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nutritional pattern and eco-physiology of hortaea werneckii, agent of human tinea nigra.the life cycle of hortaea werneckii includes yeast-like, hyphal and meristematic growth. the preponderance of each form of propagation can be influenced by environmental conditions. the clinical entity 'tinea nigra' is explained by ecological similarities between supposed natural niches and human hyperhydrotic skin. the species is recognizable by assimilation of lactose, nitrate and nitrite, no or little growth with l-lysine, cadaverine, creatine and creatinine, and tolerance of 10% nacl. it gen ...19921283680
population biology of hortaea werneckii based on restriction patterns of mitochondrial dna.fifteen isolates of hortaea werneckii, causative agent of tinea nigra in man, were examined with respect to restriction fragment length polymorphisms of mitochondrial dna. seven types of mtdna, interpreted as populations, could be distinguished, with similarities between the restriction patterns ranging from 32 to 79%. much of the variance originated from length mutations. of the seven populations four represented isolates from man, two of which also comprised isolates from other sources. this m ...19948060120
mitochondrial dna analysis of phialophora verrucosa.restriction fragment length polymorphism (rflp) of mitochondrial dna (mtdna) was examined in 32 isolates of phialophora verrucosa (eight isolates from japan, 10 from china, four from the usa, six from venezuela and four from colombia) and in three of phialophora americana using five restriction enzymes. p. verrucosa isolates were divided into 10 mtdna types based on rflp patterns. phylogeny constructed on sequence divergence of mtdna indicated that p. verrucosa is a single species and isolates a ...19979470416
salt stress affects sterol biosynthesis in the halophilic black yeast hortaea werneckii.hortaea werneckii is a black yeast recently isolated from salterns in slovenia. some of the adaptations of halophilic microorganisms to increased salinity and osmolarity of the environment are alterations in membrane properties. by modulating the fluidity, sterols play an important role as a component of eukaryotic biological membranes. we studied the regulation of sterol biosynthesis in h. werneckii through the activity and amount of 3-hydroxy-3-methylglutaryl coenzyme a reductase (hmg r), a ke ...199910556729
expression of 17beta-hydroxysteroid dehydrogenases in mesophilic and extremophilic yeast.17beta-hydroxysteroid dehydrogenases (17beta-hsds) are enzymes responsible for reversible interconversions of biologically active 17-hydroxy and inactive 17-keto steroids. we have performed a survey of 17beta-hsd activity in yeast. constitutive 17beta-hsd activity was found in three mesophilic yeast species: candida tropicalis, cryptococcus tsukubaensis, and saccharomyces cerevisiae as well as in three extremophilic black yeast species: hortaea werneckii, trimmatostroma salinum, and phaeotheca t ...200111090658
hortein, a new natural product from the fungus hortaea werneckii associated with the sponge aplysina aerophoba.the fungus hortaea werneckii isolated from the mediterranean sponge aplysina aerophoba, collected at banyuls-sur-mer in southern france, yielded a new compound named hortein (1), which possesses a unique ring system hitherto unknown for natural products. the structure of 1 was established on the basis of 1d and 2d nmr spectroscopic and mass spectrometric (esi, ci, fab, ei) data.200111374967
evidence for 1,8-dihydroxynaphthalene melanin in three halophilic black yeasts grown under saline and non-saline conditions.the ascomycetous black yeasts hortaea werneckii, phaeotheca triangularis, and trimmatostroma salinum are halophilic fungi that inhabit hypersaline water of solar salterns. they are characterized by slow, meristematic growth and very thick, darkly pigmented cell walls. the dark pigment, generally thought to be melanin, is consistently present in their cell walls when they grow under saline and non-saline conditions. we used the inhibitor tricyclazole to test the fungi in this study for the presen ...200415033240
salt-induced changes in lipid composition and membrane fluidity of halophilic yeast-like melanized fungi.the halophilic melanized yeast-like fungi hortaea werneckii, phaeotheca triangularis, and the halotolerant aureobasidium pullulans, isolated from salterns as their natural environment, were grown at different nacl concentrations and their membrane lipid composition and fluidity were examined. among sterols, besides ergosterol, which was the predominant one, 23 additional sterols were identified. their total content did not change consistently or significantly in response to raised nacl concentra ...200415064990
characterization of fungi from hypersaline environments of solar salterns using morphological and molecular techniques.the cabo rojo solar salterns located on the southwest coast of puerto rico are composed of two main ecosystems (i.e., salt ponds and microbial mats). even though these locations are characterized by high solar radiation (mean light intensity of 39 mol photons m-2d-1) they harbour a diverse microscopic life. we used morphological and molecular techniques to identify a series of halotolerant fungi. a total of 183 isolates and 36 species were cultured in this study. from the water from the salt pon ...200616904880
