PROTECTION OF SHEEP AGAINST CASEOUS-LYMPHADENITIS BY USE OF A SINGLE ORAL DOSE OF LIVE RECOMBINANT CORYNEBACTERIUM-PSEUDOTUBERCULOSIS

An inactive form of the Corynebacterium pseudotuberculosis phospholipa se D (PLD) gene was constructed and expressed in a PLD-negative strain (designated Terminus) of C. pseudotuberculosis. Antibody responses sp ecific to Terminus and both Terminus and PLD proteins were detected in sheep following oral administration of Terminus or Terminus expressin g the PLD toroid, respectively. However, only those sheep vaccinated w ith Terminus expressing PLD toroid were protected against wild-type ch allenge. These results confirm the importance of PLD as a protective a ntigen and demonstrate both the potential for developing an oral caseo us lymphadenitis vaccine and C. pseudotuberculosis Terminus as a live vaccine vector.