Trichosporon loubieri infection in a patient with adult polycystic kidney disease

First case of bloodstream infection of Trichosporon loubieri in a patient with B-cell lymphocytic leukemia in China

Trichosporon loubieri is an opportunistic pathogenic fungus that could causes invasive infections for human, which rarely been reported. In the present study, we reported a case of bloodstream infection from a patient with Ph-positive B-cell acute lymphocytic leukemia (B-ALL) due to Trichosporon loubieri. Trichosporon loubieri was identified by Internal Transcribed Spacer (ITS) gene sequencing. The patient was treated by intravenous voriconazole (VCZ) and amphotericin B (AmB) according to antifungal susceptibility testing and he was still alive so far. To the best of our knowledge, this is the fourth report of human bloodstream infection due to Trichosporon loubieri and the first survival case of its kind in an immunocompromised patient.

Cyst infection in autosomal dominant polycystic kidney disease: our experience at Toranomon Hospital and future issues

Cyst infection is a frequent and serious complication of autosomal dominant polycystic kidney disease (ADPKD) that is often difficult to treat and can be fatal. However, much is still unknown about cyst infection. Positron emission tomography (PET) is generally recommended for detecting infected cysts, but it has the disadvantages of limited availability, high cost, and radiation exposure. We have devised magnetic resonance imaging (MRI) diagnostic criteria for cyst infection. Lipid-soluble antibiotics such as fluoroquinolones show good penetration into cysts and are recommended for cyst infection. However, we reported that fluoroquinolone-resistant microorganisms showed a high prevalence in cyst infection. We should, therefore, reconsider the empirical use of fluoroquinolones for ADPKD patients with cyst infection. We have suggested a new antibiotic strategy according to the severity of cyst infection. It may be important to consider the drug half-life in serum in addition to the drug susceptibility when selecting antibiotics Cyst drainage is necessary for some patients with refractory cyst infection; however, cyst drainage can be associated with severe adverse events. We suggest adaptation criteria for cyst drainage in patients with cyst infection in ADPKD. Most causative bacteria of cyst infection are enterobacteria, and hematogenous spread via bacterial translocation in the intestine is considered the main cause of cyst infection. Therefore, intestinal flora may be important for cyst infection. The role of the intestinal flora in cyst infection in ADPKD is unknown and should be explored in future research.

Fungal Balls Mimicking Renal Calculi: A Zebra Among Horses

Background: Fungal masses (fungal ball or bezoars) rarely present as renal calculus. More so, Trichosporon species are even more uncommon among the noncandidial fungal infections affecting urinary tract. We report two such interesting cases that are not yet reported in the current literature. Case Reports: Our first case is a 48-year-old gentleman with diabetes presented with fever and flank pain. He was found to have bilateral obstructing radiolucent renal calculi with azotemia. Initially managed with bilateral Double-J stenting after one session of hemodialysis, and subsequently bilateral percutaneous nephrolithotomy (PCNL) was accomplished. Our second patient is a 37-year-old lady presented with bilateral flank pain with no comorbidity or sepsis. On evaluation, she was found to have bilateral radiolucent staghorn calculi and for which bilateral PCNL was performed. In view of high suspicion of fungal infection, extracted soft floppy materials were sent for fungal culture and were treated with antifungal agents after Trichosporon species was detected. Conclusion: Although renal fungal infections are rare, a strong suspicion and timely definitive management of such entities in patients with radiolucent renal calculus can prevent devastating invasive disease.

Two cases of fungal cyst infection in ADPKD: is this really a rare complication?

Background

Cyst infection is a prevalent complication in autosomal dominant polycystic kidney disease (ADPKD) patients, however therapeutic and diagnostic approaches towards this condition remain unclear. The confirmation of a likely episode of cyst infection by isolating the pathogenic microorganism in a clinical scenario is possible only in the minority of cases. The available antimicrobial treatment guidelines, therefore, might not be appropriate to some patients.

Case presentation

We describe two unique cases of kidney cyst infection by Candida albicans, a condition that has not been previously described in literature. Both cases presented clear risk factors for Candida spp. infection. However, since there was no initial indication of cyst aspiration and culture, antifungal therapy was not immediately started and empirical treatment was initiated as recommended by the current guidelines. Antifungal treatment was instituted in both cases along the clinical course, according to their specificities.