identification and characterization of ena atpases hwena1 and hwena2 from the halophilic black yeast hortaea werneckii.two genes, hwena1 and hwena2, which encode ena-like atpases in the extremely halotolerant black yeast hortaea werneckii, were cloned and sequenced. although the expression of both genes is responsive to salt, the transcription of the hwena1 gene was induced at a higher level when the cells were exposed to salt stress, and the expression of hwena2 gene was higher in the adapted cells, suggesting their different roles in maintaining alkali cation homeostasis. according to the phylogenetic tree bas ...200617034413
temperature and nacl-tolerance of rock-inhabiting meristematic fungi.black meristematic fungi together with lichens and cyanobacteria dominate the micro-flora of rock surfaces in arid and semi-arid environments of hot and cold deserts. this study shows that rock inhabiting meristematic fungi are extremely tolerant against high temperatures, desiccation and osmotic stress. their temperature tolerance increases with increasing dehydration of the fungal thallus. air dried mycelia of black yeasts stand temperatures up to 120 degrees c for at least 0.5 hours. as respo ...199810081587
identity and biodegradative abilities of yeasts isolated from plants growing in an arid climate.plants harvested in the canary islands lanzarote and fuerteventura were analyzed for the yeasts inhabiting their surface. half of the isolates (22 out of 44) were identified as debaryomyces hansenii. black ascomycetes, viz. hortaea werneckii and two hormonema species were represented by 7 strains. basidiomycetous yeasts, viz. cryptococcus sp. (8 strains), rhodotorula sp. (5 strains), cerinosterus cyanescens (1 strain) and pseudozyma sp. (1 strain) constituted a minority of 33%. thirty strains we ...19979298186
cell-surface hydrophobicity and lipolysis as essential factors in human tinea nigra.hydrophobic adhesion of cells of the black yeast hortaea werneckii (horta) nishimura & miyaji, causative agent of human tinea nigra, was established by microbial adhesion to hexadecane (math) and adhesion to polystyrene, and compared with adhesion of other species of black yeasts. additional ecophysiological tests were performed. hortaea werneckii cells proved to have a high degree of hydrophobicity (98.5% math). the species is unable to degrade keratin, but shows significant lipolytic activity. ...19958720202
the use of karyotyping in the systematics of yeasts.the use of electrophoretic karyotyping in systematics of yeasts is discussed. new data are provided on the karyotypes of the medically important fungi hortaea werneckii, filobasidiella (= cryptococcus) neoformans, and malassezia species. hortaea werneckii has twelve to eighteen bands of chromosomal dna, ranging in size between 500 and 2300 kb. the karyotypes of filobasidiella neoformans consist of seven to fourteen bands of chromosomal dna. the varieties neoformans and bacillispora cannot be sep ...19938259832
the fine structure of hortaea werneckii.hortaea werneckii (strain cbs 107.67) was examined by light and transmission electron microscopy (tem). special attention was paid to the wall architecture, the septum with a simple pore apparatus, the annellidic type of collar and the nuclei. two-celled organisms showed signs of distoseptation; nuclear events appeared to be rather synchronous in both cells. the fine structural results provided evidence of endogenous conidia development.19937935564
[tinea nigra palmaris: a clinical case in argentina].a clinical case of a female patient with a black spot on the palm of her left hand is presented. the infection was due to a black fungus identified as hortaea werneckii, the aetiological agent of tinea nigra palmaris. this infection can be easily diagnosed and it is important to establish the differential diagnosis from other skin pathologies. normally, the treatment has a successful outcome. in this case, the patient was treated with econazole locally applied during one month, with complete rem ...200718390155
polymerase chain reaction-mediated genotyping of hortaea werneckii, causative agent of tinea nigra.the black yeast hortaea werneckii is known to be a causative agent of human tinea nigra but is also found in the environment. strains from dissimilar sources were studied by polymerase chain reaction fingerprinting of nuclear dna, using primers annealing to repetitive and random sequences. the seven groups found correspond to those known from restriction fragment length polymorphism (rflp) studies of the mitochondrial dna of the same strains. two main groups contained strains from human as well ...19947746287
further studies on the phylogenesis of the genus exophiala and hortaea.the conidial ontogenesis of the pathogenic black yeasts is studied at an ultrastructural level and their phylogenesis is discussed. five cultures of exophiala dermatitidis, four of e. jeanselmei, one of e. moniliae, one of e. spinifera and six of h. werneckii were observed using a scanning electron microscope. the conidial ontogenesis of the exophiala species is not pleomorphic but only annellidic. there are definite differences in morphology of annellated tips among the exophiala species. the o ...19854079967
