Comparative Study On Antifungal Susceptibilities And ERG11 Sequence Of The Hyphal Form And Yeast Form Of Candida Albicans

To provide evidence for selecting the suitable form of Candiada albicans in medical mycology, the differences between the hyphal form and yeast form of C.albicans on antifungal susceptibilities and on ERG 11 sequence of both forms were compared in this study.Methods:Seven C. albicans isolates from the same strain (CA-1(K CA-11 , CA-13~CA-17) were induced to form pseudohyphae. The antifungal susceptibilities to fluconazole of the hyphal form and yeast form of C.albicans were compared using the Broth Microdilution Procedures according to the method of NCCLS M27-A. The genomic DNA of both forms of the 7 isolates were extracted. Three DNA fragments of ERG 11 (position 403 to 701, position 948 to 1254 and position 1495 to 1804) were amplified by polymerase chain reaction (PCR) technology and DNA differences between both forms of each isolate were compared by DNA sequencing.Results:1. The ERG 11 gene of all strains had been amplified successfully.2. Differences of antifungal susceptibilities to fluconazole between the hyphal form and yeast form of C.albicans were found.3. Differences on ERG 11 sequence between the hyphal form and yeast form of C.albicans were found, all were located at the position of 1547, 1587 and 1617.Conclusion:1. There were differences on DNA sequence and on antifungal susceptibilities between the hyphal form and yeast form of C.albicans.2. The hyphal form of C.albicans was thought to be the appropriate object in medical mycology.