Study on Biological Charateristics of Microsporum Canis from Kerion Strain, Tinea Capitis Strains and Tinea Corporis Strains under Different Temperatures

Objective To observe morphological differences of Microsporum canis( M.canis) isolated from Kerion (1 strain), tinea capitis(2 strains) and tinea corporis (2 strains) at different temperatures. Methods The colony morphologies of routine culture were observed when all the M.canis strains(1 kerion strain, 2 tinea capitis strains and 2 tinea corporis strains) were cultured separately at 25℃ or 37℃; the structures of rims France culture were observed with microscope and the ultrastructures of these M.canis strains cultured on rice medium at 25℃ were observed with transmission electron microscope. Results Colony diameter: three weeks later, the colony diameters of tinea capitis strains, tinea corporis strains and kerion strain at 25℃ were 8.3cm, 7.1cm and 1.9cm, separately, and at 37℃ were 5.4cm, 5.0cm and 4.0cm, separately. Microscopic structure: the amounts of mycelia and conidia(containing 6~8 septations) of tinea capitis strains were largest at 25℃. The amounts of both mycelia and conidia of kerion strain were a little larger than the other two at 37℃. Morphology under transmission electron microscope: the kerion strain of M.canis showed that the spores were round with thick cell wall and clear organelle containing plentiful mitochondrion; the tinea capitis strains showed spores of shuttle shape with little thinner cell wall; and the tinea corporis strains showed shuttle shape with thick cell wall, and big nucleoli but unclear mitochondrion. Conclusion There are differences in colony diameter morphology and microscopic structures between kerion strain, tinea capitis strains and tinea corporis strains cultured at 25℃ or 37℃. Compared with tinea capitis strains and tinea corporis strains, the kerion strain spores have the thickest cell wall and obviously visible organelle with plentiful mitochondrion.