DEGRADING PROTEINASE TEST TO DISTINGUISH BENIGN AND VIRULENT OVINE ISOLATES OF BACTEROIDES-NODOSUS

Bacteroides nodosus was recovered from naturally occurring cases of virulent ovine footrot (VFR) and benign footrot (BFR) using an artificial culture medium which incorporated trypticase, arginine, serine and 5% agar. A degrading proteinase (DP) test was developed which measured the proteinase activity of broth cultures of B. nodosus for a period of time after organism death to assess the stability of the enzyme. The spectrophotometric measurement of the release of dye from a hide powder--azure conjugate by the action of proteinase provided an objective analysis of enzyme activity. The DP test differentiated VFR and BFR isolates and promises to be a useful laboratory method for the diagnosis of benign and virulent footrot in sheep.