Abstract: Objective To explore a direct colony PCR method for rapid identification of T.asahii.Methods Four methods including direct colony,direct colony with centrifugation,enzymolysis,and improved enzymolysis method were used to preliminarily sample treatment.The sensitivity and the positive rate of colony PCR based on four methods for isolates of T.asahii were evaluated and compared with the PCR results of the traditional DNA extraction.Results The sensitivity of the improved enzymolysis method,direct colony method and the traditional DNA extraction were both 10² CFU/mL,while the positive rates were 93.75%,75% and 50%,respectively.The direct colony with centrifugation presented the sensitivity of 10⁴ CFU/mL and the positive rate of 43.75%.The enzymolysis method presented total negative results in the detection of both sensitivity and positive rate.Conclusion The improved enzymolysis method which presented the advantages of high sensitivity and positive rate of trace samples,could be applied for the rapid identification of T.asahii.

Key words: Colony PCR, Trichosporon asahii, DNA preliminary extraction