Abstract: 【Abstract】 Objective To investigate the diversity and structural characteristics of fungal communities on lesions of the face, upper limbs and back in patients with atopic dermatitis （AD）. Methods Samples were collected from the lesions on the face, upper limbs and back of 10 AD patients, who visited the Department of Dermatology, the First Affiliated Hospital of Chengdu Medical College from September to October in 2015, and collected from the corresponding body sites of 10 healthy controls. DNA was extracted from the samples, and subjected to MiSeq high-throughput sequencing for diversity index analysis, species composition analysis and principal component analysis. Statistical analysis was carried out by using two-independent-sample t test for comparisons between two groups, one-way analysis of variance for comparisons among multiple groups, and least significant difference-t test for multiple comparisons. Results Diversity index analysis showed that Shannon index was significantly higher in the samples from the lesions on the face, upper limbs and back of the AD patient group than in those from corresponding body sites of the healthy control group （t = 2.67, 2.37, 3.34 respectively, all P < 0.05）. Species composition analysis showed that Malassezia was predominant in the skin samples from the face, upper limbs and back of the AD patient group and healthy control group, and the total abundance of Malassezia globosa and Malassezia restricta was about 80%. The abundance of Candida and Aspergillus in the total samples was significantly higher in the AD patient group than in the healthy control group （t = 3.515, 2.137 respectively, both P < 0.05）. There was no significant difference in the abundance of major fungal genera on the face between the AD patient group and healthy control group（all P > 0.05）; the abundance of Candida in the upper limbs was significantly higher in the AD patient group than in the healthy control group （t = 3.186, P < 0.05）, and the abundance of Aspergillus in the back was significantly higher in the AD patient group than in the healthy control group （t = 2.736, P < 0.05）. In either the AD patient group or the healthy control group, there was no significant difference in the abundance of major fungal genera among samples from the face, upper limbs and back （all P > 0.05）. Moreover, no significant difference in the abundance of major fungal genera was observed among the mild, moderate and severe AD patient groups （all P > 0.05）. Principal component analysis showed that fungal communities in the samples from the lesions on the face, upper limbs and back of the AD patient group were not clustered by the disease severity. Conclusions The diversity of fungal communities is significantly higher in the lesions on the face, upper limbs and back of the AD patients than in the normal skin at the corresponding body sites of the healthy controls. Malassezia is the dominant fungal genus in both lesions of the AD patients and normal skin of the healthy controls at the above body sites. The composition of fungal communities in lesional samples may be uncorrelated with the disease severity in AD patients.

Key words: Dermatitis, atopic, Skin, Fungi, High-throughput nucleotide sequencing, Biodiversity