Search Results (10)

Background: Exophiala spp. are dematiaceous fungi with opportunistic pathogenic potential and a widespread environmental presence. Clinical cases of Exophiala spp. fungemia are uncommon. Although rarely encountered in the general population, these organisms are increasingly reported in immunocompromised individuals or those with complex underlying health conditions. Objectives: This review seeks to examine all documented human cases of Exophiala spp. fungemia, with particular focus on aspects such as epidemiology, microbiological features, resistance patterns, therapeutic approaches and associated mortality rates. Methods: A narrative review was conducted using data sourced from the PubMed/MedLine and Scopus databases. Results: A total of 19 articles described infections in 32 patients involving Exophiala spp. fungemia. The mean patient age was 49.2 years, and 65.6% were male. Central venous catheters emerged as the leading predisposing factor (96.9%). Fever represented the most frequent clinical presentation (50%), followed by organ dysfunction (21.9%). The yeast generally demonstrated susceptibility to voriconazole and itraconazole. Voriconazole was also the most frequently administered antifungal (62.5%), followed by amphotericin (31.3%) and micafungin (28.1%). Overall mortality reached 34.4%, with 25% of deaths specifically caused by the infection. Conclusions: Given the potential of Exophiala spp. to cause severe fungemia, healthcare professionals, particularly clinicians and microbiologists, should consider this pathogen in the differential diagnosis when black yeast is detected in blood cultures, especially in patients with immunodeficiency or significant comorbidities, to ensure timely and accurate identification. Full article

The identification of fungal pathogens in formalin-fixed paraffin-embedded (FFPE) tissues is an unmet need in human and animal medicine, and sequence-agnostic approaches are needed to identify emerging pathogens. Eleven FFPE biopsy specimens with etiologic diagnoses of fungal disease based on standard testing of paired fresh tissue samples were utilized here to evaluate metabarcoding approaches. The cases included tissues from three dogs, three cats, one box turtle, one goat, one common loon, and one gray tree frog. The diagnoses from the fresh tissues in these cases were Microsporum canis, Penicillium sp., Exophiala sp. (likely E. jeanselmei), Verticillium sp., Rhizopus sp., atypical Cryptococcus neoformans, Conidiobolus spp., Aspergillus fumigatus, Cryptococcus neoformans var grubii, Batrachochytrium dendrobatidis, Fusarium solani, Blastomyces dermatitidis, Coccidiodes immitis, and Histoplasma capsulatum. We compared the ITS1 and 28S D1 rRNA gene genetic markers in combination with several bioinformatic strategies to identify fungal pathogens in the FFPE tissue samples, with a success rate of 9/11. These methods could allow diagnosticians who receive only FFPE tissues and see fungal pathogens to speciate the pathogens and could be of value in retrospective studies wherein FFPE tissue is the only archived tissue. Furthermore, these techniques could be of use to researchers investigating polymicrobial communities where DNA preservation is suboptimal. Full article

Onychomycosis is a chronic fungal nail infection caused by several filamentous and yeast-like fungi, such as the genus Candida spp., of great clinical importance. Black yeasts, such as Exophiala dermatitidis, a closely related Candida spp. species, also act as opportunistic pathogens. Fungi infectious diseases are affected by organisms organized in biofilm in onychomycosis, making treatment even more difficult. This study aimed to evaluate the in vitro susceptibility profile to propolis extract and the ability to form a simple and mixed biofilm of two yeasts isolated from the same onychomycosis infection. The yeasts isolated from a patient with onychomycosis were identified as Candida parapsilosis sensu stricto and Exophiala dermatitidis. Both yeasts were able to form simple and mixed (in combination) biofilms. Notably, C. parapsilosis prevailed when presented in combination. The susceptibility profile of propolis extract showed action against E. dermatitidis and C. parapsilosis in planktonic form, but when the yeasts were in mixed biofilm, we only observed action against E. dermatitidis, until total eradication. Full article

