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Lancet (London, England)Superficial fungal infections arise from a pathogen that is restricted to the stratum corneum, with little or no tissue reaction. In this Seminar, three types of... (Review)
Review
Superficial fungal infections arise from a pathogen that is restricted to the stratum corneum, with little or no tissue reaction. In this Seminar, three types of infection will be covered: tinea versicolor, piedra, and tinea nigra. Tinea versicolor is common worldwide and is caused by Malassezia spp, which are human saprophytes that sometimes switch from yeast to pathogenic mycelial form. Malassezia furfur, Malassezia globosa, and Malassezia sympodialis are most closely linked to tinea versicolor. White and black piedra are both common in tropical regions of the world; white piedra is also endemic in temperate climates. Black piedra is caused by Piedraia hortae; white piedra is due to pathogenic species of the Trichosporon genus. Tinea nigra is also common in tropical areas and has been confused with melanoma.
Topics: Diagnosis, Differential; Exophiala; Humans; Piedra; Tinea; Tinea Versicolor
PubMed: 15451228
DOI: 10.1016/S0140-6736(04)17107-9 -
Revista Da Sociedade Brasileira de... 1990
Topics: Brazil; Hair Diseases; Humans; Indians, South American; Piedra
PubMed: 2104453
DOI: 10.1590/s0037-86821990000200013 -
Mycologia 1971
Topics: Agar; Ascomycota; Biotin; Culture Media; Glucose; Hair; Humans; Mycoses; Peptones; Spores; Spores, Fungal
PubMed: 5563949
DOI: No ID Found -
IMA Fungus Jun 2011The phylogenetic placement of the monotypic dematiaceous hyphomycete genus Xanthoriicola was investigated. Sequences of the nLSU region were obtained from 11 specimens...
Molecular phylogenetic studies on the lichenicolous Xanthoriicola physciae reveal Antarctic rock-inhabiting fungi and Piedraia species among closest relatives in the Teratosphaeriaceae.
The phylogenetic placement of the monotypic dematiaceous hyphomycete genus Xanthoriicola was investigated. Sequences of the nLSU region were obtained from 11 specimens of X. physciae, which formed a single clade supported both by parsimony (91 %), and maximum likelihood (100 %) bootstraps, and Bayesian Posterior Probabilities (1.0). The closest relatives in the parsimony analysis were species of Piedraria, while in the Bayesian analysis they were those of Friedmanniomyces. These three genera, along with species of Elasticomyces, Recurvomyces, Teratosphaeria, and sequences from unnamed rock-inhabiting fungi (RIF), were all members of the same major clade within Capnodiales with strong support in both analyses, and for which the family name Teratosphaeriaceae can be used pending further studies on additional taxa.
PubMed: 22679593
DOI: 10.5598/imafungus.2011.02.01.13 -
The Indian Journal of Medical Research Feb 1994The antifungal activity of the two allylamine derivatives, naftifine and terbinafine was investigated against 25 clinical isolates of filamentous fungi by agar dilution...
The antifungal activity of the two allylamine derivatives, naftifine and terbinafine was investigated against 25 clinical isolates of filamentous fungi by agar dilution method. The isolates included Aspergillus sp. (10), Penicillium sp. (3), Cladosporium sp. (3), Rhizopus sp. (3), Paecilomyces sp. (2), Syncephalastrum sp. (1), Pyrenochaeta romeroi (1), Piedraia hortae (1) and Mortierella sp. (1). Terbinafine was found to be more active than naftifine, inhibiting 50 per cent (MIC 50) and 90 per cent (MIC 90) of the isolates of Aspergillus sp., at 0.1 and 0.5 microgram/ml respectively. The MIC 50s for the other isolates of hyalohyphomycetes, dematiaceous fungi and zygomycetes were 1, 5 and 100 micrograms/ml respectively. Naftifine inhibited 50 and 90 per cent of the Aspergillus sp., at 1 and 5 micrograms/ml, respectively. The MIC 50s for the other hyalohyphomycetes, dematiaceous fungi and zygomycetes were 5, 10 and 100 micrograms/ml respectively.
Topics: Allylamine; Antifungal Agents; Microbial Sensitivity Tests
PubMed: 8005641
DOI: No ID Found -
Mykosen Nov 1968
Topics: Ascomycota; Diagnosis, Differential; Hair; Humans; Microsporum; Mycoses; Trichophyton
PubMed: 5758284
DOI: No ID Found -
The Australasian Journal of Dermatology 1992Between June 1988 and December 1990, 1018 cases of superficial mycoses were investigated. Diagnosis was confirmed by microscopic examination in 503 cases and the causal...
