nov

Trichosporon species have been reported as emerging pathogens and usually occur in severely immunocompromised patients. In the present work, 27 clinical isolates of Trichosporon species were recovered from 27 patients. The patients were not immunocompromised, except for one with acute myeloid leukemia. Sequence analysis revealed the isolation of Trichosporon dohaense Taj-Aldeen, Meis & Boekhout sp. nov., with CBS 10761(T) as the holotype strain, belonging to the Ovoides clade. In the D1-D2 large-subunit rRNA gene analysis, T. dohaense is a sister species to T. coremiiforme, and in the internal transcribed spacer analysis, the species is basal to the other species of this clade. Molecular identification of the strains yielded 17 T. asahii, 3 T. inkin, 2 T. japonicum, 2 T. faecale, and 3 T. dohaense isolates. The former four species exhibited low MICs for five antifungal azoles but showed high MICs for amphotericin B. T. dohaense demonstrated the lowest amphotericin B MIC (1 mg/liter). For the majority of T. asahii isolates, amphotericin B MICs were high (MIC at which 90% of isolates were inhibited [MIC(90)], > or = 16 mg/liter), and except for fluconazole (MIC(90), 8 mg/liter), the azole MICs were low: MIC(90)s were 0.5 mg/liter for itraconazole, 0.25 mg/liter for voriconazole, 0.25 mg/liter for posaconazole, and 0.125 mg/liter for isavuconazole. The echinocandins, caspofungin and anidulafungin, demonstrated no activity against Trichosporon species.

Systemic infection caused by Trichosporon asahii in a patient with liver transplant

Trichosporon species are emerging pathogens capable of causing severe infections in immunocompromised patients. In this paper, we report a case of systemic infection in a liver transplant patient caused by Trichosporon asahii to show the etiologic agent's aggressiveness and poor therapeutic results with the different antifungals employed.

The prophylactic effectiveness of various antifungal agents against the progression of trichosporonosis fungemia to disseminated disease in a neutropenic mouse model

Neutropenic mice with latent trichosporonemia were given various antifungal agents (amphotericin B, fluconazole, itraconazole) or saline to determine which antifungal agent could be useful for prophylaxis. The 3-week-survival rate was 80% in the fluconazole group, 50% in the amphotericin B group, 45% in the itraconazole group, and 30% in the saline group. Compared with the other antifungal agents, fluconazole offered superior prophylaxis against the progression of trichosporonosis fungemia to disseminated disease (P<0.05). These results suggest that clinical studies are warranted to investigate fluconazole prophylaxis of trichosporonosis progression in neutropenic patients, such as people receiving chemotherapy and patients who have received solid organ transplants.

Successful treatment of Trichosporon mucoides infection with lipid complex amphotericin B and 5-fluorocytosine

Infections in immunocompromised children can stem from bacteria, fungi, viruses, or protozoa, but most importantly, from the host's endogenous bacterial flora. Disseminated infection caused by Trichosporon species is one of the emerging mycoses in neutropenic patients, particularly when they are treated for haematological malignancy with cytotoxic and immunosuppressive chemotherapy. We report a 15-year-old boy with acute lymphoblastic leukaemia, whose Trichosporon mucoides infection was successfully treated with lipid complex amphotericin B plus 5-fluorocytosine.

Breakthrough Trichosporonosis in Patients with Hematologic Malignancies Receiving Micafungin

BACKGROUND

Micafungin is a newly approved antifungal agent in the echinocandin class that is active against Candida species and Aspergillus species. However, this agent has limited activity against a number of fungi, including Trichosporon species. We describe 4 patients who developed disseminated trichosporonosis during the use of micafungin. No cases of trichosporonosis had been seen in the 2 years prior to January 2003, when micafungin became available in our hospital.

METHODS

We reviewed microbiological records of patients at Kameda General Hospital (Kamogawa City, Chiba, Japan) from 1 January 2002 to 31 July 2005, and identified 4 patients whose blood culture results were positive for Trichosporon species.

RESULTS

Since January 2003, four patients--3 with acute myelocytic leukemia and 1 with myelodysplastic syndrome--developed disseminated trichosporonosis while receiving treatment with micafungin with or without amphotericin B. The initial 2 isolates were identified as Trichosporon beigelii, and the later 2 isolates were identified as Trichosporon asahii. All 4 patients received micafungin, and 2 also received amphotericin B concomitantly. Minimal inhibitory concentrations of micafungin were >16 microg/mL for the 2 isolates available for susceptibility testing. One patient with hematologic recovery (neutrophils >500 cells/mm3) showed elimination of the fungus after receiving treatment with voriconazole. However, the 3 other patients without hematologic or immunological recovery died of disseminated infection.

