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PubMed1995

Mitochondrial DNA analysis of Exophiala spinifera.

Restriction fragment length polymorphism (RFLP) of mitochondrial DNA (mtDNA) was examined in 36 isolates of Exophiala spinifera (8 isolates from Brazil, 9 from China, 15 from Columbia, 1 from the United States and 2 from Venezuela). E. spinifera isolates displayed a high degree of mtDNA diversity in RFLP patterns and were clustered into six genetically heterogeneous groups (Group 1 through Group 6). Isolates of Group 2 including the type strain seemed to have a worldwide distribution. RFLP patterns of E. spinifera were also distinct from those of other dematiaceous fungi, such as E. jeanselmei, E. moniliae, E. dermatitidis, Fonsecaea pedrosoi, Cladosporium carrionii and Phialophora verrucosa. These results indicate that E. spinifera may be a taxonomic complex and that RFLP patterns will be useful in the identification, typing and epidemiology of the E. spinifera variants.

DNA, Fungal↗

PubMed1993

A preliminary survey of cycloheximide-resistant airborne fungi in Turin, Italy.

Numbers and type of the cycloheximide-resistant part of the aerially transmitted mycoflora of Turin were studied. Samples from three areas characterized by differing human usage were taken in the first week of March. During each sampling, 12 m3 of air were aspirated, using an one-stage volumetric sieve sampler. Fifty-two mesophilic species and eight thermotolerant were isolated. Propagule load varied from 2.92 to 120.31 cfu m-3. The following species appear not to have been reported previously from air samples: Ascotricha bosei, Blastobotrys navarrensis, Cryptendoxyla hypophloia, Chrysosporium an. gymnoascus demonbreunii, Ophiostoma piceae, Penicillium vulpinum, Phialophora mustea, Rhinocladiella pedrosoi, Scopulariopsis croci, S. komngii and Sesquiallium candelabrum. A significant number of potential opportunistic pathogens was isolated.

Air Microbiology↗

PubMed2005

Fungal communities in mycorrhizal roots of conifer seedlings in forest nurseries under different cultivation systems, assessed by morphotyping, direct sequencing and mycelial isolation.

Fungi colonising root tips of Pinus sylvestris and Picea abies grown under four different seedling cultivation systems were assessed by morphotyping, direct sequencing and isolation methods. Roots were morphotyped using two approaches: (1) 10% of the whole root system from 30 seedlings of each species and (2) 20 randomly selected tips per plant from 300 seedlings of each species. The first approach yielded 15 morphotypes, the second yielded 27, including 18 new morphotypes. The overall community consisted of 33 morphotypes. The level of mycorrhizal colonisation of roots determined by each approach was about 50%. The cultivation system had a marked effect on the level of mycorrhizal colonisation. In pine, the highest level of colonisation (48%) was observed in bare-root systems, while in spruce, colonisation was highest in polyethylene rolls (71%). Direct internal transcribed spacer ribosomal DNA sequencing and isolation detected a total of 93 fungal taxa, including 27 mycorrhizal. A total of 71 (76.3%) fungi were identified at least to a genus level. The overlap between the two methods was low. Only 13 (13.9%) of taxa were both sequenced and isolated, 47 (50.5%) were detected exclusively by sequencing and 33 (35.5%) exclusively by isolation. All isolated mycorrhizal fungi were also detected by direct sequencing. Characteristic mycorrhizas were Phialophora finlandia, Amphinema byssoides, Rhizopogon rubescens, Suillus luteus and Thelephora terrestris. There was a moderate similarity in mycorrhizal communities between pine and spruce and among different cultivation systems.

Ascomycota↗

PubMed2006

Survey and significance of filamentous fungi from tap water.

