Recognizing filamentous basidiomycetes as agents of human disease: A review

Identification of Irpex and Rhodotorula on surveillance bronchoscopy in a pediatric lung transplant recipient: A case report and review of literature of these atypical fungal organisms

BACKGROUND

Invasive fungal disease (IFD) is a frequent complication in pediatric lung transplant recipients, occurring in up to 12% of patients in the first year. Risk factors for infection include impaired lung defenses and intense immunosuppressive regimens. While most IFD occurs from Aspergillus, other fungal conidia are continuously inhaled, and infections with fungi on a spectrum of human pathogenicity can occur.

CASE REPORT

We report a case of a 17-year-old lung transplant recipient in whom Irpex lacteus and Rhodotorula species were identified during surveillance bronchoscopy. She was asymptomatic and deemed to be colonized by Irpex lacteus and Rhodotorula species following transplant. 2 years after transplantation, she developed a fever, respiratory symptoms, abnormal lung imaging, and histological evidence of acute and chronic bronchitis on transbronchial biopsy. After developing symptoms concerning for a pulmonary infection and graft dysfunction, she was treated for a presumed IFD. Unfortunately, further diagnostic testing could not be performed at this time given her tenuous clinical status. Despite the initiation of antifungal therapy, her graft function continued to decline resulting in a second lung transplantation.

CONCLUSIONS

This case raises the concern for IFD in lung transplant recipients from Irpex species. Further investigation is needed to understand the pathogenicity of this organism, reduce the incidence and mortality of IFD in lung transplant recipients, and refine the approach to diagnosis and manage the colonization and isolation of rare, atypical fungal pathogens in immunocompromised hosts.

Chronic Pulmonary Aspergillosis Caused by Aspergillus tubingensis Diagnosed by a Bronchoscopic Biopsy

We herein report a case of chronic pulmonary aspergillosis (CPA) caused by Aspergillus tubingensis diagnosed by a bronchoscopic biopsy with negative serological and sputum culture findings. A 66-year-old man was referred for the assessment of a pulmonary cavity. Computed tomography showed a thick-walled cavity in the upper right pulmonary lobe. Serum β-D glucan, Aspergillus galactomannan, and Aspergillus antibody tests were negative. Aspergillus species were not detected in the sputum. Culture and pathological specimens were obtained from the mass by bronchoscopy. Microscopic examination findings were consistent with Aspergillus niger complex morphologically and identified as Aspergillus tubingensis through DNA sequencing. The patient was diagnosed with chronic pulmonary aspergillosis.

Clinical characteristics of allergic bronchopulmonary mycosis caused by Schizophyllum commune

BACKGROUND

Allergic bronchopulmonary mycosis (ABPM) is an allergic disease caused by type I and type III hypersensitivity to environmental fungi. Schizophyllum commune, a basidiomycete fungus, is one of the most common fungi that causes non-Aspergillus ABPM.

OBJECTIVE

Herein, we attempted to clarify the clinical characteristics of ABPM caused by S. commune (ABPM-Sc) compared with those of allergic bronchopulmonary aspergillosis (ABPA).

METHODS

Patients with ABPM-Sc or ABPA were recruited from a nationwide survey in Japan, a multicenter cohort, and a fungal database at the Medical Mycology Research Center of Chiba University. The definition of culture-positive ABPM-Sc/ABPA is as follows: (1) fulfills five or more of the 10 diagnostic criteria for ABPM proposed by Asano et al., and (2) positive culture of S. commune/Aspergillus spp. in sputum, bronchial lavage fluid, or mucus plugs in the bronchi.

RESULTS

Thirty patients with ABPM-Sc and 46 with ABPA were recruited. Patients with ABPM-Sc exhibited less severe asthma and presented with better pulmonary function than those with ABPA (p = 0.008-0.03). Central bronchiectasis was more common in ABPM-Sc than that in ABPA, whereas peripheral lung lesions, including infiltrates/ground-glass opacities or fibrotic/cystic changes, were less frequent in ABPM-Sc. Aspergillus fumigatus-specific immunoglobulin (Ig)E was negative in 10 patients (34%) with ABPM-Sc, who demonstrated a lower prevalence of asthma and levels of total serum IgE than those with ABPM-Sc positive for A. fumigatus-specific IgE or ABPA.

CONCLUSIONS

Clinical characteristics of ABPM-Sc, especially those negative for A. fumigatus-specific IgE, differed from those of ABPA.

The first suspected disseminated Hormographiella aspergillata infection in China, diagnosed using metagenomic next-generation sequencing: a case report and literature review

Hormographiella aspergillata is a rare and emerging cause of invasive mould infections in patients with haematological malignancies, with a mortality rate of approximately 70%. Here, we present the first reported case of suspected disseminated H. aspergillata infection in China. The patient experienced a second relapse of acute myeloid leukaemia and developed neutropenia, fever, discrepant blood pressure between limbs, and cutaneous lesions limited to the left upper extremity. Since lung tissue biopsy was not feasible, metagenomic next-generation sequencing (mNGS) and panfungal polymerase chain reaction (PCR) analysis of bronchoalveolar lavage fluid and blood samples were performed, which indicated probable H. aspergillata pulmonary infection. Histopathology of cutaneous lesions revealed numerous fungal hyphae within dermal blood vessels. mNGS of a skin biopsy sample identified H. aspergillata sequences, and the fungi was subsequently recovered from fungal culture, proving cutaneous H. aspergillata infection. Despite combined antifungal therapy, the patient died owing to disease progression. Additionally, 22 previously reported cases of invasive H. aspergillata infection were reviewed in patients with haematological malignancies. Thus, mNGS is a powerful diagnostic tool for the early and effective detection of invasive H. aspergillata infections, with the advantage of sequencing all potential pathogens, and providing results within 24 h.