Conclusion

Our report highlights the possibility of Candida spp. cyst infection. Failure of clinical improvement with antibiotics should raise the suspicion of a fungal infection. Identification of infected cysts should be pursued in such cases, particularly with PET-CT, and when technically possible followed by cyst aspiration and culture to guide treatment. Risk factors for this condition, such as Candida spp. colonization, previous antimicrobial therapy, hemodialysis, necrotizing pancreatitis, gastrointestinal/hepatobiliary surgical procedure, central venous catheter, total parenteral nutrition, diabetes mellitus and immunodeficiency (neutropenia < 500 neutrophils/mL, hematologic malignancy, chemotherapy, immunosuppressant drugs), should be also considered accepted criteria for empirical antifungal therapy.

Complicated urinary tract infection by Trichosporon loubieri

We report two cases of complicated Urinary Tract Infection, one with nephrostomy tube left in-situ and other with bladder outlet obstruction, caused by Trichosporon loubieri. Both patients responded well to antifungal treatment along with change/removal of catheters. In both the cases, correct identification of T. loubieri was done by IGS1 sequencing. Prompt identification and timely management headed to good clinical outcome. Hence, clinicians should be aware of T. loubieri as an emerging fungi causing human infections.

Trichosporon loubieri Fungemia in a 39-Year-Old Caucasian Woman With B-Cell Lymphoblastic Leukemia

We report a case of Trichosporon loubieri (T. loubieri) fungemia with likely liver involvement in a 39-year-old Caucasian patient with relapsed B-cell acute lymphoblastic leukemia after an allogeneic hematopoietic cell transplant. This is the fifth published case of T. loubieri infection and only the third case of T. loubieri fungemia, to our knowledge. All 3 cases of T. loubieri infection with fungemia had liver involvement.

A case report of a cystic fibrosis patient with repeated isolation of Trichosporon mycotoxinivorans identified by a novel short-extraction method

Background

Trichosporon mycotoxinivorans is a recently described yeast-like fungal organism and its association as a pathogen for patients with cystic fibrosis (CF) was reported previously. We show the clinical course of a CF patient over 9 years as well as the applications of modern molecular and proteomic identification techniques of this rare fungus.

Case presentation

We present the case of a 32-year-old male CF patient with sputum cultures continuously positive with the anamorphic yeast T. mycotoxinivorans during 9 years. Furthermore, susceptibility testing of T. mycotoxinivorans to different antifungals were performed. In addition, a rapid identification method of this novel fungal pathogen with matrix-assisted laser desorption ionization-time of flight mass spectrometry (MALDI-TOF MS) was applied using a simple extraction protocol.

Conclusions

Our case presentation confirms T. mycotoxinivorans as a potential emerging pathogen in patients with CF. However, our CF patient showed mild symptoms over a very long time period of 9 years. A short MALDI-TOF MS procedure allows reliable and rapid identification of T. mycotoxinivorans and therefore should facilitate further study on the clinical relevance and epidemiology of this unusual fungal organism.

[Nondermatophytic and noncandidal fungi isolated in Le Dantec University hospital of Dakar in 2014: Epidemiological, clinical and mycological study]

In recent years, the incidence of superficial fungal infections involving nondermatophytic and noncandidal fungi increased considerably. The objective of this work was to analyze the epidemiological, clinical and mycological fungal infections due to nondermatophytic and noncandidal fungi diagnosed in the laboratory of parasitology-mycology of Le Dantec hospital in Dakar. With a retrospective study of the various cases of nondermatophytic and noncandidal fungi isolated in the laboratory of parasitology-mycology during the period of November 2013 to December 2014, we collected 22 cases of infections in 11 men and 11 women; age ranging from 17 to 75 years with a mean of 45.3 years (sex ratio=1): eight cases of intertrigo, seven cases of onychomycosis, four cases of palmoplantar keratoderma (KPP), a case of onychomycosis associated with interdigital intertrigo, a case of infectious myositis and one case of African histoplasmosis. We have isolated and identified a total of 22 nondermatophytic and noncandidal fungi: ten Fusarium, five Trichosporon, two Chrysosporium, two Geotrichum, one Rhodotorula, one Neoscytalidium dimidiatum and one Histoplasma capsulatum var. duboisii. So we are seeing the emergence of nondermatophytic and noncandidal increasingly isolated from superficial and local lesions. These fungi, generally contaminants or commensal, cause a problem regarding their direct involvement in pathological processes in which they are isolated. So we should respect the recommendations proposed for their involvement in pathological processes and, by a collaboration between clinician and biologist, demonstrate their real involvement through effective, targeted treatment.