Fungi in drinking water are involved in the production of tastes and odours in water. Health problems are possible, originating from mycotoxins, animal pathogens and allergies. This report concerns the surveillance of mesophilic fungi in tap water and assessment of their potential for causing problems. The methods for the determination of the filamentous fungi (ff) were filtering, swabbing and baiting. Tap water, half-strength corn meal, neopeptone-glucose rose Bengal aureomycin (NGRBA) and oomycete selective agars for the enumeration of colony forming units (cfu) were used. Samples were taken consecutively over 16 months. Filtration and NGRBA gave the highest ff counts. A total of 340 taxa were isolated. There appeared to be a negative correlation between bacterial and yeast (b/y) and ff counts. Highest counts were found in winter months for ff and in the warmer months for b/y. Penicillium (40.6%) and Acremonium (38.8%) were the most frequently isolated ff. There was a difference in the pattern of isolation of the key taxa with season: penicillia predominated in early summer and Acremonium in winter. P. expansum was isolated in high numbers in May 2004. This species is associated with the production of the mycotoxin patulin and the odour secondary metabolite geosmin. P. brevicompactum was detected throughout the sampling period and is known to produce the immunosuppressive drug mycophenolic acid. Acremonium is associated with ocentol production which is responsible for bad tastes and flavours. The remaining taxa were Phialophora sp. (4.1%), Cladosporium sp. (3.5%), Rhizopus stolonifer (2.9%), Chaetomium sp. (0.6%), Alternaria sp. (0.3%), Aspergillus sp. (0.3%), mycelia sterilia (2.6%) and unidentified (6.2%). It is emphasised that few Aspergillus and no Fusarium strains were isolated. Rhizopus stolonifer was obtained. However, none of the fungi isolated at mesophilic temperature used could be described as being involved with pathogenicity per se.

Colony Count, Microbial↗

PubMed2001

Liquid chromatography study of pyrene degradation by two micromycetes in a freshwater sediment.

Pyrene biodegradation in a freshwater sediment without fungi supply, or inoculated with two sediment micromycetes, Mucor racemosus var. sphaerosporus and Phialophora alba was studied after 0, 5, 13, 28, 60 and 90 days. The influence of glucose addition was estimated, and a liquid chromatographic method for simultaneous quantitative determination of residual anthracene, fluoranthene and pyrene in the sediment was developed. Samples with PAHs were extracted in Soxhlet with ethyl acetate, and LC analysis was performed on a 5 microm Supelcosil column (150 x 4.6 mm I.D.) with gradient elution (2 ml min(-1)) of acetonitrile-water and UV detection at 254 nm. Recoveries of anthracene, fluoranthene and pyrene were 90.3%+/-1.1%, 93.2%+/-0.9% and 90.42%+/-1.9%, respectively, without interference. The native sediment microorganisms (with or without glucose added) have shown 35% pyrene degradation and sediment with glucose inoculated by the strains revealed 40%.

Biodegradation, Environmental↗

PubMed2000

Biodegradation of pyrene by sediment fungi.

Micromycetes were isolated from PAHS-contaminated sediment and identified. They were investigated for pyrene degradation (10 mg l-1) in liquid synthetic medium for two days. Among the 41 strains isolated, 10 highly degraded pyrene (> 2.4 mg g-1 dry weight): two Zygomycetes (Mucor racemosus, M. racemosus var. sphaerosporus), 6 Deuteromycetes (Gliocladium virens, Penicillium simplicissimum, P. janthinellum, Phialophora alba, P. hoffmannii, Trichoderma harzianum), a Dematiaceae (Scopulariopsis brumptii) and a Sphaeropsidale (Coniothyrium fuckelii). Zygomycetes appeared as one of the most efficient taxonomic groups, especially with Mucor racemosus. Penicillium crustosum was the only strain that did not degrade pyrene. Among the 10 fungi which were performant for pyrene degradation, nine were not yet reported in the literature and showed a real value for PAH remediation.

Aspergillus↗

PubMed2003

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 amplicon from only H. werneckii. This primer set did not amplify DNAs of 42 other related dematiaceous species, including the medically important dematiaceous fungi Cladophialophora carrionii, Fonsecaea pedrosoi, Phialophora verrucosa, and Exophiala dermatitidis, and eight species of medically important yeasts, including Candida (C.) albicans, C. dublinensis, C. glabrata, C. parapsilosis, C. tropicalis, Cryptococcus neoformans var. neoformans, Malassezia furfur, and Trichosporon asahii var. asahii. PCR with this primer set may be a useful technique for rapid identification of H. werneckii.

Base Sequence↗

PubMedDate not supplied

Faeriefungin: a new broad-spectrum antibiotic from Streptomyces griseus var. autotrophicus.

