Abstract
Eighty-five CF# 1 mice were inoculated with living leprosy bacilli into the left hind foot-pads, and twenty with heat-killed ones, using 103 to 104 cells per foot-pad. After three to seven and a half months the mice were sacrificed and both left and right hind foot-pads, lungs, livers, kidneys, spleens, and left inguinal lymphnodes were examined for presence of acid-fast bacilli. Multiplication of the leprosy bacilli in the left hind foot-pads of mice was confirmed in fifty-eight of eighty-five mice inoculated with living organisms. Acid-fast bacilli were also found in the tissues other than the inoculated foot-pads, regardless of viability of the leprosy bacilli. Discovery of acid-fast bacilli was 64.7 per cent in the mice inoculated with living organisms and 50.0 per cent with killed ones. Acid-fast bacilli were found most frequently in the lymphnodes draining the inoculated foot-pads, the number of bacteria being very small in most cases. The evidence presented suggests that the leprosy bacilli are carried from the site of inoculation to other sites of mice, regardless of the viability. However, the invasion or multiplication in those sites remains still doubtful.
