Mitochondrial DNA analysis of Exophiala jeanselmei and Exophiala dermatitidis

Mitochondrial DNA (mtDNA) analysis with Hae III, Hind. III and Msp I was performed in 45 Exophiala jeanselmei strains (30 Phialophora jeanselmei and 15 Phialophora gougerotii strains) and 31 Exophiala dermatitidis strains. The results were as follows, 1) P. jeanselmei and P. gougerotii are identical, 2) E. jeanselmei is classified into 18 types based on restriction profiles, 3) two strains of E. jeanselmei CBS 577.76 and CBS 578.76 are identified as E. dermatitidis, 4) E. dermatitidis has no intraspecific variation and is definitely distinct from E. jeanselmei, 5) E. jeanselmei is suggested to be a complex organism because of extensive mtDNA polymorphism.     

Deoxyribonucleic acid hybridization studies of Exophiala dermatitidis and Exophiala jeanselmei

Exophiala dermatitidis and Exophiala jeanselmei share similar morphological features and have been confused with each other. To clarify the relationship between the two fungi, we conducted a deoxyribonucleic acid (DNA)-DNA hybridization study using a dot blot method. Between E. dermatitidis and E. jeanselmei, only a very low level of DNA relatedness was seen and it was confirmed that these two fungi are distinct species based on DNA similarity. Close correspondence of DNA from the isolates of E. dermatitidis was obtained, whereas the isolates of E. jeanselmei were divided into 6 groups according to their DNA similarity and a possibility was shown that E. jeanselmei is composed of genetically heterogeneous groups. The subdivision of the species E. jeanselmei by the DNA-DNA hybridization method was in agreement with serotyping exoantigens. This result suggests that DNA-DNA hybridization studies provide an excellent tool for the identification and grouping of pathogenic dematiaceous fungi.     

Mitochondrial DNA analysis of Exophiala jeanselmei var. lecanii-corni and Exophiala castellanii

A Japanese clinical isolate (KU-A-0094) which was identified by de Hoog et al. as Exophiala jeanselmei var. lecanii-corni with difficulty, was compared with 5 strains including the type cultures of E. jeanselmei var. lecanii-corni, var. jeanselmei and E. castellanii using RFLP (restriction fragment length polymorphism) patterns of mtDNA (mitochondrial DNA). RFLP patterns of KUA-0094 were identical with those of E. jeanselmei var. lecanii-corni and different from those of E. castellanii with restriction enzymes of HaeIII, MspI and hindIII. Therefore, de Hoog et al.'s identification of KU-A-0094 was confirmed. Additionally, mtDNA-RFLP patterns of E. jeanselmei var. lecanii-corni and E. jeanselmei var. jeanselmei were also different from each other. Consequently E. jeanselmei var. lecanii-corni seem to be a species in its own right rather than a variant of E. jeanselmei. This revised version was published online in June 2006 with corrections to the Cover Date.     

Pathpgenicity of Exophiala jeanselmei for ddY mice

The pathogenicity of three cultures isolated as Phialophora jeanselmei was compared with that of three cultures of Phialophora gougerotii using ddY mice.One hundred and twenty mice were used. They were divided into 6 groups consisting of 20 each. Each culture was evaluated in 20 mice. Mice were inoculated intravenously with 0.2 ml of a 1% (wet weight/vol.) yeast-like cell suspension and sacrificed at adequate intervals until the 30th day.As results, 1) the virulence of the three cultures each of P. jeanselmei and P. gougerotii to ddY mice was mild. 2) These cultures were not neurotropic. 3) P. gougerotii survived longer in the mice than P. jeanselmei. 4) There were no major differences in histopathology of the lesions in the mice inoculated with the two taxa.     

Isolation of Exophiala jeanselmei from bat guano

Exophiala jeanselmei was isolated from two out of 75 samples of bat guano. The isolates hydrolysed urea and tyrosine, assimilated sodium nitrate and produced a zone of haemolysis on blood agar, They were pathogenic for laboratory mice when injected subcutaneously, intraperitoneally or intravenously.     

Invasion of a soft contact lens by Exophiala jeanselmei

The invasion of a soft contact lens by Exophiala jeanselmei is documented. All species in this genus are pathogenic. In humans E. jeanselmei is a recognized cause of mycetoma, phaeohyphomycosis and keratomycosis. This fungus has not been previously listed among lens invaders.     

