Skin is the largest organ system of the body and there are numerous microorganisms that inhabit it. We know little about the relationship and balance between skin microorganisms and disease even though an imbalance of these microorganisms is often associated with disease. The investigators involved with this particular study set a goal to describe the cutaneous bacterial microbiota of cats and determine whether bacterial dysbiosis occurs on the skin of allergic cats. Different skin surfaces on various regions were sampled from 11 healthy cats and 10 allergic cats (included cats with flea allergy dermatitis, cutaneous adverse food allergies and feline non-flea non-food hypersensitivity reactions).
Skin swabs were taken from different surfaces and regions, then genomic DNA was extracted from the swabs and sequenced. Swabs were collected from 12 sites from the healthy cats: axilla, chin, conjunctiva, dorsal nose, ear canal, groin, interdigital skin, lumbar region, nostril, oral cavity, pinna, and reproductive tract (prepuce and vulva). Swabs were collected from 6 sites from the allergic cat cases: axilla, ear canal, groin, interdigital skin, lumbar region, and nostril.
The investigators determined that there are many more bacterial species found on feline skin than was previously thought. In healthy cats, it was noted that there are differences in species diversity and richness between body sites and different epithelial surfaces. In these cats, the bacteria present preferred body site niches where with allergic cats the bacterial communities were more unique to the individual cat.
The authors noted that the number of bacterial species were overall not significantly different between the different health status groups of cats. Yet, the abundances of the bacterial species found were different between healthy and allergic skin. In particular, Staphyloccus, was found to be more abundant on allergic skin. Because the results showed significant bacterial clustering between healthy and allergic cats from the site of the ear canal, they state this may support the idea that “normal” bacterial microbiota may be disrupted when a cat develops allergic skin disease. Where there may be a bacterial community unique to each site, in situations with allergy flare-ups, a cat may become colonized all over the body by a single changed bacterial community. This change in the communities of all body sites may be reflective of the grooming behavior of cats. They also noted that every clinical presentation can be slightly different (clinical reaction patterns) and there does not appear to be one standard “unhealthy” microbiota. (VT)
Vientos-Plotts AI, Ericsson AC, et al. Dynamic changes of the respiratory microbiota and its relationship to fecal and blood microbiota in healthy young cats. PLoS One. 2017 Mar 9;12(3):e0173818.