Clonal structure of Trypanosoma cruzi Colombian strain (biodeme Type III): biological, isoenzymic and histopathological analysis of seven isolated clones.

The clonal structure of the Colombian strain of Trypanosoma cruzi, biodeme Type III and zymodeme 1, was analyzed in order to characterize its populations and to establish its homogeneity or heterogeneity. Seven isolated clones presented the basic characteristics of Biodeme Type III, with the same patterns of parasitemic curves, tissue tropism to skeletal muscle and myocardium, high pathogenicity with extensive necrotic-inflammatory lesions from the 20th to 30th day of infection. The parental strain and its clones C1, C3, C4 and C6, determined the higher levels of parasitemia, 20 to 30 days of infection, with high mortality rate up to 30 days (79 to 100%); clones C2, C5 and C7 presented lower levels of parasitemia, with low mortality rates (7.6 to 23%). Isoenzymic patterns, characteristic of zymodeme 1, (Z1) were similar for the parental strain and its seven clones. Results point to a phenotypic homogeneity of the clones isolated from the Colombian strain and suggest the predominance of a principal clone, responsible for the biological behavior of the parental strain and clones.

Clonal structure of Trypanosoma cruzi Colombian strain (biodeme Type III): biological, isoenzymic and histopathological analysis of seven isolated clones

The clonal structure of the Colombian strain of Trypanosoma cruzi, biodeme Type III and zymodeme 1, was analyzed in order to characterize its populations and to establish its homogeneity or heterogeneity. Seven isolated clones presented the basic characteristics of Biodeme Type III, with the same patterns of parasitemic curves, tissue tropism to skeletal muscle and myocardium, high pathogenicity with extensive necrotic-inflammatory lesions from the 20th to 30th day of infection. The parental strain and its clones C1, C3, C4 and C6, determined the higher levels of parasitemia, 20 to 30 days of infection, with high mortality rate up to 30 days (79 to 100%); clones C2, C5 and C7 presented lower levels of parasitemia, with low mortality rates (7.6 to 23%). Isoenzymic patterns, characteristic of zymodeme 1, (Z1) were similar for the parental strain and its seven clones. Results point to a phenotypic homogeneity of the clones isolated from the Colombian strain and suggest the predominance of a principal clone, responsible for the biological behavior of the parental strain and clones.

A estrutura clonal da cepa Colombiana do Trypanosoma cruzi, biodema Tipo III e zimodema 1, foi analisada com o objetivo de caracterizar as suas populações e estabelecer a homogeneidade ou heterogeneidade das mesmas. Foram isolados sete clones, os quais apresentaram as características básicas do biodema Tipo III, com o mesmo padrão de curvas parasitêmicas, tropismo tecidual para músculo esquelético e miocárdio, alta patogenicidade, com extensas lesões necrótico-inflamatórias, do 20º ao 30º dia de infecção. A cepa parental e os clones C1, C3, C4 e C6 apresentaram os niveis mais elevados de parasitemia entre 20 e 30 dias pós-infecção e alto indice de mortalidade até 30 dias (79 a 100%); os clones C2, C5 e C7 apresentaram niveis mais baixos de parasitemia com baixa mortalidade até 30 dias (7,6 a 23%). Os padrões isoenzimáticos foram característicos do zimodema 1 (Z1) para a cepa parental e os sete clones. Os achados do presente trabalho indicam uma homogeneidade fenotípica entre os clones isolados da cepa Colombiana e sugerem a predominância de um clone principal, responsável pelo padrão de comportamento biológico da cepa parental e dos clones.