Faeriefungin, a polyol polyene macrolide lactone antibiotic, was isolated from the mycelium of Streptomyces griseus var. autotrophicus, MSU-32058/ATCC 53668, collected from the soil sample of a fairy ring in an old lawn in Lansing, Michigan. Faeriefungin has some properties similar to the previously reported polyene macrolides, mycoticin and flavofungin, but possesses different physiochemical and biological properties. Aspergillus, Fusarium, Microsporum, Trichophyton, and Alternaria spp. were completely inhibited by faeriefungin at 3.2 micrograms/ml, Candida spp. at 5.5 micrograms/ml, and Pythium, Phialophora, Leptosphaeria spp., and some selected Gram-negative penicillin-resistant strains of Neisseria gonorrhoeae at 16.0 micrograms/ml. At a concentration of 100 ppm, it caused 100% mortality of mosquito larvae (Aedes aegypti, Rockefeller strain) and free-living nematodes (Panagrellus redivivus). Unlike the related polyene macrolides, faeriefungin is crystalline and stable with broad-spectrum antimicrobial and insecticidal activity. Preliminary cytotoxicity studies with human erythrocytes and rat liver epithelial cells indicated that faeriefungin and amphotericin B have comparable toxicity. Solution nmr study has indicated that faeriefungin is a mixture of two compounds, faerifungins A [1] and B [2], and that they differ in the attachment of a H or an Me at C-33.

Acetylation↗

PubMed2001

In vitro antifungal activities of voriconazole and reference agents as determined by NCCLS methods: review of the literature.

Voriconazole (VfendTM) is a new triazole that currently is undergoing phase III clinical trials. This review summarizes the published data obtained by NCCLS methods on the in vitro antifungal activity of voriconazole in comparison to itraconazole, amphotericin B, fluconazole, ketoconazole and flucytosine. Voriconazole had fungistatic activity against most yeasts and yeastlike species (minimum inhibitory concentrations [MICs] < 2 microg/ml) that was similar or superior to those of fluconazole, amphotericin B, and itraconazole. Against Candida glabrata and C. krusei, voriconazole MIC ranges were 0.03 to 8 and 0.01 to > 4 microg/ml, respectively. For four of the six Aspergillus spp. evaluated, voriconazole MICs (< 0.03 to 2 microg/ml) were lower than amphotericin B (0.25 to 4 microg/ml) and similar to itraconazole MICs. Voriconazole fungistatic activity against Fusarium spp. has been variable. Against E oxysporum and F. solani, most studies showed MICs ranging from 0.25 to 8 microg/ml. Voriconazole had excellent fungistatic activity against five of the six species of dimorphic fungi evaluated (MIC90s < 1.0 microg/ml). The exception was Sporothrix schenckii (MIC90s and geometric mean MICs > or = 8 microg/ml). Only amphotericin B had good fungistatic activity against the Zygomycetes species (voriconazole MICs ranged from 2 to > 32 microg/ml). Voriconazole showed excellent in vitro activity (MICs < 0.03 to 1.0 microg/ml) against most of the 50 species of dematiaceous fungi tested, but the activity of all the agents was poor against most isolates of Scedosporium prolificans and Phaeoacremonium parasiticum (Phialophora parasitica). Voriconazole had fungicidal activity against most Aspergillus spp., B. dermatitidis, and some dematiaceous fungi. In vitro/in vivo correlations should aid in the interpretation of these results.

Amphotericin B↗

PubMed2003

Non-conventional methods for the control of post-harvest pear diseases.

Pears are highly perishable products, especially during the post-harvest phase, when considerable losses can occur. Among the fungal diseases, blue mold caused by Penicillium expansum, grey mould caused by Botrytis cinerea, Mucor rot caused by Mucor piriformis are common on pear fruits. Other (weak) pathogens like Phialophora malorum, Alternaria spp., and Cladosporium herbarum tend to infect wounds and senescent fruits. A post-harvest fungicide treatment can reduce decay but effectiveness decreases with the appearance of resistant strains. There is a clear need to develop new and alternative methods of controlling post-harvest diseases. The emerging technologies for the control of post-harvest fungal diseases are essentially threefold: application of antagonistic microorganisms, application of natural antimicrobial substances and application of sanitizing products. Two biological control products, Aspire (Candida oleophila I-182) (Ecogen, Langhorne, PA, USA) and Bio-Save 110 (Pseudomonas syringae) (EcoScience, Worcester, MA, USA; formerly Bio-Save 11) are currently registered in the USA for post-harvest application to pears. Other potential biocontrol agents have been isolated from fruit and shown to suppress post-harvest decay in pear. It is important that evaluation of these microorganisms be carried out in a product formulation because the formulation may improve or diminish antagonistic efficacy depending on the concentration of chemical product and the duration of exposure to the treatment. Plants produce a large number of secondary metabolites with antimicrobial effects on post-harvest pathogens. Detailed studies have been conducted on aromatic compounds, essential oils, volatile substances and isothiocyanates, with encouraging results. In particular, allyl-isothiocyanate used as a volatile substance, controls blue mould in 'Conference' and 'Kaiser' pear inoculated with a thiabendazole-resistant strain. Sanitizing products such as chlorine dioxide, peracetic acid and ozone have considerable fungicidal activity against P. expansum and M. piriformis, depending on the concentration of chemical product and the duration of exposure to the treatment. Sanitizing solutions can be integrated easily with current handling and storage practices; however, further research is required to define the effective procedures better.

