Generalized lymphadenopathy caused by Trichosporon asahii in a patient with Job's syndrome

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.

A novel silkworm infection model with fluorescence imaging using transgenic Trichosporon asahii expressing eGFP

Trichosporon asahii is a pathogenic fungus that causes deep mycosis in patients with neutropenia. Establishing an experimental animal model for quantitatively evaluating pathogenicity and developing a genetic recombination technology will help to elucidate the infection mechanism of T. asahii and promote the development of antifungal drugs. Here we established a silkworm infection model with a transgenic T. asahii strain expressing eGFP. Injecting T. asahii into silkworms eventually killed the silkworms. Moreover, the administration of antifungal agents, such as amphotericin B, fluconazole, and voriconazole, prolonged the survival time of silkworms infected with T. asahii. A transgenic T. asahii strain expressing eGFP was obtained using a gene recombination method with Agrobacterium tumefaciens. The T. asahii strain expressing eGFP showed hyphal formation in the silkworm hemolymph. Both hyphal growth and the inhibition of hyphal growth by the administration of antifungal agents were quantitatively estimated by monitoring fluorescence. Our findings suggest that a silkworm infection model using T. asahii expressing eGFP is useful for evaluating both the pathogenicity of T. asahii and the efficacy of antifungal drugs.

An Unusual Cause of Fever and Rash in a Child With Severe Aplastic Anemia

A 4-year-old girl with severe aplastic anemia and 2 previous failed T-depleted haploidentical peripheral blood stem cell transplants developed persistent neutropenic fever and multiple erythematous maculopapular rashes 2 days after her third T-replete haploidentical bone marrow transplant. Skin biopsy confirmed the diagnosis of Trichosporon asahii infection. She was on caspofungin prophylaxis which is not effective against Trichosporon. A high index of suspicion, prompt investigation, and appropriate treatment with voriconazole for 4 months was instrumental in controlling the infection and she remains well presently 9 months posttransplant with full donor chimerism and free from infection.

Hyperimmunoglobulin E syndrome: Genetics, immunopathogenesis, clinical findings, and treatment modalities

The hyperimmunoglobulin E syndromes (HIESs) are very rare immunodeficiency syndromes with multisystem involvement, including immune system, skeleton, connective tissue, and dentition. HIES are characterized by the classic triad of high serum levels of immunoglobulin E (IgE), recurrent staphylococcal cold skin abscess, and recurrent pneumonia with pneumatocele formation. Most cases of HIES are sporadic although can be inherited as autosomal dominant and autosomal recessive traits. A fundamental immunologic defect in HIES is not clearly elucidated but abnormal neutrophil chemotaxis due to decreased production or secretion of interferon γ has main role in the immunopathogenesis of syndrome, also distorted Th1/Th2 cytokine profile toward a Th2 bias contributes to the impaired cellular immunity and a specific pattern of infection susceptibility as well as atopic-allergic constitution of syndrome. The ophthalmic manifestations of this disorder include conjunctivitis, keratitis, spontaneous corneal perforation, recurrent giant chalazia, extensive xanthelasma, tumors of the eyelid, strabismus, and bilateral keratoconus. The diagnosis of HIES is inconclusive, dependent on the evolution of a constellation of complex multisystemic symptoms and signs which develop over the years. Until time, no treatment modality is curative for basic defect in HIES, in terms of cytokines/chemokines derangement. Of note, bone marrow transplant and a monoclonal anti-IgE (omalizumab) are hoped to be successful treatment in future.

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.

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.

Clinicopathologic presentations of dermatomycoses in cancer patients

Many of the skin fungal infections in cancer patients may look similar to those infections in non-cancer patients. However, in some cases, they become more extensive and even life threatening. Prolonged and severe neutropenia is the main risk factor for the dramatic issue of fungal infections. The dermatomycoses in cancer patients can be classified in four broad groups: primary superficial dermatophytoses, primary superficial yeast infections, opportunistic mold infections with distinct potential for dissemination and secondary cutaneous manifestations of fungaemia. Occasionally, more than one fungus are found inside a given skin lesion. A special condition is represented by the mycotic colonization of mucosal squamous cell carcinomas. Angio-invasion by fungi accounts for the frequency of disseminated infections prevailing in immunocompromised cancer patients. In case of skin involvement, the dermatologist may assist by recognizing subtle semiological signs and performing biopsies for swift histological examination, molecular biology and/or culture.