Steroid transformations with Exophiala jeanselmei var. lecanii-corni and Ceratocystis paradoxa

The fungi Exophiala jeanselmei var. lecanii-corni [IMI (International Mycological Institute) 312989, UAMH (University of Alberta Microfungus Collection and Herbarium) 8783] and Ceratocystis paradoxa (IMI 374529, UAMH 8784) have been examined for their potential in steroid biotransformation. The study has determined that E. jeanselmei var. lecanii-corni effected overall anti-Markovnikov hydration on dehydroisoandrosterone, and side-chain degradation on a variety of pregnanes. Both ascomycetes were found to carry out redox reactions of alcohols and ketones as well as 1,4 reduction of alpha,beta-unsaturated carbonyl systems.     

Growth of the black yeast Exophiala jeanselmei on styrene and styrene-related compounds

The black yeast Exophiala jeanselmei can grow on styrene as the sole source of carbon and energy in concentrations up to 0.36 mm. No growth is observed at higher styrene concentrations. Styrene oxidation is induced by styrene or styrene-related compounds, whereas glucose represses this styrene oxidation. E. jeanselmei shows a broad substrate specificity: various aromatic compounds are used as the sole source of carbon and energy. Styrene-grown cells can oxidize styrene, styrene oxide, phenylacetaldehyde, phenylacetic acid and 2-phenylethanol at a rate of 1.3 to 3.2 g O₂·min^–1·mg^–1 protein. A pathway for the degradation of styrene in E. jeanselmei is suggested.     

Purification and Characterization of Cyclohexanone 1,2-Monooxygenase from Exophiala jeanselmei strain KUFI-6N

Baeyer-Villiger cyclohexanone 1,2-monooxygenase (CHMO) was purified 17.1-fold from cell extracts of the fungus Exophiala jeanselmei grown on cyclohexanol to electrophoretically homogeneity by serial chromatographies. The molecular mass of the native enzyme was approximately 74 kDa by gel filtration and SDS-PAGE. Some enzymic characterizations were studied. The NH₂-terminal amino acid residues were Ala-Lys-Ser-Leu-Asp-Val-Leu-Ile-Val-Gly-Ala-Gly-Phe-Gly-Gly-Ile-Tyr-Gln-Leu-, with similarity to the bacterial CHMOs of FAD-binding and NADPH-dependent type Baeyer- Villiger monooxygenases.     

Purification and characterization of cyclohexanone 1,2-monooxygenase from Exophiala jeanselmei strain KUFI-6N

Baeyer-Villiger cyclohexanone 1,2-monooxygenase (CHMO) was purified 17.1-fold from cell extracts of the fungus Exophiala jeanselmei grown on cyclohexanol to electrophoretically homogeneity by serial chromatographies. The molecular mass of the native enzyme was approximately 74 kDa by gel filtration and SDS-PAGE. Some enzymic characterizations were studied. The NH2-terminal amino acid residues were Ala-Lys-Ser-Leu-Asp-Val-Leu-Ile-Val-Gly-Ala-Gly-Phe-Gly-Gly-Ile-Tyr-Gln-Leu-, with similarity to the bacterial CHMOs of FAD-binding and NADPH-dependent type Baeyer-Villiger monooxygenases.     

Taxonomy of Exophiala werneckii and its relationship to Microsporum mansonii

Study of the neotype culture of Exophiala werneckii (Cladosporium werneckii), as well as additional isolates, has shown that the yeast-like and hyphal conidiogenous cells are annellides. E. werneckii cannot be accommodated in Cladosporium, a genus characterized by catenulate holoblastic coanidia. E. werneckii and the dematiaceous hyphomycete that Castellani misidentified as Microsporum mansonii (Cladosporium mansonii) are two entirely different fungi. M. mansonii is considered to be a synonym of the Malassezia furfur since both names were used to describe in tissue the etiologic agent of pityriasis versicolor.     

