| Objective: To study the genotype, drug sensitivity and lipase activity of Malassezia isolated from different diseases, and to analyze their correlation.Method: 1. Malassezia was cultured and identified by traditional method. The ITS region and the D1/D2 region of the mutant rDNA was amplified and sequenced by using the universal primers ITS1/ITS4 and NL1/NL4, and the base sequence was spliced by Sequencher software. The BLAST Genebank was used to identify the strains. The sequence of each strain was compared with CLUSTAL sequence analysis software. The N-J system tree was constructed by Mega software. Finally, the phylogenetic tree was used to clarify the affinity of each strain. 3. Lipase activity assay was performed with lipase activity assay kit. 4.Combined with pre-drug sensitivity results, analysis the correlation between the Malassezia genotype and drug sensitivity, lipase activity.Result:1.The results showed that use D1/D2 region premier successful sequencing 93 Malassezia,use ITS region premier successful sequencing 98 Malassezia, and the two results were consistent. 2.The results of molecular identification were 58% (57/98)compared with the traditional method. 3.In this experiment,the molecular identification results were as follows: in the experimental group, M.furfur and M.Sympodialis were the dominant species(50% and 47% of the three diseases isolates,respectively), while in the healthy group, M. Globosa and M. Sympodialis were the dominant species(56.3% and 28.1% of healthy isolates, respectively). And the results is basically consistant with the result by use traditional identification methods.4.The genetic differentiation of the same strain was not very obvious, and the genetic differentiation of the disease group was more conservative than that of the healthy group.5.In this experiment, the correlation between genotype and drug sensitivity,lipase activity are not significant . 6.The activity of lipase in the experimental group was higher than that in the healthy group, the difference was statistically significant (P<0.05).Conclusions: 1 .The results of traditional morphological and physiological and biochemical methods and the result of molecular biology ITS region, D1 / D2 region test method identification are different, molecular biology identification method of success rate is higher, and D1 / D2 area test method is better.2.The dominant species in the disease group were M.furfur and M. Sympodialis,and the dominant species in the healthy group were M. Globosa and M. Sympodialis.3.The genetic differentiation of the same strain was not very obvious, and the genetic differentiation of the disease group was more conservative than that of the healthy group. 4.1n this experiment,there was no significant correlation between genotype and drug sensitivity and lipase activity. 5.The experimental group showed higher lipase activity than the healthy group, indicating that lipase activity played an important role in the pathogenic mechanism. |