Fungal infections in primary immunodeficiencies

Patients with phagocytic, cellular, combined and other primary immunodeficiencies exhibit immune deficits that confer increased susceptibility to fungal infections. A number of yeasts and moulds, most commonly Candida and Aspergillus but also Cryptococcus, Histoplasma, Paecilomyces, Scedosporium, Trichosporon, Penicillium and other, rarely isolated, fungal organisms, have been variably implicated in causing disease in patients with chronic granulomatous disease, severe combined immunodeficiency, chronic mucocutaneous candidiasis, hyper-IgE syndrome, myeloperoxidase deficiency, leukocyte adhesion deficiency, defects in the interferon-gamma/interleukin-12 axis, DiGeorge syndrome, X-linked hyper-IgM syndrome, Wiskott-Aldrich syndrome and common variable immunodeficiency. Differences in the spectrum of fungal pathogens as well as in the incidence and clinical presentation of the infections may be observed among patients, depending upon different immune disorders. Fungal infections in these individuals may occasionally be the presenting clinical manifestation of a primary immunodeficiency and can cause significant morbidity and potentially fatal outcome if misdiagnosed or mistreated. A high degree of suspicion is needed and establishment of diagnosis should actively be pursued using appropriate imaging, mycological and histological studies. A number of antifungal agents introduced over the last fifteen years, such as the lipid formulations of amphotericin B, the second-generation triazoles, and the echinocandins, increase the options for medical management of these infections. Surgery may also be needed in some cases, while the role of adjunctive immunotherapy has not been systematically evaluated. The low incidence of primary immunodeficiencies in the general population complicates single-center prospective or retrospective clinical studies aiming to address diagnostic or therapeutic issues pertaining to fungal infections in these patients.

Hyperimmunoglobulin E syndrome: Two cases and a review of the literature

Hyperimmunoglobulin E syndrome (HIES) is a rare immunodeficiency associated with elevated serum IgE levels, eczematous skin, recurrent cutaneous infections, and distinctive musculoskeletal features. We report two cases seen at our institution and review the current literature. Patient 1 was an 18-month-old African American boy with recurrent staphylococcal cold abscesses, pneumonia, and bacteremia. He had severely eczematous skin, ultimately complicated by eczema herpeticum. After treatment of systemic infections with culture-directed antibiotics, a brief course of cyclosporine, 5 mg/kg, improved the dermatitis and allowed transition to long-term therapy with oral trimethoprim-sulfamethoxazole. Patient 2 was a 15-year-old Caucasian boy with long-standing HIES. He has been maintained on a regimen of interferon gamma injections given 3 times weekly and monthly intravenous immunoglobulin since the age of 3 years, prophylactic antibiotics, and low-dose fluconazole. He has occasional episodes of cold abscesses and sinusitis, but has had excellent control since institution of this regimen and has not experienced any adverse effects.

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 loubieri infection in a patient with adult polycystic kidney disease

A 45-year-old man from Nepal with a 13-year history of polycystic kidney disease was diagnosed as suffering from chronic renal failure with end-stage renal disease. After receiving empirical antituberculosis treatment, he was treated with broad-spectrum antibiotics. A left nephrectomy was performed, and after 4 months, he received a kidney transplant. The left kidney was grossly enlarged, with multiple cystic spaces filled with blackish material. Histologic examination of the excised left kidney tissue stained with hematoxylin and eosin and Gomori's methenamine silver stains showed numerous hyaline, septate, fungal hyphae of various lengths, many broken into rectangular arthroconidia in the cystic spaces. Culture of the kidney tissue yielded white, glabrous, yeast-like colonies. Based on its micromorphology, growth at 42 degrees C, and ribosomal DNA (rDNA) sequence analysis, and also sequence analysis of the internal-transcribed-spacer and D1/D2 rDNA regions, the yeast was identified as Trichosporon loubieri. Postsurgically, the patient was treated with amphotericin B and oral itraconazole, followed by maintenance therapy with fluconazole. He remained afebrile and asymptomatic. At the final follow-up, all parameters were found normal and the patient was doing well, with normal renal function reports. This paper presents the first known case of human infection caused by T. loubieri.