Search

The opportunistic black yeast are particularly known through the genus Exophiala, characterised by annellidic budding cells. However, this phenotype is polyphyletic within the order Chaetothyriales. Seventeen generic names are available in the family Herpotrichiellaceae, one of which is Exophiala. Future taxonomy will be based on molecular phylogeny; each multi-species clade may qualify for one of these names. This paper focuses on the genus Nadsoniella, which is the oldest valid name in the Herpotrichiellaceae. Despite its exophiala-like phenotype, the type species of Nadsoniella clusters in the jeanselmei-clade, competing with the sympodial genus Rhinocladiella. In contrast, Exophiala competes with morphologically pronounced genera Thysanorea and Veronaea. Replacing the current phenotypic system for phylogenetic nomenclature requires highly stable phylogenies, which currently are not available., (© 2017 Blackwell Verlag GmbH.)

Phaeohyphomycosis is an infection caused by a heterogeneous group of melanized fungi. Human infections due to members of genus Exophiala are rare but may occur at any part of the body. We herein report a case of an 85-year-old male with a history of bullous pemphigoid who presented with a chronic, non-healing wound on his right dorsal hand for a month. Direct microscopy of a pus sample from the base of the ulcer revealed strands of pigmented, moniliform hyphae. The isolate was identified as E. oligosperma based on morphological characters and sequencing of the rDNA internal transcribed spacers (ITS) and partial beta-tubulin gene. The patient received a three-month course of oral itraconazole with no recurrence.

Objectives: This is a retrospective and observational study addressing clinical and therapeutic aspects of melanized fungal infections in kidney transplant recipients., Methods: We retrospectively reviewed medical records of all patients admitted between January 1996 and December 2013 in a single institution who developed infections by melanized fungi., Results: We reported on 56 patients aged between 30 and 74 years with phaeohyphomycosis or chromoblastomycosis (0.54 cases per 100 kidney transplants). The median time to diagnosis post-transplant was 31.2 months. Thirty-four (60.8%) infections were reported in deceased donor recipients. Fifty-one cases of phaeohyphomycosis were restricted to subcutaneous tissues, followed by two cases with pneumonia and one with brain involvement. Most dermatological lesions were represented by cysts (23/51; 45.1%) or nodules (9/51; 17.9%). Exophiala spp. (34.2%) followed by Alternaria spp. (7.9%) were the most frequent pathogens. Graft loss and death occurred in two patients and one patient, respectively. Regarding episodes of subcutaneous phaeohyphomycosis, a complete surgical excision without antifungal therapy was possible in 21 of 51 (41.2%) patients. Long periods of itraconazole were required to treat the other 30 (58.8%) episodes of subcutaneous disease. All four cases of chromoblastomycosis were treated only with antifungal therapy., Conclusions: Melanized fungal infections should be considered in the differential diagnosis of all chronic skin lesions in transplant recipients. It is suggested that the impact of these infections on graft function and mortality is low. The reduction in immunosuppression should be limited to severely ill patients., (Copyright © 2016. Published by Elsevier Ltd.)

Exophiala is a ubiquitous pleomorphic genus comprising at least 40 species, many of which have been associated with superficial, visceral, or systemic infections in humans, other mammals, or cold-blooded animals. In this study, we investigated the potential of matrix-assisted laser desorption-ionization time of flight mass spectrometry (MALDI-TOF MS) for the identification of Exophiala species. A total of 89 isolates (including 50 human and 4 animal clinical isolates) stored in the National Collection of Pathogenic Fungi were identified by PCR amplification and sequencing of internal transcribed spacer region 1. Eighty-three of the isolates corresponded to 16 known species within Exophiala/Rhinocladiella The remaining six isolates are shown by phylogenetic analyses based on four loci to represent two novel Exophiala species. Four isolates from domestic bathrooms which form a sister species with Exophiala lecanii-corni are described here as Exophiala lavatrina sp. nov. The remaining two isolates, both from subcutaneous infections, are distantly related to Exophiala oligosperma and are described here as Exophiala campbellii sp. nov. The triazoles and terbinafine exhibited low MICs against all Exophiala isolates in vitro MALDI-TOF MS successfully distinguished all 18 species and identified all isolates after appropriate reference spectra were created and added to commercial databases. Intraspecific mean log scores ranged from 1.786 to 2.584 and were consistently significantly higher than interspecific scores (1.193 to 1.624), with the exception of E. lecanii-corni and E. lavatrina , for which there was considerable log score overlap. In summary, MALDI-TOF MS allows the rapid and accurate identification of a wide range of clinically relevant Exophiala species., (© Crown copyright 2017.)

Purpose: Corneal infections, particularly fungal keratitis due to rare fungal species, pose a diagnostic and therapeutic challenge because of difficulty in identification and varying susceptibility profiles. In this study, we report the first case of fungal keratitis because of Exophiala phaeomuriformis., Methods: We report the clinical findings and microbial identification techniques of a case of fungal keratitis due to E. phaeomuriformis. An 84-year-old woman presented with redness, pain, and itching in the left eye for 2 weeks. Slit-lamp biomicroscopy revealed one broken suture from previous penetrating keratoplasty (PKP), black infiltrates at the 4-o'clock position, without an overlying epithelial defect and hypopyon. Microbial identification was based cultures on Sabouraud dextrose agar and DNA sequencing and correlations to laser in vivo confocal microscopy (IVCM; Heidelberg Retinal Tomograph 3/Rostock Cornea Module, Heidelberg Engineering) and multiphoton microscopy (Ultima Microscope; Prairie Technologies) images., Results: Slit-lamp biomicroscopy revealed one broken suture from previous PKP, black infiltrates at the 4-o'clock position, without an overlying epithelial defect and hypopyon. Based on a clinical suspicion of fungal keratitis, antifungals and fortified antibiotics were started. However, the patient did not respond to therapy and required urgent PKP. After surgery, the patient was maintained on topical and systemic voriconazole and also topical 2% cyclosporine for 5 months because of possibility of scleral involvement noticed during surgery. At the end of the treatment period, her vision improved from hand motion to 20/40, with no recurrence observed in a follow-up period of 1 year. Results of diagnostic tests were supported by fungal elements in stroma on IVCM. Culture from the infiltrate grew black yeast. DNA sequencing led to the diagnosis of E. phaeomuriformis keratitis. Antifungal susceptibility testing revealed sensitivity to voriconazole., Conclusion: This is, to our knowledge, the first reported case of E. phaeomuriformis fungal keratitis. Diagnostic testing included slit-lamp biomicroscopy, which revealed pigmented infiltrates, culture plates grew black yeast, microscopy showed branched fungal hyphae with budding conidia, and physiological features showed tolerance to high temperatures, nitrate assimilation, and ribosomal DNA sequencing. Collectively, these tests demonstrate unique features seen for this microorganism. High suspicion should be kept with pigmented infiltrates and with dark yeast on culture plates. Prompt and aggressive medical management with voriconazole or therapeutic PKP in nonresponsive cases is essential to prevent irreversible loss of vision.

