Metagenomics of Toenail Onychomycosis in Three Victorian Regions of Australia.

Onychomycosis is a fungal disease of the nail that is found worldwide and is difficult to diagnose accurately. This study used metagenomics to investigate the microbiology of 18 clinically diagnosed mycotic nails and two normal nails for fungi and bacteria using the ITS2 and 16S loci. Four mycotic nails were from Bass Coast, six from Melbourne Metropolitan and eight from Shepparton, Victoria, Australia. The mycotic nails were photographed and metagenomically analysed. The ITS2 sequences for and averaged over 90% of hits in 14/18 nails. The high abundance of sequences of a single dermatophyte, compared to all other fungi in a single nail, made it the most likely infecting agents (MLIA). and interdigitale/mentagrophytes were found in Bass Coast and Shepparton while only was found in Melbourne. Two nails with mixed with high abundance non-dermatophyte moulds (NDMs) (, ) were also observed. The two control nails contained chiefly and . For bacteria, was in every nail and was the most abundant, including the control nails, with an overall mean rate of 66.01%. , , and also featured.