A 5-month temporal, quantitative study investigating the core microbiome on the axilla, umbilical region, and groin of 15 healthy dogs in the UK.

Abstract

Objective: To identify putative members of the canine cutaneous core flora. A knowledge of this flora is important if we are to properly understand cutaneous dysbiosis. Cutaneous dysbiosis has been reported in allergic skin conditions, for example.

Methods: The unclipped skin on the axilla, umbilical region, and groin of 15 healthy dogs was swabbed monthly for 5 months using flocked cotton swabs. The samples were taken within a sterile brass guide of the known area. The swabs were submitted for next-generation 16S rRNA and internal transcribed spacer 2 sequencing to identify components of the bacterial and fungal microbiome.

Results: The density of the bacteria and fungi were expressed as IQR/cm2. Coagulase-negative staphylococci, Sphingomonas subsp, Malassezia var, Vishniacozyma victoriae, and Cladosporium var were recovered from 70% of samples. None of these 5 were found on every dog on every occasion. The density of the bacteria was 6.4 × 104 (IQ [interquartile range] 1, 3.2 × 104; IQ3, 1.2 × 105), the density of the filamentous fungi was 1.04 × 103/cm2 (IQ1, 450; IQ3, 2.13 × 105), and the density of malassezial yeast was 1.3 × 122 (IQ1, 90; IQ3, 1.8 × 10).

Conclusions: We propose that these 2 bacterial species and 3 fungal species be considered members of the core cutaneous flora of dogs.

Clinical relevance: Knowledge of the normal flora will help our understanding of aberrations in flora that might be associated with underlying diseases, such as atopy.