Non-healing ulcer due to Trichosporon loubieri in an immunocompetent host and review of published reports

We report here a case of non-healing ulcer due to Trichosporon loubieri in an apparently immunocompetent female. The identity of isolate was confirmed by DNA sequencing of D1/D2 region of 26S rDNA. The minimum inhibitory concentrations of the isolate were amphotericin B-0.5 μg/ml; fluconazole-4 μg/ml; posaconazole-0.25 μg/ml; voriconazole-0.06 μg/ml. The patient was managed by extensive debridement and oral fluconazole 150 mg daily for 6 weeks. She responded to therapy. To the best of our knowledge, till date, this is the fourth report of human infection due to T. loubieri and the first of its kind in an immunocompetent host. A review of published literature on infections due to T. loubieri is also included.

Diagnostic accuracy of histopathologic and cytopathologic examination of Aspergillus species

To assess the diagnostic accuracy of histopatho-logic and cytopathologic examination (HCE) of Aspergillus species (spp), we performed an 11-year retrospective review to correlate surgical/cytology cases with a diagnosis of Aspergillus spp with their concurrent fungal culture results. Diagnostic accuracy was defined as the percentage of cases with culture-proven Aspergillus spp divided by the number of cases diagnosed as Aspergillus spp on HCE that had growth on fungal culture. Ninety surgical/cytology cases with concurrent fungal culture were reviewed, 58 of which grew a fungal organism. Of these 58 cases, 45 grew an Aspergillus spp, whereas 13 grew an organism other than Aspergillus spp, including both common (Scedosporium, Fusarium, and Paecilomyces spp) and uncommon mimickers (Trichosporon loubieri), resulting in a diagnostic accuracy of 78%. The low diagnostic accuracy indicates that several fungal organisms can morphologically mimic Aspergillus spp and can only be distinguished by fungal culture and DNA sequencing.

Systemic mycosis in a California sea lion (Zalophus californianus) with detection of cystofilobasidiales DNA

A 6-yr-old, intact male California sea lion (Zalophus californianus) with a systemic mycosis died after 5 wk of antifungal drug therapy. Antemortem clinical findings included hind flipper swelling, ring-lesions on skin of the flippers, and dermal nodules that increased in size and number spreading from the hind flippers and ventral abdomen to the foreflippers and muzzle. Lesions were accompanied by severe lymphadenopathy and development of systemic clinical signs despite therapy using itraconazole and later voriconazole. Histopathologic evaluation of biopsies revealed granulomatous dermatitis due to infection by fungus-producing yeast cells in tissue. Isolation attempts, using biopsied skin and tissue samples collected at necropsy, failed to yield growth of a fungus producing yeast cells like those in histologic section. Consensus polymerase chain reaction (PCR) tests of biopsied skin for fungal DNA produced an amplicon having significant sequence identity with a Cystofilobasidiales, a fungus belonging to a subclade that includes several Cryptococcus spp. Histopathologic evaluation of necropsy tissues revealed a systemic mycosis with yeast cells disseminated throughout subcutis, lymph nodes, and viscera. Hepatic necrosis was identified associated with acute liver failure, possibly from the voriconazole administration. This is the first report documenting the clinical presentation, treatment, and pathologic findings of infection associated with Cystofilobasidiales in a marine mammal and serves to expand the understanding of mycoses in pinnipeds.

Current knowledge of Trichosporon spp. and Trichosporonosis

Trichosporon spp. are basidiomycetous yeast-like fungi found widely in nature. Clinical isolates are generally related to superficial infections. However, this fungus has been recognized as an opportunistic agent of invasive infections, mostly in cancer patients and those exposed to invasive medical procedures. It is possible that the ability of Trichosporon strains to form biofilms on implanted devices, the presence of glucuronoxylomannan in their cell walls, and the ability to produce proteases and lipases are all factors likely related to the virulence of this genus and therefore may account for the progress of invasive trichosporonosis. Disseminated trichosporonosis has been increasingly reported worldwide and represents a challenge for both diagnosis and species identification. Phenotypic identification methods are useful for Trichosporon sp. screening, but only molecular methods, such as IGS region sequencing, allow the complete identification of Trichosporon isolates at the species level. Methods for the diagnosis of invasive trichosporonosis include PCR-based methods, Luminex xMAP technology, and, more recently, proteomics. Treating patients with trichosporonosis remains a challenge because of limited data on the in vitro and in vivo activities of antifungal drugs against clinically relevant species of the genus. Despite the mentioned limitations, the use of antifungal regimens containing triazoles appears to be the best therapeutic approach.