drought meets acid: three new genera in a dothidealean clade of extremotolerant fungi.fungal strains isolated from rocks and lichens collected in the antarctic ice-free area of the victoria land, one of the coldest and driest habitats on earth, were found in two phylogenetically isolated positions within the subclass dothideomycetidae. they are here reported as new genera and species, recurvomyces mirabilisgen. nov., sp. nov. and elasticomyces elasticusgen. nov., sp. nov. the nearest neighbours within the clades were other rock-inhabiting fungi from dry environments, either cold ...200819287523
novel group vii histidine kinase hwhhk7b from the halophilic fungi hortaea werneckii has a putative role in osmosensing.histidine kinases (hks) are abundant among prokaryotes and have been characterized in fungi and plants, although not yet in animals. these enzymes regulate diverse processes, including adaptation to osmotic stress and virulence of plant and animal pathogens. here, we report the cloning, characterization and phylogenetic analysis of hwhhk7a and hwhhk7b, hk genes from the fungi hortaea werneckii, a proposed model system for studying salt tolerance in eukaryotes. the two hwhhk7 isoforms are 96.7% i ...200717435999
the map kinase hwhog1 from the halophilic black yeast hortaea werneckii: coping with stresses in solar salterns.hortaea werneckii is one of the most salt-tolerant species among microorganisms. it has been isolated from hypersaline waters of salterns as one of the predominant species of a group of halophilic and halotolerant melanized yeast-like fungi, arbitrarily named as "black yeasts". it has previously been shown that h. werneckii has distinct mechanisms of adaptation to high salinity environments that are not seen in salt-sensitive and only moderately salt-tolerant fungi. in h. werneckii, the hog path ...200717349032
a case of tinea nigra palmaris in okinawa, japan.we report a case of tinea nigra on the left palm of a 13-year-old girl. she had noticed a pigmented, asymptomatic macule on the left palm approximately 4-5 years prior to her first visit to our hospital. the color of the lesion tended to change before and after a bath; it became lighter after a bath and darkened some time later. physical examination revealed that the macule was 4 cm x 5 cm in size, dark brown in color and irregularly shaped. direct potassium hydroxide (koh) microscopic examinati ...200616469080
tinea nigra: report of twelve cases in venezuela.tinea nigra is a superficial mycotic infection produced by hortaea werneckii, formerly known as phaeoannelomyces werneckii, formerly known as exophiala werneckii, and stenella araguata, the latter autochthonous in venezuela, it was first described and named as cladosporium castellanii in 1973. the present report describes 12 cases in the period of 1972-2002, diagnosed at the medical mycology section at the tropical institute of the universidad central de venezuela, in caracas. this mycosis is mo ...200516205972
identification of pathogenic dematiaceous fungi and related taxa based on large subunit ribosomal dna d1/d2 domain sequence analysis.the nucleotide sequences of the d1/d2 domains of large subunit (26s) ribosomal dna for 76 strains of 46 species of pathogenic dematiaceous fungi and related taxa were determined. intra-species sequence diversity of medically important dematiaceous fungi including phialophora verrucosa, fonsecaea pedrosoi, fonsecaea compacta, cladophialophora carrionii, cladophialophora bantiana, exophiala dermatitidis, exophiala jeanselmei, exophiala spinifera, exophiala moniliae, and hortaea werneckii were extr ...200414734185
specific oligonucleotide primers for identification of hortaea werneckii, a causative agent of tinea nigra.hortaea werneckii, a black yeast-like hyphomycete that is widely distributed in tropical and subtropical environments, can cause superficial mycotic infection in humans. this fungus was recently isolated from superficial infectious lesions of a guinea pig in japan. an oligonucleotide primer set specific for hortaea werneckii was designed on the basis of the internal transcribed spacer regions of the ribosomal dna (rdna). polymerase chain reaction (pcr) with this primer set yielded a 306 bp pcr a ...200312812723
analyses of phagocytosis, evoked oxidative burst, and killing of black yeasts by human neutrophils: a tool for estimating their pathogenicity?the pathogenicity of several dematiaceous yeasts that have, to date, rarely been isolated in humans remains unclear. because professional phagocytes are prominent in lesions caused by dematiaceous fungi, we address this issue by comparing phagocytosis, evoked oxidative burst and killing by human neutrophils of different black yeasts in vitro. whereas phagocytosis of all black yeasts tested and evoked oxidative burst yielded comparable results, in contrast, the degree of killing differed signific ...200312627799
Adaptation of the glycerol-3-phosphate dehydrogenase Gpd1 to high salinities in the extremely halotolerant Hortaea werneckii and halophilic Wallemia ichthyophaga.We report the first identification and characterisation of the glycerol-3-phosphate dehydrogenase (GPD) genes from extremely halophilic fungi. The black ascomycetous yeast Hortaea werneckii and the non-melanised basidiomycetous fungus Wallemia ichthyophaga inhabit similar hypersaline environments, yet they have two different strategies of haloadaptation through Gpd1-regulated glycerol synthesis. The extremely halotolerant H. werneckii codes for two salt-inducible GPD1 genes that show similar gen ...201121944208
