Experimental benznidazole treatment of Trypanosoma cruzi II strains isolated from children of the Jequitinhonha Valley, Minas Gerais, Brazil, with Chagas disease.

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

Caracterização biológica e molecular de amostras do Trypanosoma cruzi isoladas de escolares e de suas mães residentes no Vale do Jequitinhonha, MG.

Este estudo explorou a hipótese da correlação entre a genética e as características morfobiológicas do T. cruzi com a evolução clínica da doença da doença de Chagas. Desta forma, amostras de parasitos de seis crianças e quatro de suas mães, residentes em Berilo e José Gonçalves de Minas, Vale do Jequitinhonha, MG, foram isoladas, sendo avaliadas quatro pares de amostras filho/mãe e mais duas amostras de crianças. Foram analisados a clínica dos pacientes por meio de exame clínico, ECG e raio-X do tórax e esôfago contrastado.Cinco crianças apresentaram a forma indeterminada da doença de Chagas e uma a forma cardíaca moderada enquanto todas as mães eram cardíacas com diferentes níveis de alteração. A caracterização morfobiológica foi feita em amostras isoladas das crianças em grupos de 8 camundongos Swiss, inoculados com 10.000 tripomastigotas sanguíneos, via IP, sendo analisados a curva de parasitemia, o período pré-patente, período patente, pico máximo de parasitemia, dia do pico máximo de parasitemia, morfologia do parasito no sangue periférico e a taxa de mortalidade. Foram realizadas posteriormente, passagens sucessivas do T. cruzi nestes animais, inoculados nas mesmas condições, no intuito de verificar seu comportamento após este manuseio. A caracterização morfobiológica permitiu concluir que todas as cepas apresentaram comportamento similar em camundongos, com 100% de infectividade, baixa virulência, mortalidade nula e predominância de formas largas durante a fase aguda infecção, sendo estas características também observadas após cinco passagens sucessivas. A caracterização bioquímica e molecular foi feita de todas as amostras isoladas das crianças e de suas mães, e consistiu na análise dos perfis de isoenzimas, de rDNA 24 Sα, do gene mitocondrial da Citocromo Oxidase II (COII) e de microssatélites. A caracterização bioquímica e molecular revelou que todas as amostras pertencem ao zimodema 2, grupo T. cruzi II, subgrupo 2b. Apesar de todas as cepas apresentarem a mesma classificação genética, a análise de microssatélites foi capaz de revelar perfis distintos entre as cepas e idênticos quando os perfis das cepas de cada par filho/mãe foram comparados o que sugere a ocorrência de transmissão congênita. Embora os microssatélites apresentem alto poder para segregar cepas da mesma classificação genética quando comparados com os outros marcadores, não há correlação entre o perfil de microssatélites e as características biológicas ou condição clínica de cada par filho/mãe. Os resultados sugerem que outros fatores tais como hospedeiro e/ou o tempo de infecção pode(m) desempenhar um importante papel na determinação da evolução clínica da doença de Chagas.This study intended to explore the hypothesis of straight correlation between T. cruzi genetics and biological characteristics with the development of Chagas disease clinical status. For this, T. cruzi strains were isolated from two children and four child/mother pairs, from Berilo and José Gonçalves de Minas municipalities, Jequitinhonha Valley, MG. The clinical status of the patients was analyzed by clinical examination, electrocardogram, rays-X of thorax and esophagus contrasted. Morphobiological characterization of children’s strains was studied in groups of eight Swiss mice, inoculated with 10.000 blood trypomatigotes, via IP, being analyzed the parasitemia curve, pre-patent period, patent period, maximum peak of parasitemia, day of maximum of parasitemia, morphology of blood trypomastigotes and mortality. Following, successive blood passages of the strains were performed in these animals, inoculated at the same conditions, to verify their behaviour after this manipulation. Molecular characterization of all strains was performed by the analysis of isoenzymes, rDNA 24Sα, COXII gene and microssatelites profiles. Five children displayed the indeterminate clinical form of the disease and one cardiac moderate, whereas all mothers were cardiac with distinct clinical status. All children’s strains showed similar behavior in mice, being observed 100% of infection, low virulence, null mortality and predominance of large blood trypomastigotes, being these characteristics also observed after successive blood passages. Despite all strains presented the same genetic classification, the microssatelites analysis was able to reveal distinct profiles for each pair of strains child/mother, suggestive of congenital transmission. Although the microssatelites showed stronger discrimination power to segregate strains of same genetic classification as compared to other markers, there is no correlation between the microsatelites profile with the biological characteristics of the strains and clinical status of each pair child/mother. Results suggest that other elements such as host factors and/or the length of infection may play important role determining the clinical evolution of Chagas disease

Caracterização biológica e molecular de amostras do Trypanosoma cruzi isoladas de escolares e de suas mães residentes no Vale do Jequitinhonha, MG.

