Poster Presentation The 2nd Prato Conference on the Pathogenesis of Bacterial Diseases of Animals 2012

Ovine footrot is a contagious disease that affects the feet of sheep in which Dichelobacter nodosus, a Gram-negative anaerobic bacterium, is the main causative agent. In Sweden, diagnosis is based on clinical examination of sheep feet where the feet are scored according to the Australian system for scoring footrot¹, and with the definition of footrot as score ≥2 lesions. Diagnosis is often complemented by detection of D. nodosus by real-time PCR.

Very few of the D. nodosus strains isolated from more severe cases of footrot in Swedish flocks meet the criteria required for virulence in this case, the gelatin gel test², which leaves us questioning why the diagnostics is not consistent with the clinics for our conditions. Hence the aim of this study was to try and find a correlation between the clinical manifestations of footrot and D. nodosus strain differences by the comparison of strains isolated from flocks with different clinical status.

Eighteen sheep flocks were classified into four categories (A-D) according to their clinical status where categories A and B were clinically healthy and C and D affected by footrot. About 900 swab samples, 50 from each flock, were analyzed for D. nodosus by a specific real-time PCR assay³ and by culturing as seen in Table 1. To summarize, D. nodosus was frequently found in all of the footrot affected flocks (n=8) but only found in three out of 10 clinically healthy flocks. The obtained D. nodosus strains are under characterization and the swab samples are being analyzed for the presence of other relevant bacterial species than D. nodosus.