Trypanosoma (Herpetosoma) rangeli Tejera, 1920: influence of host weight, size of inoculum, and route of infection upon experimental parasitemia.

To study the influence o f host age, inoculum size, and route o f infection on Trypanosoma (Herpetosoma) rangeli, 12 lots o f 6.0 g albino mice (NMRI strain) were infected up. with from 25x101 to 25xl(fi trypomastigotes/gram body weight harvested from LIT medium. The lower inocula produced low but persistent parasitemias, while the higher inocula produced high levels o f parasitemia that fell quickly, suggesting the mobilization o f resistance mechanisms. In other experiments, i.p. inoculation produ­ ced higher parasitemias than s.c. inoculation, and 6.0 g mice had higher parasitemias than 16.0 or 26.0 g mice. Thus, a standard methodology would seem to be necessary in the study of the various strains and/or species that may make up the T. rangeli complex.