Abstract
Of 6, 129 healthy pigs slaughtered at the Tokachishimizu Abattoir, Hokkaido, from April, 1969, to July, 1970, 173 pigs (2.8%) showed tuberculous lesions in the mesenteric lymph-Knodes. These lesions were also present in the submaxillary lymph nodes in 16 pigs (0.2%). The incidence of such lesions rather varied from one piggery to another according to sanitary and feeding conditions.
Acid-fast organisms were demonstrated microscopically in 65 materials (67%) out of 97 collected caseous or calcified lymph nodes. They were isolated in pure state in nearly 100 per cent by cultural experiments.
Thirty isolated strains tested showed almost the same cultural and biochemical characteristics: slows growth, non-pigmented, light or dark in color, niacin negative, smooth-type colony formation, ability to grow at 22 or 44°C, catalase positive, and urease negative.
No guinea pigs produced any lesion. Rabbits and chickens, when inoculated intravenously, developed tuberculous lesions in the liver, spleen, or lung, some of them succumbing 23-66days after inoculation.
The organisms isolated were identified tentatively as members of the nonphotochromogenic group (Runyon's group III), though further experiments might be needed for accurate classification.
