Skin microbiota of first cousins affected by psoriasis and atopic dermatitis

Abstract

Background Psoriasis and atopic dermatitis (AD) are chronic inflammatory skin diseases, which negatively influence the quality of life. In the last years, several evidences highlighted the pivotal role of skin bacteria in worsening the symptomatology of AD and psoriasis. In the present study we evaluated the skin microbiota composition in accurately selected subjects affected by (AD) and psoriasis.Methods Three first cousins were chosen for the study according to strict selection of criteria. One subject was affected by moderate AD, one had psoriasis and the last one was included as healthy control. Two lesional skin samples and two non-lesional skin samples (for AD and psoriatic subjects) from an area of 2 cm2 behind the left ear were withdrawn by mean of a curette. For the healthy control, two skin samples from an area of 2 cm2 behind the left ear were withdrawn by mean of a curette. DNA was extracted and sequencing was completed on the Ion Torrent PGM platform. Culturing of Staphylococcus aureus from skin samples was also performed.ResultsThe psoriatic subject showed a decrease in Firmicutes abundance and an increase in Proteobacteria abundance. Moreover, an increase in Streptococcaceae, Rhodobacteraceae, Campylobacteraceae and Moraxellaceae has been observed in psoriatic subject, if compared with AD individual and control. Finally, AD individual showed a larger abundance of S. aureus than psoriatic and healthy subjects. Moreover, the microbiota composition of non-lesional skin samples belonging to AD and psoriatic individuals was very similar to the bacterial composition of skin sample belonging to the healthy control.ConclusionSignificant differences between the skin microbiota of psoriatic individual and healthy and AD subjects were observed.

A Metagenomic Analysis Provides a Culture-Independent Pathogen Detection for Atopic Dermatitis

“…Therefore, 2 different microbial signatures represented the 2 states of normal controls and AD patients. Drago et al23 also reported that Firmicutes and Staphylococcaceae were the most abundant phylum and family, respectively, and S. aureus accounted 73% of total staphylococci load in the skin of AD patients. However, unlike our study, they failed to show the different microbial composition between AD patients and normal controls except higher frequency of S. aureus .…”

The Role of the Skin and Gut Microbiome in Psoriatic Disease

“…The gut microbiome can be obtained from stool, while the skin microbiome can be sampled by biopsy,[14] curette,[15] or skin swabs with or without culturing. [16] Biopsy captures internalized bacteria and bacteria in deeper skin layers.…”

“…At the phylum level, Firmicutes, Proteobacteria , and Actinobacteria were the three most prevalent phyla in psoriatic and normal skin. [14, 16, 22, 15] In psoriatic lesions, both Gao and Fahlen found that Firmicutes was the most common phylum. Using another approach, Alekseyenko and colleagues were able to separate samples into two different clusters, representing distinct cutaneotypes.…”

“…However, some controls switched from cutaneotype 1 to 2 and there was a trend towards increasing prevalence of cutaneotype 2 over the course of 36 weeks, which may have been due to a decreasing number of available samples over time. [22] Unlike lesional skin, non-lesional sites were not significantly different from healthy control skin at the phylum level,[22, 15, 16] indicating that changes in unaffected skin may be more subtle.…”

“…At the family level, Drago and colleagues discovered that psoriasis lesions had a higher relative abundance of Streptococcaceae , Rhodobacteraceae , Campylobacteraceae , and Moraxellaceae than eczema lesions and control skin. At the genus level, several studies have suggested an underrepresentation of Propionibacterium ,[16, 14, 15] an overabundance of Streptococcus ,[16, 14, 22] and mixed changes in Staphylococcus in psoriasis lesions compared to healthy skin. The decrease in Propionibacterium may be driven in part by significant reductions in the species Propionibacterium acnes .…”