Various fungi have the ability to colonize surfaces and to form biofilms. Fungal biofilm-associated infections are frequently refractory to targeted treatment because of resistance to antifungal drugs. One fungus that frequently colonises the respiratory tract of cystic fibrosis (CF) patients is the opportunistic black yeast-like fungus Exophiala dermatitidis. We investigated the biofilm-forming ability of E. dermatitidis and its susceptibility to various antiinfective agents and natural compounds. We tested 58 E. dermatitidis isolates with a biofilm assay based on crystal violet staining. In addition, we used three isolates to examine the antibiofilm activity of voriconazole, micafungin, colistin, farnesol, and the plant derivatives 1,2,3,4,6-penta-O-galloyl-b-D-glucopyranose (PGG) and epigallocatechin-3-gallate (EGCG) with an XTT reduction assay. We analysed the effect of the agents on cell to surface adhesion, biofilm formation, and the mature biofilm. The biofilms were also investigated by confocal laser scan microscopy. We found that E. dermatitidis builds biofilm in a strain-specific manner. Invasive E. dermatitidis isolates form most biomass in biofilm. The antiinfective agents and the natural compounds exhibited poor antibiofilm activity. The greatest impact of the compounds was detected when they were added prior cell adhesion. These findings suggest that prevention may be more effective than treatment of biofilm-associated E. dermatitidis infections.

Mycetoma is a chronic granulomatous, subcutaneous disease endemic in tropical and subtropical countries. It is currently a health problem in rural areas of Africa, Asia and South America. Nine cases of mycetoma were analysed in a retrospective study. All isolates were identified by morphological features. The level of species identification was reached by molecular tools. Definitive identification of fungi was performed using sequence analysis of the ITS of the ribosomal DNA region and the ribosomal large-subunit D1/D2. Identification of actinomycetes was accomplished by the 16S rRNA gene sequence. Six unusual clinical isolates were identified: Aspergillus ustus, Cyphellophora oxyspora, Exophiala oligosperma, Madurella pseudomycetomatis, Nocardia farcinica and Nocardia wallacei. The prevalence of mycetoma in Venezuela remains unknown. This study represents the first report in the literature of mycetoma caused by unusual pathogens identified by molecular techniques., (© 2016 Blackwell Verlag GmbH.)

Background: Subcutaneous phaeohyphomycosis is an infection caused by melanized fungi and is increasingly reported among immunosuppressive patients. The most commonly cited etiologic agent is Exophiala jeanselmei, followed by Alternaria spp. We present a case of subcutaneous phaeohyphomycosis in a 48-yearold woman, with a history of lepromatous leprosy, using corticosteroid in immunosuppressive doses due to a type 2 repetitive reaction leprosy outbreak., Result and Discussion: The diagnosis was confirmed by fine-needle aspiration of the secretion, with subsequent direct mycological observations, culture and molecular analysis. The species agent was identified by culture and nucleotide sequences of ribosomal DNA as Exophiala dermatitidis., (Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.)

Exophiala spinifera is a dematiaceous fungus responsible for rare skin infections presenting as phaeohyphomycosis or chromoblastomycosis which has been primarily reported in tropical and subtropical areas (Asia, South and North America). We report the first case of E. spinifera phaeohyphomycosis in a European patient. The phaeohyphomycosis was limited to the skin, involving the finger of an immunocompromised patient presenting with a large B-cell lymphoma treated by R-mini-CHOP regimen. Remission was initially achieved by surgical excision; however, a local subcutaneous relapse required treatment with itraconazole. We performed a literature review of the 32 previously published cases of E. spinifera phaeohyphomycosis highlighting its clinical phenotype: disseminated infection with extracutaneous involvement and poor prognosis were reported in young patients, of whom some were recently associated with CARD9 mutations, whereas cases in older immunocompromised patients were limited to the skin and showed better prognosis. There is currently no standard treatment for E. spinifera phaeohyphomycosis; however, itraconazole, alone or in combination, allowed partial or complete response in 16 out of 20 cases., (© 2016 Blackwell Verlag GmbH.)

