Immunisation against ovine caseous lymphadenitis: correlation between Corynebacterium pseudotuberculosis toxoid content and protective efficacy in combined clostridial-corynebacterial vaccines.
Groups of sheep were dosed with vaccines containing Corynebacterium pseudotuberculosis toxoid combined in varying amounts with 5 clostridial antigens. Resistance of the sheep to infection with C pseudotuberculosis was tested at 1, 6 and 12 months after vaccination by infection with pus from ovine lymph glands actively infected with C pseudotuberculosis. The outcome was assessed 3 months after challenge by slaughter and inspection of the sheep for caseous lymphadenitis lesions. Protection was demonstrated by a significant reduction in the proportion of immunised sheep exhibiting lesions compared with control sheep, and by fewer abscesses in affected immunised sheep than in affected control sheep. A positive correlation was found between amount of C pseudotuberculosis toxoid administered and degree of protection obtained. Chromatographically-purified toxoid induced essentially the same protection, suggesting that anti-toxic immunity is the major factor in protection.
Eggleton
D G
DG
Commonwealth Serum Laboratories, Parkville, Victoria.
Haynes
J A
JA
Middleton
H D
HD
Cox
J C
JC
D000818:Animals; D000907:Antibodies, Bacterial / Q000096:biosynthesis; D001428:Bacterial Vaccines / Q000276:immunology; D003013:Clostridium / Q000276:immunology; D003015:Clostridium Infections / Q000517:prevention & control / Q000662:veterinary; D003354:Corynebacterium Infections / Q000517:prevention & control / Q000662:veterinary*; D016925:Corynebacterium pseudotuberculosis / Q000276:immunology*; D008199:Lymphadenitis / Q000517:prevention & control / Q000662:veterinary*; D008297:Male; D012756:Sheep; D012757:Sheep Diseases / Q000517:prevention & control*; D014121:Toxoids / Q000276:immunology
D000907:Antibodies, Bacterial; D001428:Bacterial Vaccines; D014121:Toxoids