阴道白色念珠菌致病株与携带株两相性与毒力关系研究

Relationship between activity and virulence of secretory acid proteinase and extracellular phospholipase of Candida albicans from secretion of vagina in two forms

目的探讨阴道白色念珠菌致病株和携带株菌丝相和酵母相分泌型酸性蛋白酶和细胞外磷脂酶活性以及与其毒力的关系。方法分别采用牛奶平板和卵黄培养基法检测白色念珠菌致病株和携带株200株分泌型酸性蛋白酶和细胞外磷脂酶的活力,分别将致病产酶株的菌丝相和孢子相菌悬液(5×106CFU/ml)注射小鼠尾静脉,1个月内观察小鼠死亡率及平均存活时间,以平均存活时间评价菌株毒力。结果白色念珠菌致病株和携带株分泌型酸性蛋白酶检出率分别为83.3%和35.7%(P<0.01);细胞外磷脂酶阳性率分别为87.5%和39.3%(P<0.01)。动物实验结果表明,白色念珠菌致病株菌丝相分泌型酸性蛋白酶和细胞外磷脂酶的活力均显著高于孢子相(P<0.01,P<0.005);注射菌丝相白色念珠菌的小鼠死亡率高于注射孢子相的小鼠(P<0.01),且平均存活期短于注射孢子相的小鼠(P<0.01)。结论分泌型酸性蛋白酶和细胞外磷脂酶是白色念珠菌重要毒力因子,致病株毒力高于携带株,菌丝相毒力高于酵母相。

Objective To study the relationship between activity and virulence of secretory acid proteinase and extraeellular phospholipase of different Candida albicans isolated from secretion of vaginiti in two form. Method 200 Pathogenic strains and Carry strains of Candida albicans were isolated from secretion of vaginiti of patients with Candida albicans infection in hospital. 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 two forms. The suspension of two forms of Candida albicans （5 ×10^6 CFU/rnl） were administered to mice by intraveinous injection in tail respectively to test the virulence. The mortality and mean survival time of mice were observed within 1 month. The virulence was determined by the mean survival time of mice. Result Of the 200 Pathogenic strains and Carry strains, the positive detectable rates of secretory acid proteinase were 83.3% and 35.7%, and the positive detectable rates of extracellular phospholipase were 87.5% and 39.3%, respectively. Animal experimental results showed the activities of secretory acid proteinase and extraeellular phospolipase in hyphal forms were significantly higher than those in spore form （P 〈0.01, P 〈0. 005）. The mortality of mice injected with hyphal forms was higher than that of mice injected with spore forms （ P 〈 0.01 ） and the mean survival time of mice injected with hyphal forms was shorter than that of mice injected with spore forms （P 〈 0.01 ）. Conclusion Secretory acid proteinase and extraeellular phospholipase are important virulence factors of Candida albicans. The activities of secretory acid proteinase and extracellular phospholipase can be used as direct parameters for virulence of Candida albicans. The activity and virulence of Pathogenic strains was higher than the Carry strains＇. The activity and virulence of the hyphal forms of Candida albicans was higher than the spore forms＇.