Study On The Effect Of PQ-LRP Gene Silencing On The Growth And Virlence Of Microsporum Canis & Surgery To Treat A Case Of Lymphocytic Infiltration Of The Skin

Objctive:1. Observing morphological differences between wild and interference strains.2. Observing the expression of m RNA of PQ-LRP in the liguid sabouraud with L- cysteine.3. Assessing the strength of virulence of guinea pigs infected.4. Investigate the effect of PQ-LRP gene on the growth and virulence of Microsporum canisMethod:1. Culture M. canis wild and interference strains in Sabouraud agar(SDA)separately under 25 ℃and observe the growth and morphology of the colonies.2. Culture M. canis wild and interference strains in rice medium under 25 ℃and observe the morphology of mycelia and condidia of M. canis by scanningelectron microscope and projection electron microscope.3. M. canis wild and interference strains were inoculated in guinea pigs separately to bulid the infective models. Histopathology was done in the infective models.4. The expression of m RNA of PQ-LRP in the liquid sabouraud with L-cysteine(0ug/m L,2 ug/m L,200 ug/m L) was detected before and after the PQ-LRP gene was silenced by realtime PCR.Results:1. colony morphology: The growth of interference strain was restricted afterculturing in SDA separately, 25℃,8 days and 16 days, mainly for the smaller colony diameter, less gas mycelium and wrinkles, more powder, lighten pigmentation;while the growth rate of no significant changes between them.2. The morphology of condidia by microscope: the morphology of condidia of interference strain form a significant change, large and small, irregular shape, bending;spore wall rough, wrinkled, incomplete; separate unlaw or absent; cell content is uneven, concentrated, vacuoles, missing.3. SEM: Large and small wild strain spores full, regular shape,and hyphae mellow,uniform thickness. While large interference strain condidium is was mainly for bend,not full, or even broken, spores with empty contents; small spores shrinkage;mycelium is not full, flat, uneven thickness and distortion.4. TEM: the large wild strain spores :wall smooth, cell contents plump, showing the nucleus, organelles. While interference strain was mainly for cell wall thickening,not smooth, broken wall, the nucleus and organelles reducing or even absent.5. Guinea pigs model: The interference strain didn’t infect the host more easily than the wild strain in the guinea pigs; There were more spores and intra-hair-shaft hypha in wild strains than in interference strain.The inflammatory granuloma was found in the guinea pig inoculated with wild strain while the inflammation was not obvious in the guinea pig inoculated with interference strain.6. The expression of PQ-LRP before and after interference:The expression of PQ-LRP of wild strain was upregulated in the higher concentration of L-cysteine medium.There was no similar result observed in interference strain.Conclusion:The growth and virulence of Microsporum canis was restricted when silencing the PQ-LRP. We suggested that PQ-LRP be the one of pathogenesis genes of Microsporum canis which leads to tinea capitis.