Nucleotide sequencing for diagnosis of sinusal infection by Schizophyllum commune, an uncommon pathogenic fungus

Resolving the pathogenicity factors of a novel opportunistic fungus Schizophyllum commune at molecular level

Schizophyllum commune is a well-known mushroom forming fungi which is an edible one due to its nutritive value. It exhibits a special wood degrading mechanism to grow in decay matters by releasing a series of enzymes. These enzymes might make them an opportunistic pathogen which has been reported to infect various animals and human beings too. Although these fungi were identified as human and animal pathogens, their mechanisms of pathogenesis and the key virulence factors involved in disease establishment are not known. In this study, we reported this fungal infection in freshwater fish for the first time and its morphological features. Further, we employed RNA-seq technique to identify the major virulence factors involved in the pathogenesis in fish and the network of interaction between the identified virulence factors were analysed. Also, we confirmed the virulence roles of this fungus during infection by qRT-PCR analysis. This study emphasizes the virulence nature of the common mushroom forming food fungus and the involvement of enzymes such as phosphoinositide phospholipase C, hexosaminidase and few toxins such as pesticidal and insecticidal crystal proteins which opened a new avenue in the virulence nature of edible mushrooms.

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.

Maxillary fungus balls due to Fusarium proliferatum

Fungus ball is the most common form of non-invasive fungal rhinosinusitis. Aspergillusfumigatus (between 44.8% and 75%) and Aspergillusflavus (14%) are the two most common species recovered. However, recent advances in mycological laboratory methods have enhanced the detection and identification of fungi within fungus balls. Fusarium species, sometimes recovered from other forms of fungal rhinosinusitis such as allergic fungal rhinosinusitis or acute invasive fungal rhinosinusitis, are poorly associated with sinonasal fungus ball. Here, we describe two further cases of a fungus ball due to Fusariumproliferatum and provide the first description of this fungal pathogen with a fungus ball of odontogenic origin. These case reports demonstrate that uncommon fungal species such as Fusarium spp. might be underestimated as agents of sinusal cavity fungus ball. Enhanced mycological detection and diagnostic techniques might give rise, in the near future, to the emergence of new or rare fungal species associated with this clinical entity.

First report on cutaneous infectious granuloma caused by Schizophyllum commune

Background

Schizophyllum commune, a basidiomycetous fungus, is a common invader of rotten wood. This fungus rarely causes mycotic disease in humans, especially cutaneous infection. In this paper, we describe the first case of cutaneous granuloma caused by S. commune in a Chinese woman.

Case presentation

A 25-year-old female with a two-year history of erythema, papules, nodules, and scales on her sole of left foot was presented to our outpatient center. Samples were obtained by the scraping of lesion and for light microscopy. Hyphae were observed by microscopic examination. We carried out a skin tissue biopsy, which showed multiple granulomatous nodules. Biopsy specimens were also inoculated onto media. After being cultured on SDA at 27 °C for 7 days, spreading-woolly-white colonies grew on the inoculation sites of media containing chloramphenicol only and there^,s no other colonies grew. S. commune was identified by morphology methods, biochemical tests, and PCR sequencing. Pathological findings also aided in diagnosing cutaneous fungal granuloma. Oral itraconazole was applied. After 1 month of therapy, rashes on her left foot and pain were improved.

Conclusion

We describe the first case of cutaneous granuloma caused by Schizophyllum commune, which illustrates the importance of recognizing uncommon pathogenic fungal infections.

Allergic fungal sinusitis caused by Schizophyllum commune

A case of allergic fungal sinusitis (AFS) due to Schizophyllum commune was reported. The pathogen was identified using molecular bioanalysis. The patient underwent the functional endoscopic sinus surgery followed by the radical maxillary sinusotomy with canine fossa trephine. This case suggested that complete surgery allowed optimal disease clearance for AFS caused by Schizophyllum commune.

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.

Schizophyllum commune: an emergent or misdiagnosed fungal pathogen in rhinology?