The opportunistic yeast pathogen Trichosporon asahii colonizes the skin of healthy individuals: analysis of 380 healthy individuals by age and gender using a nested polymerase chain reaction assay

Deep-seated trichosporonosis is an opportunistic fungal infection with a poor prognosis and high mortality rate. The major causative agent is Trichosporon asahii; its route of infection is not clear. To elucidate whether this microorganism is part of the cutaneous microbiota, we examined skin samples from 380 healthy Japanese ranging in age from 0 to 82 years using a nested PCR assay. The colonization frequency of T. asahii increased with age up to 13-15 years in male and 30-39 years in female subjects, subsequently decreasing gradually in both sexes until senescence. Of the nine genotypes of the intergenic spacer region of the T. asahii rRNA gene, type 1 predominated (81.7%), followed by types 4 (6.7%) and 6 (5.5%). The distribution of identified genotypes was similar to that for T. asahii isolated from clinical specimens (blood and urine) of patients with deep-seated trichosporonosis and quite different from that of environmental isolates. Additionally, T. asahii DNA was detected stably from skin samples over 1 year. The opportunistic yeast pathogen T. asahii is part of the cutaneous fungal microbiota in humans. Cutaneous T. asahii may be one of the routes through which deep-seated trichosporonosis is acquired, whereas environmental T. asahii is not associated with this infection.

Trichosporon mycotoxinivorans, a novel respiratory pathogen in patients with cystic fibrosis

This report describes the molecular epidemiology, in vitro susceptibility, colonial and microscopic morphologies, and biochemical features of Trichosporon mycotoxinivorans, a newly recognized pathogen that appears to have a propensity for patients with cystic fibrosis. The index patient died with histologically documented Trichosporon pneumonia complicating cystic fibrosis. This is also the first report of disease caused by a Trichosporon species in a nontransplant patient with cystic fibrosis. As T. mycotoxinivorans has not previously been recognized as a respiratory pathogen, the significance of its recovery from sputum samples was not initially appreciated. Genetic analysis of archived clinical samples found three additional cases of T. mycotoxinivorans infection which had previously been identified as other members of the genus. An additional isolate of T. mycotoxinivorans was identified from a clinical sample on initial testing. Three of these four cases were also patients with cystic fibrosis. All isolates had MICs at 48 h of amphotericin B of > or = 1 microg/ml and of echinocandins of > or = 16 microg/ml, but they displayed various susceptibilities to the triazoles. In summary, Trichosporon mycotoxinivorans is a newly recognized human pathogen that is associated with cystic fibrosis.

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.

Bloodstream infections due to Trichosporon spp.: species distribution, Trichosporon asahii genotypes determined on the basis of ribosomal DNA intergenic spacer 1 sequencing, and antifungal susceptibility testing

The reevaluation of the genus Trichosporon has led to the replacement of the old taxon Trichosporon beigelii by six new species. Sequencing of the ribosomal DNA (rDNA) intergenic spacer 1 (IGS1) is currently mandatory for accurate Trichosporon identification, but it is not usually performed in routine laboratories. Here we describe Trichosporon species distribution and prevalence of Trichosporon asahii genotypes based on rDNA IGS1 sequencing as well as antifungal susceptibility profiles of 22 isolates recovered from blood cultures. The clinical isolates were identified as follows: 15 T. asahii isolates, five Trichosporon asteroides isolates, one Trichosporon coremiiforme isolate, and one Trichosporon dermatis isolate. We found a great diversity of different species causing trichosporonemia, including a high frequency of isolation of T. asteroides from blood cultures that is lower than that of T. asahii only. Regarding T. asahii genotyping, we found that the majority of our isolates belonged to genotype 1 (86.7%). We report the first T. asahii isolate belonging to genotype 4 in South America. Almost 50% of all T. asahii isolates exhibited amphotericin B MICs of >or=2 microg/ml. Caspofungin MICs obtained for all the Trichosporon sp. isolates tested were consistently high (MICs >or= 2 microg/ml). Most isolates (87%) had high MICs for 5-flucytosine, but all of them were susceptible to triazoles, markedly to voriconazole (all MICs <or= 0.06 microg/ml).

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.

