Abstract
Four atypical isolates of Microsporum canis, three from humans and one from a cat, were obtained from North-West London. These and a further human isolate were compared with each other and with a typical isolate of the fungus. Immediately after isolation the atypical isolates were very labile, but were stabilised after a few subcultures from selected sectors. The stable forms differed from each other, but all had a tendency to brown rather than yellow pigmentation, to feathery submerged mycelium and to abnormal macroconidia. The macroscopic appearance and texture of the colonies depended on the density, orientation and branching pattern of the submerged mycelium.
In recent years similar brown, feathery forms of M. canis have been reported from monkeys but not from cats. It is suggested that all such isolates may be culturally stable forms of a very unstable strain, probably feline in origin, which has yet to be described.
Similar content being viewed by others
References
Ainsworth, G. C. 1971. Dictionary of the Fungi. Commonwealth Agricultural Bureaux, Farnham Royal.
Carter, G. R., E. S. Beneke & H. A. McAllister. 1970. Ringworm of the horse caused by an atypical form of Microsporum canis. J. Amer. Vet. med. Ass. 156: 1048–1050.
Conant, N. F. 1937. Studies in the genus Microsporum. III. Taxonomic studies. Arch. Derm. Syph. 36: 801–806.
Conant, N. F. 1941. A. statistical analysis of spore size in the genus Microsporum. J. invest. Derm. 44: 265–278.
Johnstone, K. I. & C. J. La Touche. 1956. Cultural characteristics of dysgonic strains of Microsporum canis Bodin. Trans. Brit. Mycol. Soc. 39: 442–448.
Klokke, A. H. & G. A. de Vries. 1963. Tinea capitis in chimpanzees caused by Microsporum canis Bodin 1902 resembling M. obesum Conant 1937. Sabouraudia 2: 268–270.
Ragot, Jacqueline & A. Clerivet. 1972. Etude des exigences nutritives de quatre souches de Trichophyton verrucosum. Sabouraudia 10: 284–297.
Sabouraud, R. 1910. Les Teignes. Masson et Cie, Paris, pp. 226, 242.
Scully, J. P. & A. M. Kligman. 1951. Coincident infection of a human and an anthropoid with Microsporum audouini. Arch. Derm. Syph. 64: 495–498.
Seeliger, H. P. R., W. Bisping & B. P. Brandt. 1963. Über eine Microsporum enzootie bei Kappen-Gibbons (Hylobates lar) verursacht durch eine variante von Microsporum canis. Mykosen 6: 61–68.
Taylor, R. T., F. C. Cadigan & V. Chiacumpa. 1973. Infections among Thai gibbons and humans caused by atypical Microsporum canis. Lab. Animal Sci. 23: 226–231.
Walker, Jacqueline. 1950. Variation in Microsporum canis and Microsporum audouinii. Br. J. Derm. 62: 395–401.
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
English, M.P., Tucker, W.D.L. Atypical strains of Microsporum canis. Mycopathologia 63, 113–120 (1978). https://doi.org/10.1007/BF00441257
Issue Date:
DOI: https://doi.org/10.1007/BF00441257