Study of skin and nail Candida species as a normal flora based on age groups in healthy persons in Tehran-Iran.

The skin is the body's largest organ that hosts heterogeneous inhabitants. Until now, the diversity of the cutaneous microbiome was mainly investigated for bacteria and there is a little information about the skin fungal flora. Also, among skin fungal flora, Candida is found as a main member whose distribution is affected by sex, age, climate. In this study, differences in Candida community structure associated with 9 different skin sites of 238 healthy people during 10 months from July to March 2016, are described. These subjects were divided by age into 4 groups: infants, children, adults and geriatrics. The collected samples were examined by culture on Sabouraud Chloramphenicol Agar and CHROM-agar Candida. For precise identification of species ITS1-5. 8S-ITS2 rDNA regions were sequenced where needed. The frequency of Candida species was significantly different between age groups. The most Candida isolations were related to the elderly age group and the fewest in the infants. C. parapsilosis virtually, was the predominant isolated species in all age groups. This study showed no statistically significant effect of the subject's sex on Candida population resident on human skin surface.