Sternal wound infection by Trichosporon inkin following cardiac surgery

Wound infection following cardiac surgery is well described but is rarely due to fungal infection. We describe a case of sternal wound infection caused by Trichosporon inkin with a fatal outcome, in an immunocompetent patient following aortic root surgery.

Use of DNA sequencing analysis to confirm fungemia due to Trichosporon dermatis in a pediatric patient

This is the first reported case of human disease caused by Tricosporon dermatis, an organism recently transferred to the genus Trichosporon from Cryptococcus and now confirmed to be a human pathogen.

Characterization of Trichosporon species isolated from clinical specimens in Kuwait

Invasive trichosporonosis is an emerging infection of severely immunocompromised patients. It is principally caused by Trichosporon asahii, although some other species of the genus have also been implicated in the aetiology. In this work, 29 clinical isolates of Trichosporon species recovered from 29 different patients over a 6-year period were studied for phenotypic and genotypic characteristics. Two morphotypes were recognized on the basis of colony characteristics. The colonies of 25 isolates appeared flat and centrally wrinkled, while the other four isolates appeared dry and irregularly folded or verrucosed. Based on substrate assimilation profiles, all 29 isolates were identified as T. asahii using the Vitek 2 system. However, PCR amplification of rRNA gene sequences identified only 25 of the 29 isolates as T. asahii. The identity of the remaining four isolates was established as Trichosporon asteroides by direct DNA sequencing of the internally transcribed spacer (ITS)-1 and ITS-2 regions in the rRNA gene fragment amplified by PCR using panfungal primers. Fingerprinting carried out by randomly amplified polymorphic DNA analysis showed genotypic heterogeneity among the 25 T. asahii and four T. asteroides isolates. These data suggest that T. asahii is the major species associated with clinical specimens in Kuwait.

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.

Trichosporon mycotoxinivorans sp. nov., A New Yeast Species Useful in Biological Detoxification of Various Mycotoxins

A yeast strain isolated from the hindgut of the lower termite Mastotermes darwiniensis (Mastotermitidae) was found to represent a new member of the genus Trichosporon. Trichosporon mycotoxinivorans is closely related to T. loubieri on the basis of the phylogenetic trees based on the D1/D2 region of 26S rDNA, an approx. 600 bp fragment of the 18S rDNA and both ITS regions. However, the two species differ at nine positions in the D1/D2 region of 26S rDNA. The IGS1 region of T. mycotoxinivorans is 401 bp long. T. mycotoxinivorans is distinguished from T. loubieri by its ability to assimilate inulin and galactitol, and its inability to grow at 40 degrees C. The name of this newly isolated strain refers to an important characteristics of T. mycotoxinivorans to detoxify mycotoxins such as ochratoxin A and zearalenone. Therefore this strain can be used for the deactivation of the respective mycotoxins in animal feeds.

High-throughput detection of pathogenic yeasts of the genus trichosporon

The need for a rapid and accurate method for the detection of fungal pathogens has become imperative as the incidence of fungal infections has increased dramatically. Herein, we tested the Luminex 100, a novel flow cytometer, for the detection of the medically important genus Trichosporon. This genus was selected as our proof-of-concept model due to the close phylogenetic relationship between the species. The method, which is based on a nucleotide hybridization assay, consists of a combination of different sets of fluorescent beads covalently bound to species-specific capture probes. Upon hybridization, the beads bearing the target amplicons are classified by their spectral addresses with a 635-nm laser. Quantitation of the hybridized biotinylated amplicon is based on fluorescence detection with a 532-nm laser. We tested in various multiplex formats 48 species-specific and group-specific capture probes designed in the D1/D2 region of ribosomal DNA, internal transcribed spacer regions, and intergenic spacer region. Species-specific biotinylated amplicons were generated with three sets of primers to yield fragments from the three regions. The assay was specific and fast, as it discriminated species differing by 1 nucleotide and required less than 50 min following amplification to process a 96-well plate. The sensitivity of the assay allowed the detection of 10(2) genome molecules in PCRs and 10(7) to 10(8) molecules of biotinylated amplification product. This technology provided a rapid means of detection of Trichosporon species with the flexibility to identify species in a multiplex format by combining different sets of beads.

Disseminated trichosporonosis caused by Trichosporon loubieri

Trichosporonosis is an emerging invasive fungal infection in immunosuppressed patients; a case of disseminated infection caused by Trichosporon loubieri presented confirms its role as a human pathogen.