Hyphal Fusions in Dermatophytes

Davidson, A. M.; Dowding, Eleanor Silver; Buller, A. H. Reginald

doi:10.1139/cjr32-001

Cited by 28 publications

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“…The description of new species has progressed continuously, usually upon slight differences in the gross appearance of cultures on Sabouraud's standard media, rather than upon the morphology of microscopic organs. Davidson, Dowding and Buller (1932) introduced a new criterion of specific differentiation among the dermatophytes which in time may have the effect of disciplining the multitude of species to which ringworm is attributed. These writers regarded the fusions or anastomoses between the vegetative hyphae of the mycelium as significant.…”

Section: The Dmmatophytesmentioning

confidence: 99%

The Dermatophytes

Gregory¹

1935

Biological Reviews

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Summary. The dermatophytes are a group of fungi which parasitise animals by invading the keratinised portions of the epidermis. They appear to be unable to attack internal organs and are apparently dermatotropic. Ringworm in its various forms is a primary localised dermatophyte infection. The concept of the activity of the dermatophytes has been enlarged by the recognition that they can also determine secondary non‐parasitic skin lesions on distant parts of the body. Several records of isolations of these fungi from the blood indicate that spores may be carried from the primary lesion to other parts of the body by means of the blood stream. Hairs infected by certain species of dermatophytes show a green fluorescence in ultra‐violet light not possessed by uninfected hairs. This phenomenon can be utilised to detect infected hairs among normal ones. The fluorescence is due to a water‐soluble substance which can be extracted from infected hairs. The wealth of spores and other organs produced in cultures on certain animal and vegetable media suggests that these fungi have a natural saprophytic stage in their life history. It is also possible that the saprophytic stage occurs on naturally infected hairs after they fall from the animal body. The dermatophytes in culture are subject to variation. The particular irreversible degenerative mutation known as “pleomorphism” can take place in isolates derived from either a single aleuriospore or a single fuseau. Pleomorphism appears to be due to a toxic action on the organism of monosaccharides and disaccharides. In media containing polysaccharides pleomorphism is not observed. Asci have been reported by several workers. While certain of these records appear to be unsubstantiated, others point to an affinity between the dermatophytes and the Gymnoascaceae. The classification of the 200 or more species is in a state of chaos. The newer systems show few advantages over Sabouraud's revised classification.

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Section: The Dmmatophytesmentioning

confidence: 99%

The Dermatophytes

Gregory¹

1935

Biological Reviews

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“…Obwohl aile bisherigen Versuche aus diesen Hefen wieder Fruchtkorperstrukturen zu erhalten -wie dies bei A. lycoperdoides gelang -, fehl schlugen, glaube ich, in der nachgewiesenen vegetativen Anastomosenbildung ein gutes Kriterium fiir die Konspezifitat von Hefen und Hyphen zu haben (vgl. REINHARDT 1892, DAVIDSON et al 1932, VAN UDEN 1951, KEMP 1970, 1975, BURPEE et al 1980, AGERER et al 1980. Vegetative Anastomosen wurden auf Objekttragerkulturen zwischen dem aus Hefekulturen hervorgegangenen Pseudomycel und den Hyphen eines haploiden Mycel- System-inherenten genetischen Isolationsmechanismus eine entscheidende Rolle fur das Verstandnis einer sympatrischen Artbildung bei Pilzen zukommt (vgl.…”

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