Placental infection in the fetuses of pregnant murine leprous mice.

In the previous paper the authors reported that acid-fast bacilli were discovered in normal mice, even as young as 3 days, in addition, acid-fast bacilli were found occasionally in the fetus of pregnant mice. These bacilli were scattered or in packet arrangement and did not grow on the ordinary culture media. This paper reports on following experiments carried out by the authors. Two different groups (A and B) of mice were kept together in the breeding cages. The first group, (A) was composed of murine leprous females and normal males; the second group, (B) was composed of normal females and murine leprous males. Pregnant mice were picked up from both group A and group B, and autopsied, and carefully examined. When the female mice of group A and B were delivered of off-spring, they were also examined. In the second experiment normal females (in group B) and normal males (in group A) which had been kept together with leprous mice for a few months were examined. Both the fetus and also the off-spring of these females were investigated for the presence of acid-fast bacilli. The results were as follows : 1. Twelve of the 41 leprous females (group A) became pregnant and acid-fast bacilli were found in 15 of their 77 fetus. In some fetus globi were discovered. 2. Only 4 of the 19 normal females (group B) which were kept together with murine lerpous males became pregnant, and in a total of 22 fetus, no acid-fast bacilli were found. 3. Only in one of the 41 total off-spring were a few scattered acid-fast bacilli found. 4. Acid-fast bacilli were found in 2 of the 13 normal males and in 2 of the 12 normal females which were kept together with the leprous mice. In one of the normal females globi were found in the liver.