Isolation of filamentous basidiomycetes from respiratory samples in a tertiary care Spanish hospital

BACKGROUND

The clinical significance of the filamentous basidiomycetes isolated from clinical samples is not always clear. Thus, these fungi have been considered environmental contaminants traditionally.

AIMS

To review those clinical cases in which filamentous basidiomycetes from respiratory samples had been isolated.

METHODS

The retrospective study was carried out in a single tertiary care hospital. We recovered all culture-confirmed isolations of filamentous basidiomycetes from respiratory samples (bronchial aspirate [BAS], bronchoalveolar lavage [BAL] and sputum) analyzed between the years 2020 and 2023. Isolates were identified by ITS region sequencing.

RESULTS

In six patients a filamentous basidiomycete had been isolated from a respiratory sample. The species identified were all different: Fomitopsis sp. (BAS), Trametes ljubarskyi (BAL), Stereum gausapatum (BAS), Porostereum spadiaceum (BAS), Phlebia subserialis (sputum) and Inonotus levis (BAL). All the patients were immunosuppressed or had an underlying disease with pulmonary involvement. None of them received any specific antifungal treatment (in relation with the fungus isolated) and all six improved clinically and were discharged.

CONCLUSIONS

The isolation of filamentous basidiomycetes in these patients had uncertain clinical significance. However, the isolation of any filamentous basidiomycete in respiratory samples from immunosuppressed patients or patients with chronic pulmonary disease is an emerging situation that should be carefully assessed in the context of chronic allergic episodes or suspicion of invasive fungal infections.

Subcutaneous mycosis caused by filamentous basidiomycete Megasporoporia setulosa-first report of human infection

Filamentous basidiomycetes are an emerging cause of human infection in tropical and subtropical regions. We report a case of subcutaneous infection caused by the shelf fungus, Megasporoporia setulosa, in an immunocompetent male. This is also the first report of human infection caused by this filamentous basidiomycete. Identification of the fungus could only be achieved by sequencing the ITS and LSU regions of rDNA. The patient recovered following surgery and treatment with amphotericin B and oral itraconazole. This report underscores the cross-kingdom pathogenicity of plant fungi and the importance of molecular tools for definitive identification of nonsporulating fungal species.

Mycotoxigenic fungal growth inhibition and multi-mycotoxin reduction of potential biological control agents indigenous to grain maize

The present work investigated the potential of fungal species from grain maize farms in Malaysia as antagonists against the indigenous mycotoxigenic fungal species and their subsequent mycotoxin production. Dual-culture assay was conducted on grain maize agar (GMA) with 12 strains of potential fungal antagonists namely Bjerkandra adusta, Penicillium janthinellum, Schizophyllum commune, Trametes cubensis, Trichoderma asperelloides, Trichoderma asperellum, Trichoderma harzianum, and Trichoderma yunnanense against seven mycotoxigenic strains namely Aspergillus flavus, Aspergillus niger, Fusarium verticillioides, and Fusarium proliferatum producing aflatoxins, ochratoxin A, and fumonisins, respectively. Based on fungal growth inhibition, Trichoderma spp. showed the highest inhibitory activity (73-100% PIRG, Percentage Inhibition of Radial Growth; 28/0 I_D, Index of Dominance) against the tested mycotoxigenic strains. Besides, B. adusta and Tra. cubensis showed inhibitory activity against some of the tested mycotoxigenic strains. All fungal antagonists showed varying degrees of mycotoxin reduction. Aflatoxin B₁ produced by A. flavus was mainly reduced by P. janthinellum, Tra. cubensis, and B. adusta to 0 ng/g. Ochratoxin A produced by A. niger was mainly reduced by Tri. harzianum and Tri. asperellum to 0 ng/g. Fumonisin B₁ and FB₂ produced by F. verticillioides was mainly reduced by Tri. harzianum, Tri. asperelloides, and Tri. asperellum to 59.4 and 0 µg/g, respectively. Fumonisin B₁ and FB₂ produced by F. proliferatum were mainly reduced by Tri. asperelloides and Tri. harzianum to 244.2 and 0 µg/g, respectively. This is the first study that reports on the efficacy of Tri. asperelloides against FB₁, FB₂, and OTA, P. janthinellum against AFB₁, and Tra. cubensis against AFB₁.

Functional Clustering of Metabolically Related Genes Is Conserved across Dikarya

Transcriptional regulation is vital for organismal survival, with many layers and mechanisms collaborating to balance gene expression. One layer of this regulation is genome organization, specifically the clustering of functionally related, co-expressed genes along the chromosomes. Spatial organization allows for position effects to stabilize RNA expression and balance transcription, which can be advantageous for a number of reasons, including reductions in stochastic influences between the gene products. The organization of co-regulated gene families into functional clusters occurs extensively in Ascomycota fungi. However, this is less characterized within the related Basidiomycota fungi despite the many uses and applications for the species within this clade. This review will provide insight into the prevalence, purpose, and significance of the clustering of functionally related genes across Dikarya, including foundational studies from Ascomycetes and the current state of our understanding throughout representative Basidiomycete species.

