Different degrees of morbidity, in the white mouse, induced by Nocardia brasiliensis, Nocardia asteroides and Nocardia caviae.

The respective degrees of morbidity induced by 6 strains each of Nocardia brasiliensis, N. asteroides and N. caviae were investigated by the method of inoculation in the plantar pad of the white mouse, using a suspension of these nocardiae at a concentration of 10 mg/0-1 ml., and inspecting the animals one month, two months and three months following inoculation. All of the strains of N. brasiliensis produced attack greater and more consistent than that of the other species, N. caviae and N. asteroides showing patterns of attack similar to each other, but substantially lower than those obtained with N. brasiliensis. The 6 strains of N. brasiliensis showed different rates of infection at different times of observation, but it was constantly high for all of them; on the other hand, the infectiousness of the different strains of N. caviae and N. asteroides was low, and there were no substantial differences between them. To sum up, these results with 6 strains of each species confirm those that were published in 1973 which dealt with only one strain of each species.