Coal is the most abundant fossil fuel containing sulfur and other elements which promote environmental pollution after burning. Also the silicon impurities make the transportation of coal expensive. In this research, two isolated fungi from oil contaminated soil with accessory number KF554100 (Fusarium oxysporum FE) and KC925672 (Exophiala spinifera FM) were used for heterotrophic biological leaching of coal. The leaching were detected by FTIR, CHNS, XRF analyzer and compared with iron and sulfate released in the supernatant. The results showed that E. spinifera FM produced more acidic metabolites in growing cells, promoting the iron and sulfate ions removal while resting cells of F. oxysporum FE enhanced the removal of aromatic sulfur. XRF analysis showed that the resting cells of E. spinifera FM proceeded maximum leaching for iron and silicon (48.8, 43.2 %, respectively). CHNS analysis demonstrated that 34.21 % of sulfur leaching was due to the activities of resting cells of F. oxysporum FE. Also F. oxysporum FE removed organic sulfur more than E. spinifera FM in both growing and resting cells. FTIR data showed that both fungi had the ability to remove pyrite and quartz from coal. These data indicated that inoculations of these fungi to the coal are cheap and impurity removals were faster than autotrophic bacteria. Also due to the removal of dibenzothiophene, pyrite, and quartz, we speculated that they are excellent candidates for bioleaching of coal, oil, and gas.

Several species of the genus Exophiala are found as opportunistic pathogens on humans, while others cause infections in cold-blooded waterborne vertebrates. Opportunism of these fungi thus is likely to be multifactorial. Ecological traits [thermotolerance and pH tolerance, laccase activity, assimilation of mineral oil, and decolorization of Remazol Brilliant Blue R (RBBR)] were studied in a set of 40 strains of mesophilic Exophiala species focused on the salmonis-clade mainly containing waterborne species. Thermophilic species and waterborne species outside the salmonis-clade were included for comparison. Strains were able to tolerate a wide range of pHs, although optimal growth was observed between pH 4.0 and 5.5. All strains tested were laccase positive. Strains were able to grow in the presence of the compounds (mineral oil and RBBR) with some differences in assimilation patterns between strains tested and also were capable of degrading the main chromophore of RBBR. The study revealed that distantly related mesophilic species behave similarly, and no particular trend in evolutionary adaptation was observed.

Mycotoxins are putative virulence factors of fungi that play an important role in the pathogenesis of fungal infections. Mycotoxin production has been used as a diagnostic marker for the early diagnosis of fungal diseases. Using high-performance liquid chromatography, we investigated whether the fungal strains recovered from eye tissue samples obtained from patients with ocular mycoses produced the mycotoxin xanthomegnin. We tested 62 well-characterized strains of fungi, including Aspergillus spp. (n = 14), Exophiala spp. (n = 9), Fusarium spp. (n = 15), and several molds (n = 24). All isolates were identified to the species level using PCR and DNA sequencing of rRNA genes. We detected xanthomegnin activity (0.02 µg/ml) in one of the three Aspergillus flavus strains. However, we were unable to detect xanthomegnin in any of the other 61 fungal strains. Our result suggests that xanthomegnin production was infrequent in fungal strains recovered from patients with ocular mycoses.

We present a rare case of a 30-year-old woman who presented with a swelling on the lateral aspect of her left forearm, present since 6 months, adjacent to a 16-year-old burn scar. X-ray of elbow joint and forearm revealed the subcutaneous nature of the swelling. Giemsa and periodic acid-Schiff-stained smears and potassium hydroxide mount of fine-needle aspirate of the swelling revealed dematiaceous, branching, and septate fungal hyphae. Fungal culture of the aspirated pus showed growth of Exophiala jeanselmei. Histopathological examination revealed brown-coloured hyphae with foreign body giant cell reaction and palisading granulomas in the surrounding tissue. The patient was successfully treated with surgical excision of the swelling. All the cases of phaeohyphomycosis due to Exophiala spp. in India are also reviewed.

Primary central nervous system phaeohyphomycosis is a fatal fungal infection due mainly to the neurotropic melanized fungiCladophialophora bantiana,Rhinocladiella mackenziei, andExophiala dermatitidis.Despite the combination of surgery with antifungal treatment, the prognosis continues to be poor, with mortality rates ranging from 50 to 70%. Therefore, a search for a more-appropriate therapeutic approach is urgently needed. Ourin vitrostudies showed that with the combination of amphotericin B and flucytosine against these species, the median fractional inhibitory concentration (FIC) indices for strains ranged from 0.25 to 0.38, indicating synergy. By use of Bliss independence analysis, a significant degree of synergy was confirmed for all strains, with the sum ΔE ranging from 90.2 to 698.61%. No antagonism was observed. These results indicate that amphotericin B, in combination with flucytosine, may have a role in the treatment of primary cerebral infections caused by melanized fungi belonging to the orderChaetothyriales Furtherin vivostudies and clinical investigations to elucidate and confirm these observations are warranted., (Copyright © 2016, American Society for Microbiology. All Rights Reserved.)

We report a case of cutaneous phaeohyphomycosis caused by Exophiala dermatitidis. An adult male presented with a 1 month history of erythematous swelling and ulcer on the right forearm. E. dermatitidis was identified from the lesion through microscopic examination, in vitro culture, cutaneous biopsy and molecular analysis. He was treated with oral itraconazole (400 mg/day) and showed improvement.

We investigated the diversity and distribution of fungi in nine different sites inside 30 residential dishwashers. In total, 503 fungal strains were isolated, which belong to 10 genera and 84 species. Irrespective of the sampled site, 83% of the dishwashers were positive for fungi. The most frequent opportunistic pathogenic species were Exophiala dermatitidis, Candida parapsilosis sensu stricto, Exophiala phaeomuriformis, Fusarium dimerum, and the Saprochaete/Magnusiomyces clade. The black yeast E. dermatitidis was detected in 47% of the dishwashers, primarily at the dishwasher rubber seals, at up to 106 CFU/cm2; the other fungi detected were in the range of 102 to 105 CFU/cm2. The other most heavily contaminated dishwasher sites were side nozzles, doors and drains. Only F. dimerum was isolated from washed dishes, while dishwasher waste water contained E. dermatitidis, Exophiala oligosperma and Sarocladium killiense. Plumbing systems supplying water to household appliances represent the most probable route for contamination of dishwashers, as the fungi that represented the core dishwasher mycobiota were also detected in the tap water. Hot aerosols from dishwashers contained the human opportunistic yeast C. parapsilosis, Rhodotorula mucilaginosa and E. dermatitidis (as well as common air-borne genera such as Aspergillus, Penicillium, Trichoderma and Cladosporium). Comparison of fungal contamination of kitchens without and with dishwashers revealed that virtually all were contaminated with fungi. In both cases, the most contaminated sites were the kitchen drain and the dish drying rack. The most important difference was higher prevalence of black yeasts (E. dermatitidis in particular) in kitchens with dishwashers. In kitchens without dishwashers, C. parapsilosis strongly prevailed with negligible occurrence of E. dermatitidis. F. dimerum was isolated only from kitchens with dishwashers, while Saprochaete/Magnusiomyces isolates were only found within dishwashers. We conclude that dishwashers represent a reservoir of enriched opportunistic pathogenic species that can spread from the dishwasher into the indoor biome.