Pulmonary infection of Schizophyllum commune diagnosed by metagenomic next- generation sequencing: A case report

RATIONALE

Fungal infection is common and difficult to be diagnosed timely in clinical, for its various kinds and similar manifestations. The rare pulmonary fungal infection such as Schizophyllum commune was one of the harder ones and misdiagnosed in usual.

PATIENT CONCERNS

We report a 32-year-old female which was diagnosed with Metagenomic Next-Generation Sequencing (mNGS). She was hospitalized with the complaint of 4 months and more of repeated cough and expectorating. The chest computer tomography revealed left lower lobe pathological changes, but antibiotics were ineffective. No positive results were found in laboratory tests, including sputum culture and the pathology of lung puncture biopsy.

DIAGNOSES

mNGS of lung biopsy was performed and detected the sequence number of Schizophyllum for 11.

INTERVENTIONS

The patient was treated with voriconazole and itraconazole successively.

OUTCOMES

She recovered to health. There was no recurrence during follow-up.

LESSONS

mNGS as a diagnostic method could quickly detect pathogens through the processing of fragment, synthesis, comparison, and analysis of sample genes. It is suitable for detecting especially rare and polymicrobial infections. To our best knowledge, infection of Schizophyllum commune have not been reported in English literature with diagnostic method of mNGS.

Fungal Keratitis and Corneal Perforation as a Rare Complication of Corneal Collagen Cross-Linking Treatment

PURPOSE

The aim of this study was to report a case of fungal keratitis with subsequent corneal perforation after corneal collagen cross-linking (CXL) treatment performed for keratoconus.

CASE REPORT

A 20-year-old woman presented with redness and discharge in the left eye. She had a history of bilateral CXL procedure performed for keratoconus elsewhere 4 days earlier. The visual acuity was hand motion in the left eye. Slit-lamp examination revealed extended corneal melting with surrounding infiltrates. The patient was hospitalized, and corneal epithelial scraping samples were sent for microbiological assessment. In the meantime, empirical antibiotic therapy (fortified topical antibiotics: vancomycin 50 mg/mL, ceftazidime 50 mg/mL, and fluconazole 2 mg/mL q1 hour) was initiated. In direct microscopy of the corneal scraping, septate hyaline fungal hyphae were detected and topical fluconazole was switched to topical voriconazole (10 mg/mL). Three days after hospitalization, corneal melting progressed to perforation and corneal suturing with 10-0 monofilament was performed to reform the anterior chamber. Complete resolution of keratitis with residual scarring was noticed in 2 weeks. Three months later, penetrating keratoplasty was performed to obtain better visual acuity.

CONCLUSIONS

CXL with riboflavin has become a common procedure to prevent keratoconus progression by strengthening the biomechanical specialties of the cornea. Although the treatment itself has been used in the management of microbial keratitis and related corneal melting, fungal keratitis and corneal perforation after a CXL procedure for keratoconus might also be detected. Clinicians should be aware of this rare but devastating complication of CXL treatment and start prompt treatment when suspected.

Successful Treatment of Rare Pulmonary Coprinopsis cinerea Infection in a 17-Year-Old Female After Hematopoietic Stem Cell Transplantation: A Case Report

Invasive fungal infections (IFIs) are among the most severe complications in recipients of hematopoietic stem cell transplantation (HSCT) recipients and in patients with hematological malignancies. An increasing number of uncommon fungal infections have been reported in this era of antifungal prophylaxis. Coprinopsis cinerea is a rare pathogen that causes opportunistic infections in the immunocompromised patients, including HSCT recipients and is associated with very high mortality rates. Herein, we present a successfully treated pediatric HSCT patient with breakthrough pulmonary IFI caused by Coprinopsis cinerea despite posaconazole, prophylaxis using multidisciplinary approaches.

Fusel oil reaction in pressurized water: characterization and antimicrobial activity

This work aimed to investigate the reaction of fusel oil (FO) with pressurized water in a continuous flow reactor, in order to verify the effect of operating conditions (temperature and alcohol to water ratio) on the formation of reaction products, as well as to potentiate the antimicrobial activity of FO. The characterization of the FO was performed by high resolution mass spectrometry (ESI-TOF) and by a chromatograph coupled to mass spectrometry (GC-MS), and the reaction products were characterized by ESI-TOF and evaluated for antifungal potential. From the results, it was verified that the FO contained 70.58 wt% of isoamyl alcohol and was formed mainly by the organic functions alcohols, aldehydes, ketones and lipids. The reaction mechanisms that prevailed during the reactions conducted in subcritical and supercritical states were dehydration and reduction, respectively, making it possible to identify pyrazine derivatives compounds in the reaction products. The fungus Irpex lacteus showed greater resistance under the application of reaction products, and the products obtained at 300 °C and 400 °C showed an inhibition percentage of 96.07% to Schizophyllum commune and 96.50% to Trametes versicolor, respectively.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13205-022-03429-3.