the mycobiota of the salterns.solar salterns are constructed as shallow multi-pond systems for the production of halite through evaporation of seawater. the main feature of salterns is the discontinuous salinity gradient that provides a range of well-defined habitats with increasing salinities, from moderate to hypersaline. these present one of the most extreme environments, because of the low levels of biologically available water and the toxic concentrations of ions. up to the year 2000, hypersaline environments were consi ...201222222830
the hog pathway in the halophilic black yeast hortaea werneckii: isolation of the hog1 homolog gene and activation of hwhog1p.the mitogen-activated protein kinase (mapk) hog1p plays an essential role in the yeast hyperosmotic response. a homolog of the hog1 gene was isolated from the halophilic black yeast hortaea werneckii encoding a putative 359 amino acid protein, hwhog1p, with high homology to saccharomyces cerevisiae hog1p and to other eukaryotic hog1p homologs. hwhog1p contains a tgy motif within a protein kinase catalytic domain and a c-terminal common docking (cd) motif. its activation by increased salinity is ...200212435502
cellular responses to environmental salinity in the halophilic black yeast hortaea werneckii.the development of crop plants with increased salt tolerance necessitates the study of naturally salt-tolerant eukaryotic species. we studied the bio-synthesis of glycerol as a compatible solute in the halophilic eukaryotic microorganism, black yeast hortaea werneckii. a restriction fragment-differential display technique was used to investigate the transcriptome of the organism. eight differentially expressed genes were identified in response to growth at different salinities. although the puta ...200212139614
superficial phaeohyphomycosis caused by aureobasidium melanogenum mimicking tinea nigra in an immunocompetent patient and review of published reports.aureobasidium pullulans is a ubiquitous black yeast-like fungus belonging to order dothideales. it was regarded as a contaminant, but is now considered a pathogen causing a wide range of human infections. we report a case of superficial phaeohyphomycosis in an immunocompetent patient with clinical presentations mimicking tinea nigra. on microscopic examination of lesion scales, multiple thick-walled, pigmented oval spores with septa were noted. a fungus with black mucoid colonies was repeatedly ...201626883514
hypersaline waters in salterns - natural ecological niches for halophilic black yeasts.hypersaline waters in salterns have so far been considered to be populated only with halophilic algae and bacteria and completely lacking halophilic fungi. in this paper we present population dynamics of polymorphic black yeasts, isolated from hypersaline waters (3-30% nacl) of a saltern, in relation to different physicochemical parameters. hortaea werneckii, phaeotheca triangularis, trimmatostroma salinum, aureobasidium pullulans and cladosporium spp. were detected with the highest frequency ju ...200010858582
tinea nigra: a diagnostic pitfall. 201627846967
tinea nigra dermoscopy: a useful assessment. 201627185451
transport systems in halophilic fungi.fungi that tolerate very high environmental nacl concentrations are good model systems to study mechanisms that enable them to endure osmotic and salinity stress. the whole genome sequences of six such fungal species have been analysed: hortaea werneckii, wallemia ichthyophaga and four aureobasidium spp.: a. pullulans, a. subglaciale, a. melanogenum and a. namibiae. these fungi show different levels of halotolerance, with the presence of numerous membrane transport systems uncovered here that ar ...201626721280
differential gene expression and hog1 interaction with osmoresponsive genes in the extremely halotolerant black yeast hortaea werneckii.fluctuations in external salinity force eukaryotic cells to respond by changes in the gene expression of proteins acting in protective biochemical processes, thus counteracting the changing osmotic pressure. the high-osmolarity glycerol (hog) signaling pathway is essential for the efficient up-regulation of the osmoresponsive genes. in this study, the differential gene expression of the extremely halotolerant black yeast hortaea werneckii was explored. furthermore, the interaction of mitogen-act ...200717705830
osmotic adaptation of the halophilic fungus hortaea werneckii: role of osmolytes and melanization.this study was intended to determine the osmoadaptation strategy of hortaea werneckii, an extremely salt-tolerant melanized ascomycetous fungus that can grow at 0-5.1 m nacl. it has been shown previously that glycerol is the major compatible solute in actively growing h. werneckii. this study showed that the exponentially growing cells also contained erythritol, arabitol and mannitol at optimal growth salinities, but only glycerol and erythritol at maximal salinities. the latter two were both de ...200718048939
