1973 Volume 42 Issue 4 Pages 228-237
The bacillus employed for the test was the 2 nd subculture, 3-month-old on the 1% egg yolk medium, of the supposed4) Keishicho strain. Male mice of ddN strain were divided into 6 groups of 12 each and the groups were inoculated either subcutaneously or intravenously with 3 different doses (10-1, 10-2 and 10-3mg) of the bacillus. The mice subcutaneously inoculated were sacrificed at the end of 3, 6, 8, 10 and 13 months and the mice intravenously inoculated at the end of 3, 6, and 8 months (Table 1).
Observations of gross disease were made at necropsy. Spleens were weighed and their weight per gram of body weight were recorded. The internal organs, super-ficial lymph nodes and local lesions were removed, homogenized, and then submitted to microscopic examination and cultural recovery (Tables 2, 3, 4 & 7). The Ziehl-Neelsen stained smears were rated not only for the number of acid-fast bacilli under oil-immersion but also for the relative numbers and maximum sizes of globi under low magnification (Tables 6&8). In some instances histopathologic examinations were also performed (Table 5).
The results obtained indicated that in the mice inoculated with each of the doses subcutaneously or intravenously there was gross and bacteriologic evidence of infection, supported in some by histopathologic evidence. The findings were more pronounced in the animals intravenously inoculated than in those subcutaneously inoculated. In either case, however, they showed a tendency to become more marked in the course of infec-tion. It seemed reasonable to conclude that the disease in mice was fairly consistently reproduced with the test organisms.
