Susceptibility to Mycobacterium avium of C3H/He Mice

C3H/He strain mice, approximately 6 weeks of age, were inoculated intraperitoneally with 0.5mg of M. avium, strain Kirchberg. The inoculum was prepared by the grinding method from a 13-day culuture of M. avium grown on 1% Ogawa's medium. The susceptibility of these mice to the bacilli was evaluated mainly by the average survivalThe susceptibility of mice of 5 inbred strains, C3H, C57BL/6, DDD, BALB/c and KK, was also examined by the same manner above mentioned, as controls.Clear differences in the host resistance to M. avium could be demonstrated in these strains, markedly between C3H and the other strains, including C3H/He. Average survival time and grade of visceral lesions of C3H/He mice were intermediate to those observed in C3H and the other 4 strains, but far distant to those of C3H strain.