mitochondrial mediation of environmental osmolytes discrimination during osmoadaptation in the extremely halotolerant black yeast hortaea werneckii.we have investigated the mitochondrial responses to hyperosmotic environments of ionic (4.5 m nacl) and non-ionic (3.0 m sorbitol) osmolytes in the most halo/osmo-tolerant black yeast, hortaea werneckii. adaptation to both types of osmolytes resulted in differential expression of mitochondria-related genes. live-cell imaging has revealed a condensation of mitochondria in hyperosmotic media that depends on osmolyte type. in the hypersaline medium, this was accompanied by increased atp synthesis a ...200818343697
aspects of the progesterone response in hortaea werneckii: steroid detoxification, protein induction and remodelling of the cell wall.progesterone in sublethal concentrations temporarily inhibits growth of hortaea werneckii. this study investigates some of the compensatory mechanisms which are activated in the presence of progesterone and are most probably contributing to escape from growth inhibition. these mechanisms lead on the one hand to progesterone biotransformation/detoxification but, on the other, are suggested to increase the resistance of h. werneckii to the steroid. biotransformation can detoxify progesterone effic ...200818793662
tinea nigra by hortaea werneckii, a report of 22 cases from mexico.tinea nigra is a superficial mycosis caused by hortaea werneckii. it is an infrequent asymptomatic infection that affects human palms and soles, and is mostly observed in tropical countries. we evaluate retrospectively twenty-two confirmed cases of tinea nigra from a total of eleven yr (1997-2007) and discuss the epidemiology, clinical features and treatment of this disease. in twelve cases, adults were involved, in 10, children. in nineteen cases the disorder was located on palms of hands and i ...200819287529
novel 3'-phosphoadenosine-5'-phosphatases from extremely halotolerant hortaea werneckii reveal insight into molecular determinants of salt tolerance of black yeasts.the 3'-phosphoadenosine-5'-phosphatase encoded by hal2 gene, is a ubiquitous enzyme required for the removal of the cytotoxic 3'-phosphoadenosine-5'-phosphate produced during sulfur assimilation in eukaryotes. salt toxicity in yeast and plants results from hal2 inhibition by sodium or lithium ions. two novel hal2-like genes, hwhal2a and hwhal2b, have been cloned from saltern-inhabited extremely halotolerant black yeast hortaea werneckii. expression of both hwhal2 isoforms was differentially indu ...200717420146
salt stress and plasma-membrane fluidity in selected extremophilic yeasts and yeast-like fungi.we have investigated changes in plasma-membrane fluidity in relation to nacl concentrations in yeasts and yeast-like fungi that were isolated from either subglacial ice or hypersaline waters. in both of these natural environments, these organisms are exposed to low water activity, due to either high nacl concentrations or low temperatures. our data indicate that the fluidity of the plasma membrane can be used as an indicator of fitness for survival in extreme environments. fungi that can survive ...200717298474
global analysis of the hortaea werneckii proteome: studying steroid response in yeast.the response of the halophilic black yeast hortaea werneckii to the steroid hormone progesterone has been studied at the protein level using fluorescent two-dimensional differential gel electrophoresis (2d-dige) technology in combination with mass spectrometry. data on protein identification from this study reveal molecular mechanisms of the response to progesterone. in particular, the overexpression of pck2 and pac2 in the stimulated cells indicates the interactions of progesterone with the cel ...200516335949
the halophilic fungus hortaea werneckii and the halotolerant fungus aureobasidium pullulans maintain low intracellular cation concentrations in hypersaline environments.hortaea werneckii and aureobasidium pullulans, black yeast-like fungi isolated from hypersaline waters of salterns as their natural ecological niche, have been previously defined as halophilic and halotolerant microorganisms, respectively. in the present study we assessed their growth and determined the intracellular cation concentrations of salt-adapted and non-salt-adapted cells of both species at a wide range of salinities (0 to 25% nacl and 0 to 20% nacl, respectively). although 5% nacl impr ...200516269687
the mycological and molecular study of hortaea werneckii isolated from blood and splenic abscess.hortaea werneckii is an environmental dematiaceous fungus found in the halophilic environment. it causes tinea nigra. we report the isolation of h. werneckii from blood and splenic abscess of two patients with acute myelomonocytic leukaemia. h. werneckii grew at room temperature but not at 37 degrees c, it was identified by biochemical tests, growth characteristics and the presence of conspicuous collarette intercalary on dividing yeast cells. the use of specific oligonucleotide primer hor-f (5' ...200515983734
the first isolation of hortaea werneckii from a household guinea pig.hortaea werneckii, a black yeast and the causative agent of tinea nigra (a superficial type of dermatomycosis), is a human pathogen and is also found in the environment. it is not highly pathogenic but in the last fifteen to twenty years has been isolated from various human and environmental sources in japan. as far as we know, there has been no report on the isolation of h. werneckii from animals. recently, we found a case of a guinea pig with dark superficial lesions on the palm and dorsal are ...200212145633
