Oral Presentation The Prato Conference on the Pathogenesis of Bacterial Infections of Animals 2016

Correlation of Ovine Footrot Interdigital Microbial Communities with Pro-inflammatory Cytokine Expression (#33)

Adam Blanchard 1 , Grazieli Maboni 1 , Sara Frosth 2 , Anna Aspan 2 , Richard Emes 1 , Sabine Totemeyer 1
  1. School of Veterinary Medicine and Science, University of Nottingham, Leicestershire, United Kingdom
  2. Department of Microbiology, Swedish Veterinary Institute, Uppsala, Sweden

Ovine footrot is characterised by the separation of the hoof from the underlying tissue. Footrot is a major welfare concern for sheep farmers worldwide and untreated cases cause a significant animal welfare issue. The disease is of a multifactorial nature and only occurs after physical damage to the interdigital skin, allowing for the invasion of the specific aetiologic bacterium, Dichelobacter nodosus. Footrot has been identified as a polymicrobial disease with Fusobacterium necrophorum and Trueparella pyogenes, both proposed to enhance the establishment of D. nodosus and exacerbate the condition. There are, however, multiple different bacteria present within the interdigital space, which could alter conditions favorably for pathogenic species.

Previous research on host immune response, in relation to footrot, has shown an increased expression of IL-1β. In this context, we hypothesised that the local immune response is associated with bacterial colonisation. In order to understand the microbial communities present during high and low levels of inflammation, interdigital biopsies were collected from post-slaughter sheep and from tissue samples a 16S rRNA amplicon survey was conducted. Samples were grouped based on qPCR quantified levels of IL1β expression, and high-throughput sequence data of the 16S rRNA V3/V4 variable region was used to identify bacteria genera present.

Several bacterial genera were identified to have an increased abundance within the “high inflammation” set; Dichelobacter and Fusobacteria which have a known role in ovine footrot, Prevotella and Porphyromonas also routinely isolated from cases of footrot, Corynebacteria which are abundant in cases of ovine interdigital dermatitis, Treponema which are linked to contagious ovine and bovine digital dermatitis and Mycoplasma which have been associated with bovine digital dermatitis. These data have shown that there is a distinct microbial community associated with footrot and high IL1β expression, comprising of bacteria known to be associated with similar conditions and in other species.