Influence of the inoculation route in BALB/c mice infected by Leishmania infantum.

Mice of the BALB/c strain are frequently used, due to their high susceptibility to Leishmania infection. Most of the studies in visceral leishmaniasis use the endovenous or the intraperitoneal routes to inoculate the parasites. In this study, the development of experimental visceral leishmaniasis infection was evaluated in BALB/c mice inoculated with Leishmania infantum parasites by endovenous (EV group) or intraperitoneal (IP group) routes. The results shows that both inoculation routes were able to produce progressive infection in mice. However, a higher dispersion of the values of parasite density was detected among the animals of the EV group than the IP group. Our results indicate that the intraperitoneal inoculation results in a higher homogeneity of infections, so we suggest that this route should be preferentially used in experimental infections in the mice model, particularly when pools of samples are required for immune cellular studies.