Severe Disseminated Phaeohyphomycosis in an Immunocompetent Patient Caused by Veronaea botryosa

Evaluation of three inactive vaccines against Veronaea botryosa infection in white sturgeon (Acipenser transmontanus)

Veronaea botryosa is the etiological agent of a systemic phaeohyphomycosis known as "fluid belly" in white sturgeon (Acipenser transmontanus). Fluid belly is a critical disease affecting sturgeon aquaculture and the caviar industry for which there are no commercially available vaccines or approved antifungal treatments to manage outbreaks. The primary aim of this study was to investigate the effect of a V. botryosa [conidia], a V. botryosa [mold], and a Saccharomyces cerevisiae [yeast] formalin-killed vaccine on sturgeon immune responses to fungal challenge. Immunization consisted of an initial intracoelomic injection with one of the three treatment preparations, followed by a vaccine booster four weeks later by the same route and dose. Experimental challenge by intramuscular injection with a virulent V. botryosa conidia suspension followed after another four weeks. Non-challenged control fish received injections of PBS. The inactivated vaccines proved safe for white sturgeon fingerlings. Sturgeon immunized with either V. botryosa [mold] or S. cerevisiae [yeast] exhibited a significantly different pro-inflammatory response upon challenge with V. botryosa compared to non-immunized fish. Challenged fish developed clinical signs similar to those reported during natural outbreaks of fluid belly. Positive control treatments (those not immunized but challenged with V. botryosa) experienced the highest mortality; however, survival curves were similar amongst all treatments (p < 0.05). Furthermore, the S. cerevisiae [yeast] vaccine resulted in comparatively lower fungal persistence and fewer lesions following histological analysis. Further efforts evaluating the potential of Saccharomyces spp. as a vaccine candidate against fluid belly are warranted.

Osteoarticular Mycoses

Osteoarticular mycoses are chronic debilitating infections that require extended courses of antifungal therapy and may warrant expert surgical intervention. As there has been no comprehensive review of these diseases, the International Consortium for Osteoarticular Mycoses prepared a definitive treatise for this important class of infections. Among the etiologies of osteoarticular mycoses are Candida spp., Aspergillus spp., Mucorales, dematiaceous fungi, non-Aspergillus hyaline molds, and endemic mycoses, including those caused by Histoplasma capsulatum, Blastomyces dermatitidis, and Coccidioides species. This review analyzes the history, epidemiology, pathogenesis, clinical manifestations, diagnostic approaches, inflammatory biomarkers, diagnostic imaging modalities, treatments, and outcomes of osteomyelitis and septic arthritis caused by these organisms. Candida osteomyelitis and Candida arthritis are associated with greater events of hematogenous dissemination than those of most other osteoarticular mycoses. Traumatic inoculation is more commonly associated with osteoarticular mycoses caused by Aspergillus and non-Aspergillus molds. Synovial fluid cultures are highly sensitive in the detection of Candida and Aspergillus arthritis. Relapsed infection, particularly in Candida arthritis, may develop in relation to an inadequate duration of therapy. Overall mortality reflects survival from disseminated infection and underlying host factors.

First recorded outbreak of Veronaea botryosa in North American amphibians: Clinicopathologic features of a rare cause of phaeohyphomycosis in captive White's tree frogs (Litoria caerulea)

We describe fatal phaeohyphomycosis due to Veronaea botryosa in captive White’s tree frogs (Litoria caerulea), the first confirmed report in amphibians in North America. Over 15 months, six frogs developed ulcerative dermatitis on distal extremities/ventrum, which in one animal progressed to vasculitis and necrotizing osteomyelitis. All six frogs died. Clinicopathologic findings, diagnostic challenges, and control are discussed. Emerging fungi such as V. botryosa pose serious concerns for zoonosis and potential spread through the pet trade.