CONCLUSIONS

The rarity of trichosporonosis in our hospital and its emergence after the introduction of micafungin therapy support the idea that micafungin may exert a significant, selective pressure toward resistant fungi, such as Trichosporon species. Therefore, care should be taken regarding the possibility of trichosporonosis in patients receiving micafungin with or without amphotericin B.

Non-Aspergillus Fungal Pneumonia in Transplant Recipients

Although species of Aspergillus and Candida account for most deeply invasive and life-threatening fungal infections, the past decades have seen a rise in the immunocompromised population. With this increase, additional fungi have emerged as important agents of morbidity and mortality. These opportunistic fungi are characterized by their ubiquitous presence in the environment, their ability to cause disease in immunosuppressed patients, and their diminished susceptibility to the currently available antifungal agents. Pneumonia, one aspect of a myriad of clinical manifestations caused by these fungal pathogens, is discussed in this article.

Invasive infections caused by Trichosporon species and Geotrichum capitatum in patients with hematological malignancies: a retrospective multicenter study from Italy and review of the literature

Trichosporonosis is an uncommon but frequently fatal mycosis in immunocompromised patients. A multicenter retrospective study was conducted to characterize cases of proven or probable invasive trichosporonosis diagnosed over the past 20 years in Italian patients with hematological diseases. Of the 52 cases identified, 17 were classified as Trichosporon sp. infections and 35 were attributed to Geotrichum capitatum. Acute myeloid leukemia accounted for 65.4% of the cases. The incidence rates of Trichosporon sp. and G. capitatum infections in acute leukemia patients were 0.4 and 0.5%, respectively. Overall, 76.9% of cases had positive blood cultures. Pulmonary involvement was documented in 26.9% of cases. Death was reported for 57.1% of G. capitatum infections and for 64.7% of Trichosporon sp. infections. A literature review on trichosporonosis in patients with any underlying disease or condition reveals G. capitatum as a predominantly European pathogen, particularly in certain Mediterranean areas, while Trichosporon sp. infections are seen with similar frequencies on all continents. The majority of published Trichosporon sp. and G. capitatum infections occurred in patients with hematological diseases (62.8 and 91.7%, respectively). Well over half of these were suffering from acute leukemia (68 and 84% of patients with Trichosporon sp. and G. capitatum infections, respectively). Crude mortality rates were 77% for Trichosporon spp. and 55.7% for G. capitatum. The optimal therapy for trichosporonosis has yet to be identified; however, in vitro experiences are providing encouraging evidence of the potential role of the new triazoles, in particular, voriconazole.

In vitro susceptibility of yeasts isolated from patients in intensive care units to fluconazole and amphotericin B during a 3-year period

Fungal infections have increased dramatically in recent years and candidemia is a major risk factor for morbidity and mortality in intensive care units (ICUs). Candidemia has been considered to be a nosocomial infection that is strongly associated with neutropenia, recent surgery or presence of intravascular lines, and previous colonization is an independent risk factor. We evaluated the in vitro efficacy of fluconazole and amphotericin B against yeasts isolated from various clinical specimens of colonized or infected patients treated in the ICUs of the Institute of Cardiology, Istanbul University. A total of 1397 ICU patients were treated at the Institute of Cardiology between January 2000 and December 2002. A total of 117 yeasts isolated from 97 patients were included in this study. These ICU patients were hospitalized for a mean of 29 days. All yeasts were identified by conventional methods and using the API (20C AUX, ID 32C) system (Bio Meriéux, France). Susceptibility to fluconazole and amphotericin B was evaluated using the E-test (AB Biodisk, Solna, Sweden). The most commonly isolated yeast was Candida albicans (72.6%), followed by Candida tropicalis (16.2%), Candida kefyr, Candida krusei, Candida parapsilosis, Trichosporon mucoides and Geotrichum spp. Fluconazole and amphotericin B MIC90 values were 0.75 microg/ml; 0.19 microg/ml and 1 microg/ml; 0.38 microg/ml for C. albicans and C. tropicalis, respectively. All Geotrichum spp. were found to be susceptible-dose dependent (SDD) (MIC=16-32 microg/ml) to fluconazole. Two C. albicans, two C. tropicalis, one C. krusei and one Geotrichum spp. had a MIC value of > or = 0.38 microg/ml for amphotericin B. The rate of colonization was 3.36% (47/1397). Only 10 (0.71%) patients out of a total of 1397 developed candidemia during the period of the investigation. Of these, 7 (70%) were caused by non-albicans Candida spp.