Antibiosis↗

PubMed2002

Subcutaneous pheohyphomycosis in India--a case report and review.

BACKGROUND: Pheohyphomycosis is a rare infection caused by dematiaceous fungi, affecting the skin and subcutis, paranasal sinuses, or central nervous system. METHODS: A case of subcutaneous pheohyphomycosis in the lumbar region is reported. The Indian literature on subcutaneous pheohyphomycosis is also reviewed. RESULTS: In India, 23 patients with subcutaneous pheohyphomycosis have been reported, distributed throughout the country in a belt from north to south, sparing the eastern and western regions. The age of the patients ranged from 3 to 60 years, with a male to female ratio of 1.3 : 1. A relatively early age of onset was observed. A history of prior injury was recalled by five patients. The lower extremities were involved in eight cases, upper extremities in five, gluteal region in two, lumbar area and submandibular area in one, face in two and disseminated disease was seen in four cases. Three of these cased died during follow up. Osteomyelitis was observed in two cases, hepatosplenomegaly in one, and lymph node involvement in two. Carcinomatous change developed in a long-standing lesion of 33 years. Thirteen species from seven genera of dematiaceous fungi were isolated. Phialophora dermatidis was the most common isolate. CONCLUSIONS: Indian patients with subcutaneous pheohyphomycosis are afflicted at an earlier age. Exophiala dermatidis seems to be associated with more fatalities. Treatment with newer azoles seems promising, and excision alone or combined with azoles is a good therapeutic modality.

Chromoblastomycosis↗

PubMed1999

Dematiaceous fungal pathogens: analysis of ribosomal DNA gene polymorphism by polymerase chain reaction-restriction fragment length polymorphism.

Restriction fragment length polymorphisms (RFLP) of ribosomal gene small subunit (SSU rDNA) and internal transcribed spacer (ITS) regions was examined in 12 isolates of dematiaceous agents of chromoblastomycosis and phaeohyphomycosis. The amplicon length of the fragment ITS1-ITS4, comprising the 5.8 rDNA and ITS1-ITS2 spacers, ranged in size from 620 to 690 bp. This result indicated a polymorphism of size in this region. Additionally the RFLP profiles showed a high degree of inter- and intra-specific variability. In contrast, the SSU rDNA amplification, using NS1-NS2 primers, originated a fragment of approximately 570 bp and its restriction profile proved to be well conserved among the species studied and was clustered into only two genetically heterogeneous groups, the first one formed by Fonsecaea pedrosoi and Fonsecaea compacta and the second one formed by Cladophialophora (Cladosporium) carrionii, Cladophialophora (Xylohypha) bantiana, Phialophora verrucosa and Rhinocladiella species.

Base Sequence↗

PubMed2001

Chromoblastomycosis: a review of 100 cases in the state of Rio Grande do Sul, Brazil.