Schizophyllum commune is a common basidiomycete fungus that is rarely involved in human disease. The medical records of patients operated on for fungal rhinosinusitis (FRS) in two University Hospitals between 2012 and 2014 were reviewed. Within the two-year survey, six female, and notably no male, patients were diagnosed with S. commune rhinosinusitis. Mean age was 44.6 years at diagnosis (30 to 68 years). Mean time between onset of symptoms and diagnosis was 8.5 months (2 to 12 months). All six patients were immunocompetent and had no particular host factor for FRS. S. commune was identified using MALDI-TOF mass spectrometry and identifications were confirmed via DNA sequence analysis. Chronic invasive fungal rhinosinusitis was diagnosed in three of our six patients. Based on histological findings, antifungal treatment was delivered in association with surgery. The basidiomycete fungus S. commune is an emerging cause of rhinosinusitis probably as a direct consequence of the recent technological progress in fungal identification methods (DNA sequencing and MALDI-TOF mass spectrometry).

Classification of fungal and bacterial lytic polysaccharide monooxygenases

Background

Lytic polysaccharide monooxygenases are important enzymes for the decomposition of recalcitrant biological macromolecules such as plant cell wall and chitin polymers. These enzymes were originally designated glycoside hydrolase family 61 and carbohydrate-binding module family 33 but are now classified as auxiliary activities 9, 10 and 11 in the CAZy database. To obtain a systematic analysis of the divergent families of lytic polysaccharide monooxygenases we used Peptide Pattern Recognition to divide 5396 protein sequences resembling enzymes from families AA9 (1828 proteins), AA10 (2799 proteins) and AA11 (769 proteins) into subfamilies.

Results

The results showed that the lytic polysaccharide monooxygenases have two conserved regions identified by conserved peptides specific for each AA family. The peptides were used for in silico PCR discovery of the lytic polysaccharide monooxygenases in 79 fungal and 95 bacterial genomes. The bacterial genomes encoded 0 – 7 AA10s (average 0.6). No AA9 or AA11 were found in the bacteria. The fungal genomes encoded 0 – 40 AA9s (average 7) and 0 – 15 AA11s (average 2) and two of the fungi possessed a gene encoding a putative AA10. The AA9s were mainly found in plant cell wall-degrading asco- and basidiomycetes in agreement with the described role of AA9 enzymes. In contrast, the AA11 proteins were found in 36 of the 39 ascomycetes and in only two of the 32 basidiomycetes and their abundance did not correlate to the degradation of cellulose and hemicellulose.

Conclusions

These results provides an overview of the sequence characteristics and occurrence of the divergent AA9, AA10 and AA11 families and pave the way for systematic investigations of the of lytic polysaccharide monooxygenases and for structure-function studies of these enzymes.

Electronic supplementary material

The online version of this article (doi:10.1186/s12864-015-1601-6) contains supplementary material, which is available to authorized users.

Fatal empyema thoracis caused by Schizophyllum commune with cross-reactive cryptococcal antigenemia

We report a fatal case of Schizophyllum commune empyema thoracis with cross-reactive cryptococcal antigenemia. In vitro testing confirmed the ability of the fungus to cause a positive cryptococcal antigen latex agglutination system (CALAS) test result. Such a result may lead to delay in diagnosis and treatment, as most strains of S. commune are resistant to fluconazole.

A case of Schizophyllum commune sinusitis following unrelated cord blood transplantation for acute lymphoblastic leukemia

Schizophyllum commune is a globally distributed basidiomycete fungus that is known as a rare cause of sinusitis, for which no prompt treatment has been established. We describe the first report of S. commune sinusitis following unrelated cord blood transplantation for acute lymphoblastic leukemia. Thirteen days after transplantation, a 23-year-old female developed maxillary and ethmoid sinusitis. The sinusitis was antimicrobial-resistant, and the sinus aspirate culture revealed white wooly mold, which was identified as S. commune by nucleotide sequencing. The patient was successfully treated with intravenous administration of liposomal amphotericin B for 2 months, followed by oral voriconazole. This report suggests the effectiveness of liposomal amphotericin B and voriconazole for S. commune infection in immunocompromised patients. Given the difficulty in distinguishing S. commune infection from aspergillosis by standard culture methods, the incidence of S. commune infection following allogeneic hematopoietic stem cell transplantation may be underestimated. Nucleotide sequencing may be useful in the diagnosis of S. commune infection.

Schizophyllum commune: a new organism in eye infection

PURPOSE

We report a case of mycotic keratitis caused by a rare fungus Schizophyllum commune.

METHODS

Clinical examination, slit-lamp examination, and microbiological evaluation of the corneal ulcer were done, and its treatment outcome was studied. The fungal etiology was established by conventional microbiological techniques, polymerase chain reaction and speciation by DNA sequencing.

