Trypanosoma cruzi: Infectivity of clonal genotype infections in acute and chronic phases in mice

Eight Trypanosoma cruzi stocks pertaining to the clonal genotypes 19/20, 32 , and 39 have been characterized for three experimental parameters of infec tivity in Balb/c mice: (i) percentage of mice with a patent parasitemia (% MPP), (ii) maximum parasitemia (MP), and (iii) percentage of mice with posi tive hemoculture (% MPH). By order of decreasing values, the values recorde d for the clonal genotypes ranked as follows: 19/20, 32, and 39, except for the % MPP parameter, for which 19/20 and 32 were not statistically differe nt. The rate of successful reisolation after infection in mice, analyzed by multilocus enzyme electrophoresis and random amplified polymorphic DNA typ ing, was statistically different according to the clonal genotype and was d ifferent for uniclonal infections and for mixed infections by two different clonal genotypes. These results confirm that T. cruzi clonal genotypes dif fer significantly in their infectivity in mice. (C) 2000 Academic Press.