Este estudo explorou a hipótese da correlação entre a genética e as características morfobiológicas do T. cruzi com a evolução clínica da doença da doença de Chagas. Desta forma, amostras de parasitos de seis crianças e quatro de suas mães, residentes em Berilo e José Gonçalves de Minas, Vale do Jequitinhonha, MG, foram isoladas, sendo avaliadas quatro pares de amostras filho/mãe e mais duas amostras de crianças. Foram analisados a clínica dos pacientes por meio de exame clínico, ECG e raio-X do tórax e esôfago contrastado.Cinco crianças apresentaram a forma indeterminada da doença de Chagas e uma a forma cardíaca moderada enquanto todas as mães eram cardíacas com diferentes níveis de alteração. A caracterização morfobiológica foi feita em amostras isoladas das crianças em grupos de 8 camundongos Swiss, inoculados com 10.000 tripomastigotas sanguíneos, via IP, sendo analisados a curva de parasitemia, o período pré-patente, período patente, pico máximo de parasitemia, dia do pico máximo de parasitemia, morfologia do parasito no sangue periférico e a taxa de mortalidade. Foram realizadas posteriormente, passagens sucessivas do T. cruzi nestes animais, inoculados nas mesmas condições, no intuito de verificar seu comportamento após este manuseio. A caracterização morfobiológica permitiu concluir que todas as cepas apresentaram comportamento similar em camundongos, com 100% de infectividade, baixa virulência, mortalidade nula e predominância de formas largas durante a fase aguda infecção, sendo estas características também observadas após cinco passagens sucessivas. A caracterização bioquímica e molecular foi feita de todas as amostras isoladas das crianças e de suas mães, e consistiu na análise dos perfis de isoenzimas, de rDNA 24 Sα, do gene mitocondrial da Citocromo Oxidase II (COII) e de microssatélites. A caracterização bioquímica e molecular revelou que todas as amostras pertencem ao zimodema 2, grupo T. cruzi II, subgrupo 2b. Apesar de todas as cepas apresentarem a mesma classificação genética, a análise de microssatélites foi capaz de revelar perfis distintos entre as cepas e idênticos quando os perfis das cepas de cada par filho/mãe foram comparados o que sugere a ocorrência de transmissão congênita. Embora os microssatélites apresentem alto poder para segregar cepas da mesma classificação genética quando comparados com os outros marcadores, não há correlação entre o perfil de microssatélites e as características biológicas ou condição clínica de cada par filho/mãe. Os resultados sugerem que outros fatores tais como hospedeiro e/ou o tempo de infecção pode(m) desempenhar um importante papel na determinação da evolução clínica da doença de Chagas.This study intended to explore the hypothesis of straight correlation between T. cruzi genetics and biological characteristics with the development of Chagas disease clinical status. For this, T. cruzi strains were isolated from two children and four child/mother pairs, from Berilo and José Gonçalves de Minas municipalities, Jequitinhonha Valley, MG. The clinical status of the patients was analyzed by clinical examination, electrocardogram, rays-X of thorax and esophagus contrasted. Morphobiological characterization of children’s strains was studied in groups of eight Swiss mice, inoculated with 10.000 blood trypomatigotes, via IP, being analyzed the parasitemia curve, pre-patent period, patent period, maximum peak of parasitemia, day of maximum of parasitemia, morphology of blood trypomastigotes and mortality. Following, successive blood passages of the strains were performed in these animals, inoculated at the same conditions, to verify their behaviour after this manipulation. Molecular characterization of all strains was performed by the analysis of isoenzymes, rDNA 24Sα, COXII gene and microssatelites profiles. Five children displayed the indeterminate clinical form of the disease and one cardiac moderate, whereas all mothers were cardiac with distinct clinical status. All children’s strains showed similar behavior in mice, being observed 100% of infection, low virulence, null mortality and predominance of large blood trypomastigotes, being these characteristics also observed after successive blood passages. Despite all strains presented the same genetic classification, the microssatelites analysis was able to reveal distinct profiles for each pair of strains child/mother, suggestive of congenital transmission. Although the microssatelites showed stronger discrimination power to segregate strains of same genetic classification as compared to other markers, there is no correlation between the microsatelites profile with the biological characteristics of the strains and clinical status of each pair child/mother. Results suggest that other elements such as host factors and/or the length of infection may play important role determining the clinical evolution of Chagas disease

