Observations on goats experimentally infected with Corynebacterium pseudotuberculosis

Moxoto goats (n=17) were experimentally inoculated intradermally with broth culture containing varying numbers of living Corynebacterium pseudotuberculosis and its exotoxin, five goats with broth culture supernatant containing solely crude exotoxin and five goats with washed C. pseudotuberculosis suspended in physiological saline. Three goats inoculated with sterile medium only and four uninoculated goats served as controls. Compared with controls, Moxoto goats inoculated with broth cultures of C. pseudotuberculosis and exotoxin, or solely with the crude exotoxin, became acutely ill, with depression, rises in rectal temperature and edema at the site of inoculation. The hematocrit, total serum protein and serum immunoglobulin levels decreased in these animals. Control goats and goats inoculated with washed bacteria did not exhibit these changes. These results indicate that the intradermal inoculation of goats with washed bacterial cell preparations results in the manifestation of a disease closely resembling naturally occurring caseous lymphadenitis and, thus, serves as an appropriate challenge system for vaccine studies.