Rigidoporus corticola Colonization and Invasive Fungal Disease in Immunocompromised Patients, United States

We report 2 cases of Rigidoporus corticola (Oxyporus corticola) infection in humans in the United States. Clinical manifestations consisted of angioinvasive fungal sinusitis in 1 patient and pulmonary intracavitary fungus ball in the other patient. These cases illustrate previously undescribed clinicopathologic manifestations of infection by this filamentous basidiomycete in humans.

First case of Tropicoporus tropicalis keratitis in an immunocompetent host from India and review of the literature

Tropicoporus tropicalis is an environmental basidiomycete that has been implicated in nine cases of cutaneous (n = 7) and pulmonary (n = 2) human infections predominantly in chronic granulomatous disease patients. We report here the first case of keratitis caused by Tropicoporus tropicalis in a 40-year-old immunocompetent patient, who presented with sudden diminution of vision in right eye. Corneal scrapings revealed hyaline, septate hyphae in microscopy and culture showed growth of white non-sporulating mycelial growth which was confirmed as Tropicoporus tropicalis by sequencing of ITS region of 28S rDNA. The patient was initiated on topical voriconazole along with natamycin, gatifloxacin and atropine drops. However, despite treatment, corneal ulcer perforated, for which penetrating keratoplasty was performed. Thereafter, he was prescribed amphotericin B (AMB) drops sixteen times a day and ketoconazole 200 mg twice a day with no recurrence reported over one year of follow up. The case represents the first case of infection by this fungus from India and also is the first case to be reported in an immunocompetent host.

Dietary supplementation with Ceriporia lacerata improves learning and memory in a scopolamine-induced amnesia mouse model

Ceriporia lacerata (CL) is a species of white rot fungi. In this study, we have examined the beneficial effect of CL on scopolamine-induced memory impairment in mice. A freeze-dried CL mycelial culture broth was dissolved and orally administered to scopolamine-treated C57BL/6J mice followed by behavioral tests using the Y-maze, passive avoidance, and Morris water maze tasks. CL administration at a daily dose of 200 mg/kg body weight resulted in restoration of exploration reduction and improvement of associative and spatial learning and memory impairment in scopolamine-treated mice. Concomitantly, heme oxygenase-1 was highly expressed in the hippocampal region of CL-administered mice. Moreover, the ethanolic extract of CL significantly increased the transcriptional activity of antioxidant response element and attenuated the glutamate-induced cytotoxicity in HT22 mouse hippocampal neuronal cells. These findings suggest that the CL intake can confer a beneficial effect on learning and memory presumably through protecting hippocampal neuronal cells from oxidative stress-induced damage.

SUPPLEMENTARY INFORMATION

The online version contains supplementary material available at 10.1007/s10068-021-00945-5.

Identification of Volatile Sulfur Compounds Produced by Schizophyllum commune

Schizophyllum commune is a causative agent of allergic bronchopulmonary mycosis, allergic fungal rhinosinusitis, and basidiomycosis. Diagnosis of these diseases remains difficult because no commercially available tool exists to identify the pathogen. Unique volatile organic compounds produced by a pathogen might be useful for non-invasive diagnosis. Here, we explored microbial volatile organic compounds produced by S. commune. Volatile sulfur compounds, dimethyl disulfide (48 of 49 strains) and methyl ethyl disulfide (49 of 49 strains), diethyl disulfide (34 of 49 strains), dimethyl trisulfide (40 of 49 strains), and dimethyl tetrasulfide (32 of 49 strains) were detected from headspace air in S. commune cultured vials. Every S. commune strain produced at least one volatile sulfur compound analyzed in this study. Those volatile sulfur compounds were not detected from the cultures of Aspergillus spp. (A. fumigatus, A. flavus, A. niger, and A. terreus), which are other major causative agents of allergic bronchopulmonary mycosis. The last, we examined H₂S detection using lead acetate paper. Headspace air from S. commune rapidly turned the lead acetate paper black. These results suggest that those volatile sulfur compounds are potent targets for the diagnosis of S. commune and infectious diseases.

Gloeostereum cimri, a novel shelf fungus isolated from a human pulmonary cyst

Filamentous basidiomycetes are uncommon agents of human diseases, despite their ubiquitous presence in the environment. We present a case of symptomatic pulmonary infection in a 38-year-old male with cough and fever; a thin-walled cyst in the posterior left upper pulmonary lobe was revealed by radiography. A non-sporulating fungus was isolated from sputum and biopsy material from the cyst. ITS and LSU sequences placed the fungus phylogenetically in Agaricales, family Cyphellaceae, and identified it as a member of shelf fungi in Gloeostereum, but without identity to any known species. The new species is described as Gloeostereum cimri. The clinical strain showed high MIC to voriconazole (>8 µg/ml) but had low MIC to amphotericin B (0.5 µg/ml).

First case report of fungal meningitis due to a polypore mushroom Irpex lacteus

A 73-year-old Japanese man with a medical history of sarcoidosis was diagnosed with meningitis caused by an undetermined fungus. For further identification, the cerebrospinal fluid sample was analyzed for the rDNA internally transcribed spacer regions, and the fungus was identified as Irpex lacteus. I. lacteus is classified under phylum Basidiomycota and is a wood-rotting bracket mushroom. Although there is no standard treatment regimen for I. lacteus infections, amphotericin B was effective in this patient. Herein, we present, to our knowledge, the first reported case of fungal meningitis caused by I. lacteus, its treatment course, and review relevant published literature.

