Systemic infection of Leishmania tropica (major) in various strains of mice.

The spleen cells of different strains of mice were cultured and examined for the presence of viable promastigotes one to three months following a cutaneous inoculation of 1 to 2 X 10(6) promastigotes of Leishmania tropica (major). The spleen cultures of all five strains tested (BALB/c, DBA/3, C3H, CBA and C57B1/6) contained organisms. Viable parasites were present in the spleen of resistant strains (C3H, CBA, C57B1/6) even after recovery from their cutaneous lesion. The possible implication of this finding in the long lasting immunity observed in this disease is discussed.