The Enzymic Activity And Influential Factor In Candida Albicans

Vulvovaginal candidiasis is a widespread and common infectious disease in women of reproductive age.The infection affects75%of women at least once during their lives of which40%-50%will experience a recurrence,5%-8%of adult women have recurrent vulvovaginal candidosis. Therefore,VVC become a common vaginal inflammatory disease which female is persecuted by it and it is harmful to reproductive health. So it is particularly important to make a correlational study of VVC. VVC is frequently caused by the conditioned pathogen Candida albicans. C. Albicans is a dimorphic fungus that colonizes in skin, mucosal surfaces, vagina cavities, the digestive tract and the other organs as a commensal of human.It can easily infect immunocompromised human body or when the in vivo condition change. C.Albicans expresses several virulence factors that contribute to pathogenesis. The hydrolyase and yeast-hyphae transition are considered the most important virulence factors because of they are correlated with vasion and damage in host tissue. At present, the treatment of VVC is relatively single and because of the resistant strains emerge,the incidence of VVC is higher. But the treatment isn’t satisfactory. In this study, we discuss the difference between enzymic activity and virulence of dimorphism in C.albicans. The influence of external environment on enzymic activity were also investigated.We expect to have in-depth understanding of pathogenic mechanism of C.albicans by the study and to provide more understanding in VVC.The main results are as follows:PART ONEDIFFERENCE BETWEEN ENZYMIC ACTIVITY AND VIRULENCE OF DIMORPHISM IN CANDIDA ALBICANSObjective Investigated the difference between enzymic activity of dimorphism in C.albicans and study the relationships between enzymic activity and virulence.Method200strains of C.albicans 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 phospholipase of C.albicans in hyphal form and in spore form.24strains of candida albicans were used to infect the vascular endothelial cells in two forms and the virulence of C.albicans were computed.Results The value of PA was0.681±0.105in spore form and 0.641±0.096in hyphal form.The value of PZ was0.621±0.113in spore form and0.558±0.102in hyphal form. The activities of secretory acid proteinase and phospolipase between the two forms were significantly different(p<0.001).The virulence was0.299±0.129in spore form and0.577±0.217in hyphal form and the Pearson correlation of PZ-virulence was-0.485in spore form and-0.629in hyphal form.The virulence of the two forms were significantly different(p<0.05).Conclusion The activities of secretory acid proteinase and 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 C.albicans in hyphal form was high positively correlated with its enzymic activity and moderate positively correlated with enzymic activity in spore form.PART TWO THE INFLUENCE FACTOR ON THE ENZYME ACTIVITY IN CANDIDA ALBICANSObjective Investigated the influence of external environment alteration on enzymic activity of dimorphism in C.albicans.Method20strains of C.albicans were used to test the enzymic activity by Milk-plate medium and egg-yolk medium with different PH value in hyphal form and in spore form, to detect the enzymic activity was in hyphal form and in spore form which added in different concentrations of the lactobacillus.Results The enzymic activity of C.albicans was lowest when PH value was4and then increased gradually as the PH value increased, the enzyme activity decreased when PH value reached7. The enzymic activity of C.albicans was highest in the no lactobacillus group and the enzyme activity would decrease as lactobacillus concentration was added gradually.Conclusion The enzyme activity of C.albicans was influenced by PH value,the lower of PH value, the lower of enzyme activity.The enzyme activity would increase along with the PH value. However the enzyme activity would be restrained when the PH value increased to a certain level. The enzyme activity would be reduced in overly acidic or alkaline environment. The enzyme activity was inhibited by Lactobacillus and the inhibition in hyphae was stronger than in yeast.