A case of allergic fungal rhinosinusitis caused by Schizophyllum commune identified in both patient's nasal sputum and veranda's soil samples

This is a case report of allergic fungal rhinosinusitis caused by Schizophyllum commune (S. commune) identified in a patient's nasal mucus and environmental soil sample using (r)DNA sequencing. Although filamentous basidiomycetes, including S. commune, are known as environmental pathogens causing allergic respiratory diseases worldwide, many patients with infections caused by S. commune have not been correctly diagnosed. Repeated exposures to environmental floating fungi supposedly make an easy sensitization and colonization of fungi in the nasal passages, resulting in the onset of allergic fungal rhinosinusitis due to S. commune in our living environments. This report indicates the importance of reconsidering allergic respiratory diseases associated with our living environments.

Hormographiella aspergillata: an emerging basidiomycete in the clinical setting? A case report and literature review

Background

Filamentous basidiomycetes are mainly considered to be respiratory tract colonizers but the clinical significance of their isolation in a specimen is debatable. Hormographiella aspergillata was first reported as a human pathogen in 1971. We discuss the role of this mold as a pathogen or colonizer and give an update on diagnostic tools and in vitro antifungal susceptibility.

Case presentation

We identified three cases of H. aspergillata with respiratory symptoms in a short period of time. One invasive infection and two colonizations were diagnosed. Culture supernatants showed that H. aspergillata can produce galactomannan and β-D-glucan but not glucuronoxylomannan. For the first time, isavuconazole susceptibility was determined and high minimum inhibitory concentrations (MICs) were found. Liposomal amphotericin B and voriconazole have the lowest MICs.

Conclusion

To date, 22 invasive infections involving H. aspergillata have been reported. On isolation of H. aspergillata, its pathogenic potential in clinical settings can be tricky. Molecular identification and antifungal susceptibility testing are essential considering high resistance against several antifungal therapies.

Unexpected mould diversity in clinical isolates from French Guiana and associated identification difficulties

New mold species are increasingly reported in invasive fungal infections. However, these fungi are often misdiagnosed or undiagnosed due to the use of inappropriate laboratory diagnostic tools. Tropical countries, such as French Guiana, harbor a vast diversity of environmental fungi representing a potential source of emerging pathogens. To assess the impact of this diversity on the accuracy of mold-infection diagnoses, we identified mold clinical isolates in French Guiana during a five-month follow-up using both microscopy and matrix-assisted laser desorption ionization time-of-flight mass spectrometry. In total, 38.8% of the 98 obtained molds isolates could not be identified and required a DNA-based identification. Fungal diversity was high, including 46 species, 26 genera, and 13 orders. Fungal ecology was unusual, as Aspergillus species accounted for only 27% of all isolates, and the Nigri section was the most abundant out of the six detected Aspergillus sections. Macromycetes (orders Agaricales, Polyporales, and Russulales) and endophytic fungi accounted for respectively 11% and 14% of all isolates. Thus, in tropical areas with high fungal diversity, such as French Guiana, routine mold identification tools are inadequate. Molecular identifications, as well as morphological descriptions, are necessary for the construction of region-specific mass spectrum databases. These advances will improve the diagnosis and clinical management of new fungal infections.

LAY SUMMARY

In French Guiana, environmental fungal diversity may be a source of emerging pathogens. We evaluated microscopy and mass spectrometry to identify mold clinical isolates. With 39% of unidentified isolates, a region-specific mass spectrum database would improve the diagnosis of new fungal infections.

Emerging mould infections: Get prepared to meet unexpected fungi in your patient

Invasive fungal diseases are increasing issues in modern medicine, where the human immunodeficiency virus (HIV) pandemic and the wider use of immunosuppressive drugs generate an ever-growing number of immunocompromised patients with an increased susceptibility to uncommon fungal pathogens. In the past decade, new species have been reported as being responsible for disseminated and invasive fungal diseases in humans. Among them, the following genera are rare but seem emerging issues: Scopulariopsis, Hormographiella, Emergomyces, Westerdykella, Trametes, Actinomucor, Saksenaea, Apophysomyces, and Rhytidhysteron. Delay in diagnosis, which is often the case in these infections, jeopardizes patients' prognosis and leads to increased mortality. Here we summarize the clinical and biological presentation and the key features to identify these emerging pathogens and we discuss the available antifungal classes to treat them. We focused on Pubmed to recover extensively reported human invasive cases and articles regarding the nine previously cited fungal organisms. Information concerning patient background, macroscopic and microscopic description and pictures of these fungal organisms, histological features in tissues, findings with commonly used antigen tests in practice, and hints on potential efficient antifungal classes were gathered. This review's purpose is to help clinical microbiologists and physicians to suspect, identify, diagnose, and treat newly encountered fungi in hospital settings.

Schizophyllum commune sphenoidal sinusitis as presentation of a non-Hodgkin Lymphoma

Schizophyllum commune is a basidiomycetes worldwide distributed that has emerged as cause of invasive infections in immunosuppressed patients. We present a case of a man who was simultaneously diagnosed with a small cell non-Hodgkin lymphoma and a sphenoid sinusitis by S. commune. Intraoperative observation and histology description were crucial to consider an alternative diagnosis to mucormycosis suggested by the MRI. The diagnosis was made based on PCR identification and sequencing.