Epidemia de febre amarela na bacia do Rio Doce: análise de fatores ambientais, epidemiológicos e efeitos indiretos do rompimento da barragem de Fundão (Samarco S/A)

O rompimento da barragem de rejeitos de Fundão (Samarco S/A no município de Mariana – MG), em novembro de 2015, liberou 55 milhões m³ de rejeitos, provocando a morte da biota aquática na calha central do Rio Doce e danos nos ecossistemas adjacentes. No início de 2017, iniciou-se uma epidemia de febre amarela em Minas Gerais, com grande parte das ocorrências na região da bacia do Rio Doce. Assim, este trabalho buscou verificar a existência de relação entre os dois fatos ocorridos. Os dados epidemiológicos e de monitoramento da água foram relacionados por meio de Análise de Componentes Principais (ACP), não sendo identificada relação direta entre o dano ambiental e a epidemia. Todavia, fatores como a dizimação dos predadores do mosquito vetor, a proximidade entre o homem e as florestas, e a baixa cobertura vacinal da população foram também considerados como aspectos relevantes. Desse modo, esse estudo analisou os fatores que devem ser considerados em conjunto, no intuito de compreender o aumento da febre amarela na Bacia do Rio Doce após o rompimento da barragem de Fundão

Sesquiterpene lactone in nanostructured parenteral dosage form is efficacious in experimental Chagas disease.

The drugs available for Chagas disease treatment are toxic and ineffective. We studied the in vivo activity of a new drug, lychnopholide (LYC). LYC was loaded in nanocapsules (NC), and its effects were compared to free LYC and benznidazole against Trypanosoma cruzi. Infected mice were treated in the acute phase at 2.0 mg/kg/day with free LYC, LYC-poly- -caprolactone NC (LYC-PCL), and LYC-poly(lactic acid)-co-polyethylene glycol NC (LYC-PLA-PEG) or at 50 mg/kg/day with benznidazole solution by the intravenous route. Animals infected with the CL strain, treated 24 h after infection for 10 days, evaluated by hemoculture, PCR, and enzyme-linked immunosorbent assay exhibited a 50% parasitological cure when treated with LYC-PCL NC and 100% cure when treated with benznidazole, but 100% of the animals treated during the prepatent period for 20 days with these formulations or LYC-PLA-PEG NC were cured. In animals with the Y strain treated 24 h after infection for 10 days, only mice treated by LYC-PCL NC were cured, but animals treated in the prepatent period for 20 days exhibited 100, 75, and 62.5% cure when treated with LYC-PLA-PEG NC, benznidazole, and LYC-PCL NC, respectively. Free LYC reduced the parasitemia and improved mice survival, but no mice were cured. LYC-loaded NC showed higher cure rates, reduced parasitemia, and increased survival when used in doses 2five times lower than those used for benznidazole. This study confirms that LYC is a potential new treatment for Chagas disease. Furthermore, the long-circulating property of PLA-PEG NC and its ability to improve LYC efficacy showed that this formulation is more effective in reaching the parasite in vivo

Molecular and biological characterization of Trypanosoma cruzi strains isolated from children from Jequitinhonha Valley, State of Minas Gerais, Brazil

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

Molecular and biological characterization of Trypanosoma cruzi strains isolated from children from Jequitinhonha Valley, State of Minas Gerais, Brazil

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&#177;0.25 to 13.7&#177;3.08 days), whereas the patent period ranged from 3.3&#177;1.08 to 34.5&#177;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

Trypanosoma cruzi Discret Typing Units (TcII and TcVI) in samples of patients from two municipalities of the Jequitinhonha Valley, MG, Brazil, using two molecular typing strategies.

Background: Trypanosoma cruzi is classified into six discrete taxonomic units (DTUs). For this classification, different biological markers and classification criteria have been used. The objective was to identify the genetic profile of T. cruzi samples isolated from patients of two municipalities of Jequitinhonha Valley, MG, Brazil. Methods: Molecular characterization was performed using two different criteria for T. cruzi typing to characterize 63 T. cruzi samples isolated from chronic Chagas disease patients. The characterizations followed two distinct methodologies. Additionally, the RAPD technique was used to evaluate the existence of genetic intragroup variability. Results: The first methodology identified 89 % of the samples as TcII, but it was not possible to define the genetic identity of seven isolates. The results obtained with the second methodology corroborated the classification as TcII of the same samples and defined the classification of the other seven as TcVI. RAPD analysis showed lower intra-group variability in TcII. Conclusions: The results confirmed the preliminary data obtained in other municipalities of the Jequitinhonha Valley, showing a predominance of TcII, similar to that verified in northeast/south axis of Brazil and the first detection of TcVI in the study region. The second protocol was more simple and reliable to identify samples of hybrid character