Study On The Pathogenesis Of Candida In Vitro

Objective To investigate the pathogenic mechanisms of candidiasis,so that to provide valuable data for the prevention and the curation of Candida infection.Methods 24 Candida strains were cultured in yeast trypton dextrose medium and yeast trypton dextrose agar medium seperatively.Flocculation and adhesion were detected.Candida biofilm models were developed in 96-well tissure culture plates.The kinetics of biofilm formation was measured in a microtiter plate reader at 492nm and Candida biofilm morphologies were detected with an inverted microscope.Results were analyzed by using a Student-Newman-Keuls test.Results (1)24 Candida strains had the unique function:flocculation and C.albicans, C.kefyr and C.tropicalis couldn't be resuspended with light vibration, but Saccharomyces cerevisiae could be.(2)24 Candida strains could adhere to the surface of the yeast trypton dextrose agar medium,the adhesion was better in C.albicans,C.kefyr,C.glabrata and C.tropicalis,but the adhesion was less in the other strains. (3)The common pathogenic Candida strains could produce biofilm and the metabolic activity of cells in the biofilm increased over time as the cellular mass increased,the biofilm matured after 48h of growth. C.albicans and C.kefyr showed significantly more biofilm growth than the other strains (P < 0.05);C.tropicalis and C.glabrata showed significantly more biofilm growth than C.krusei,C.parapsilosis and C.gulliermondii ( P < 0.05 ) .But the nonpathogenic Saccharomyces cerevisiae couldn't produce biofilm.Conclusions â‘ Candida strains had the function:flocculation,which indicated the existence of cell-cell adhesion,but the cell-cell adhesion was better in pathogenic Candida strains,less in nonpathogenic Saccharomyces cerevisiae .â‘¡Candida strains could adhere to the surface of the agar medium, there was some correlation with pathogenicity.â‘¢The common pathogenic Candida strains could produce biofilm,nevertheless there was some correlation with pathogenicity.But nonpathogenic Saccharomyces cerevisiae couldn't produce biofilm.