Infectious Keratitis Caused by Rare and Emerging Micro-Organisms

PURPOSE

To provide a comprehensive review of rare and emerging micro-organisms causing infectious keratitis.

MATERIAL AND METHODS

A literature search was performed using PubMed Medline, Cochrane Library Database, EMBASE and Scopus (1960 onwards), using the terms: keratitis caused by rare pathogens; mycotic keratitis; fungal keratitis; bacterial keratitis; infectious keratitis; infective keratitis; atypical fungal keratitis; fungal keratitis caused by rare organisms; fungal keratitis caused by rare ocular pathogen; atypical bacterial keratitis; bacterial keratitis caused by rare organisms; bacterial keratitis caused by rare ocular pathogen. All relevant articles were included in this review.

RESULTS

A total of 1232 articles matched our search strategy of which 124 articles were included in this mini-review. The rare and emerging bacteria causing keratitis include atypical mycobacteria, Nocardia spp., Chrysebacterium spp., Delftia acidovorans, Kocuria spp., Enterococcus spp., Bartonella henslae, Achromobacter spp. and others. The rare and emerging fungi causing keratitis include Pythium spp., Alternaria spp., Acremonium spp., Cladosporium spp., Curvularia spp., Bipolaris spp., Microsporidia spp., Pseudallescheria spp., Colletotrichum spp., and others. The clinical presentation of these cases is variable. While a few organisms produce characteristic clinical features, rest present similar to bacterial or fungal keratitis with variable response to routine treatment. A strong degree of suspicion is therefore essential for its diagnosis. Special investigations like polymerase chain reaction, gene sequencing, mass spectroscopy and enzyme-linked immunosorbent assay are required for accurate identification of these organisms. Culture-sensitivity is extremely useful as drug resistance to routinely used anti-microbial drugs is common. Prognosis is usually poor for keratitis with Pythium spp., Pseudallescheria spp., Arthrographis spp., Purpureocillium spp., Kociria spp. and Achromobacter spp.

CONCLUSION

Keratitis caused by rare and emerging micro-organisms must be suspected in cases where the infection runs an unusual course or shows a poor response to standard anti-microbial drugs. Early diagnosis and timely treatment hold the key for a good outcome.

Phylogeny and taxonomy of Ceriporia and other related taxa and description of three new species

Species of Ceriporia (Irpicaceae, Basidiomycota) are saprotrophs or endophytes in forest ecosystems. To evaluate the taxonomy and generic relationships of Ceriporia and other related taxa, we used morphology and multigene phylogenetic analyses based on sequence data from nuc rDNA internal transcribed spacer ITS1-5.8S-ITS2 (ITS) region, nuc 28S rDNA (28S), and RNA polymerase II largest subunit (rpb1). Our results show that Ceriporia sensu lato is polyphyletic and distributed across multiple clades in the Irpicaceae, Phanerochaetaceae, and Meruliaceae. Some species previously considered in Ceriporia are now recovered in Meruliopsis, resulting in four new combinations: M. albomellea, M. crassitunicata, M. nanlingensis, and M. pseudocystidiata. Two new species of Meruliopsis are described: M. leptocystidiata from northeast China and South Korea and M. parvispora from Taiwan. Ceriporia arbuscula is described as a new species from Taiwan. Ceriporia mellita and Meruliopsis nanlingensis are newly recorded from Japan and Taiwan, and M. taxicola is recorded from Taiwan for the first time.

Human infections due to Schizophyllumcommune: Case report and review of the literature

Schizophyllumcommune is an environmental basidiomycetous fungus, causing occasional, predominantly respiratory, infections in humans. Although S. commune is considered an emerging pathogen, some authors pointed out the possibility that the increase in the diagnosed cases may be also due to recent advances in diagnostic technologies now allowing a more prompt and precise identification at the species level. Here we describe the first Italian case of chronic non-invasive fungal rhinosinusitis due to S. commune in an immunocompetent subject and update the literature review on S. commune sinusitis published between 2012-2019. A timely diagnosis is important to avoid local and systemic complications due to infection with this fungus. In our case, prompt identification at species level was only possible with the use of MALDI-TOF mass spectrometry and confirmed by sequence analysis of ribosomal DNA ITS regions, due to the difficulty in achieving a correct and rapid identification using routine morphological analysis.

Mycosis Due to Tropicoporus tropicalis (= Inonotus tropicalis) in a Domestic Dog

Mycelial basidiomycetes rarely produce mycoses in animals including humans. We report a case of a 9-year-old female mongrel dog with lesions in the prescapular lymph nodes. The histopathology of a lymph node sample showed flexuous septate hyphae, and a sterile mold grew in culture from that specimen. DNA sequencing of the ITS region allowed us to identify the fungus as Tropicoporus tropicalis. The dog was treated with itraconazole, but it was euthanized six months later due to an unfavorable clinical outcome. Tropicoporus tropicalis is an infrequent pathogen of pets, and the use of molecular tools is needed for its identification. Animal infections due to T. tropicalis were not previously been reported in Argentina.