Hortaea werneckii isolates exhibit different pathogenic potential in the invertebrate infection model Galleria mellonella

Hortaea werneckii is a black yeast with a remarkable tolerance to salt. Most studies have been dedicated to understanding how H. werneckii adapts to hypersaline environments. H. werneckii has an unconventional cell cycle in which it alternates between fission and budding, which is modulated by cell density. Additionally, H. werneckii can cause superficial mycosis of the palm and sole of humans. Here, we determine the impact of salt concentration on the EXF-2000 strain's cell division pattern and morphology by performing timelapse microscopy at different salt concentrations. At low density and no salt, EXF-2000 primarily grows as pseudohyphae dividing mainly by septation. When grown in the presence of salt at a similar concentration to saltwater or hypersaline environments, we observe it grows first by undergoing fission followed by budding at the poles. Then, we examined a collection of 16 isolates in the presence of 0.6M NaCl, including isolates from marine and hypersaline environments and isolates from patients. These isolates exhibit a wide diversity in colony shape and cellular morphology. The isolates grew as yeast, pseudohyphae, and true hyphae, indicating that isolates can exhibit various cell morphologies under similar environmental conditions. We used the insect larvae Galleria mellonella to determine the pathogenic potential of our isolates. We observe that only a subset of isolates can cause death in our model, and there was no correlation between H. werneckii morphology and capacity to cause disease. Taken together, H. werneckii genomic and phenotypic diversity can serve as a model to better understand how phenotypes and pathogenic potential evolve in environmental fungi.

Ten decadal advances in fungal biology leading towards human well-being

Fungi are an understudied resource possessing huge potential for developing products that can greatly improve human well-being. In the current paper, we highlight some important discoveries and developments in applied mycology and interdisciplinary Life Science research. These examples concern recently introduced drugs for the treatment of infections and neurological diseases; application of -OMICS techniques and genetic tools in medical mycology and the regulation of mycotoxin production; as well as some highlights of mushroom cultivaton in Asia. Examples for new diagnostic tools in medical mycology and the exploitation of new candidates for therapeutic drugs, are also given. In addition, two entries illustrating the latest developments in the use of fungi for biodegradation and fungal biomaterial production are provided. Some other areas where there have been and/or will be significant developments are also included. It is our hope that this paper will help realise the importance of fungi as a potential industrial resource and see the next two decades bring forward many new fungal and fungus-derived products.

Post-translational changes in Phialophora verrucosa via lysine lactylation during prolonged presence in a patient with a CARD9-related immune disorder

CARD9-related inherited immune disorders are a major risk factor for chronic disseminated fungal infection. In addition to pathogens of Candida and dermatophytes, the environmental opportunists of the black yeast-like fungi are relatively frequent in this patient cohort. Particularly the genus Phialophora is overrepresented. We investigated two isolates of a strain of P. verrucosa residing in a CARD9 patient, sampled with a period of ten years apart. Genomes, melanization and antifungal susceptibility of progenitor and derived strains were compared, and potential adaptation to the host habitat was investigated with proteomic techniques using post-translational modification as a proxy. Global lactylation analysis was performed using high accuracy nano-LC-MS/MS in combination with enrichment of lactylated peptides from digested cell lysates, and subsequent peptide identification. The genome of the derived isolate had accumulated 6945 SNPs, of which 31 were detected in CDS. A large number of identified proteins were significantly enriched, e.g. in melanin biosynthesis. A total of 636 lactylation sites on 420 lactylated proteins were identified, which contained in 26 types of modification motifs. Lysine lactylation (Kla) was found in 23 constituent proteins of the ribosome, indicating an impact of Kla in protein synthesis. Twelve lactylated proteins participated in pathogenicity. A protein-protein interaction (PPI) network analysis suggested that protein lactylations are widely distributed influencing various biological processes. Our findings reveal widespread roles for lysine lactylation in regulating metabolism and melanin biosynthesis in black fungi. Several large rearrangements and inversions were observed in the genome, but genomic changes could not be linked to adaptation or to known clinically relevant properties of progenitor to derived isolate; in vitro antifungal susceptibility had largely remained unaltered.

Invasive Rhinosinusitis Caused by Alternaria infectoria in a Patient with Autosomal Recessive CARD9 Deficiency and a Review of the Literature

Phaeohyphomycoses comprise a heterogeneous group of fungal infections caused by dematiaceous fungi and have primarily been reported in patients with underlying acquired immunodeficiencies, such as hematological malignancies or solid-organ transplants. Over the past decade, a growing number of patients with phaeohyphomycosis but otherwise healthy were reported with autosomal recessive (AR) CARD9 deficiency. We report a 28-year-old woman who presented with invasive rhinosinusitis caused by Alternaria infectoria. Following a candidate gene sequencing approach, we identified a biallelic loss-of-function mutation of CARD9, thereby further broadening the spectrum of invasive fungal diseases found in patients with inherited CARD9 deficiency. In addition, we reviewed 17 other cases of phaeohyphomycosis associated with AR CARD9 deficiency. Physicians should maintain a high degree of suspicion for inborn errors of immunity, namely CARD9 deficiency, when caring for previously healthy patients with phaeohyphomycosis, regardless of age at first presentation.