ergosterol biosynthesis in novel melanized fungi from hypersaline environments.halotolerant and halophilic melanized fungi were recently described in hypersaline waters. a close study of the sterol composition of such fungi, namely hortaea werneckii, alternaria alternata, cladosporium sphaerospermum, cladosporium sp., and aureobasidium pullulans revealed the dominance of ergosterol and the presence of 29 intermediates of its biosynthesis pathway. the presence or absence of intermediates from distinct synthesis routes gave insight into the operative synthetic pathways from ...200111254746
the expressions of delta 9-, delta 12-desaturases and an elongase by the extremely halotolerant black yeast hortaea werneckii are salt dependent.the black yeast-like fungus hortaea werneckii is the predominant fungal species in salterns, and it is extremely halotolerant. the restructuring of the h. werneckii membrane lipid composition is one of its adaptations to high concentrations of salt, which is mainly achieved by increasing the unsaturation of its phospholipid fatty acids. genes encoding three fatty acid-modifying enzymes, delta(9)-, delta(12)-desaturases and an elongase, have been identified in the genome of h. werneckii, each in ...200919220869
adaptation of extremely halotolerant black yeast hortaea werneckii to increased osmolarity: a molecular perspective at a glance.halophilic adaptations have been studied almost exclusively on prokaryotic microorganisms. discovery of the black yeast hortaea werneckii as the dominant fungal species in hypersaline waters enabled the introduction of a new model organism to study the mechanisms of salt tolerance in eukaryotes. its strategies of cellular osmotic adaptations on the physiological and molecular level revealed novel, intricate mechanisms to combat fluctuating salinity. h. werneckii is an extremely halotolerant euka ...200819287528
role of oxidative stress in the extremely salt-tolerant yeast hortaea werneckii.eukaryotic halotolerant microorganisms are important as model organisms to understand the general mechanisms of resistance to environmental salinity. the ability of the extremely halotolerant black yeast hortaea werneckii to combat oxidative stress was addressed, using hydrogen peroxide to generate the reactive oxygen species. increasing environmental salinity was found to have no effect on its high ability to degrade hydrogen peroxide but resulted in a decrease in viability in response to exter ...200616879431
β-galactofuranose-containing structures present in the cell wall of the saprophytic fungus cladosporium (hormoconis) resinae.a peptidogalactomannan was isolated from mycelia of cladosporium (hormoconis) resinae and characterized using methylation-fragmentation analysis, partial acid hydrolysis and ¹h and ¹³c-nmr spectroscopy. the galactomannan component was a branched structure and consisted of a main chain containing (1→6)-linked α-d-manp residues substituted at o-2 by side chains containing (1→2)-linked α-d-manp residues. β-d-galf residues were present as side chains of 3-4 units that are (1→5)-interlinked. this str ...201020696239
tinea nigra presenting speckled or "salt and pepper" pattern.a 7-year-old caucasian female resident of the southern coast of brazil presented dark spots on the left palm that converged to a unique macule with speckled pattern at about 1 month. the mycological exam and the fungi culture were typical of hortaea werneckii, the agent of the superficial mycosis tinea nigra. the patient received butenafine hydrochloride 1% for 30 days, resulting in a complete remission of the lesion. at a follow-up visit 12 months after treatment, there was no lesion recurrence ...201424898980
adaptation to high salt concentrations in halotolerant/halophilic fungi: a molecular perspective.molecular studies of salt tolerance of eukaryotic microorganisms have until recently been limited to the baker's yeast saccharomyces cerevisiae and a few other moderately halotolerant yeast. discovery of the extremely halotolerant and adaptable fungus hortaea werneckii and the obligate halophile wallemia ichthyophaga introduced two new model organisms into studies on the mechanisms of salt tolerance in eukaryotes. h. werneckii is unique in its adaptability to fluctuations in salt concentrations, ...201424860557
halotolerant and halophilic fungi.extreme environments have for long been considered to be populated almost exclusively by prokaryotic organisms and therefore monopolized by bacteriologists. solar salterns are natural hypersaline environments characterized by extreme concentrations of nacl, often high concentrations of other ions, high uv irradiation and in some cases extremes in ph. in 2000 fungi were first reported to be active inhabitants of solar salterns. since then many new species and species previously known only as food ...200919747974
scanning electron microscopy of tinea nigra.tinea nigra is a rare superficial mycosis caused by hortaea werneckii. this infection presents as asymptomatic brown to black maculae mostly in palmo-plantar regions. we performed scanning electron microscopy of a superficial shaving of a tinea nigra lesion. the examination of the outer surface of the sample showed the epidermis with corneocytes and hyphae and elimination of fungal filaments. the inner surface of the sample showed important aggregation of hyphae among keratinocytes, which formed ...201724770516
