A Comparison Study between Culture Based Technique and Op-site Non-Culture Based Technique for Identifying Malassezia Yeasts on Normal Skin

Lim, Sang Hee; Kim, Yu Ri; Jung, Jae Wook; Hahn, Hyung Jin; Lee, Yang Won; Choe, Yong Beom; Ahn, Kyu Joong

Abstract

BACKGROUND
Culture based technique, a traditional method for extraction of DNA from a cultured colony, was complex in culture conditions and was associated with a lower chance of successful culture. Recently, non-culture based technique, which skipped the culture process and directly extracted fungal DNA and differentiated Malassezia species, has been introduced.
OBJECTIVE
Using 26S rDNA PCR-RFLP, the authors identified Malassezia yeasts and compared the yield of Malassezia DNA by the traditional culture based technique and the non-culture based technique via Op-site adhesive tape.
METHODS
DNA of Malassezia yeasts were extracted using the culture based technique and the non-culture based technique from normal adults. Comparison was performed in order to clarify the differences between these two techniques.
RESULTS
Use of the culture based technique resulted in a culture rate of 57.8% (78 out of 135 samples). On the other hand, using the non-culture based technique, fungal species were identified from all 135 samples. Using both techniques, M. globosa was the most identified species. The identification rate of the non-culture based technique was 100%; however, 7 repeats of PCR were required to reach 100% identification. Among samples from five body sites, those from the thigh required 5.5 repeats of PCR.
CONCLUSION
The non-culture based technique was better than the culture based technique. However, due to the low amount of DNA extracts from the body sites with low habitation of Malassezia yeasts, repeated PCR was required for differentiation of Malassezia species.