Abstract
Inbred mice ddN were divided into 5 groups and infected with murine type leprosy bacilli by pernasal instillation, intratesticular inoculation, intracerebral inoculation, intravenous inoculation and by direct inoculation into the spleen after laparotomy. In order to know the proliferation of inoculated bacilli in various organs of the mice, 2-3 mice of each group were sacrificed periodically with certain intervals. Then, smears were prepared for the examination of the growth of bacilli, their state of dissemination, and to know the kinds of infiltrating cells. Organs like testicles, spleen, lymphnodes etc were removed and the number of the bacilli contained in them was estimated. Curves of the changes in the number of bacilli contained in various organs were drawn for each group. Stated in the following are the results obtained thereof. 1. Mice infected by pernasal instillation in a dose of approximately 34×104 bacilli developed no lesion detectable by smear for a period of 7 months. Whereas, the detection became suddenly positive and the bacilli showed logarithmic proliferation thereafter. (Table 1, Fig. 1) 2. Bacilli inoculated into testicles showed a logarithmic proliferation with a generation time of 7-10 days (calculating from the duration doubled in the number of bacilli) . (Fig. 2, 3). 3. Murine leprosy bacilli inoculated intracerebrally into mice also showed a good growth but the proliferation of the bacilli in the brain was not lethal to the animal. (Fig. 4) 4. No significant difference was recognized in the growth curve of the bacilli in the spleen between the animal received indirect intravenous inoculation and those received direct inoculation into the spleen after laparotomy. (Fig. 5)
