First report of otitis externa caused by Schizophyllum commune and review of the literature

Molecular epidemiology of clinical filamentous fungi in Qatar beyond Aspergillus and Fusarium with notes on the rare species

Due to an increasing number of patients at risk (i.e., those with a highly compromised immune system and/or receiving aggressive chemotherapy treatment), invasive fungal infections (IFI) are increasingly being reported and associated with high mortality rates. Aspergillus spp., particularly A. fumigatus, is the major cause of IFI caused by filamentous fungi around the world followed by Fusarium spp., however, other fungi are emerging as human pathogens. The aim of this study was to explore the epidemiology and prevalence of the non-Aspergillus and non-Fusarium filamentous fungi in human clinical samples over an 11-year period in Qatar using molecular techniques. We recovered 53 filamentous fungal isolates from patients with various clinical conditions. Most patients were males (75.5%), 9.4% were immunocompromised, 20.7% had IFI, and 11.3% died within 30 days of diagnosis. The fungal isolates were recovered from a variety of clinical samples, including the nasal cavity, wounds, respiratory samples, body fluids, eye, ear, tissue, abscess, and blood specimens. Among the fungi isolated, 49% were dematiaceous fungi, followed by Mucorales (30%), with the latter group Mucorales being the major cause of IFI (5/11, 45.5%). The current study highlights the epidemiology and spectrum of filamentous fungal genera, other than Aspergillus and Fusarium, recovered from human clinical samples in Qatar, excluding superficial infections, which can aid in the surveillance of uncommon and emerging mycoses.

A case of primary pulmonary Schizophyllum commune empyema treated with video-assisted thoracoscopic decortication

Schizophyllum commune (S. commune) is an environmental basidiomycete bracket fungus that can rarely cause invasive fungal disease. Its diagnosis is challenging and often missed. We present a rare case of a 56-year-old diabetic gentleman with a 6-months history of progressive productive cough, small volume hemoptysis and non-resolving fungal empyema treated with video-assisted thoracoscopic decortication. Pulmonary infection of S. Commune is extremely rare and can manifest as complex fungal empyema. Close cooperation between respirologists, thoracic surgeons and microbiologists is critical in the diagnosis and treatment of such cases.

Agricultural systems as potential sources of emerging human mycoses caused by Trichoderma: a successful, common phylotype of Trichoderma longibrachiatum in the frontline

Trichoderma species are abundant in different agricultural habitats, but some representatives of this genus, mainly clade Longibrachiatum members are also emerging as causative agents of various human diseases with even fatal outcome. Strains of these species frequently show resistance to commonly used azole antifungals. Based on previous data it is hypothesized that Trichoderma isolates identified in human infections derive from environmental-including agricultural-origins. We examined Trichoderma longibrachiatum Rifai and Trichoderma bissettii Sandoval-Denis & Guarro strains recovered from four novel cases of human mycoses, along with isolates from previous case reports and different agricultural habitats, using multilocus phylogenetic analysis, BIOLOG Phenotype Microarrays and Etest. Strains attributed to T. bissettii were more abundant in both clinical and agricultural specimens compared to T. longibrachiatum. The majority of the isolates of both taxa could tolerate >256, >32 and >32 μg/ml fluconazole, itraconazole and posaconazole, respectively. None of the obtained results revealed characteristic differences between strains of clinical and agricultural origin, nor between the two taxa, supporting that agricultural environments may be significant sources of infections caused by these emerging human fungal pathogens. Furthermore, based on our findings we propose the re-classification of T. bissettii as T. longibrachiatum f. sp. bissettii.

Successful allogeneic stem cell transplantation in a case with acute myeloid leukemia and invasive Schizophyllum commune rhinosinusitis

Schizophyllum commune, a basidiomycete fungus, is a quite rare cause of invasive sinusitis for which no standard treatment has yet been established. We report herein a 59-year-old woman who developed S. commune rhinosinusitis after remission induction chemotherapy for her acute myeloid leukemia. No causative microorganisms were identified in the sinus lavage fluid culture, whereas nucleotide sequencing of the internal transcribed spacer region using endoscopic sinus biopsy specimen could confirm the pathogen as S. commune. Liposomal amphotericin B and voriconazole (VRCZ) treatment ameliorated both her clinical symptoms and laboratory findings. The patient was successfully treated with allogeneic stem cell transplantation, under continuous VRCZ administration, without aggravation of S. commune sinusitis. Molecular diagnosis and prompt intervention with suitable antifungal drugs may be crucial to manage this rare infectious complication.

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.

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.

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.