Exophiala jeanselmei is an opportunistic pathogenic black yeast growing in humid environments such as water reservoirs of air-conditioning systems. Because this fungal contaminant could be vaporized into the air and subsequently cause health problems, its monitoring is recommended. Currently, this monitoring is based on culture and microscopic identification which are complex, sometimes ambiguous and time-demanding, i.e., up to 21 days. Therefore, molecular, culture-independent methods could be more advantageous for the monitoring of E. jeanselmei. In this study, we developed a SYBR®green real-time PCR assay based on the internal transcribed spacer 2 from the 18S ribosomal DNA complex for the specific detection of E. jeanselmei. The selectivity (100 %), PCR efficiency (95.5 %), dynamic range and repeatability of this qPCR assay were subsequently evaluated. The limit of detection for this qPCR assay was determined to be 1 copy of genomic DNA of E. jeanselmei. Finally, water samples collected from cooling reservoirs were analyzed using this qPCR assay to deliver a proof of concept for the molecular detection of E. jeanselmei in environmental samples. The results obtained by molecular analysis were compared with those of classical methods (i.e., culture and microscopic identification) used in routine analysis and were 100 % matching. This comparison demonstrated that this SYBR®green qPCR assay can be used as a molecular alternative for monitoring and routine investigation of samples contaminated by E. jeanselmei, while eliminating the need for culturing and thereby considerably decreasing the required analysis time to 2 days.

The present study compared two chemical-based methods, namely, matrix-assisted laser desorption/ionization-time-of-flight mass spectrometry (MALDI-TOF MS) and attenuated total reflectance-Fourier transform infrared (ATR-FTIR) spectroscopy, to understand the misidentification of Exophiala dermatitidis and Exophiala phaeomuriformis. The study utilized 44 E. dermatitidis and 26 E. phaeomuriformis strains, which were partially treated with strong acids and bases for further evaluation. MALDI-TOF MS and ATR-FTIR spectroscopy data of the two Exophiala species were compared. Data groupings were observed for the chromic acid- and nitric acid-treated species when the black yeast sources were categorized as creosoted-oak sleepers, concrete sleepers, or dishwasher isolates. The MALDI-TOF MS data for the metalloenzyme-containing regions were consistent with the ATR-FTIR spectroscopy data. These results indicated that environmental isolates might contain metals not found in human isolates and might interfere with chemical-based identification methods. Therefore, MALDI-TOF MS reference libraries should be created for clinical strains and should exclude petroleum-associated environmental isolates.

A fungus was isolated from a nail of a 54-year-old female patient with onychomycosis in Taiwan. Based on ITS rDNA as well as beta tubulin gene sequences and microscopic analyses, this fungus was identified as Exophiala oligosperma. This is the first record of E. oligosperma in Taiwan. Negative keratin azure test indicates that keratin degradation is not involved in cases of E. oligosperma associated with skin and nail diseases.

Phaeohyphomycosis is an infection caused by a filamentous fungus that contains pigment melanin in its cell wall. We report two cases caused by Exophiala sp. emphasizing the clinical variability of the disease, as well as diagnostic and therapeutic difficulties of this opportunistic infection in immunosuppressed patients (kidney transplant).

A 7-year-old female-spayed, domestic short-haired cat was presented to her veterinarian with a mass on the hind paw. Histopathologic examination of a tissue biopsy revealed nodular pyogranulomatous panniculitis with intralesional pigmented fungal hyphae. A dematiaceous fungal isolate was isolated with a micromorphological phenotype consistent with the anamorphic genus Exophiala: budding cells, torulose mycelium and annellidic conidiogenesis from simple conidiophores consisting of terminal and lateral cells that tapered to a short beak at the apex. Sequence homology of the internal transcribed spacer region of the rDNA gene confirmed the identification of the isolate as Exophiala attenuata. Reported here is the first confirmed case of feline phaeohyphomycosis caused by E. attenuata in North America. Similar to historical cases of feline phaeohyphomycosis caused by Exophiala spp., there was no history or postmortem evidence to suggest the patient was in an immunocompromised state (e.g., suffering from FeLV or FIV). Although aggressive surgical excision of local lesions is recommended prior to drug treatment when dealing with subcutaneous phaeohyphomycosis, surgery followed by itraconazole treatment did not resolve the E. attenuata infection in this cat.

Exophiala species are capable of causing cutaneous and subcutaneous infections in immunocompromised patients. An Exophiala isolate was cultured from a biopsy specimen of a lesion on the forearm of a patient with myasthenia gravis. The patient also had lesions on the palm and distal aspects of the hand, which were successfully treated with a long-term course of itraconazole. A detailed morphological and molecular characterization of the isolate was undertaken. Phylogenetic analysis of the internal transcribed spacer region and portions of the β-tubulin and translation elongation factor 1-alpha genes indicated that the isolate was a novel species closely related to but genetically distinct from species within the Exophiala spinifera clade; the name Exophiala polymorpha sp. nov. is proposed. Morphologically, E. polymorpha most closely resembles E. xenobiotica but it differs in possessing phialides bearing prominent, wide collarettes, and it does not produce chlamydospores., (Copyright © 2015, American Society for Microbiology. All Rights Reserved.)