A cystic fibrosis child with lung function decline

Respiratory infections are a major threat to cystic fibrosis patients. Besides bacteria, many fungi colonize the cystic fibrosis respiratory tract where an important fungal biota has been described. We report here the case of a 7-year-old cystic fibrosis child with pulmonary exacerbation and Arthrographis kalrae isolated from bronchoalveolar lavage fluid. To the best of our knowledge, this is the first reported case of lung infection due to Arhtrographis kalrae in a cystic fibrosis pediatric patient.

A case of otitis externa caused by Schizophyllum commune: An approach to antimicrobial stewardship using Gram staining of otorrhea in a medical clinic

Recently, basidiomycete Schizophyllum commune has been reported as a cause of allergic bronchopulmonary mycosis. However, it is rare as a cause of otitis externa. We experienced a very rare case of otitis externa caused by S. commune in a 68-year-old man with a history of chronic otitis media. We performed Gram staining at the first consultation and follow-up treatment and found fungal cells on the smear and treated him with an appropriate antifungal drug. The results of identification and antifungal susceptibility testing obtained in cooperation with clinical microbiologists at other facilities was very important for future treatment planning decisions. Medical practitioners worldwide should introduce a Gram staining tool into their workflow and cooperate closely with clinical microbiologists to achieve antimicrobial stewardship.

Role of Serological Tests in the Diagnosis of Mold Infections

Purpose of Review

To understand the role of antibody detection in the diagnosis of infections caused by filamentous fungi (molds). Rapid and accurate profiling of infection-causing fungal pathogens remains a significant challenge in modern health care. Classical fungal culture and serology continue to be relevant even though over the past few decades, antigen (biomarker) assays such as ELISA and lateral flow devices have been developed and validated.

Recent Findings

This article reviews the current antibody detection systems (serological tests) for the diagnosis of mold infections associated with pulmonary disease and introduces new developments. Classic and more recently developed serological techniques and their performance characteristics, including immunodiffusion, complement fixation, and ELISA.

Summary

The diseases covered are allergic bronchopulmonary aspergillosis, chronic pulmonary aspergillosis, invasive aspergillosis, mucormycosis, diseases caused by filamentous basidiomycetes, infection caused by Talaromyces marneffei and pythiosis. Serology remains a cornerstone for fungal diagnostic testing.

Inonotosis in Patient with Hematologic Malignancy

We report a lung-invasive fungal disease with possible cutaneous needle tract seeding in a patient with a febrile neutropenia caused by the Basidiomycetes mold Inonotus spp. Although rare, Inonotus spp. should be added to the list of microorganisms causing invasive fungal disease in neutropenic patients with hematologic malignancies.

Immunological corollary of the pulmonary mycobiome in bronchiectasis: the CAMEB study

Understanding the composition and clinical importance of the fungal mycobiome was recently identified as a key topic in a “research priorities” consensus statement for bronchiectasis.

Patients were recruited as part of the CAMEB study: an international multicentre cross-sectional Cohort of Asian and Matched European Bronchiectasis patients. The mycobiome was determined in 238 patients by targeted amplicon shotgun sequencing of the 18S–28S rRNA internally transcribed spacer regions ITS1 and ITS2. Specific quantitative PCR for detection of and conidial quantification for a range of airway Aspergillus species was performed. Sputum galactomannan, Aspergillus specific IgE, IgG and TARC (thymus and activation regulated chemokine) levels were measured systemically and associated to clinical outcomes.

The bronchiectasis mycobiome is distinct and characterised by specific fungal genera, including Aspergillus, Cryptococcus and Clavispora. Aspergillus fumigatus (in Singapore/Kuala Lumpur) and Aspergillus terreus (in Dundee) dominated profiles, the latter associating with exacerbations. High frequencies of Aspergillus-associated disease including sensitisation and allergic bronchopulmonary aspergillosis were detected. Each revealed distinct mycobiome profiles, and associated with more severe disease, poorer pulmonary function and increased exacerbations.

The pulmonary mycobiome is of clinical relevance in bronchiectasis. Screening for Aspergillus-associated disease should be considered even in apparently stable patients.

The airway mycobiome in bronchiectasis is associated with clinically significant diseasehttp://ow.ly/MCKj30knVrn

Allergic bronchopulmonary mycosis - pathophysiology, histology, diagnosis, and treatment

Allergic bronchopulmonary mycosis (ABPM) develops mainly in patients with asthma or cystic fibrosis via types I and III hypersensitivity reactions to filamentous fungi. Aspergillus spp., especially Aspergillus fumigatus, is the major causative fungus because of its small conidia, thermophilic hyphae, and ability to secrete serine proteases. The cardinal histological feature of ABPM is allergic (eosinophilic) mucin-harboring hyphae in the bronchi, for which the formation of extracellular DNA trap cell death (ETosis) of eosinophils induced by viable fungi is essential. Clinically, ABPM is characterized by peripheral blood eosinophilia, increased IgE levels in the serum, IgE and IgG antibodies specific for fungi, and characteristic radiographic findings; however, there are substantial differences in the clinical features of this disease between East and South Asian populations. Systemic corticosteroids and/or antifungal drugs effectively control acute diseases, but recurrences are quite common, and development of novel treatments are warranted to avoid adverse effects and emergence of drug-resistance due to prolonged treatment with corticosteroids and/or antifungal drugs.

