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Two types of caseous lymphadenitis vaccines were prepared from a Corynebacterium
pseudotuberculosis local strain CP41N that causes caseous lymphadenitis in sheep
and goats. The first vaccine was a cell wall lysate (CW) which contained 8 mg
protein/1ml and the second was a cell wall lysate of 8mg protein/1ml plus toxoid of
7mg protein/0.5ml. Three doses of each vaccine were injected s/c at one month
interval in two groups of goats (five animals each). The third group was used as a
non-vaccinated control. Three weeks after the last vaccination, all animals were
challenged i/v with 1.2Χ105 CFU/ml of Corynebacterium pseudotuberculosis (CP
41N). One month after the challenge, all animals were slaughtered and autopsied for
caseous lymphadenitis lesions. Significant reduction (P<0.01) had occurred in
number of lesions in animals vaccinated with first and the second vaccines
compared with the controls. On the other hand, there was a significant reduction
(P<0.05) in the number of lesions in animals vaccinated with the second vaccine
compared with animals vaccinated with the first one. The protective efficacy
conferred on internal organs (lungs, livers, spleens, kidneys, pericardia, omenta,
mediastinal and mesenteric lymph nodes) from lesions, amounted to 65.2% and
57% for the second and the first vaccines, respectively. The results obtained were
promising and encouraging to test CW lysate + toxoid vaccine for disease prevention in
the fields.
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