Abstract
BACKGROUND: Psoriasis is an immune-mediated cutaneous disease that may have shifts in the skin microbiome. Prior research on the skin microbiome in psoriasis has been limited to rRNA based approaches that lack resolution of taxonomic and functional level assessment. OBJECTIVE: To further illuminate strain and sub-strain level analysis of psoriatic lesions using the CosmosID-HUB Microbiome pipeline. METHODS: A previous study completed by Tett et al recruited patients with psoriasis who had skin microbiome samples taken from psoriatic plaques on the ear and the elbow as well as sites on the skin unaffected by psoriasis. They performed whole genome shotgun sequencing and made their dataset publicly available. We analyzed the dataset using the CosmosID-HUB Microbiome pipeline to evaluate the strain and sub-strain taxonomic analysis as well as functional gene profiling. RESULTS: When analyzed with the CosmosID pipeline, both ear and elbow sites in affected areas had decreased alpha diversity compared to unaffected areas. There was an increased relative abundance of Staphylococcus and Corynebacteria at affected sites. We identified distinguishing species and strains of the yeast Malassezia, including M. restricta. that were significantly enriched in healthy elbow samples. Vitamin B12 production genes were not present in psoriatic skin whereas it was present in healthy samples, supporting the notion of relative vitamin B12 deficiency in psoriatic plaques. Phage analysis revealed a greater diversity of Staphylococcus-related phages in unaffected elbow samples. CONCLUSION: A greater diversity of microbial strains and their functional roles identified in this study may help to tailor treatment for psoriasis.