DNA metabarcoding uncovers fungal diversity of mixed airborne samples in Italy

Fungal spores and mycelium fragments are particles which become and remain airborne and have been subjects of aerobiological studies. The presence and the abundance of taxa in aerobiological samples can be very variable and impaired by changeable climatic conditions. Because many fungi produce mycotoxins and both their mycelium fragments and spores are potential allergens, monitoring the presence of these taxa is of key importance. So far data on exposure and sensitization to fungal allergens are mainly based on the assessment of few, easily identifiable taxa and focused only on certain environments. The microscopic method used to analyze aerobiological samples and the inconspicuous fungal characters do not allow a in depth taxonomical identification. Here, we present a first assessment of fungal diversity from airborne samples using a DNA metabarcoding analysis. The nuclear ITS2 region was selected as barcode to catch fungal diversity in mixed airborne samples gathered during two weeks in four sites of North-Eastern and Central Italy. We assessed the taxonomic composition and diversity within and among the sampled sites and compared the molecular data with those obtained by traditional microscopy. The molecular analyses provide a tenfold more comprehensive determination of the taxa than the traditional morphological inspections. Our results prove that the metabarcoding analysis is a promising approach to increases quality and sensitivity of the aerobiological monitoring. The laboratory and bioinformatic workflow implemented here is now suitable for routine, high-throughput, regional analyses of airborne fungi.

First description of a local Coprinopsis cinerea skin and soft tissue infection

Coprinopsis cinerea is an environmental fungus which can cause disseminated infections in immunocompromised patients, often leading to death. Here we report the case of a paediatric patient with an invasive wound infection due to C. cinerea, which was successfully treated with surgical debridement and oral posaconazole.

Cutaneous Emboli of Invasive Basidiomycosis in a Child With Aplastic Anemia

Invasive fungal diseases are a significant cause of mortality among the immunocompromised. This report documents an unusual case of disseminated fungal infection in a child with severe aplastic anemia. The offending fungus, a Basidiomycete, is rarely known to cause human infections. The patient presented acutely with multiple purpuric skin lesions in various parts of the body. The skin biopsy revealed septated fungal hyphae embolized within small dermal blood vessels. Molecular sequencing indicated Earliella scabrosa as the likely organism. The clinical course of the infection was inexorable despite systemic antifungal treatment, resulting in mortality. The literature of human infections due to Basidiomycetes, the usefulness of histopathology in the early diagnosis of the infection, and possible treatment options are discussed.

Trametes polyzona, an emerging filamentous basidiomycete in Réunion Island

We describe two serious Trametes polyzona pulmonary infections, which occurred in Réunion Island, in critically ill patients. The identification was performed using sequencing of the internal transcribed spacer region of ribosomal DNA and D1/D2 region of 28S rDNA. In one case, the significance of T. polyzona in the pathological process was certain, proven by histopathological evidence of fungal lung infection. T. polyzona, an emerging filamentous basidiomycete, prevalent in tropical areas, has not been described so far in human infections.

Fungal keratitis due to Schizophyllum commune: an emerging pathogenic fungus

Fungal keratitis due to Schizophyllum commune is very rare. In this study, we report the clinical and microbiological profile of five patients with fungal keratitis due to S. commune. Direct microscopic examination of corneal scrapings from all five patients showed septate branching hyaline fungal filaments. Similarly, in all five patients Sabouraud dextrose agar (SDA) plates inoculated with corneal scrapings showed white, cottony colonies on the second day of incubation. Lactophenol cotton blue stained wet preparation of 7-day-old colonies on SDA revealed clamp connections and no spores. The fungus was identified by its characteristic clamp connections, fan-shaped bracket fruiting body with pinkish-grey longitudinally split-radiating gills. The phenotypic identification of one of the five isolates further conformed by ITS sequencing. Treatment outcome was available for two of the five patients; in these two patients, the keratitis resolved with topical natamycin.

First isolation of Schizophyllum commune in a harbor seal (Phoca vitulina)

To date, Schizophyllum commune infection has been identified in only humans and dogs. A 7-year-old female harbor seal (Phoca vitulina) died after exhibiting corneal opacity, anorexia, and labored respiration. At necropsy, phthisis of the left eyeball was detected, and multiple nodular lesions were observed in the thoracic and abdominal regions, especially in the lung, heart, and lymph nodes. Histopathologically, numerous hyphae were seen in granulomatous lesions in the eyes, lung, heart, and lymph nodules. An isolate on potato dextrose agar from the eyes, lung, and sputum yielded a rapidly growing white woolly mycelia with basidiocarps (fruiting bodies) at 37°C. A suitable temperature for mycelial growth was obtained at 25°C, although sustained growth also occurred at 37°C. The fungal isolate, KH-JPN15-011, had distinctive features including hyphae bearing spicules and clamp connections, which were consistent with the characteristics of basidiomycete fungus. The sequence of the internal transcribed spacer region of nuclear ribosomal DNA showed 99.67% (617 bp) similarity with those of S. commune Phylogenetic analysis showed that the present isolate is most closely related to the samples from the Old World. This is the first report of a fatal disease caused by S. commune in exotic animals. Previously reported human and canine infections have not included granulomatous endophthalmitis and myocarditis. After considering these and previous findings, there is a possibility that S. commune from the Old World may include numerous highly pathogenic strains.