Between June 1988 and December 1990, 1018 cases of superficial mycoses were investigated. Diagnosis was confirmed by microscopic examination in 503 cases and the causal agent was isolated in 490 cases. Tinea capitis accounted for 47.7% (92.5% in children below 10 years of age). The frequency of other clinical types in descending order was pityriasis versicolor 25.8%, tinea corporis 9%, onychomycosis 5.8%, tinea pedis 4%, intertrigo 3.9% and tinea cruris 2.8%. Erythrasma was encountered three times and mixed piedra and trichomycosis axillaris once. Microsporum canis was the commonest aetiological agent, responsible for 46.9% of ringworm infections. Malassezia furfur was the next most common agent (26.5%) followed by Candida albicans (8.6%) and Trichophyton violaceum (8.2%). Other species were found less frequently. T.simii was isolated from four cases of tinea cruris and one each of tinea capitis and tinea corporis, and Piedraia hortae and Trichosporon beigelii from a case of mixed piedra infection.
Topics: Adolescent; Adult; Aged; Child; Child, Preschool; Dermatomycoses; Female; Hair Diseases; Humans; Incidence; Infant; Male; Middle Aged; Mycoses; Nail Diseases; Saudi Arabia
PubMed: 1445094
DOI: 10.1111/j.1440-0960.1992.tb00053.x -
Journal of Medical and Veterinary... 1997The ultrastructural pattern of human hair infection by Piedraia hortae in vivo has been studied. The fungus destroyed the cuticular layers of the hair and was able to...
The ultrastructural pattern of human hair infection by Piedraia hortae in vivo has been studied. The fungus destroyed the cuticular layers of the hair and was able to penetrate deeply into the cortex. The course of destruction of human hair is described and compared with that produced by other fungi. Two well-defined types of cortex digestion were characterized. The slow rate of keratin degradation at the cortex together with the compacted stromatic organization of the nodules are argued as the main reasons that guarantee the long survival of the fungus, and therefore the chronic course of the disease. The data provided in this paper may help to understand the mechanisms that regulate the pathogenicity of this fungus.
Topics: Ascomycota; Brazil; Hair; Humans; Indians, South American; Microscopy, Electron; Microscopy, Electron, Scanning; Piedra
PubMed: 9061578
DOI: 10.1080/02681219780000791 -
Antonie Van Leeuwenhoek Nov 1997The elements present in the fungal structures produced by Piedraia hortae in vivo and in vitro have been investigated using electron microscopy X-ray microanalysis....
The elements present in the fungal structures produced by Piedraia hortae in vivo and in vitro have been investigated using electron microscopy X-ray microanalysis. Phosphorus, sulphur and calcium were detected in the nodules which developed on hair and on colonies on culture. These elements belong to the extracellular material that compacts the pseudoparenchymatous organization of the fungus. They may be present due to the capacity of melanin-like pigments to sequester ions and/or they may form part of the sulphates and phosphates of the polyanionic mucopolysaccharides that constitute the extracellular material. Environmental contaminants such as aluminium, silicon and iron were detected exclusively on the surface of the nodule. They were deposited or linked to the residual molecules produced during the breakdown of the cuticular keratin. The advantages of these techniques for elucidating the chemical nature of fungal structures are discussed.
Topics: Ascomycota; Electron Probe Microanalysis; Hair; Humans; Male; Microscopy, Electron, Scanning; Piedra
PubMed: 9442268
DOI: 10.1023/a:1000409311166 -
Mycoses 1991Black piedra or nodular trichomycosis is a superficial mycosis of the hair shaft, prevalent in the tropical areas of South America and Asia and caused by the fungus...
Black piedra or nodular trichomycosis is a superficial mycosis of the hair shaft, prevalent in the tropical areas of South America and Asia and caused by the fungus Piedraia hortai. By scanning electron microscopy the invasion of the hair keratin and the elimination of spores through canals was seen. Transmission electron microscopy showed a complex, well-organized microsystem, in which cement-producing hyphae constitute the pseudoparenchyma. Both sexual and asexual reproduction were found. Sexual reproduction gives rise to ascospores and asexual reproduction to arthrospores. The ascospores were found in thick-walled bags, the asci; the arthrospores, that undergo gemmation, are eliminated through canals, disseminating the disease.
Topics: Fungi; Hair; Hair Diseases; Humans; Microscopy, Electron; Microscopy, Electron, Scanning; Piedra
PubMed: 1824414
DOI: 10.1111/j.1439-0507.1991.tb00859.x