Gram stain to the rescue: a case report of cerebral phaeohyphomycosis by Cladophialophora bantiana in an immunocompetent 24-year-old

BACKGROUND

Fungal brain abscesses in immunocompetent patients are exceedingly rare. Cladophialophora bantiana is the most common cause of cerebral phaeohyphomycosis, a dematiaceous mold. Radiological presentation can mimic other disease states, with diagnosis through surgical aspiration and growth of melanized fungi in culture. Exposure is often unknown, with delayed presentation and diagnosis.

CASE PRESENTATION

We present a case of cerebral phaeohyphomycosis in a 24-year-old with no underlying conditions or risk factors for disease. He developed upper respiratory symptoms, fevers, and headaches over the course of 2 months. On admission, he underwent brain MRI which demonstrated three parietotemporal rim-enhancing lesions. Stereotactic aspiration revealed a dematiaceous mold on staining and the patient was treated with liposomal amphotericin B, 5-flucytosine, and posaconazole prior to culture confirmation. He ultimately required surgical excision of the brain abscesses and prolonged course of antifungal therapy, with clinical improvement.

CONCLUSIONS

Culture remains the gold standard for diagnosis of infection. Distinct microbiologic findings can aid in identification and guide antimicrobial therapy. While little guidance exists on treatment, patients have had favorable outcomes with surgery and combination antifungal therapy. In improving awareness, clinicians may accurately diagnose disease and initiate appropriate therapy in a more timely manner.

Reviewing the Etiologic Agents, Microbe-Host Relationship, Immune Response, Diagnosis, and Treatment in Chromoblastomycosis

Chromoblastomycosis (CBM) is a neglected human disease, caused by different species of pigmented dematiaceous fungi that cause subcutaneous infections. This disease has been considered an occupational disease, occurring among people working in the field of agriculture, particularly in low-income countries. In 1914, the first case of CBM was described in Brazil, and although efforts have been made, few scientific and technological advances have been made in this area. In the field of fungi and host cell relationship, a very reduced number of antigens were characterized, but available data suggest that ectoantigens bind to the cell membrane of host cells and modulate the phagocytic, immunological, and microbicidal responses of immune cells. Furthermore, antigens cleave extracellular proteins in tissues, allowing fungi to spread. On the contrary, if phagocytic cells are able to present antigens in MHC molecules to T lymphocytes in the presence of costimulation and IL-12, a Th1 immune response will develop and a relative control of the disease will be observed. Despite knowledge of the resistance and susceptibility in CBM, up to now, no effective vaccines have been developed. In the field of chemotherapy, most patients are treated with conventional antifungal drugs, such as itraconazole and terbinafine, but these drugs exhibit limitations, considering that not all patients heal cutaneous lesions. Few advances in treatment have been made so far, but one of the most promising ones is based on the use of immunomodulators, such as imiquimod. Data about a standard treatment are missing in the medical literature; part of it is caused by the existence of a diversity of etiologic agents and clinical forms. The present review summarizes the advances made in the field of CBM related to the diversity of pathogenic species, fungi and host cell relationship, antigens, innate and acquired immunity, clinical forms of CBM, chemotherapy, and diagnosis.

Veronaeaaquatica sp. nov. (Herpotrichiellaceae, Chaetothyriales, Eurotiomycetes) from submerged bamboo in China

Background

Freshwater fungi are highly diverse and ecologically important in freshwater systems. In China, more than 1000 species of freshwater fungi are known. Here, we present a brown-spored hyphomycetes that was collected on a submerged decaying bamboo culm in a forest stream in China.

New information

Phylogenetic analyses of combined LSU, ITS and TUB2 sequences confirm the placement of our new strain in Veronaea (Herpotrichiellaceae), sister to V.japonica. Veronaeaaquatica sp. nov. differs from related taxa V.compacta and V.japonica in having longer conidiophores and cylindrical to pyriform or subclavate conidia with 0–2 septa. Veronaeaaquatica also has darker brown hyphae compared to V.japonica. A morphological description and detailed illustrations of V.aquatica are provided.