BACKGROUND: If not diagnosed earlier, chromoblastomycosis has a chronic evolutional course that may cause several problems, such as difficulty in managing therapy because of the recrudescent character of the disease, potential association with the growth of epidermoid carcinoma in affected regions, and poor quality of life and work incapacity to the patient. Although infrequent, new cases are reported in the state of Rio Grande do Sul every year, ratifying the necessity for further studies on this disease. OBJECTIVE: The purpose of this study was to review clinical features and response to therapy in patients with chromoblastomycosis and present data on the demography and history of this disease in the state of Rio Grande do Sul, Brazil. METHODS: We reviewed case records of 100 patients with skin lesions caused by chromoblastomycosis, who were treated between 1963 and 1998. The cases were confirmed by the histopathologic and mycologic analyses made by the Dermatology Service of the Universidade Federal do Rio Grande do Sul at the Santa Casa de Misericórdia Hospital. RESULTS: There was a predominance of male patients (4:1) and of white farmers whose ages ranged from 50 to 59 years, with lesions on their lower limbs. Most of them were from the northern regions of the state. The average time between the appearance of the disease and medical diagnosis was 14 years. The verrucous type proved to be the most frequently reported lesion (53%). Thorn wounds were associated with the disease in 16% of the cases. Lesions uncommon to some parts of the body were also reported. In two of the cases, cutaneous lesions caused by paracoccidioidomycosis and chromoblastomycosis were found in the same patient. Epidermoid carcinoma was found in the same parts of the body affected by chromoblastomycosis. Eumycotic mycetoma and chromoblastomycosis were associated. Fonsecaea pedrosoi was found in 96% of the cases, and Phialophora verrucosa in 4% of the cases. CONCLUSION: In our study, we observed a predominance of cases in the regions of Missões and Alto Uruguay, followed by the upper and lower northeastern slopes and the lowlands. Severe cases of chromoblastomycosis with intense skin involvement (eg, lesions with carcinoma) were observed. Statistical analysis showed recrudescence of the disease in 43% of cases despite the treatment used.

Adult↗

PubMedDate not supplied

Chronic mucocutaneous candidosis and other superficial and systemic mycoses successfully treated with ketoconazole.

Four patients with chronic mucocutaneous candidosis from early infancy were treated successfully with ketoconazole given orally. All thrush lesions were clinically and mycologically cured within a few days of treatment with 100-400 micrograms of ketoconazole daily; skin lesions were cured within a few weeks, and nails were cured after about three months of treatment. Delayed cutaneous hypersensitivity to candidin was acquired by the third month. Cellular and humoral immunologic responses were related to the suppression of Candida albicans antigen by ketoconazole. A fifth patient with chronic lingual granuloma due to C. albicans improved considerably. Favorable results also were seen in individual patients with oral and disseminated histoplasmosis due to Histoplasma capsulatum; laryngeal, pulmonary, and hepatic disease with continuous fever also due to H. capsulatum; pulmonary histoplasmosis due to Histoplasma duboisii; cutaneous sporotrichosis; and cutaneous blastomycosis due to Blastomyces dermatitidis and in three patients with favus due to Trichophyton schoenleinii; six of seven patients with tinea capitis due to Trichophyton violaceum (after one month of treatment); and four patients with infections due to Petriellidium boydii, Phialophora pedrosoi, or Beauveria species. All patients responded rapidly to 400 mg of ketoconazole per day given orally. Only the patient with hepatic histoplasmosis required 800 mg per day. Measurements of ketoconazole in the serum during treatment were useful in the evaluation of therapy.

Adolescent↗

PubMed1998

In-vitro activity of voriconazole, itraconazole and amphotericin B against filamentous fungi.

The in-vitro fungistatic and fungicidal activities of voriconazole were compared with those of itraconazole and amphotericin B. MICs for 110 isolates belonging to 11 species of filamentous fungi were determined by a broth microdilution adaptation of the method recommended by the National Committee for Clinical Laboratory Standards. Minimum lethal concentrations (MLCs) of the three antifungal agents were also determined. The MIC ranges of the three compounds were comparable for Aspergillus flavus, Aspergillus fumigatus, Cladophialophora bantiana and Exophiala dermatitidis. Voriconazole and itraconazole were more active than amphotericin B against Fonsecaea pedrosoi, but the two azole agents were less active against Sporothrix schenckii. Voriconazole was more active than itraconazole or amphotericin B against Scedosporium apiospermum, but less active than the other two agents against two mucoraceous moulds, Absidia corymbifera and Rhizopus arrhizus. Voriconazole and amphotericin B were more active than itraconazole against Fusarium solani. With the exception of S. apiospermum, all the moulds tested had MLC50 values of < or =2 mg/L and MLC90 values of < or =4 mg/L against amphotericin B. Voriconazole and itraconazole showed fungicidal effects against five of the 1 1 moulds tested (A. flavus, A. fumigatus, C. bantiana, E. dermatitidis and F. pedrosoi) with MLC90 values of < or =2 mg/L. In addition, voriconazole was fungicidal for Phialophora parasitica. Our results suggest that voriconazole could be effective against a wide range of mould infections in humans.

