Production of A Caseous Lymphadenitis Vaccine for Dromedaries

CLA is one of the most important bacterial infectious diseases of dromedaries and generally in livestock. For the development of CLA, the main antigen of the pathogen is its exotoxin phospholipase D (PLD) which is produced by all C. pseudotuberculosis strains. Therefore, PLD is essential for the production of a vaccine. The highest amount of PLD is already found in the Brain Heart Infusion Broth supernatant after 24 hours incubation at 37°C. The mixture of two CLA biotypes (ovine/caprine; equine/bovine) containing 750 μg PLD gave a complete protection against a challenge doses containing 4.0×103 cfu/ml of an ovine/caprine biotype. Seroconversion was tested with a newly established indirect ELISA using PLD as antigen and protein A as conjugate.