Staphylococcus aureus as dominant bacterial species in the cutaneous microbiome of prurigo nodularis

Introduction:
Prurigo nodularis is a chronic and debilitating condition of not fully elucidated etiopathogenesis. There are scarce data in the literature on the presence of microorganisms in the lesional skin of prurigo nodularis.

Objective:
To explore the microbiome composition in patients with prurigo nodularis using amplicon-based next-generation sequencing.

Material and methods:
Adult patients with prurigo nodularis were recruited for the study. Controls were healthy volunteers who presented for a routine nevi check-up. Skin swabs for microbiome analysis were collected, without prior cleaning, from active nodules in patients with prurigo nodularis and corresponding skin areas in healthy volunteers. The V3-V4 region of the 16S rRNA gene was amplified from the extracted DNA. Illumina platform on the MiSeq instrument was used for sequencing. The Silva v.138 database was utilized for identification of taxa.

Results:
In total, the microbiome profile of 60 active nodules from 24 patients with prurigo nodularis and corresponding skin areas (n = 14) from 9 healthy volunteers was analyzed. Skin microbiome of prurigo nodularis lesions showed decreased alpha and beta diversity when compared with healthy volunteers. Staphylococcus aureus was significantly more abundant in samples from prurigo nodularis patients than in the control samples, while Pseudomonas stutzeri had a greater share in the microbiome from healthy volunteers than from prurigo nodularis patients.

Conclusions:
Our results highlight several alterations in the diversity and composition of cutaneous microbiome in prurigo nodularis. However, further research on the role of microorganisms in this debilitating condition is necessary.