Sulfur dioxide which is released from petroleum oil combustion causes pollution over the atmosphere and the soil. Biodesulfurization can be used as a complementary method of hydrodesulfurization, the common method of petroleum desulfurization in refineries. Many studies have been carried out to develop biological desulfurization of dibenzothiophene (DBT) with bacterial biocatalysts. However, fungi are capable to metabolize a wide range of aromatic hydrocarbons through cytochrome P450 and their extracellular enzymes. The aim of the present work was isolation and identification of fungi biocatalysts capable for DBT utilization as sulfur source and production of novel metabolites. DBT consumption and the related produced metabolites were analyzed by HPLC and GC-MS respectively. One of the isolated fungi that could utilize DBT as sole sulfur source was identified by both traditional and molecular experiments and registered in NCBI as Exophiala spinifera FM strain (accession no. KC952672). This strain could desulfurize 99 % of DBT (0.3 mM) as sulfur source by co-metabolism reaction with other carbon sources through the same pathway as 4S and produced 2-hydroxy biphenyl (2-HBP) during 7 days of incubation at 30 °C and 180 rpm shaking. However, the isolate was able to transform 2-HBP to 1,3-benzenediol, 5-hexyl. While biphenyl compounds are toxic to leaving cells, biotransformation of them can reduce their toxicity and the fungi will be more tolerant to the final product. These data are the first report about the desulfurization of DBT comparable to 4S-pathway and production of innovative metabolite by E. spinifera FM strain.

Background: During a research project on fungal Candida species in patients wearing obturator treated with radiotherapy for their recurrent nasopharyngeal carcinoma, we serendipitously observed the presence of black fungus in two consecutive samples from a patient., Case Presentation: The samples were collected from a 57 year-old Hong Kong gentleman who diagnosed to have undifferentiated type of nasopharyngeal carcinoma. He was treated with definitive concurrent chemoradiotherapy followed by adjuvant chemotherapy and then received a second-course radiotherapy with IMRT. 18S rDNA sequencing revealed that the isolates belong to Exophiala dermatitidis which was susceptible to fluconazole, itraconazole, ketoconazole and voriconazole. Interestingly, E. dermatitidis isolates were resistant to caspofungin and one isolate was resistant to amphotericin B. Both isolates formed biofilms comparable to that of Candida albicans. Single isolate of E. dermatitidis showed hemolysin and proteinase ability comparable to C. albicans whilst the other isolate was not., Conclusion: We, for the first time, reported the discovery of a black fungus-E. dermatitidis isolates derived from a patient with nasopharyngeal carcinoma treated with radiotherapy. These isolates were shown to be resistant to caspofungin, a major antifungal agent for systemic candidiasis. As little is known about the black fungus in the clinical setting, it is important that clinicians must keep abreast of the new discovery in this field.

Energy constraints have altered consumer practice regarding the use of household washing machines. Washing machines were developed that use lower washing temperatures, smaller amounts of water and biodegradable detergents. These conditions may favour the enrichment of opportunistic human pathogenic fungi. We focused on the isolation of fungi from two user-accessible parts of washing machines that often contain microbial biofilms: drawers for detergents and rubber door seals. Out of 70 residential washing machines sampled in Slovenia, 79% were positive for fungi. In total, 72 strains belonging to 12 genera and 26 species were isolated. Among these, members of the Fusarium oxysporum and Fusarium solani species complexes, Candida parapsilosis and Exophiala phaeomuriformis represented 44% of fungi detected. These species are known as opportunistic human pathogens and can cause skin, nail or eye infections also in healthy humans. A machine learning analysis revealed that presence of detergents and softeners followed by washing temperature, represent most critical factors for fungal colonization. Three washing machines with persisting malodour that resulted in bad smelling laundry were analysed for the presence of fungi and bacteria. In these cases, fungi were isolated in low numbers (7.5 %), while bacteria Micrococcus luteus, Pseudomonas aeruginosa, and Sphingomonas species prevailed., (Copyright © 2014 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.)

No more than 30 cases of phaeohyphomycosis caused by Exophiala spinifera have been reported up to now in English and Chinese literature over the past half century. Here, we reported two cases of phaeohyphomycosis caused by E. spinifera and reviewed all the five cases reported from mainland China. These two involved were both young female, one patient experiencing recurrence during pregnancy and the other developing multiple-site infections without apparent immunodeficiency. The aetiological agents were both identified as E. spinifera by molecular analysis. Oral itraconazole was proved effective enough for the first patient, while the combination of itraconazole and terbinafine was needed for the second patient. It seems that infections due to E. spiniferais increasing in China mainland nowadays, usually involving young female., (© 2015 Blackwell Verlag GmbH.)

Exophiala is a genus of slow-growing, melanin-producing, saprophytic fungi most commonly found in soil, faeces and decaying plant matter. It is an unusual fungal pathogen capable of causing a variety of ophthalmic manifestations, including keratitis, scleritis and endophthalmitis. In this report, we present a rare case of delayed-onset postoperative endophthalmitis confined to the anterior segment, secondary to Exophiala species. Previous reported cases of delayed-onset postoperative endophthalmitis have been treated medically, with suboptimal outcomes. Our experience supports the use of anterior segment surgery to clear the nidus of disease combined with intravitreal voriconazole to prevent recurrence of the infection., (2015 BMJ Publishing Group Ltd.)

