Rhytidhylides A and B, Two New Phthalide Derivatives from the Endophytic Fungus Rhytidhysteron sp. BZM-9.

Two new phthalide derivatives, rhytidhylides A (1) and B (2), together with ten known compounds (3-12) were isolated from cultures of Rhytidhysteron sp. BZM-9, an endophyte isolated from the leaves of Leptospermum brachyandrum. Their structures were identified by an extensive analysis of NMR, HRESIMS, ECD, and through comparison with data reported in the literature. In addition, the cytotoxic activities against two human hepatoma cell lines (HepG2 and SMMC7721) and antibacterial activities against MRSA and E. coli were evaluated.

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.

Subcutaneous phaeohyphomycosis caused by a black pigmented mould (Rhytidhysteron species) in rural north-western New South Wales, Australia.

Invasive fungal infections are becoming increasingly more prevalent in clinical practice. This corresponds with more patients living with immunosuppression and improved techniques to identify fungal infections. Subcutaneous fungal masses can often masquerade and imitate common dermatological lesions such as cysts. Querying a fungal aetiology of a mass is important, as fungal elements can be missed on histological examination, and special stains may be needed to identify spores and hyphae to make the diagnosis. Skin trauma with inoculation of fungal elements contained in soil and vegetable matter is the most common source of subcutaneous fungal masses. While traditionally considered a disease of the tropics, subcutaneous fungal masses can present worldwide in both immunosuppressed and immunocompetent patients. This case study describes a subcutaneous knee mass in a 53-year-old immunosuppressed farmer in Australia. A subcutaneous phaeohyphomycosis was diagnosed with a black pigmented mould, Rhytidhysteron species. A latent period of 12 years was observed between traumatic inoculation with farm soil and wheat dust in north-western New South Wales and development of the knee mass. Rhytidhysteron is considered a disease of the tropics, most commonly reported in India. This case, to the author's knowledge, is the first case report of pathogenic Rhytidhysteron from Australia. Surgery and antifungal therapy are recommended to treat Rhytidhysteron infection. This patient's recommended antifungal treatment was shortened due to severe hepatic disease. The clinical course was complicated by three localised recurrences in the patient's knee over 14 months. At the time of the third localised recurrence, this patient could tolerate posaconazole therapy for a month only. Surgical excision using general anaesthesia, use of diathermy for excision and wound lavage with iodine, hydrogen peroxide and saline has coincided in remission of clinical disease for 3 years at the time of writing.

Two new species of Gloniopsis (Hysteriales, Ascomycota) from clinical specimens: Morphological and molecular characterisation.

BACKGROUND: The coelomycetes comprise a wide range of fungal species distributed in at least three different classes of the phylum Ascomycota. These are morphologically characterised by producing their conidia inside of fruiting bodies called pycnidia or acervuli, and only a reduced number of species are able to cause human infections. However, their identification in the clinical laboratory is often difficult, due to their few morphological features or because they remain sterile. MATERIALS AND METHODS: In the present study, three isolates of coelomycetes of clinical origin were phenotypically and molecularly studied, by sequencing the D1-D2 fragment of the 28S nuclear ribosomal RNA (nrRNA) (LSU), the internal transcribed spacer region (ITS1-5.8S-ITS2) and a fragment of the translation elongation factor 1-alpha (tef1) genes. RESULTS AND CONCLUSIONS: As result of the molecular analysis, the isolates were identified as belonging to the genus Gloniopsis (order Hysteriales, Dothideomycetes) but without the characteristics of any of the species described so far. Therefore, we propose the new species Gloniopsis percutanea and Gloniopsis pneumoniae. Furthermore, this study revealed that some isolates from clinical specimens identified previously as Rhytidhysteron spp. were misidentified, and considering the few studies in the order Hysteriales and the scarce number of sequences of phylogenetic markers, future revisions of this order should be performed to clarify their taxonomy and obtain a better identification from isolates involved in human mycoses.

Rapid and Robust Identification of the Agents of Black-Grain Mycetoma by Matrix-Assisted Laser Desorption Ionization-Time of Flight Mass Spectrometry.

Eumycetoma, a chronic fungal infection endemic in India, Indonesia, and parts of Africa and South and Central America, follows traumatic implantation of saprophytic fungi and frequently requires radical surgery or amputation in the absence of appropriate treatment. Fungal species that can cause black-grain mycetomas include Madurella spp., Falciformispora spp., Trematosphaeria grisea, Nigrograna mackinnonii, Pseudochaetosphaeronema larense, Medicopsis romeroi, and Emarellia spp. Rhytidhysteron rufulum and Parathyridaria percutanea cause similar subcutaneous infections, but these infections lack the draining sinuses and fungal grains characteristic of eumycetoma. Accurate identification of the agents of subcutaneous fungal infection is essential to guide appropriate antifungal therapy. Since phenotypic identification of the causative fungi is often difficult, time-consuming molecular approaches are currently required. In the study described here we evaluated whether matrix-assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry might allow the accurate identification of eumycetoma agents and related fungi. A panel of 57 organisms corresponding to 10 different species from confirmed cases of eumycetoma and subcutaneous pedal masses, previously formally identified by PCR amplification and sequencing of internal transcribed spacer 1 (ITS1), was employed. Representative isolates of each species were used to create reference MALDI-TOF spectra, which were then used for the identification of the remaining isolates in a user-blinded manner. Here, we demonstrate that MALDI-TOF mass spectrometry accurately identified all of the test isolates, with 100%, 90.4%, and 67.3% of isolates achieving log scores greater than 1.8, 1.9, and 2.0, respectively.

