Comparative Study On ERG11 Sequence And The Activity Of Secreted Aspartyl Proteinase Between The Hyphal Form And The Yeast Form Of Candida Albicans

Objective:To provide evidence for selecting the suitable form of Candiada albicans in medical mycology, the differences between the hyphal form and the yeast form of C. albicans on ERGll gene sequence and on the activity of secreted aspartyl proteinase were compared in this study.Materials and Methods:Twelve isolates of C. albicans from a single HIV-seropositive patient (CA-1, CA-2, CA-4, CA-6, CA-7, CA-9, CA-11, CA-13—CA-17) were grown to form yeast cells and hyphal cells respectively, and the genomic DNA was extracted. Then ERGll was amplified with polymerase chain reaction (PCR) technology and cleaved by two restriction enzymes Acc I and Mun I . The products were electrophored. Furthermore, DNA differences between both forms of five C. albicans isolates (CA-1, CA-2, CA-4, CA-6, CA-7) were compared through DNA sequencing. Bovine serum albumin (BSA) medium was used to test the activity of secreted aspartyl proteinase between the dimorphic C. albicans.Results:1. The ERG 11 gene of all isolates had been amplified successfully. There were some differences on both the Ace I and the Mun I endonuclease maps of ERG 11 gene between the hyphal form and the yeast form of C. albicans.2. Differences on ERG11 sequence between the hyphal form and the yeast form of C.albicans were found, they were located at the positions of 1 547, 1 587 and 1 617.3. The activity of secreted aspartyl proteinase in hyphal form was significantly higher than that of yeast form of C. albicans.Conclusion:1. There are some differences on DNA sequence between the hyphal form and the yeast form of C. albicans.2. There are some differences on the activity of secreted aspartyl proteinase between the hyphal form and the yeast form of C. albicans.3. The hyphal form of C.albicans is thought to be the appropriate object in medical mycology.