Serological studies on Corynebacterium pseudotuberculosis infections in goats using enzyme-linked immunosorbent assay

Corynebacterium pseudotuberculosis was isolated from a goat suffering from caseous lymphadenitis and used for preparation of cell wall antigens and exotoxin for detection of specific antibodies in enzyme-linked immunosorbent assay (ELISA). In immunoblotting sodium dodecyt sulphate (SDS) extracted cell wall antigens revealed molecular weights ranging from 20 to 120 kDa. The raw exotoxin showed molecular weights of 30 and 55 kDa and an inhibition of the haemolysis of a Staphylococcus aureus strain. For validation of the ELISA 109 goats of known clinical status were examined reaching a sensitivity of 96% and a specificity of 76% for this test. No serological reactions showed in 191 goats originating from 11 flocks which never had suffered from caseous lymphadenitis. Using this ELISA test 24 goats originating from flocks suffering from caseous lymphadenitis were examined serologically before and after vaccination with a bacterin. Before vaccination one of the five goats with clinical signs showed no positive reaction in ELISA. After vaccination all 24 animals showed positive reactions. Of a total of 1868 goats sampled in Baden-Wuerttemberg 41 (2.2%) in 22 (10%) flocks showed positive reactions in ELISA.