阴道白假丝酵母菌二相性的酶活性和毒力的差异

Difference between enzymic activity and virulence of dimorphism in candida albicans

目的探讨阴道白假丝酵母菌菌丝相和酵母相的酶活性和毒力的差异。方法收集2009年1-12月北京大学第一医院妇产科门诊标本,经形态学和生化学鉴定证实为白假丝酵母菌,共200株。分别用牛奶平板和卵黄培养基法检测其菌丝相和酵母相时分泌型酸性蛋白酶和细胞外磷脂酶的活力。并从中挑选24株分别用其菌丝相和酵母相感染血管内皮细胞,再以四甲基偶氮唑蓝比色法计算菌丝相和酵母相的细胞毒力。结果酵母相和菌丝相分泌型酸性蛋白酶的活力(PA值)分别为0.681±0.105和0.641±0.096;细胞外磷脂酶的活力(PZ值)分别为0.621±0.113和0.558±0.102,差异具有统计学意义(P<0.001)。酵母相和菌丝相毒力值分别为0.299±0.129和0.577±0.217且PZ值-毒力Pearson系数分别为-0.485和-0.629,差异具有统计学意义(P<0.05)。结论菌丝相分泌型酸性蛋白酶和细胞外磷脂酶活性均高于酵母相;菌丝相毒力强于酵母相;白假丝酵母菌毒力强弱与其酶活性高低呈高度正相关。

Objective To investigate the difference between enzymic activity and virulence of dimorphism in candida albicans. Methods 200 strains of candida albieans were collected from secretion of vaginitis of patients. Milk-plate medium and egg-yolk medium were used respectively to test the activities of secretory acid proteinase and extracellular phospholipase of Candida albicans in hyphal form and in spore form. 24 strains of candida albicans were used to infect the vascular endothelial cells in two forms, the virulence of candida albicans were computed. Results The value of PA was 0. 681±0. 0105 in spore form and 0. 641 ±0. 096 in hyphal form. The value of PZ was 0. 621 ±0. 113 in spore form and 0. 558 ± 0. 102 in hyphal form. The activities of secretory acid proteinase and extracellular phospolipase between the two forms were significantly different（P 〈0. 001 ）. The virulence was 0. 299 ±0. 129 in spore form and 0. 577 ±0. 217 in hyphal form, the Pearson correlation of PZ- virulence was - 0. 485 in spore form and - 0. 629 in hyphal form. The virulence between the two forms were significantly different （P 〈 0. 05 ）. Conclusion The activities of secretory acid proteinase and extracellular phospolipase in hyphal form was significantly higher than that in spore form. The virulence in hyphal form was stronger than that in spore form. The virulence of candida albicans was positive correlation with its enzymic activity.