Identification of spirobisnaphthalene derivatives with anti-tumor activities from the endophytic fungus Rhytidhysteron rufulum AS21B.

The cultivation of the mangrove-derived fungus Rhytidhysteron rufulum AS21B in acidic condition changed its secondary metabolite profile. Investigation of the culture broth extract led to the isolation and identification of two new spirobisnaphthalenes (1 and 2) together with eleven known compounds (3-13) from the crude extract of the fungus grown under an acidic condition as well as six known compounds (4, 10, 14-17) were isolated from the crude extract of the fungus grown under a neutral condition. Their structures were elucidated on the basis of extensive spectroscopic data. The isolated compounds were evaluated for their cytotoxicity against two human cancer cell lines, Ramos lymphoma and drug resistant NSCLC H1975. Compounds 2 and 10 displayed the most promising anti-tumor activity against both cancer cell lines.

Phaeohyphomycosis Caused by Rhytidhysteron rufulum and Review of Literature.

Phaeohyphomycosis is caused by a heterogeneous group of mycelial dematiaceous (phaeoid) fungi, which produce melanin pigment. This condition is often confused with chromoblastomycosis. Rhytidhysteron is a dematiaceous fungus, which has been recently found to be causing human infections. Till date only three cases of infection with Rhytidhysteron rufulum have been reported in the literature. All three cases have been from North India. Hereby, we present another two cases where Rhytidhysteron was isolated. Both the patients belonged to Chandigarh (India) and presented with subcutaneous lesions. The isolates were confirmed by ITS sequencing. Both the patients were immunocompetent and gave no history of trauma or any other predisposing factor. Phaeohyphomycosis are often missed due to lack of knowledge regarding the fungi causing the infections and there is need for clinical, pathological and microbiological correlation for effective diagnosis and treatment in these cases.

Cytology of Rhytidhysteron rufulum: An emerging cause of phaeohyphomycosis.

Fine-needle aspiration cytology (FNAC) is often the first-line investigation for detection of any fungal infection. Rhytidhysteron rufulum is an emerging dematiaceous fungus detected as a human pathogen. FNAC combined with molecular techniques helps in the detection of rare fungal species, especially in cases of non-sporulating fungi. We describe the cytomorphologic features of this species in a 62-year immunocompetent male who presented with a localised subcutaneous infection. Molecular studies helped in the final diagnosis.

Implantation subcutaneous phaeohyphomycosis caused by Rhytidhysteron rufulum: A case report.

Subcutaneous phaeohyphomycosis is caused by traumatic implantation of melanized environmental fungi. The majority of cases occur in tropical areas of the world or are associated with travel from these regions. Herein, we describe a rare case of subcutaneous phaeohyphomycosis caused by Rhytidhysteron rufulum in an immunocompetent Somalia-born patient. The use of molecular diagnostics as an essential tool for identification of rare fungal pathogens is highlighted.

Subcutaneous Rhytidhysteron Infection: A Case Report from South India with Literature Review.

Rhytidhysteron is a saprophytic dematiaceous fungus which rarely infects humans. Though virtually all individuals are exposed, very few develop the disease. Only seven human cases are reported till date. The present case is the second case from South India. A 40-year-old immunocompetent female agricultural worker, presented with a swelling on the dorsum of the right hand. Fine needle aspiration cytology (FNAC) of the swelling revealed short, thick, branched septate fungal hyphae. The isolate was moderately slow growing; grayish white colonies were observed on Sabouraud's Dextrose Agar (SDA) slant. On further incubation, the colonies turned floccose, greyish black and the black pigment was observed on the reverse. Microscopy of lactophenol cotton blue tease mount showed thick, brown septate hyphae without any fruiting bodies. Molecular typing confirmed the isolates as Rhytidhysteron rufulum. Identification of all clinical isolates of nonsporulating fungi to genus level is necessary to identify rare fungi infecting humans.

Highly oxygenated chromones from mangrove-derived endophytic fungus Rhytidhysteron rufulum.

Five highly oxygenated chromones, rhytidchromones A-E, were isolated from the culture broth of a mangrove-derived endophytic fungus, Rhytidhysteron rufulum, isolated from Thai Bruguiera gymnorrhiza. Their structures were determined by analysis of 1D and 2D NMR spectroscopic data. The structure of rhytidchromone A was further confirmed by single-crystal X-ray diffraction analysis. These compounds were evaluated for cytotoxicity against four cancer cell lines (MCF-7, Hep-G2, Kato-3 and CaSki). All compounds, except for rhytidchromone D, displayed cytotoxicity against Kato-3 cell lines with IC50 values ranging from 16.0 to 23.3µM, while rhytidchromones A and C were active against MCF-7 cells with IC50 values of 19.3 and 17.7µM, respectively.

Subcutaneous mycoses caused by Rhytidhysteron species in an immunocompetent patient.

Subcutaneous mycoses are chronic fungal infections of the skin and subcutaneous tissues caused by variety of fungal agents and usually occur following trauma with vegetative matter. We report a case of subcutaneous mycoses caused by rare fungus belonging to the genus Rhytidhysteron, in an immunocompetent male who presented with a subcutaneous nodule on left foot. This unusual species was identified and confirmed by molecular methods.