Recent developments in less known and multi-resistant fungal opportunists

Fungal infections have increased in recent years due to host factors, such as oncohaematological and transplant-related disorders, immunosuppressive therapy, and AIDS. Additionally, molecular and proteomic facilities have become available to identify previously unrecognizable opportunists. For these reasons, reports on less-known and recalcitrant mycoses, such as those caused by black fungi, hyaline filamentous fungi, coelomycetes, Mucorales, and non-Candida yeasts have emerged. In this review, novel taxonomy in these groups, which often are multi-resistant to one or several classes of antifungals, is discussed. Clinical presentations, diagnosis and current treatment of some major groups are summarised.

Phaeohyphomycosis due to Veronaea botryosa in cultured white sturgeon (Acipenser transmontanus Richardson) from California USA during 2006 to 2015

Infection with Veronaea botryosa can result in rare cutaneous or disseminated, granulomatous to pyogranulomatous phaeohyphomycosis in humans, although disease due to the fungus has also been reported in non-mammalian vertebrates. This report documents disease due to V. botryosa in captive, juvenile to subadult or young adult white sturgeon (Acipenser transmontanus Richardson) from California USA and complements a previous report of the disease in captive Siberian sturgeon (Acipenser baerii) from Florida USA. Pathological examinations revealed granulomatous to pyogranulomatous inflammation of multiple organs. Isolates of the fungal agent were phenotypically consistent with V. botryosa, and molecular analyses of the D1/D2 region of the fungal 28S rRNA gene and the internal transcribed spacer (ITS) region located between the fungal 18S and 28S rRNA genes confirmed the aetiologic agent as V. botryosa. The disease in captive sturgeon results in a considerable economic encumbrance to the producer due to the loss of the cumulative financial resources invested in the production of older subadult to young adult sturgeon.

Comparative genomics of opportunistic Phialophora species involved in divergent disease types

BACKGROUND

Black opportunists Phialophora verrucosa complex species can cause different disease types in competent and in immunocompromised individuals, but are remarkably overrepresented in CARD9-related infections.

OBJECTIVES

To better understand the ecology and potential pathogenicity of opportunistic Phialophora species and reveal eventual genetic parameters associated with the behaviour in vivo and genetic profiles in patients with CARD9 immunodeficiency.

METHODS

Genomes of 26 strains belonging to six species of the Phialophora verrucosa complex were sequenced. Using multilocus analysis, all environmental and clinical strains were identified correctly. We compared the genomes of agents from different disease types among each other including CARD9 immunodeficiency.

RESULTS

We obtained genome sizes of the 26 Phialophora strains ranged between 32 and 37 MB. Some species showed considerable intraspecific genomic variation. P americana showed the highest degree of variability. P verrucosa was variable in CAZy enzymes, whereas P americana varied in PKS-related genes. Phialophora species, particularly P verrucosa, are relatively frequent in patients with CARD9-related immunodeficiency. Different mutations in the CARD9 gene seem to increase susceptibility for infection by different groups of species, that is either Candida, dermatophytes or black fungi. A number of patients with chromoblastomycosis revealed an as yet unknown CARD9 mutation. TNFα impairment was prevalent in patients with CARD9 infections, while CBM patients were invariably IFNγ.

CONCLUSIONS

From genomic investigations, the known virulence factors between clinical and environmental strains did not reveal any significant difference. Phialophora complex has an equal chance to cause infection in humans, either healthy or CARD9-impaired.

New molecular marker for phylogenetic reconstruction of black yeast-like fungi (Chaetothyriales) with hypothetical EIF2AK2 kinase gene

In eukaryotes, phosphorylation of the α-subunit of eIF2 is a mechanism to adjust cellular gene expression profiles in response to specific signals. The eIF2α kinases are a group of serine-threonine kinases that perform important functions in response to infection, proteotoxicity, and nutrient scavenging. The conserved nature of eIF2α kinases among fungi makes them potential evolutionary markers, which may contribute to deeper understanding of taxonomy and evolution. To date, only few studies are available of eIF2α kinases in black yeasts, which are members of Chaetothyriales containing potential agents of a gamut of major human diseases, such as chromoblastomycosis, phaeohyphomycosis and mycetoma. To establish the phylogenetic validity of sequences of eIF2α kinases hypothetical genes, we compared these genes between members of different classes of fungi, including black yeasts and allies, aiming at evaluation of the phylogeny of this group using an alternative molecular marker, compared to standard ribosomal genes. Trees generated with eIF2α kinase sequences of fungi were compared with those generated by ribosomal internal transcribed spacers (ITS rDNA) sequences from the same species. Sequences used were obtained from the protein Non-redundant database of NCBI, were aligned using CLUSTALX v1.8 and alignments were analyzed with RAxML v8.2.9 on the CIPRES Science Gateway portal. The trees generated had similar topologies, demonstrating that eIF2α kinases hypothetical gene sequences present a coherent reflection of evolution among fungi, compared to trees reconstructed by the use of ribosomal sequences. Our preliminary findings with a limited dataset strongly suggest that the evolution of kinases among black yeasts follows a similar path as revealed by ribosomal data, which underlines the validity of current taxonomy of black yeasts and relatives.

