Longitudinal study of the cutaneous microbiota of healthy horses

Abstract

Background Next‐generation sequencing techniques have revealed that human and animal skin is colonised by a rich and diverse population of bacteria, and that microbial composition varies between different body sites and individuals. Very little is known about the normal microbiota of healthy equine skin. Hypothesis/Objectives To describe the taxonomic distributions of cutaneous bacterial microbiota in a population of healthy horses in Ontario, Canada, and to evaluate the effects of body site, individual and time of year on microbial diversity and community composition. Animals Samples were collected from four body sites (dorsum, ventral abdomen, pastern and groin) from 12 clinically healthy horses from the same farm. Samples were collected from all individuals at four time points (winter, spring, summer, autumn) within a calendar year. Methods and materials Illumina sequencing of the V4 region of the 16S rRNA gene was performed following DNA extraction. Data were analysed using mothur software. Results Bacteria from 38 phyla and 1,665 genera were identified. Alpha diversity was higher in the winter and summer than spring and autumn although this was not statistically significant. Community membership and structure clustered more based on season than skin site. Conclusions and clinical importance Healthy equine skin is inhabited by a marked diversity of microbiota. Individuals living in a similar environment share overlapping cutaneous microbial populations. These populations vary significantly over time and between body sites.

Environment rather than breed or body site shapes the skin bacterial community of healthy sheep as revealed by metabarcoding

“…In the present study, the sheep skin samples were taken in one season only. However, season influenced the skin bacterial diversity of horses, where the alpha diversity was higher in winter and summer and in beta diversity the samples clustered more by season than by skin site 21 …”

Common superficial and deep cutaneous bacterial infections in domestic animals: A review

“…65 The most common bacterial genera on equine skin include Psychrobacter, Macrococcus, Pseudomonas, Acinetobacter, Planomicrobium, Arthrobacter, Carnobacterium, Desemzia, and Corynebacterium, and the microbiota composition in this species is mainly influenced by body site. 70 In cattle, microbiome studies have focused on the udder, which is predominantly colonized by the families Corynebacteriaceae and Staphylococcaceae, 76 and the feet. 101 The skin is a nutrient-poor environment, which by itself regulates the composition of its bacterial community.…”

Wound healing of experimental equine skin wounds and concurrent microbiota in wound dressings following topical propylene glycol gel treatment

“…As the equine cutaneous microbiome differs between seasons (31) and anatomical areas (12,31,32) it may not be surprising that prevalent genera in this investigation (Staphylococcus, Streptococcus and Trabulsiella spp) differed to those previously described (Actinobacillus and Pseudomonas spp) using the same experimental animal model (12). However, at the phylum level most prevalent OTUs were identical to the only other study on experimental equine wound healing (Proteobacteria, Firmicutes, Fusobacteria and Bacteroidetes) (12) and in a study of the equine cutaneous microbiome (Proteobacteria and Firmicutes) (31). A similar temporal pattern, i.e., a decline in the prevalence of Proteobacteria with concurrent increase in prevalence of Firmicutes and gradual appearance of members belonging to Fusobacteria and Bacteroidetes phyla was also observed (12).…”