Amphotericin B↗

PubMed2005

High specificity generally characterizes mycorrhizal association in rare lady's slipper orchids, genus Cypripedium.

Lady's slipper orchids (Cypripedium spp.) are rare terrestrial plants that grow throughout the temperate Northern Hemisphere. Like all orchids, they require mycorrhizal fungi for germination and seedling nutrition. The nutritional relationships of adult Cypripedium mycorrhizae are unclear; however, Cypripedium distribution may be limited by mycorrhizal specificity, whether this specificity occurs only during the seedling stage or carries on into adulthood. We attempted to identify the primary mycorrhizal symbionts for 100 Cypripedium plants, and successfully did so with two Cypripedium calceolus, 10 Cypripedium californicum, six Cypripedium candidum, 16 Cypripedium fasciculatum, two Cypripedium guttatum, 12 Cypripedium montanum, and 11 Cypripedium parviflorum plants from a total of 44 populations in Europe and North America, yielding fungal nuclear large subunit and mitochondrial large subunit sequence and RFLP (restriction fragment length polymorphism) data for 59 plants. Because orchid mycorrhizal fungi are typically observed without fruiting structures, we assessed fungal identity through direct PCR (polymerase chain reaction) amplification of fungal genes from mycorrhizally colonized root tissue. Phylogenetic analysis revealed that the great majority of Cypripedium mycorrhizal fungi are members of narrow clades within the fungal family Tulasnellaceae. Rarely occurring root endophytes include members of the Sebacinaceae, Ceratobasidiaceae, and the ascomycetous genus, Phialophora. C. californicum was the only orchid species with apparently low specificity, as it associated with tulasnelloid, ceratobasidioid, and sebacinoid fungi in roughly equal proportion. Our results add support to the growing literature showing that high specificity is not limited to nonphotosynthetic plants, but also occurs in photosynthetic ones.

Base Sequence↗

PubMed1989

Physiological characteristics of environmental isolates of pathogenic dematiaceous fungi.

A total of 39 environmental isolates of pathogenic dematiaceous fungi (Fonsecaea pedrosoi: 14 isolates, Phialophora verrucosa: 6, Cladosporium carrionii: 9, Exophiala jeanselmei: 2, Ramichloridium subulatum: 6, Cladosporium tenuissimum: 1 and Phaeoisaria clematidis: 1) were evaluated for their various physiological characteristics including the ability to produce extracellular enzymes. Significant physiological characteristics included the ability of isolates of all the species except C. tenuissimum to decompose tyrosine, lyse human red blood cells, conversion of R. subulatum from filamentous to yeast form when cultured on Czapek-Dox agar and also on blood agar and the growth of C. tenuissimum on Sabouraud dextrose agar incorporating 3.6 M NaCl. Isolates of all the species except those of C. carrionii produced lipase, while only the isolates of P. verrucosa, E. jeanselmei and Ph. clematidis were positive for phospholipase.

Mitosporic Fungi↗

PubMedDate not supplied

The medically important dematiaceous fungi and their identification.

Dematiaceous fungi include a large group of organisms that are darkly pigmented (dark brown, olivaceous, or black). In most cases the pigment is melanin, and specifically, dihydroxynaphthalene melanin. The diseases produced include chromoblastomycosis, eumycotic mycetoma, and phaeohyphomycosis. Phaeohyphomycosis is a new classification for a diverse group of previously known entities grouped together on the basis of finding dematiaceous hyphal and/or yeast-like forms in tissue; tissue involvement may be superficial, cutaneous and corneal, subcutaneous, or systemic. Identification of these fungi is based mostly upon morphology. Important structures include annellides (Phaeoannellomyces, Exophiala), phialides (Phialophora, Wangiella), adelophialides (Phialemonium without collarettes, Lecythophora with collarettes), differentiation of conidiophores (Xylohypha versus Cladosporium) and conidial hilum, septation and germination (Bipolaris, Drechslera, Exserohilum). Useful laboratory tests include the 12% gelatin test (controversial), nitrate assimilation (W. dermatitidis is negative, most other species are positive), and determination of temperature maxima (especially 37 degrees C for E. jeanselmei, 40 degrees C for W. dermatitidis and B. spicifera, 42 degrees C for X. bantiana, and 45 degrees C for Dactylaria constricta var. gallopava and Scedosporium inflatum).

Fungi↗