Ocular Phaeohyphomycosis Caused by Veronaea botryose: A Novel Fungal Infection in Human Beings

PURPOSE

To describe an aggressive, refractory case of Veronaea botryosa-associated mycokeratitis progressing to endophthalmitis.

METHODS

Observational case report and review of relevant literature.

RESULTS

An 80-year-old man with a history of lung cancer and diabetes mellitus type 2 presented as an emergent referral to the corneal service with a corneal ulcer and associated endothelial plaque that responded initially to topical steroid and antiviral therapy but subsequently progressed to fungal endophthalmitis. The patient underwent an emergent penetrating keratoplasty and pars plana vitrectomy. Despite multiple negative Grocott methenamine silver smears, gram stains, eye cultures (aerobic, anaerobic, and fungal), and inconclusive confocal microscopy, the host corneal tissue pathology revealed melanin-containing fungi (phaeohyphomycosis). Further speciation of the pathology specimen revealed mold and phenotypic characterization and DNA sequencing confirmed V. botryose.

CONCLUSIONS

Veronaea botryose is a rare fungal infection with previously reported human cutaneous, subcutaneous, and submucosal infections. This is the first documented case of phaeohyphomycosis caused by V. botryosa infection in human ocular tissue.

Environmental prospecting of black yeast-like agents of human disease using culture-independent methodology

Melanized fungi and black yeasts in the family Herpotrichiellaceae (order Chaetothyriales) are important agents of human and animal infectious diseases such as chromoblastomycosis and phaeohyphomycosis. The oligotrophic nature of these fungi enables them to survive in adverse environments where common saprobes are absent. Due to their slow growth, they lose competition with common saprobes, and therefore isolation studies yielded low frequencies of clinically relevant species in environmental habitats from which humans are thought to be infected. This problem can be solved with metagenomic techniques which allow recognition of microorganisms independent from culture. The present study aimed to identify species of the family Herpotrichiellaceae that are known to occur in Brazil by the use of molecular markers to screen public environmental metagenomic datasets from Brazil available in the Sequence Read Archive (SRA). Species characterization was performed with the BLAST comparison of previously described barcodes and padlock probe sequences. A total of 18,329 sequences was collected comprising the genera Cladophialophora, Exophiala, Fonsecaea, Rhinocladiella and Veronaea, with a focus on species related to the chromoblastomycosis. The data obtained in this study demonstrated presence of these opportunists in the investigated datasets. The used techniques contribute to our understanding of environmental occurrence and epidemiology of black fungi.

Effect of Fonsecaea monophora on the Polarization of THP-1 Cells to Macrophages

BACKGROUND

Chromoblastomycosis is a chronic, progressive fungal disease of the skin and subcutaneous tissue caused by a unique group of dematiaceous fungi. Fonsecaea monophora, a new species distinct from Fonsecaea pedrosoi strains, is the main pathogen responsible for chromoblastomycosis in south China. Macrophages can be polarized into two categories: classically activated and alternatively activated.

OBJECTIVES

Little is known about the relationship between F. monophora and macrophage polarization. This study aimed to study the effect of F. monophora on the polarization of THP-1 cells to macrophages.

METHODS

We established coculture systems of F. monophora and THP-1-derived macrophages in different activation states.

RESULTS

F. monophora enhanced the phagocytosis by macrophages in the initially activated state and weakened the phagocytosis by classically activated macrophages without affecting that by alternatively activated macrophages. Classically activated macrophages had the strongest killing effect on F. monophora, while the initially activated macrophages had the weakest. The pathogen could not be rapidly cleared by any type of macrophage. F. monophora promoted the expression of proinflammatory cytokines and inhibited that of anti-inflammatory cytokines.

CONCLUSIONS

F. monophora promoted the polarization of THP-1 cells to classically activated macrophages and inhibited that of THP-1 cells to alternatively activated macrophages.