Isolation of Exophiala jeanselmei associated with esophageal pathology — Three cases,laboratory and clinical features

Exophiala jeanselmei was isolated from three esophageal cultures over an 11-month period at Lutheran General Hospital. We believe this provides evidence for a new site of isolation, since previous reports of the organism's incidence were confined to skin and lung. Case 1 is an eight-year-old female with a three-year history of gagging and vomiting. Esophagoscopy revealed a mass biopsied as vegetable material. Case 2 is a 66-year-old retired male with a history of obesity, diabetes and spinal stenosis. Following back surgery, the patient developed odynophagia. Esophageal biopsies showed ulceration and bacterial colonies with no evidence of fungus. Case 3 is a 62-year-old male gardener who is also a nail biter. Esophagoscopy revealed a gastro-esophageal stricture with reflux and evidence of a hiatus hernia. Material biopsied was consistent with Barrett's esophagus and evidence of fungi was seen. The esophageal mass of case 1 and the esophageal brushings of case 2 and 3 grew E. jeanselmei. Aspiration, reflux, and mechanical disruption of the esophageal mucosa are possible predisposing factors in colonization of esophageal lesions by this ubiquitous, normally low virulence organism.     

Degradation of monohydroxylated benzoates by strain KUFI-6N of the yeast-like fungus Exophiala jeanselmei

Strain KUFI-6N of Exophiala jeanselmei, a cyclohexanol-utilizing yeast-like fungus, was found to grow on 3 isomers of hydroxybenzoate that functioned as the sole carbon sources. Distinct and highly specific hydroxylases converted p- and m-hydroxybenzoate to protocatechuate and o-hydroxybenzoate to catechol.     

Styrene metabolism in Exophiala jeanselmei and involvement of a cytochrome P-450-dependent styrene monooxygenase.

The yeast-like fungus Exophiala jeanselmei degrades styrene via initial oxidation of the vinyl side chain to phenylacetic acid, which is subsequently hydroxylated to homogentisic acid. The initial reactions are catalyzed by a NADPH- and flavin adenine dinucleotide-dependent styrene monooxygenase, a styrene oxide isomerase, and a NAD(+)-dependent phenylacetaldehyde dehydrogenase. The reduced CO-difference spectrum of microsomal preparations of styrene-grown cells shows a characteristic absorption maximum at 450 nm, which strongly suggests the involvement of a cytochrome P-450-dependent styrene monooxygenase. Inhibition of styrene monooxygenase activity in cell extracts by cytochrome P-450 inhibitors SKF-525-A, metyrapone, and CO confirms this assumption.     

Influence of the water content and water activity on styrene degradation by Exophiala jeanselmei in biofilters

 The performance at low water availability of styrene-degrading biofilters with the fungus Exophiala jeanselmei growing on perlite, the inert support, was investigated. E. jeanselmei degrades styrene at a water activity of 0.91–1. In biofilters, the styrene elimination capacity at a water activity of 0.91 is 5% of the maximal elimination capacity of 79 g m^-3 h^-1 (water activity 1). Application of dry air results in a rapid loss of styrene degradation activity, even at 40%–60% (w/w) water in the filter bed and at a water activity of 1. Humidification of the gas and an additional supply of water to the filter bed are necessary to maintain a high and stable styrene elimination capacity. Received: 7 August 1995 / Received revision: 29 January 1996 / Accepted: 5 February 1996     

Cutaneous Phaeohyphomycosis of the Right Hand Caused by Exophiala jeanselmei: A Case Report and Literature Review

Mycopathologia - Exophiala spp. is increasingly reported as a pathogen causing the cutaneous, subcutaneous or invasive infection. In this report, we present a case of cutaneous phaeohyphomycosis...     

Application of flow cytometry to differentiating Exophiala dermatitidis E. moniliae and E. jeanselmei from each other

We applied a flow cytometry apparatus (FCM) to differenciating Exophiala dermatitidis, E. moniliae and E. jeanselmei from each other. The wavelength of the argon laser emitted from the FCM was 488 nm and the aperture of nozzle from which the stream of fluid containing single cells was blown out was 100 m. By irradiating the stream with laser by either the forward light scatter (FLS) or by the perpendicular light scattr (PLS), we were able to get two pieces of informations. Histograms displayed by the FLS indicate the cell size, while dot displays by the PLS reflect the cell structure. As a result, E. dermatitidis was clearly differenciated from either E. moniliae or E. jeanselmei by their histograms by FLS. In addition, dot displays by the PLS differenciated E. moniliae from E. jeanselmei.In conclusion, flow cytometry is available for differenciating E. dermatitidis, E. moniliae and E. jeanselmei from each other.