whole genome duplication and enrichment of metal cation transporters revealed by de novo genome sequencing of extremely halotolerant black yeast hortaea werneckii.hortaea werneckii, ascomycetous yeast from the order capnodiales, shows an exceptional adaptability to osmotically stressful conditions. to investigate this unusual phenotype we obtained a draft genomic sequence of a h. werneckii strain isolated from hypersaline water of solar saltern. two of its most striking characteristics that may be associated with a halotolerant lifestyle are the large genetic redundancy and the expansion of genes encoding metal cation transporters. although no sexual stat ...201323977017
melanin is crucial for growth of the black yeast hortaea werneckii in its natural hypersaline environment.melanin has an important role in the ability of fungi to survive extreme conditions, like the high nacl concentrations that are typical of hypersaline environments. the black fungus hortaea werneckii that has been isolated from such environments has 1,8-dihydroxynaphthalene-melanin incorporated into the cell wall, which minimises the loss of glycerol at low nacl concentrations. to further explore the role of melanin in the extremely halotolerant character of h. werneckii, we studied the effects ...201323719222
identification and characterization of putative osmosensors, hwsho1a and hwsho1b, from the extremely halotolerant black yeast hortaea werneckii.in saccharomyces cerevisiae, the sho1 protein is one of two potential osmosensors that can activate the kinase cascade of the hog pathway in response to increased extracellular osmolarity. two novel sho1-like genes, hwsho1a and hwsho1b, have been cloned from the saltern-inhabiting, extremely halotolerant black yeast hortaea werneckii. the hwsho1 protein isoforms are 93.8% identical in their amino-acid sequences, and have a conserved sh3 domain. when the hwsho1 genes were transferred into s. cere ...201121281727
[tinea nigra: a allochthonous case report in chile].tinea nigra is a superficial mycosis caused by hortaea werneckii. it is an infrequent asymptomatic infection that affects mainly human palms and soles, and it is mostly seen in tropical countries. it has not been reported in chile yet. the clinical presentation is generally a single macule, not symptomatic, of brown color in palms and soles. we report a case of a chilean woman that developed brown macules on both soles after travel to the united states and central america. the diagnosis of tinea ...201323450418
Fungal adaptation to extremely high salt concentrations.Hypersaline environments support substantial microbial communities of selected halotolerant and halophilic organisms, including fungi from various orders. In hypersaline water of solar salterns, the black yeast Hortaea werneckii is by far the most successful fungal representative. It has an outstanding ability to overcome the turgor loss and sodium toxicity that are typical for hypersaline environments, which facilitates its growth even in solutions that are almost saturated with NaCl. We propos ...201122050822
Extremophilic yeasts: plasma-membrane fluidity as determinant of stress tolerance.Our aim was to investigate the response of selected yeasts and yeast-like fungi from extreme environments to various temperatures at the level of their plasma membranes, in order to elucidate the connections between their plasma-membrane fluidity (measured by electron paramagnetic resonance spectroscopy - EPR), growth temperature range, stress tolerance, and ecological distribution. Although all studied fungi can be considered mesophilic according to their growth temperature profiles, their plas ...201121944207
chaophilic or chaotolerant fungi: a new category of extremophiles?it is well known that few halophilic bacteria and archaea as well as certain fungi can grow at the highest concentrations of nacl. however, data about possible life at extremely high concentrations of various others kosmotropic (stabilizing; like nacl, kcl, and mgso4) and chaotropic (destabilizing) salts (nabr, mgcl2, and cacl2) are scarce for prokaryotes and almost absent for the eukaryotic domain including fungi. fungi from diverse (extreme) environments were tested for their ability to grow a ...201425566222
steroid toxicity and detoxification in ascomycetous fungi.in the last couple of decades fungal infections have become a significant clinical problem. a major interest into fungal steroid action has been provoked since research has proven that steroid hormones are toxic to fungi and affect the host/fungus relationship. steroid hormones were found to differ in their antifungal activity in ascomycetous fungi hortaea werneckii, saccharomyces cerevisiae and aspergillus oryzae. dehydroepiandrosterone was shown to be the strongest inhibitor of growth in all t ...201323257178