Experimental Infection of Mice with Veronaea botryosa as a Model for Human Phaeohyphomycosis

Veronaea botryosa is a ubiquitous, dematiaceous mold capable of causing cutaneous and subcutaneous lesions in humans. In the last decade, V. botryosa has been associated with emergent systemic fungal infections in aquatic animals, including cultured sturgeon (Acipenser spp.), captive amphibians, and wild reptiles. Recently, repetitive extragenic palindromic PCR (rep-PCR) fingerprinting has demonstrated intraspecific variability among V. botryosa isolates from different clinically affected hosts and geographic regions. However, little is known regarding the pathogenic potential of the different genetic clades, and no mammalian model currently exists to investigate V. botryosa phaeohyphomycosis. In this study, we inoculated immunocompetent heterozygotic (nu/+) and immunodeficient homozygotic (nu/nu) Hsd:Athymic Nude-Fox1^nu mice subcutaneously or through orogastric gavage with 1 of 3 representative V. botryosa strains that had been recovered from white sturgeon (Acipenser transmontanus), green sea turtle (Chelonia mydas), and human hosts and typed by using rep-PCR analysis. Daily mortality and morbidity were recorded, and dissemination of the fungus was investigated through culture of splenic samples and histologic analysis of the injection site, regional lymph nodes, salivary gland, spleen, liver, mesenteric lymph node, and gastrointestinal tract. No differences in survival, fungal burden, or dissemination were observed between fungal strains, routes of inoculation, or host immune status. Fungal infection was observed after subcutaneous inoculation only, was localized to the inoculation site, and was identified in both nu/nu and nu/+ mice. Fungal strain variability was not associated with virulence in a murine model of infection, and this novel mouse model of V. botryosa phaeohyphomycosis recapitulates the human clinical condition.

Disseminated Mycosis by Arthrocladium fulminans Jeopardizing a Patient with GATA2 Deficiency

GATA2 deficiency is characterized by monocytopenia, deficiency of dendritic cells, and a variable degree of lymphocytopenia affecting B cells and NK cells, leading to an enhanced risk of mycobacterial, viral, and fungal infections. Here we present a patient with a heterozygous intronic GATA2 mutation who acquired a fatal disseminated mycosis due to the black yeast-like fungus Arthrocladium fulminans following an infection with Mycobacterium sherrisii. This case illustrates that in patients with severe uncommon infections, immunodeficiency syndromes must be ruled out.

Effects of temperature on Veronaea botryosa infections in white sturgeon Acipenser transmontanus and fungal induced cytotoxicity of fish cell lines

Veronaea botryosa is a melanized mold and cause of systemic fungal infections in cultured sturgeon (Acipenser spp.). Mortality in adult female sturgeon caused by this emergent pathogen results in significant economic losses for the caviar industry. Little is known regarding environmental conditions conducive to V. botryosa infection. This study evaluated the effect of temperature on V. botryosa infectivity and dissemination following intramuscular injection challenge of white sturgeon maintained at 13 or 18 °C for 40 days. Daily mortality was recorded and persistence of the fungus in the livers of moribund and surviving fish was investigated using culture and histopathological analysis. Fish maintained at 18 °C developed systemic phaeohyphomycosis and had significantly greater mortality than controls and fish maintained at 13 °C (p < 0.05). Challenged fish, regardless of temperature, exhibited lesions in multiple organs. However, muscle lesions, angioinvasion, and systemic dissemination were more severe and widespread in fish challenged at the higher temperature. In vitro cytotoxicity of V. botryosa was evaluated in white sturgeon skin (WSSK-1) and epithelioma papulosum cyprini (EPC) cell lines inoculated at spore:cell ratios of 1:10, 1:1 and 10:1, then incubated 15, 20 and 25 °C. Cytotoxicity, as indicated by quantifying the release of lactate dehydrogenase into culture supernatants, increased with increasing spore dose and incubation temperature in both fish cell lines. Findings suggest that temperature significantly influences the development of systemic V. botryosa infection in white sturgeon and that WSSK-1 and EPC cells are suitable in vitro models for the study of host–pathogen interactions between V. botryosa and fish epithelial cells.