RESULTS

Corneal scraping showed the presence of fungal filaments. The fungus was identified as S. commune based on DNA sequence analysis of the internal transcribed spacer region. The organism was susceptible to amphotericin B and voriconazole and demonstrated resistance to anidulafungin, itraconazole, and fluconazole. Therapeutic keratoplasty was performed but there was recurrence of the infection in the graft, which was controlled with topical voriconazole and intracameral amphotericin B. At the end of 3 months, the affected eye had developed phthisis bulbi.

CONCLUSION

The best of our knowledge, this is the first reported case of keratitis caused by the rare fungus S. commune. Management of these cases is difficult, and surgical procedures may be needed.

Molecular identification of Schizophyllum commune as a cause of allergic fungal sinusitis

Schizophyllum commune, a basidiomycetous fungus, rarely causes disease in humans. We report a rare case of allergic fungal sinusitis caused by S. commune in a 14-yr-old girl. The patient presented with nasal obstruction and a purulent nasal discharge. Materials obtained during endoscopic surgery of the frontal recess revealed allergic mucin and a few fungal hyphae. A potato dextrose agar (PDA) culture from the allergic mucin yielded a rapidly growing white woolly mold. Although no distinctive features including hyphae bearing spicules or a clamp connection were present, the case isolate disclosed compatible mycological features including growth at 37℃, susceptibility to cycloheximide, and production of a tart and disagreeable smell. S. commune was confirmed by sequence analysis of the internal transcribed spacer region and D1/D2 regions of the 26S ribosomal DNA. We believe this is the first report of allergic fungal sinusitis caused by S. commune in Korea. Moreover, this report highlights the value of gene sequencing as an identification tool for non-sporulating isolates of S. commune.

A case of sino-orbital infection caused by the Schizophyllum commune

Schizophyllum commune, a basidiomycetous fungus, is a rare cause of mycotic disease in humans. We describe the first case of sino-orbital infection caused by S. commune in an immunocompetent woman who presented with maxillary sinusitis and inferior orbital tumor. Identification of the organism was confirmed by rRNA sequencing.

Schizophyllum commune as an emerging fungal pathogen: a review and report of two cases

We report Schizophyllum commune as the aetiological agent of one case each of allergic broncho-pulmonary mycosis (ABPM) and pulmonary fungal ball, and present a literature review. The fungus was characterised by clamp connections, hyphal spicules, and formation of basidiocarps with basidiospores. The phenotypic identification was confirmed by sequencing of the ITS region. To-date, ABPM and pulmonary fungal ball to S. commune have been reported exclusively from Japan and North America respectively. Of the 71 globally reported cases due to S. commune, 45 (63%) were bronchopulmonary, 22 (31%) sinusitis and 4 extrapulmonary. Taken together, cases of bronchopulmonary disease and sinusitis numbered 67 (94%), indicating the respiratory tract as the primary target of disease. Concerning the country-wise distribution, Japan topped the list with 33 cases (46%), followed by Iran - 7 cases (10%), U.S.A. - 6 cases (9%), and a lower prevalence of 1.4-6% for the remaining 12 countries. The preponderance of the disease in Japan may be attributed to its greater awareness vis-à-vis that in other countries rather than to any geographical/climatic factors. We believe that the burden of S. commune-incited disease is currently underestimated, warranting comprehensive prospective studies to determine its prevalence.

Nasal polyposis and fungal Schizophyllum commune infection: a case report

We present a rare case of eosinophilic fungal rhinosinusitis with nasal polyps in a 32-year-old woman caused by basidiomycete fungus Schizophyllum commune. Diagnosis was done by the endoscopic nasal examination, computed tomography (CT) of the paranasal sinuses, the histopathological examination of polyps, the presence of eosinophils and fungal hyphae in nasal mucus and by the detection of S. commune by culture. The patient was successfully treated by combination of oral itraconazole and topical corticosteroid therapy combined with surgery. The pathogenesis and diagnosis of allergic fungal rhinosinusitis are also discussed.

Disseminated Oxyporus corticola infection in a German shepherd dog

The filamentous basidiomycetous fungus, Oxyporus corticola, has not previously been reported in the human or veterinary medical literature. Identification of this organism as the etiologic agent of fungal osteomyelitis and multiorgan dissemination in a German shepherd dog was confirmed by comparison of ITS and D1/D2 sequences with known isolates.