identification of hortaea werneckii isolated from mangrove plant aegiceras comiculatum based on morphology and rdna sequences.hortaea werneckii is a black yeast-like ascomycetous fungi associated with the human superficial infection tinea nigra, which commonly occurs in tropical and subtropical countries. now, this fungus has been found in the halophilic environment all over the world and recognized as a new model organism in exploring the mechanisms of salt tolerance in eukaryotes. during a survey of endophytic fungi of mangrove forest at south china sea, two isolates of h. werneckii were recovered from medicinal plan ...201222864562
immune gene expression profile of penaeus monodon in response to marine yeast glucan application and white spot syndrome virus challenge.immunostimulant potential of eight marine yeast glucans (yg) from candida parapsilosis r20, hortaea werneckii r23, candida spencermartinsiae r28, candida haemulonii r63, candida oceani r89, debaryomyces fabryi r100, debaryomyces nepalensis r305 and meyerozyma guilliermondii r340 were tested against wssv challenge in penaeus monodon post larvae (pl). structural characterization of these marine yeast glucans by proton nuclear magnetic resonance (nmr) indicated structures containing (1-6)-branched ...201525555812
hortaea werneckii isolated from silicone scuba diving equipment in spain.during a survey of black yeasts of marine origin, some isolates of hortaea werneckii were recovered from scuba diving equipment, such as silicone masks and snorkel mouthpieces, which had been kept under poor storage conditions. these yeasts were unambiguously identified by phenotypic and genotypic methods. phylogenetic analysis of both the d1/d2 regions of 26s rrna gene and its-5.8s rrna gene sequences showed three distinct genetic types. this species is the agent of tinea nigra which is a rarel ...201222548240
bilateral tinea nigra plantaris with good response to isoconazole cream: a case report.tinea nigra is a superficial fungal infection caused by hortaea werneckii. it typically affects young individuals as an asymptomatic unilateral macule, from light brown to black on the palms and soles, mainly in tropical and subtropical regions. in 1997, gupta et al. [br j dermatol 1997;137:483-484] described the dermoscopic characteristics of tinea nigra. topical antifungals with or without keratolytic agents can be used for the treatment. the authors report a case of a 47-year-old man with asy ...201726594169
osmoadaptation-dependent activity of microsomal hmg-coa reductase in the extremely halotolerant black yeast hortaea werneckii is regulated by ubiquitination.we have investigated regulation of hmg-coa reductase (hmgr) in one of the most salt-tolerant fungi, hortaea werneckii, under different salinities and at the level of protein degradation. two different hwhmgr isoenzymes were identified, specific to mitochondria and endoplasmic reticulum: hwhmg1 and hwhmg2, respectively. the activity of microsomal hwhmg2 is highest under hypo-saline and extremely hyper-saline conditions, and down-regulated under optimal growth conditions. we show that this is due ...200717604023
enzymatic activity and susceptibility to antifungal agents of brazilian environmental isolates of hortaea werneckii.four strains of hortaea werneckii were isolated from different substrates in brazil (a salt marsh macrophyte, a bromeliad and a marine zoanthid) and had their identification confirmed by sequencing of the 26s rdna d1/d2 domain or its region. most of the strains were able to express amylase, lipase, esterase, pectinase and/or cellulase, enzymes that recognize components of plant cells as substrates, but did not express albuminase, keratinase, phospholipase and dnase, whose substrates are animal-r ...201526162643
the unique characteristics of hog pathway mapks in the extremely halotolerant hortaea werneckii.hwhog1a/b, hortaea werneckii homologues of the map kinase hog1 from saccharomyces cerevisiae, are vital for the extreme halotolerance of h. werneckii. in mesophilic s. cerevisiae, hog1 is phosphorylated already at low osmolyte concentrations, and regulates expression of a similar set of genes independent of osmolyte type. to understand how hwhog1 kinases activity is regulated in h. werneckii, we studied hwhog1a/b activation in vivo, by following phosphorylation of hwhog1a/b in h. werneckii expos ...201525825474
tinea nigra showing a parallel ridge pattern on dermoscopy.an 18-year-old healthy female student noticed a brown macule measuring 21 mm in diameter on the left palm and visited our clinic concerned about a cancerous mole. dermoscopic examination revealed a brown, fine-dotted and granule-like structure overlapping an amorphous light brown macule. however, unlike previous cases, analysis of the high dynamic range-converted image revealed the parallel ridge pattern frequently observed in malignant melanomas. brown mycelia were detected on direct microscopi ...201525766573
hwhog1 kinase activity is crucial for survival of hortaea werneckii in extremely hyperosmolar environments.although suggested, the involvement of the hog pathway in adaptation processes in extremely halotolerant fungus hortaea werneckii has never been specifically demonstrated. here, we show that the h. werneckii hog pathway is very robust, and that it includes two functionally redundant mapk homologues, hwhog1a and hwhog1b, that show osmolyte-type-dependent phosphorylation. inhibition of hwhog1 kinase activity with the atp analogue bptip restricts h. werneckii colony growth at 3.0m nacl, kcl and sor ...201525483129
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