ABSTRACT
Trypanosoma cruzi strains from distinct geographic areas show differences in drug resistance and association between parasites genetic and treatment response has been observed. Considering that benznidazole (BZ) can reduce the parasite burden and tissues damage, even in not cured animals and individuals, the goal is to assess the drug response to BZ of T. cruzi II strains isolated from children of the Jequitinhonha Valley, state of Minas Gerais, Brazil, before treatment. Mice infected and treated with BZ in both phases of infection were compared with the untreated and evaluated by fresh blood examination, haemoculture, polymerase chain reaction, conventional (ELISA) and non-conventional (FC-ALTA) serologies. In mice treated in the acute phase, a significant decrease in parasitaemia was observed for all strains. Positive parasitological and/or serological tests in animals treated during the acute and chronic (95.1-100%) phases showed that most of the strains were BZ resistant. However, beneficial effect was demonstrated because significant reduction (p < 0.05%) and/or suppression of parasitaemia was observed in mice infected with all strains (acute phase), associated to reduction/elimination of inflammation and fibrosis for two/eight strains. BZ offered some benefit, even in not cured animals, what suggest that BZ use may be recommended at least for recent chronic infection of the studied region.
Subject(s)
Humans , Drug Discovery , Industrial Waste/analysis , Nootropic Agents/isolation & purification , Plant Extracts/chemistry , Plant Shoots/chemistry , Stilbenes/isolation & purification , Vitis/chemistry , Agriculture/economics , Amyloid beta-Peptides/antagonists & inhibitors , Amyloid beta-Peptides/metabolism , Benzofurans/analysis , Benzofurans/chemistry , Benzofurans/economics , Benzofurans/isolation & purification , Chromatography, High Pressure Liquid , France , Industrial Waste/economics , Molecular Structure , Neuroprotective Agents/chemistry , Neuroprotective Agents/economics , Neuroprotective Agents/isolation & purification , Neuroprotective Agents/pharmacology , Nootropic Agents/chemistry , Nootropic Agents/economics , Nootropic Agents/pharmacology , Protein Aggregation, Pathological , Peptide Fragments/antagonists & inhibitors , Peptide Fragments/metabolism , Phenols/chemistry , Phenols/economics , Plant Extracts/economics , Protein Aggregates/drug effects , Spectrometry, Mass, Electrospray Ionization , Stereoisomerism , Stilbenes/analysis , Stilbenes/chemistry , Stilbenes/economics , Stilbenes/pharmacologyABSTRACT
Introduction The biological diversity of Trypanosoma cruzi strains plays an important role in the clinical and epidemiological features of Chagas disease. Methods Eight T. cruzi strains isolated from children living in a Chagas disease vector-controlled area of Jequitinhonha Valley, State of Minas Gerais, Brazil, were genetically and biologically characterized. Results The characterizations demonstrated that all of the strains belonged to T. cruzi II, and showed high infectivity and a variable mean maximum peak of parasitemia. Six strains displayed low parasitemia, and two displayed moderate parasitemia. Later peaks of parasitemia and a predominance of intermediate and large trypomastigotes in all T. cruzi strains were observed. The mean pre-patent period was relatively short (4.2±0.25 to 13.7±3.08 days), whereas the patent period ranged from 3.3±1.08 to 34.5±3.52 days. Mortality was observed only in animals infected with strain 806 (62.5%). Histopathological analysis of the heart showed that strains 501 and 806 caused inflammation, but fibrosis was observed only in animals infected with strain 806. Conclusions The results indicate the presence of an association between the biological behavior in mice and the genetic characteristics of the parasites. The study also confirmed general data from Brazil where T. cruzi II lineage is the most prevalent in the domiciliary cycle and generally has low virulence, with some strains capable of inducing inflammatory processes and fibrosis. .