Phaeohyphomycosis caused by Exophiala species represents an important disease of concern for farmed and aquarium-housed fish. The objective of this study was to summarize the clinical findings and diagnosis of Exophiala infections in aquarium-housed Cyclopterus lumpus. Clinical records and postmortem pathology reports were reviewed for 15 individuals from 5 public aquaria in the United States and Canada from 2007 to 2015. Fish most commonly presented with cutaneous ulcers and progressive clinical decline despite topical or systemic antifungal therapy. Antemortem fungal culture of cutaneous lesions resulted in colonial growth for 7/12 samples from 8 individuals. Amplification of the internal transcribed spacer region (ITS) of nuclear rDNA identified Exophiala angulospora or Exophiala aquamarina in four samples from three individuals. Postmortem histopathologic findings were consistent with phaeohyphomycosis, with lesions most commonly found in the integument (11/15), gill (9/15), or kidney (9/15) and evidence of fungal angioinvasion and dissemination. DNA extraction and subsequent ITS sequencing from formalin-fixed paraffin-embedded tissues of seven individuals identified E. angulospora, E. aquamarina, or Cyphellophora sp. in four individuals. Lesion description, distribution, and Exophiala spp. identifications were similar to those reported in farmed C. lumpus. Antemortem clinical and diagnostic findings of phaeohyphomycosis attributable to several species of Exophiala provide insight on the progression of Exophiala infections in lumpfish that may contribute to management of the species in public aquaria and under culture conditions. Full article

Several fungi species are reported to act as opportunistic agents of infection in avian species. After the isolation of Exophiala spp., a dematiaceous fungal pathogen associated with a mucosal lesion in a military macaw (Ara militar), samples were collected from another 24 birds of the order Psittaciformes to study the possibility of Exophiala spp. being part of the commensal microbiota of these animals or its possible association with other clinical conditions. Swab samples were collected from the trachea and/or choanae of the birds and inoculated in Sabouraud chloramphenicol agar for fungal isolation. After incubation, fungal species were identified through their macroscopic and microscopic morphology. The presence of Exophiala spp. was identified in 15 of the 25 birds sampled and no statistical association was found between the clinical record of the birds and the fungal isolation. Our results suggest that Exophiala spp. can colonize the upper respiratory airways of psittaciform birds and has a low pathogenic potential in these animals. To the authors’ knowledge, this is the first report of Exophiala spp. isolation from samples of the upper respiratory tract of Psittaciformes. Full article

Subcutaneous fungal infections, which typically result from traumatic introduction (implantation) of fungal elements into the skin or underlying tissues, can present as a range of different clinical entities including phaeohyphomycosis, chromoblastomycosis, subcutaneous nodules or masses, and genuine eumycetoma. Here, we mined our laboratory information management system for such infections in humans and domestic animals for the period 2016–2022, including (i) fungal isolates referred for identification and/or susceptibility testing; (ii) infections diagnosed at our laboratory using panfungal PCR approaches on infected tissue; and (iii) organisms cultured in our laboratory from biopsies. In total, 106 cases were retrieved, involving 39 fungal species comprising 26 distinct genera. Subcutaneous infections with Alternaria species were the most frequent (36 cases), which possibly reflects the ubiquitous nature of this common plant pathogen. A substantial proportion of Alternaria spp. isolates exhibited reduced in vitro susceptibility to voriconazole. Notably, a significant number of subcutaneous infections were diagnosed in renal and other solid organ transplant recipients post transplantation, suggesting that humans may harbour “inert” subcutaneous fungal elements from historical minor injuries that present as clinical infections upon later immunosuppression. The current study underscores the diversity of fungi that can cause subcutaneous infections. While most organisms catalogued here were responsible for occasional infections, several genera (Alternaria, Exophiala, Phaeoacremonuim, Scedosporium) were more frequently recovered in our searches, suggesting that they possess virulence factors that facilitate subcutaneous infections and/or inhabit natural niches that make them more likely to be traumatically inoculated. Full article