A 56-year-old Japanese female presented to our hospital in March complaining of asymptomatic skin lesions on both cheeks for the past few years. She had been receiving treatment for phlebosclerotic colitis and gastroesophageal reflux disease. We identified subcutaneous nodules with scale, erosion, and necrotic crusts on the surface, with one on the right cheek and two on the left. The patient said that the eruptions almost disappeared every summer but always recurred in winter, a phenomenon that we confirmed. Histopathology revealed pseudoepitheliomatous hyperplasia and marked infiltration from various inflammatory cells with a granulomatous reaction in the dermis. Brown fungal elements were scattered around the epidermis and dermis in the form of single spore or toruloid hyphae. We identified the fungus as Exophiala lecanii-corni based on morphological and physiological characteristics, as well as rRNA gene analysis. The strain grew well at 27 ℃, but growth was remarkably suppressed at 33 ℃ and not observed at all at 37 ℃. Treatment with itraconazole 200 mg / day for 6 months resulted in complete remission of the lesions.

Conventional mycological identifications based on the recognition of morphological characteristics can be problematic. A relatively new methodology applicable for the identification of microorganisms is based on the exploitation of taxon- specific mass patterns recorded from abundant cell proteins directly from whole-cell preparations, using matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). This study reports the application of MALDI-TOF MS for the differentiation and identifications of black yeasts, isolated from the respiratory tracts of patients with cystic fibrosis (CF). Initial phenotypic and DNA sequence-based analyses identified these isolates to be Exophiala dermatitidis. The type strains of E. dermatitidis (CBS 207.35(T)) and other species of Exophiala were included in the MALDI-TOF MS analyses to establish the references for comparing the mass spectra of the clinical isolates of Exophiala. MALDI-TOF MS analyses exhibited extremely close relationships among the clinical isolates and with the spectra generated from the type strain of E. dermatitidis. The relationships observed between the E. dermatitidis strains from the MALDI-TOF MS profiling analyses were supported by DNA sequence-based analyses of the rRNA ITS1 and ITS2 regions. These data demonstrated the applicability of MALDI-TOF MS as a reliable, rapid and cost-effective method for the identification of isolates of E. dermatitidis and other clinically relevant fungi and yeasts that typically are difficult to identify by conventional methods., (© FEMS 2014. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Exophiala jeanselmei, a saprobe in the environment, is an opportunistic pathogen. We present a rare case of subcutaneous phaeohyphomycosis caused by E jeanselmei in a man aged 66 years with a 3-month history of a tender swelling on the dorsal area of the left middle finger. Purulent fluid was aspirated from the area, and the culture yielded black colonies composed of conidiophores, phialides, and yeast cells. After sequencing of the rDNA ITS1-5.8S-ITS2 gene, the pathogen was confirmed as E jeanselmei. The patient was cured by surgical excision without any antifungal agents., (Copyright © 2012. Published by Elsevier B.V.)

Objective: To summarize the clinical features, imaging characteristics, diagnosis and treatment of a case with central nervous system infection caused by Exophiala dermatitidis, as well as to review the related literature., Method: Associated literature and clinical data of an 8-year-old boy who was diagnosed as central nervous system infection caused by Exophiala dermatitidis in Beijing Children's Hospital Affiliated to Capital Medical University and hospitalized twice from 2012 to 2014 were analyzed retrospectively., Result: The boy was 8 years old with the chief complaint of dizziness for 2 months, intermittent fever for 1 month accompanied with spasm twice. He was diagnosed as bile ducts space-occupying lesions 2 years ago, when the pathological diagnosis was fungal infection. The boy was treated with irregular anti-fungal therapy. Then the boy developed nervous symptoms, impaired consciousness and abnormal physical activity that developed gradually. After hospitalization the cerebral MRI of the boy showed space-occupying lesions accompanied with edema of surrounding area. Filamentous fungi was found by brain biopsy, which was culture positive for Exophiala dermatitidis. After diagnosis the boy was treated with amphotericin B (AMB), voriconazole and 5-Fu, as well as symptomatic treatment. The state of the boy was improved gradually. Two months later, the boy could communicate with others normally and move personally. The lesions and edema seen on the MRI was decreased moderately. Accordingly, the boy was treated with oral voriconazole maintenance treatment for about 1 year and 4 months after discharge. During this period, the state of him was stable without symptoms. The lesions shown by MRI did not disappear but decreased on regular examination. However, recently the disease of the boy progressed again, with dizziness, neck pain, headache and progressive nervous symptoms (intermittent spasm, inability to cough, and impaired consciousness). The boy died at last, even with the active treatment at the second hospitalization. Exophiala dermatitidis was culture-positive again in his CSF, and was confirmed by PCR successfully., Conclusion: The central nervous system infection caused by Exophiala dermatitidis is rare. Clinical features of this disease were similar to those of other fungal CNS infection, cerebral MRI of which could show the similar lumpy lesions. Diagnosis of the disease should be based on pathology and culture.

We report a rare case of phaeohyphomycotic cyst in an immunocompetent patient caused by Exophiala oligosperma. This fungus is earlier known to cause infections in the immunocompromised. Identification of black fungi at species level is more challenging by conventional methods, and hence final identification of the fungi was based on sequencing of rDNA. The patient was managed with surgical excision. To the best of our knowledge, this is the first case report of E. oligosperma human infection from India.

Infection with the dematiaceous environmental fungus Exophiala, an emerging pathogen in immunocompromised individuals, poses a diagnostic and therapeutic challenge. Herein, we report the first Exophiala dermatitidis fungemia case, to our knowledge, in an allogeneic hematopoietic stem cell transplant patient with graft-versus-host disease, expanding the clinical setting where Exophiala species mycosis should be suspected., (© 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Exophiala dermatitidis pneumonia is extremely rare. Here we report a case of E. dermatitidis pneumonia successfully treated with long-term itraconazole therapy. A 63-year-old woman without a remarkable medical history developed a dry and chest pain. Chest radiographs revealed consolidation in the middle lobe of the lung. Cytologic examination by bronchoscopy showed filamentous fungi and E. dermatitidis was detected in the bronchoalveolar lavage fluid. After 5 months of itraconazole therapy, her symptoms improved and the area of consolidation diminished. Two weeks after discontinuing the itraconazole therapy, the area of consolidation reappeared. Itraconazole therapy was restarted and continued for 7 months. The abnormal shadow observed on the chest X-ray gradually diminished. Over a 27-month follow-up with periodic examination, there was no relapse and the patient had a favorable clinical course., (Copyright © 2014 Japanese Society of Chemotherapy and The Japanese Association for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.)

