Study On Biological Charateristics And Genotyping Under Different Temperatures Of Microsporum Canis Kerion Strains, Tinea Capitis Strains And Tinea Corporis Strains

Microsporum canis also known as Microsporum lanosum， a kind of superficialfungal infections prevailing in the worldwide and increasing year by year, is hair theappearance of zoophile dermaterphyte commonly attached in cats and dogs with nopathogenicity, but it can infect human beings, especially children as their fragilesebaceous glands, low ability to avoid bacteria and easy to get infected when in closecontact with animals. M. Canis can cause tinea capitis, tinea corporis, tinea cruris,tinea pedis and sometimes onychomycosis, under certain conditions it can get deep intothe scalp and cause kerion, the popularization of pet keeping at home becomes one ofthe major bacteria for children scalp kerion.So far, the research on pathogenesis of Microsporum canis mainly focus on thetypes, activities and toxicity of keratinase it secreted. But still have little knowledgeabout the genotyping and morphology changes of the same bacteria which is obtainedfrom different part of body under different temperature. This article considered to studyon the kerion strains, tinea capitis strains and the tinea corporis strains of Microsporumcanis, and discuss about the relationship between the pathogenesis and the genotypingdifferences or morphology changes under different temperature. Provide the basis forfurther research on Microsporum canis from clinic and treatment side.Objective: To observe Morphological differences of Microsporum canis fromdifferent parts of the body under various temperatures and also to observe the genotypedifferences in order to provide a basis for further study of its pathogenesis.Method:1. Inoculate the M.canis kerion strains, tinea capitis strains, tinea corporis strainswhich were saved in lab to the plate separately under temperature25℃and37℃,culture them with the method of rims France culture and observe the growth and morphology of the colonies with microscope.2. TEM: Identified as kerion strains,tinea capitis strains, tinea corporis strains ofMicrosporum Canis, and were inoculated on rice medium and cultured at25°C underincubator. Seven days later, the colony is observed under the electron microscope formorphology.3. RAPD: The RAPD use the oligonucleotides which is composed randomly asprimer and proceed to PCR spread based on the DNA template from kerion strains,tinea capitis strains, tinea corporis strains of Microsporum Canis.Results:1.Colony morphology: The growth of tinea capitis strains of Microsporum canis isbetter than tinea corporis strains, and tinea corporis strains better than kerion strains at25℃.Kerion strains grows faster at37℃, and tinea capitis strains better than tineacorporis strains. The yellow pigment can be found on kerion strains, tinea capitis strainsand tinea corporis strains at25℃, but no pigment at37℃(see Figure1、2、3、4).2.Morphology under microscope: The fungus and conidia can be found on kerionstrains, tinea capitis strains and tinea corporis strains of Microsporum canis under twodifferent temperature; the differences among the three is that the amount of funguson tinea capitis strains and tinea corporis strains much than on kerion strains, whileinterleaving and separated them, the conidia is full at25℃;the amount of fungus onkerion strains much than on tinea capitis strains, while interleaving and separated them,the conidia is full; tinea corporis strains at the second place（see Figure5）.3.Morphology under electronic microscope: Kerion strains spore of MicrosporumCanis is plumpness with thick cell wall and organelle can be seen clearly with plentifulmitochondrion; the tinea capitis strains shows shuttle shape with little thinner cell walland organelle can be seen with mitochondrion; tinea corporis strains shows shuttleshape with thin cell wall unclear organelle and mitochondrion(see Figure6).4.RAPD: it shows that there is the same amplified band and the Microsporumcanis from different part have different bands and types(see Figure7).Conclusion1.There is discrepancy on the morphology of Microsporum canis kerion strains,tinea capitis beads, tinea beads which were cultured under temperature25°C and37°C.2.When the temperature is37℃, tinea capitis strains is more heat-resistant thantinea corporis strains,and tinea corporis strains is more heat-resistant than kerion strains.3.There is ultrastructure difference among kerion strains, tinea capitis strains and tinea corporis strains of Microsporum canis under electronic microscope, comparingwith tinea capitis strains and tinea corporis strains, the kerion strains spore pumplessthin cell wall and visible organelle an plentiful mitochondrion.4.RAPD can be used for DNA typing of Microsporum canis, different stains butsame type of Microsporum canis shows differences in fingerprints after electrophoresis.