RESUMO
A bulk analysis of inter-simple sequence repeat-polymerase chain reaction (ISSR-PCR) provides a quick, reliable, and highly informative system for DNA banding patterns that permit species identification. The present study evaluates the applicability of this system to Trichinella species identification. After a single amplification carried out on a single larva with the primer 816([CA]nRY) under high stringency conditions, which provide high reproducibility, we were able to identify by consistent banding patterns 5 sibling species: Trichinella spiralis (ISS48), 2 Trichinella britovi isolates (ISS11 and ISS86), Trichinella murrelli (ISS35), Trichinella nativa (ISS71), Trichinella nelsoni (ISS29); 3 additional Trichinella genotypes: T8 (ISS149), T9 (ISS408 and ISS409), and T6 (ISS34); and the nonencapsulated species Trichinella pseudospiralis (ISS13). Moreover, 33 new Trichinella isolates from 2 zoogeographical regions were unequivocally identified. All Trichinella isolates have shown an identical pattern with those produced by the reference strain. According to these data, we have demonstrated that ISSR-PCR is a robust technique that emerges as a useful new application for the molecular identification of Trichinella isolates in epidemiological studies.
Assuntos
DNA de Helmintos/química , Reação em Cadeia da Polimerase/métodos , Trichinella/genética , Animais , Canidae , Primers do DNA/química , DNA de Helmintos/isolamento & purificação , Eletroforese em Gel de Ágar , Feminino , Genótipo , Masculino , Repetições de Microssatélites/genética , Sus scrofa , Trichinella/classificaçãoRESUMO
Biological parameters of five Trypanosoma cruzi strains from different sources were determined in order to know the laboratory behaviour of natural populations. The parameters evaluated were growth kinetics of epimastigotes, differentiation into metacyclic forms, infectivity in mammalian cells grown in vitro and parasite susceptibility to nifurtimox, benznidazole and gentian violet. Differences in transformation to metacyclic, in the percentage of infected cells as well as in the number of amastigotes per cell were observed among the strains. Regarding to pharmacological assays, Y strain was the most sensitive to the three assayed compounds. These data demonstrate the heterogeneity of natural populations of T. cruzi, the only responsible of infection in humans.
Assuntos
Trypanosoma cruzi/crescimento & desenvolvimento , Animais , Doença de Chagas/parasitologia , Chlorocebus aethiops , Variação Genética , Genética Populacional , Violeta Genciana/farmacologia , Estágios do Ciclo de Vida , Macrófagos/parasitologia , Camundongos , Nifurtimox/farmacologia , Nitroimidazóis/farmacologia , Testes de Sensibilidade Parasitária , Trypanosoma cruzi/efeitos dos fármacos , Trypanosoma cruzi/genética , Células Vero/parasitologiaRESUMO
Once known some biological characteristics of six Trypanosoma cruzi strains, randomly amplified polymorphic DNA (RAPD) analysis was made. Cluster analysis by UPGMA (unweighted pair group method analysis) was then applied both to biological parameters and RAPD profiles. Inspection of the UPGMA phenograms indicates identical clusters, so supporting that usefulness of biological parameters to characterization of T. cruzi strains still remains.