Background: The clinical importance of airway colonisation by the fungus Exophiala dermatitidis in patients with cystic fibrosis (CF) is unclear. We have previously shown that E. dermatitidis frequently colonises the airways of patients with CF. The aims of the present study were to determine whether patients who are colonised by E. dermatitidis have detectable fungal antigens in the circulation, develop anti-fungal antibodies, and show signs of inflammation and impaired respiratory function., Methods: We collected sputum and serum samples consecutively from 98 sputum-producing patients with CF aged more than 12 years. The serum samples were subjected to bacterial and fungal culturing and analyses for fungal antigens and inflammatory factors., Results: E. dermatitidis was recovered from 17 (17%) patients, the same isolation rate as for Aspergillus fumigatus. There were no difference regarding the levels of β-glucan in the sera from E. dermatitidis culture-positive and culture-negative patients with CF. Serological analysis revealed significantly higher levels of IgG antibodies to E. dermatitidis cell wall fragments in the E. dermatitidis culture-positive patients. Patients with higher level of E. dermatitidis IgG antibodies were more often colonised with non-tuberculous Mycobacteria, and less often with Staphylococcus aureus. The increased levels of IgG antibodies directed against E. dermatitidis were positively associated with higher white blood cell counts, increased erythrocyte sedimentation rate, pancreatic insufficiency, intravenous antibiotic treatment, and they were negatively associated with respiratory function (FEV1 % predicted). Overall, 4/17 Exophiala-positive patients were diagnosed as having symptomatic infection with E. dermatitidis and were treated with broad-spectrum azoles., Conclusion: E. dermatitidis triggers antibody production and may cause significant airway infection in patients with cystic fibrosis., (Copyright © 2014 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Black or dark brown (phaeoid) fungi cause cutaneous, subcutaneous, and systemic infections in humans. Black fungi thrive in stressful conditions such as intense light, high radiation, and very low pH. Wangiella (Exophiala) dermatitidis is arguably the most studied phaeoid fungal pathogen of humans. Here, we report our comparative analysis of the genome of W. dermatitidis and the transcriptional response to low pH stress. This revealed that W. dermatitidis has lost the ability to synthesize alpha-glucan, a cell wall compound many pathogenic fungi use to evade the host immune system. In contrast, W. dermatitidis contains a similar profile of chitin synthase genes as related fungi and strongly induces genes involved in cell wall synthesis in response to pH stress. The large portfolio of transporters may provide W. dermatitidis with an enhanced ability to remove harmful products as well as to survive on diverse nutrient sources. The genome encodes three independent pathways for producing melanin, an ability linked to pathogenesis; these are active during pH stress, potentially to produce a barrier to accumulated oxidative damage that might occur under stress conditions. In addition, a full set of fungal light-sensing genes is present, including as part of a carotenoid biosynthesis gene cluster. Finally, we identify a two-gene cluster involved in nucleotide sugar metabolism conserved with a subset of fungi and characterize a horizontal transfer event of this cluster between fungi and algal viruses. This work reveals how W. dermatitidis has adapted to stress and survives in diverse environments, including during human infections.

Dental health care providers and patients are exposed during ongoing work to contamination by the water used in the dental units, due to accidental swallowing or aspiration of the sprays generated by the high-speed handpiece and the threeway syringe. This study evaluated the quality of water in dental units in the public dental care system of Maceio, Alagoas, Brazil, by conducting analyses of contamination by total coliforms, E.Coli, heterotrophic bacteria and filamentous fungi. We collected 200 mL of water at 5 sites in 6 dental offices of the Department of Health located in different parts of the city. A total 212 isolates and 16 genera of filamentous fungi were identified in the water collected from the dental units. Total coliforms indicated that the water used in dental units was not appropriate for human consumption. The high levels of contamination found in this study showed that water was a potential source of cross-infection.

In black fungal infections, Exophiala species are frequently encountered as causative agents of human mycosis, particularly in immunocompromised patients. Among them, Exophiala jenselmei was previously reported as the most common etiological agent. Advances in molecular taxonomy proved this taxon to be heterogeneous, and led to newly introduced or redefined species. Exophiala xenobiotica is one of the novel species differentiated from E. jenselmei on the basis of molecular phylogeny.Here, we report a case of pheomycotic cyst caused by E. xenobiotica, which was well controlled via drainage and local thermotherapy. A 70-year-old man developed a cystic nodular lesion on the dorsum of his right thumb over the previous 3 months. He had been treated with prednisolone and methotrexate for 4 years for rheumatoid arthritis. The patient also had lung cancer with vertebral bone metastasis. Direct microscopic examination of the greenish pus aspirated from the cyst revealed mycelial elements. Culture of the pus on blood and Sabouraud dextrose agar yielded numerous black colonies multiple times. Histopathological examination of a biopsy specimen showed subcutaneous abscess formation surrounded by granulomatous tissues. Faintly pigmented pseudohyphae were seen within the abscess. The presence of melanin in the fungal cells was determined by Fontana-Masson staining. Initial microscopic examination of the isolate revealed annellidic conidiogenous cells, suggestive of E. jenselmei. This strain was further identified as E. xenobiotica by sequence analysis of the internal transcribed spacer (ITS) region of ribosomal RNA, showing a 100% sequence homology with the strain type.Pheomycotic cysts should be considered on identifying a slowly developing chronic subcutaneous abscess in immunocompromised patients. Sequencing is recommended for accurate species identification of causative pathogens.

