Longitudinal Evaluation of the Skin Microbiome and Association with Microenvironment and Treatment in Canine Atopic Dermatitis

Abstract

Host-microbe interactions may play a fundamental role in the pathogenesis of atopic dermatitis (AD), a chronic relapsing inflammatory skin disorder characterized by universal colonization with Staphylococcus. To examine the relationship between epidermal barrier function and the cutaneous microbiota in AD, this study employed a spontaneous model of canine AD (cAD). In a cohort of 14 dogs with cAD, the skin microbiota was longitudinally evaluated with parallel assessment of skin barrier function at disease flare, during antimicrobial therapy and posttherapy. Sequencing of the bacterial 16S ribosomal RNA gene revealed decreased bacterial diversity and increased proportions of Staphylococcus (S. pseudintermedius in particular) and Corynebacterium in comparison to a cohort of healthy control dogs (n=16). Treatment restored bacterial diversity with decreased Staphylococcus proportions, concurrent with decreased cAD severity. Skin barrier function, as measured by corneometry, pH, and transepidermal water loss (TEWL) also normalized with treatment. Bacterial diversity correlated with TEWL and pH, but not corneometry. These findings provide insights into the relationship between the cutaneous microbiome and skin barrier function in AD, the impact of antimicrobial therapy on the skin microbiome, and highlight the utility of cAD as a spontaneous non-rodent model of AD.

Isotretinoin and lymecycline treatments modify the skin microbiota in acne

“…We speculate that the increased alpha diversity is most probably due to the reduction of propionibacterial colonisation, which in turn makes other flora more visible, or even encourages their growth by freeing up niche space. Our findings resemble those of a study in canine atopic eczema, in which previously high proportions of Staphylococcus were reduced and decreased diversity restored after systemic antimicrobial treatment . This is the opposite of what is seen with throat and gut biomes, where bacterial diversity reduces rapidly after beginning antibiotics and remains perturbed from its initial state for months or even years after treatment cessation .…”

The cutaneous ecosystem: the roles of the skin microbiome in health and its association with inflammatory skin conditions in humans and animals

“…The allergic dogs had lower richness of their skin microbiota and were colonized with different abundances of bacterial populations than the healthy dogs. A longitudinal study including 14 dogs showed that the skin of AD dogs had increased relative abundances of S. pseudintermedius during development of skin lesions, which resulted in reduced diversity of the microbiota, similar to that described previously in humans . Bacterial diversity also correlated with transepidermal water loss and pH changes.…”

A distinct bacterial dysbiosis associated skin inflammation in ovine footrot

“…Surprisingly, the microbial community composition appears to show a stronger correlation with inflammation level rather than disease state since there is very little difference between the microbiome of healthy and footrot low inflammation biopsies while the microbial community and the dominant genera differed greatly between healthy high inflammation ( Acinetobacter, Corynebacterium, Flavobacterium ) and footrot high inflammation tissues ( Treponema, Mycoplasma, Porphyromonas ). Increased proportions of Corynebacteria were also observed in canine atopic dermatitis34. Of the bacterial genera identified, Dichelobacter, Fusobacteria and Treponema all linked to ovine or bovine foot disease467810.…”