Human-made hydrocarbon-rich environments are important reservoirs of microorganisms with specific degrading abilities and pathogenic potential. In particular, black fungi are of great interest, but their presence in the environment is frequently underestimated because they are difficult to isolate. In the frame of a biodiversity study from fuel-contaminated sites involving 30 diesel car tanks and 112 fuel pump dispensers (52 diesel and 60 gasoline, respectively), a total of 181 black fungal strains were isolated. The long cold incubation (LCI) of water-suspended samples, followed by plating on Dichloran Rose Bengal Chloramphenicol Agar (DRBC), gave isolation yields up to six times (6.6) higher than those of direct plating on DRBC, and those of enrichment with a phenolic mix. The sequencing of ITS and LSU-rDNA confirmed the dominance of potentially pathogenic fungi from the family Herpotrichiellaceae and Exophiala xenobiotica. Moreover, other opportunistic species were found, including E. opportunistica, E. oligosperma, E. phaeomuriformis, and Rhinocladiella similis. The recurrent presence of E. crusticola, Knufia epidermidis, Aureobasidium melanogenum, Cladosporium spp., and Scolecobasidium spp. was also recorded. Interestingly, 12% of total isolates, corresponding to 50% of taxa found (16/32), represent new species. All the novel taxa in this study were isolated by LCI. These findings suggest that black fungal diversity in hydrocarbon-rich niches remains largely unexplored and that LCI can be an efficient tool for further investigations. Full article

Cystic fibrosis is the most common autosomal-recessive metabolic disease in the Western world. Impaired trans-membrane chloride transport via the cystic fibrosis transmembrane conductance regulator (CFTR) protein causes thickened body fluids. In the respiratory system, this leads to chronic suppurative cough and recurrent pulmonary infective exacerbations, resulting in progressive lung damage and respiratory failure. Whilst the impact of bacterial infections on CF lung disease has long been recognized, our understanding of pulmonary mycosis is less clear. The range and detection rates of fungal taxa isolated from CF airway samples are expanding, however, in the absence of consensus criteria and univocal treatment protocols for most respiratory fungal conditions, interpretation of laboratory reports and the decision to treat remain challenging. In this review, we give an overview on fungal airway infections in CF and CF-lung transplant recipients and focus on the most common fungal taxa detected in CF, Aspergillus fumigatus, Candida spp., Scedosporium apiospermum complex, Lomentospora species, and Exophiala dermatitidis, their clinical presentations, common treatments and prophylactic strategies, and clinical challenges from a physician’s point of view. Full article

Since Aromatic hydrocarbons are recalcitrant and toxic, strategies to remove them are needed. The aim of this work was to isolate fungi capable of using aromatic hydrocarbons as carbon sources. Two isolates from an oil polluted site in Mexico were identified through morphological and molecular markers as a novel Rhodotorula sp. and an Exophiala sp. Both strains were able to grow in a wide range of pH media, from 4 to 12, showing their optimal growth at alkaline pH’s and are both halotolerant. The Exophiala strain switched from hyphae to yeast morphotype in high salinity conditions. To the best of our knowledge, this is the first report of salt triggering dimorphism. The Rhodotorula strain, which is likely a new undescribed species, was capable of removing singled ringed aromatic compounds such as benzene, xylene, and toluene, but could not remove benzo[a] pyrene nor phenanthrene. Nevertheless, these hydrocarbons did not impair its growth. The Exophiala strain showed a different removal capacity. It could remove the polyaromatic hydrocarbons but performed poorly at removing toluene and xylene. Nevertheless, it still could grow well in the presence of the aromatic compounds. These strains could have a potential for aromatic compounds removal. Full article

The goal of this research was to analyze the fungal community responsible for the biodeterioration of a pirogue in the National Maritime Museum of China and to make recommendations for the protection of this artifact. Molecular identification of fungal strains isolated from the surface of the pirogue and the air of the storage room that were most closely related to Cladosporium, Penicillium, Talaromyces and Trichoderma spp. DNA extracted from the samples was sequenced on the Illumina MiSeq platform. The results showed that the predominant fungal genera present were Penicillium sp., Cladosporium sp. and Exophiala sp. Thereafter, cellulose degradation experiments were carried out on the predominant fungi screened by pure culturing. Finally, we tested the sensitivity of the predominant fungal isolates to four biocides. This work suggests that we should pay more attention to Penicillium sp. and Cladosporium sp. in the protection of wooden artifacts, and environmental control is recommended as the main means of protecting the pirogue. Full article