Purpose: To describe a patient with Exophiala jeanselmei keratitis and to review the prior cases reported in the literature., Methods: We report one patient with keratitis after remote injury and chronic steroid use and review the six prior reported cases., Results: Culture plates from corneal scraping revealed growth of the dematiaceous fungi, E. jeanselmei, a rare causative organism of ocular infection. The patient underwent therapy with topical and intracameral antifungals and subsequently required a corneal transplant. Biopsy of the donor graft confirmed the diagnosis of E. jeanselmei. This is the first reported case to use intracameral antifungal agents and the first biopsy proven case. Half of reported cases experienced associated trauma, and severity was generally related to delay in diagnosis., Conclusions: Trauma and chronic topical steroid use contributed to the development of severe keratitis in this patient. Patients on chronic steroids should be monitored closely. Topical, subconjunctival, and intracameral antifungals have all been effective in treating this pathogen. If diagnosed and treated early, E. jeanselmei keratitis can have a good visual outcome.

Eumycetomas are chronic infectious entities characterized by presence of mycotic grains in (sub-)cutaneous tissues, after accidental inoculation of an exogenous filamentous fungus in the skin. The lesions evolve towards painless pseudotumor of the soft parts. We report the original case of a Guinean woman exhibiting eumycetoma of the right foot. Both laboratory tests identified a dematiaceous fungus, Exophiala jeanselmei, as the responsible infectious agent. A medical treatment with voriconazole alone was sufficient to notice a substantial clinical improvement. This finding is unusual as E. jeanselmei is uncommon in Guinea-Conakry, and as optimal treatment rather associate antifungal azoles and surgical excision., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

Deep infections by melanized fungi deserve special attention because of a potentially fatal, cerebral or disseminated course of disease in otherwise healthy patients. Timely diagnostics are a major problem with these infections. Rolling circle amplification (RCA) is a sensitive, specific and reproducible isothermal DNA amplification technique for rapid molecular identification of microorganisms. RCA-based diagnostics are characterized by good reproducibility, with few amplification errors compared to PCR. The method is applied here to species of Exophiala known to cause systemic infections in humans. The ITS rDNA region of five Exophiala species (E. dermatitidis, E. oligosperma, E. spinifera, E. xenobiotica, and E. jeanselmei) was sequenced and aligned in view of designing specific padlock probes to be used for the detection of single nucleotide polymorphisms (SNPs) of the Exophiala species concerned. The assay proved to successfully amplify DNA of the target fungi at the level of species; while no cross-reactivity was observed. Amplification products were visualized on 1% agarose gels to verify the specificity of probe-template binding. Amounts of reagents were minimized to avoid the generation of false positive results. The sensitivity of RCA may help to improve early diagnostics of these difficult to diagnose infections., (© 2013 Elsevier B.V. All rights reserved.)

A 90-year-old Japanese woman, taking prednisolone (5-10 mg/day) for polyarthritis, presented to our hospital with multiple subcutaneous lesions on her left arm in 2009. Her history included excision of a phaeomycotic cyst on the left middle finger in 2007. There were three subcutaneous nodules approximately 15 mm in diameter around her left wrist and a large soft cystic lesion measuring 80 mm × 60 mm on her left elbow. A granuloma with neutrophilic infiltration was detected in the deep dermis of a biopsy specimen. Chains composed of round brown cells and short pseudomycelia were found in the granuloma. Fungal cultures from the samples confirmed Exophiala sp. to be the causative agent. Treatment with terbinafine and local hyperthermia seemed effective as all the lesions tended to subside. However, the patient died due to pneumonia approximately 1 month after commencement of therapy., (© 2013 Japanese Dermatological Association.)

In order to reveal the source of contamination of opportunistic fungi, their natural habitat has to be understood. Black yeast-like fungi are abundant in man-made environments, particularly in those that are rich in toxic hydrocarbons such as railway ties. In this study, we investigated the presence of black fungi on creosote-treated oak railway ties and concrete sleepers stained with petroleum oil. Samples were collected at two central stations in Turkish cities, Mersin and Adana, and from Tarsus town station located between these two. The sample locations had subtropical climates. A total of 570 railway samples, including 320 from oak and 250 from concrete, were collected. Cotton swabs moistened with sterile physiological saline were applied to the ties and inoculated onto malt extract agar followed by incubation at 37 °C. Overall, we recovered 97 black yeast-like fungi (17.0 % positive). Sixty-three fungi (19.7 %) were collected from creosote-treated oak, whereas 34 isolates (13.6 %) were derived from concrete; the difference was significant (P = 0.05). Identification using rDNA internal transcribed spacer revealed Exophiala dermatitidis (57.7 %) and Exophiala phaeomuriformis (42.3 %). This study suggested that hydrocarbons enrich these opportunistic black yeasts. An eventual health risk is discussed.

Several dematiaceous fungi frequently isolated from nature are involved in cases of superficial lesions to lethal cerebral infections. Antifungal susceptibility data on environmental and clinical isolates are still sparse despite the advances in testing methods. The objective of this study was to examine the activities of 5-flucytosine, amphotericin B, itraconazole, voriconazole and terbinafine against environmental isolates of Exophiala strains by minimum inhibition concentration (MIC) determination. The strains were obtained from hydrocarbon-contaminated soil, ant cuticle and fungal pellets from the infrabuccal pocket of attine gynes. Broth microdilution assay using M38-A2 reference methodology for the five antifungal drugs and DNA sequencing for fungal identification were applied. Terbinafine was the most active drug against the tested strains. It was observed that amphotericin B was less effective, notably against Exophiala spinifera, also studied. High MICs of 5-flucytosine against Exophiala dermatitidis occurred. This finding highlights the relevance of studies on the antifungal resistance of these potential opportunistic species. Our results also contribute to a future improvement of the standard methods to access the drug efficacy currently applied to black fungi.