马拉色菌与花斑癣色素改变的相关性初探

目的探讨马拉色菌与花斑癣皮疹色素改变及色氨酸产色三者之间的关系.方法从花斑癣患者皮损分离马拉色菌株,采用国际通用的生化鉴定方法鉴定,然后在不同浓度L-色氨酸的培养基上培养7 d,观察产色反应.结果每个菌种均有产色反应阳性和阴性菌株,产色反应阳性菌株更易引起皮损色素沉着(P＜0.005),且产色反应阳性标本颜色按色氨酸浓度递减而变淡.结论菌株的产色反应与马拉色菌的种属分类无必然的联系,色氨酸参与了马拉色菌产色反应.

Preliminary Study on the Pigmentogenesis of Malassezia in Pityriasis Versicolor

Objective To investigate the relationship among the pigment change in the skin lesions of pityriasis versicolor, the tryptophan-induced pigment production, and the 7 species of Malassezia. Methods 171 strains of 7 species of Malassezia were isolated from the patients with pityriasis versicolor, and identified by the internationally used biochemical tests. The strains were then cultured on the media with 4 different concentrations of L-tryptophan for 7 days. The degree of pigment production was observed. Results Positive- and negative- pigment-producing strains were observed in all the 7 species. The degree of the pigment production was positively correlated with the concentration of L-tryptophan. The positive-pigment-producing strains were prone to cause the pigmentation in the skin lesion of pityriasis versicolor (P < 0.005). Conclusions The pigment production has no relationship with the species of Malassezia. L-Tryptophan is involved in the pigment production of Malassezia.