Severe Chromoblastomycosis-Like Cutaneous Infection Caused by Chrysosporium keratinophilum

Chrysosporium species are saprophytic filamentous fungi commonly found in the soil, dung, and animal fur. Subcutaneous infection caused by this organism is rare in humans. We report a case of subcutaneous fungal infection caused by Chrysosporium keratinophilum in a 38-year-old woman. The patient presented with severe chromoblastomycosis-like lesions on the left side of the jaw and neck for 6 years. She also got tinea corporis on her trunk since she was 10 years old. Chrysosporium keratinophilum was isolated from the tissue on the neck and scales on the trunk, respectively. The patient showed satisfactory response to itraconazole therapy, although she discontinued the follow-up.

A rare fungal infection: Phaehyphomycosis due to Veronaea botryosa and review of literature

We report a rare case of phaehyphomycosis in a 71-year-old heart transplant recipient Togo native patient. Four months after the transplant, he presented painless nodules on the right heel with superficial ulceration. The polyphasic identification uncovered a rare cause of phaehyphomycose: V. botryosa. The treatment combined surgical excision of the lesions and anti-fungal therapy with posaconazole. We discussed eleven reported cases in literature since 1990.

Dematiaceous Molds

Dematiaceous fungi are the cause of phaeohyphomycosis, a term that encompasses many clinical syndromes, from local infections due to trauma to widely disseminated infection in immunocompromised patients. These fungi are unique owing to the presence of melanin in their cell walls, which imparts the characteristic dark color to their spores and hyphae. Melanin may also be a virulence factor. Local infection may be cured with excision alone, whereas systemic disease is often refractory to therapy. Azoles have the most consistent in vitro activity. Further studies are needed to better understand the pathogenesis and treatment of these uncommon infections.

Shared Physiological Traits of Exophiala Species in Cold-Blooded Vertebrates, as Opportunistic Black Yeasts

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.

Arthrocladium, an unexpected human opportunist in Trichomeriaceae (Chaetothyriales)

The family Trichomeriaceae (Chaetothyriales) mainly comprises epiphytic and epilithic organisms. In some species elaborate ascomata are formed, but for the great majority the species no asexual conidium formation is known other than simple fragmentation of the thallus. The present paper re-establishes the genus Arthrocladium with three non-sporulating species. One of these is described for a strain causing a fatal infection in a human patient with a rare genetic immune disorder.

Phaeohyphomycosis Caused by a Novel Species, Pseudochaetosphaeronema martinelli

Among the opportunistic mycoses that are emerging in patients with immunosuppression or severe underlying illness, many isolates lack of characteristic sporulation and until recently could not be identified. Clinical signs are mostly nonspecific and therefore such infections have often been disregarded. In the present paper we describe a novel, nonsporulating fungal species causing subcutaneous phaeohyphomycosis in two patients of different origin. One is a 73-year-old female from Martinique who suffered from rheumatoid arthritis, while the other case concerns a 72-year-old male from Mexico who had a history of type 2 diabetes mellitus. Sequencing of the partial ribosomal operon revealed that in both cases a member of the order Pleosporales was concerned which could not be affiliated to any family within this order. Multilocus analysis revealed that the fungus was related to another, unaffiliated agent of human mycetoma, Pseudochaetosphaeronema larense, and therefore the name Pseudochaetosphaeronema martinelli was introduced.

Fonsecaea pugnacius, a Novel Agent of Disseminated Chromoblastomycosis

We report a fatal case of a chromoblastomycosis-like infection caused by a novel species of Fonsecaea in a 52-year-old immunocompetent Caucasian male from an area of chromoblastomycosis endemicity in Brazil. The patient had a 30-year history of slowly evolving, verrucous lesions on the right upper arm which gradually affected the entire arm, the left hemifacial area, and the nose. Subsequent dissemination to the brain was observed, which led to death of the patient. The internal transcribed spacer (ITS) and partial large subunit (LSU), BT2, and CDC42 genes of the isolates recovered from skin and brain were sequenced, confirming the novelty of the species. The species is clinically unique in causing brain abscesses secondary to chromoblastomycosis lesions despite the apparent intact immunity of the patient. Histopathologic appearances were very different, showing muriform cells in skin and hyphae in brain.

