Death of Mycobacterium lepraemurium after multiplication in CBA, BALB/c and nude mice

The unexpected death of Mycobacterium lepraemurium in the course of systemic infection of mice, previously noted in the spleens of CBA mice, has been demonstrated in the spleens of BALB/c nu/+ and BALB/c nu/nu mice and also in the livers and other organs of mice of all three strains. That the same phenomenon was observed in nu/nu mice indicates that the mechanism of bacterial death does not involve a T-lymphocyte-mediated cellular immune response on the part of the mice.