马拉色菌局部感染豚鼠致病性研究

Study on local pathogenicity of malassezia in guinea pig

目的研究马拉色菌局部感染豚鼠的致病情况。方法皮内注射马拉色菌菌悬液建立糠秕马拉色菌、合轴马拉色菌、斯洛菲马拉色菌局部感染的三组豚鼠动物模型,观察其局部反映、病理改变及超微结构变化。结果豚鼠局部皮肤注射菌悬液后,出现红色炎性丘疹,每组左右侧炎性丘疹直径值在注射后1d及3d后比较,差异均有统计学意义(t分别=2.11、2.60、2.31、2.62、2.51、3.15,P均<0.05)。三组间左侧炎性丘疹直径值在注射后3d后比较,差异均有统计学意义(F=1.52,P均<0.05)。注射后2周三组内左右侧感染灶马拉色菌已清除病灶数的比值的比较运用Fisher's精确概率检验,差异亦均有统计学意义(P均<0.05)。病灶内可见炎细胞浸润及肉芽肿改变等病理变化。透射电镜下观察发现巨噬细胞内马拉色菌孢子细胞壁变形及穿孔,细胞内结构改变或消失。结论豚鼠局部皮肤感染马拉色菌的炎症反应程度与马拉色菌的数量相关,不同菌种感染引起的炎症反应之间有差异。豚鼠局部皮肤感染灶内菌体可被噬菌细胞清除,清除实践与感染灶内菌体数量呈正相关。感染灶内可见肉芽肿改变。

Objective To study local pathogenicity of malassezia in guinea pig. Methods Guinea pig animal model of local infection with M. furfur, M. sympodialis and M. sloofiae was made to explore the pathogenesis, histopathological changes and uhrastructure changes of local focuses. Results Local focuses appeared red inflammatory papula after injecting malassezia suspensions. The diameter of both sides papula of each group had significant difference on 1st and 3rd days （t=2.11,2.60,2.31,2.62,2.51,3.15,P〈0.05）. The papula diameter of left focuses among three groups had significant difference on 3rd days （F=1.52,P〈0.05）. The ratio of focus malassezia eliminated had significant difference in both sides focuses of each group on 2nd week by Fisher＇s exact test （P〈0.05）. Inflammatory cells infiltration and granuloma could be observed in focuses. Detecting by transmission electron microscope, the malassezia in macrophage could be observed cell distortion, cell wall perforation, the inner structural change or disappearance. Conclusions The inflammatory reaction degrees in guinea pig local skin＇s focus are related with the malassezia quantities in focuses. The inflammatory reaction degrees are also related with the malassezia species. The malassezia in focus of infection can be eliminated by phagocyte. The time of eliminating malassezia has a direct correlation with quantities of malassezia in focus of infection. The changes of granuloma can be observed in focus of infection.