Phaeohyphomycosis resulting in obstructive tracheitis in three green sea turtles Chelonia mydas stranded along the Florida coast

Three wild immature green sea turtles Chelonia mydas were found alive but lethargic on the shores of the Indian River Lagoon and Gulf of Mexico in Florida, USA, and subsequently died. Necropsy findings in all 3 turtles included partial occlusion of the trachea by a mass comprised of granulomatous inflammation. Pigmented fungal hyphae were observed within the lesion by histology and were characterized by culture and sequencing of the internal transcribed spacer 2 domain of the rRNA gene and D1/D2 region of the fungal 28s gene. The dematiaceous fungus species Veronaea botryosa was isolated from the tracheal mass in 2 cases, and genetic sequence of V. botryosa was detected by polymerase chain reaction in all 3 cases. Genetic sequencing and fungal cultures also detected other dematiaceous fungi, including a Cladosporium sp., an Ochroconis sp., and a Cochliobolus sp. These cases are the first report of phaeohyphomycosis caused by V. botryosa in wild marine animals.

Black Molds and Melanized Yeasts Pathogenic to Humans

A review is given of melanized fungi involved in human infection, including species forming budding cells and strictly filamentous representatives. Classically, they are known as "phaeoid" or "dematiaceous" fungi, and, today, agents are recognized to belong to seven orders of fungi, of which the Chaetothyriales and Pleosporales are the most important. Infections range from cutaneous or pulmonary colonization to systemic or disseminated invasion. Subcutaneous involvement, either primary or after dissemination, may lead to host tissue proliferation of dermis or epidermis. Particularly in the Chaetothyriales, subcutaneous and systemic infections may occur in otherwise apparently healthy individuals. Infections are mostly chronic and require extended antifungal therapy and/or surgery.

New disease records for hatchery-reared sturgeon. II. Phaeohyphomycosis due to Veronaea botryosa

A series of fungal cases in hatchery-reared juvenile and young adult Siberian sturgeon Acipenser baerii and white sturgeon A. transmontanus occurred at production facilities in Florida and California, USA, respectively. Affected fish exhibited abnormal orientation and/or buoyancy, emaciation, coelomic distension, exophthalmos, cutaneous erythema, and ulcerative skin and eye lesions. Necropsies revealed haemorrhage throughout the coelom, serosanguinous coelomic effusion and organomegaly with nodular or cystic lesions in multiple organs. Fungal hyphae were observed in 27 fish (24 A. baerii and 3 A. transmontanus) via microscopic examination of tissue wet mounts and on slides prepared from colonies grown on culture media. Histopathological examination of these infected tissues revealed extensive infiltration by melanised fungal hyphae that were recovered in culture. Phenotypic characteristics and sequencing of the fungal isolates with the use of the internal transcribed spacer region and 28S rRNA gene confirmed the aetiological agent as Veronaea botryosa. To our knowledge, this is the first documentation of V. botryosa infection in fish, although melanised fungi of the closely related genus Exophiala are well-known pathogens of freshwater and marine fishes.

In vitro activities of eight antifungal drugs against 106 waterborne and cutaneous exophiala species

The in vitro activities of eight antifungal drugs against 106 clinical and environmental isolates of waterborne and cutaneous Exophiala species were tested. The MICs and minimum effective concentrations for 90% of the strains tested (n = 106) were, in increasing order, as follows: posaconazole, 0.063 μg/ml; itraconazole, 0.25 μg/ml; micafungin, 1 μg/ml; voriconazole, 2 μg/ml; isavuconazole, 4 μg/ml; caspofungin, 8 μg/ml; amphotericin B, 16 μg/ml; fluconazole, 64 μg/ml.

Black yeasts-like fungi isolated from dialysis water in hemodialysis units

Hemodialysis in patients with chronic renal failure promotes the removal of toxic substances, water, and minerals from the body and often takes place in specialized clinics. Microbial contamination of dialysis fluid is a serious problem in therapy. One of the sources of contamination is the water used to prepare the dialysate. In Brazil, legislation regulating the microbiological quality of water for dialysis does not cover waterborne microbes such as Pseudomonas, mycobacteria, and fungi. The aim of the present study was to quantify, isolate, and identify fungi present in water systems in six hemodialysis units in Curitiba, Paraná state, Brazil. Fungi were analyzed by surface plating and membrane filtration. Isolates were identified by morphology, while the dematiaceous fungi were identified by sequencing the rDNA ITS region. It was found that 66 % of the samples presented fungi, while black fungi were present in 46 % of all samples. Twenty-eight isolates from treated water for dialysis and dialysate were identified by sequencing and were found to be Exophiala pisciphila, E. cancerae, E. equina, and Rhinocladiella similis. The presence of dematiaceous fungi may pose a risk for debilitated hospitalized patients.