Trypanosoma Cruzi Isolated From A Triatomine Found In One Of The Biggest Metropolitan Areas Of Latin America

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)To characterize Trypanosoma cruzi (TcI) isolated from a Panstrongylus megistus specimen found in one of the biggest metropolitan areas of Latin America, the relationship between the TcI group of T. cruzi and the transmission cycle in the urban environment was studied. Methods: The T. cruzi strain, Pm, was isolated in a culture medium from the evolutionary forms present in the hindgut of a live male specimen of P. megistus found in the Jabaquara subway in Sao Paulo City. The sample from the triatomine showed trypomastigote forms of Trypanosomatidae, which were inoculated in the peritoneum of Balb/c mice. The sample was then inoculated in Liver Infusion Tryptose medium and J774 cells for the molecular identification and characterization of the parasite. The Pm strain of T. cruzi was identified by isolation in axenic culture medium, and based on the morphology, cell infection, growth kinetics, and molecular characterization. Results: After isolation, the protozoan was identified as T. cruzi. No parasites were detected in the peripheral blood of the animal, which can be a characteristic inherent to the strain of T. cruzi that was isolated. Cell invasion assays were performed in triplicate in the J774 cell line to confirm the invasive ability of the Pm strain and revealed amastigote forms of the parasite within macrophages. Conclusions: Our biological and molecular characterizations helped understand parasite-host interactions and their evolutionary history in context of the associations between vectors, ecotopes, hosts, and groups of the parasite.492183189Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior (CAPES), Brasilia, DF, BrazilPrograma de Apoio ao Desenvolvimento Cientifico (PADC)Faculdade de Ciencias Farmaceuticas (FCFAR)Campus de Araraquara, Universidade Estadual Paulista (UNESP)Instituto de Biologia (IB), Universidade Estadual de Campinas (UNICAMP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Trypanosoma cruzi isolado de triatomíneos coletados na Bahia e Rio Grande do Sul

Collection of triatomines in domestic, peridomestic and sylvatic environments in states of Bahia and Rio Grande do Sul, Northeastern and Southern Brazil respectively, and isolation of Trypanosoma cruzi strains. METHODS First, the captured triatomines were identified using insect identification keys, then their intestinal content was examined by abdominal compression, and the samples containing trypanosomatid forms were inoculated in LIT medium and Swiss mice. RESULTS Six triatomine species were collected in cities in Bahia, namely Panstrongylus geniculatus (01), Triatoma melanocephala (11), T. lenti (94), T. pseudomaculata (02), T. sherlocki (26) and T. sordida (460), and two in cities in Rio Grande do Sul, namely T. circummaculata (11) and T. rubrovaria (115). Out of the specimens examined, T. cruzi was isolated from 28 triatomine divided into four different species: T. melanocephala (one), T. lenti (one), T. rubrovaria (16) and T. sordida (10). Their index of natural infection by T. cruzi was 6.4%. CONCLUSIONS The isolation of T. cruzi strains from triatomines found in domestic and peridomestic areas shows the potential risk of transmission of Chagas disease in the studied cities. The maintenance of those T. cruzi strains in laboratory is intended to promote studies that facilitate the understanding of the parasite-vector-host relationship482295302COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP23038.005285/2011-1213/08826-5Isolar cepas de Trypanosoma cruzi em triatomíneos capturados nos ambientes domiciliar, peridomiciliar e silvestre da Bahia e do Rio Grande do Sul. MÉTODOS Os triatomíneos capturados nos estados da Bahia e Rio Grande do Sul foram identificados por meio de chaves entomológicas. O conteúdo intestinal foi examinado por compressão abdominal e as amostras que continham formas de Trypanosomatidae foram inoculadas em meio de cultura Liver Infusion Tryptose e em camundongos Swiss. RESULTADOS Foram identificadas seis espécies de triatomíneos nas coletas realizadas em municípios do Estado da Bahia: Panstrongylus geniculatus (01), Triatoma melanocephala (11), T. lenti (94), T. pseudomaculata (02), T. sherlocki (26) e T. sordida (460), e duas no Estado do Rio Grande do Sul: T. circummaculata (11) e T. rubrovaria (115). Dos exemplares examinados, T. cruzi foi isolado de 28 triatomíneos pertencentes a quatro espécies: T. melanocephala (uma), T. lenti (uma), T. rubrovaria (16) e T. sordida (10). O índice de infecção natural de triatomíneos por T. cruzi foi de 6,4%. CONCLUSÕES O isolamento de cepas de T. cruzi em triatomíneos encontrados no intra e peridomicílio reflete o potencial risco de transmissão da doença de Chagas nos municípios estudado

Trypanosoma cruzi isolado de triatomíneos coletados na Bahia e Rio Grande do Sul

OBJECTIVE Collection of triatomines in domestic, peridomestic and sylvatic environments in states of Bahia and Rio Grande do Sul, Northeastern and Southern Brazil respectively, and isolation of Trypanosoma cruzi strains. METHODS First, the captured triatomines were identified using insect identification keys, then their intestinal content was examined by abdominal compression, and the samples containing trypanosomatid forms were inoculated in LIT medium and Swiss mice. RESULTS Six triatomine species were collected in cities in Bahia, namely Panstrongylus geniculatus (01), Triatoma melanocephala (11), T. lenti (94), T. pseudomaculata (02), T. sherlocki (26) and T. sordida (460), and two in cities in Rio Grande do Sul, namely T. circummaculata (11) and T. rubrovaria (115). Out of the specimens examined, T. cruzi was isolated from 28 triatomine divided into four different species: T. melanocephala (one), T. lenti (one), T. rubrovaria (16) and T. sordida (10). Their index of natural infection by T. cruzi was 6.4%. CONCLUSIONS The isolation of T. cruzi strains from triatomines found in domestic and peridomestic areas shows the potential risk of transmission of Chagas disease in the studied cities. The maintenance of those T. cruzi strains in laboratory is intended to promote studies that facilitate the understanding of the parasite-vector-host relationship.OBJETIVO Isolar cepas de Trypanosoma cruzi em triatomíneos capturados nos ambientes domiciliar, peridomiciliar e silvestre da Bahia e do Rio Grande do Sul. MÉTODOS Os triatomíneos capturados nos estados da Bahia e Rio Grande do Sul foram identificados por meio de chaves entomológicas. O conteúdo intestinal foi examinado por compressão abdominal e as amostras que continham formas de Trypanosomatidae foram inoculadas em meio de cultura Liver Infusion Tryptose e em camundongos Swiss. RESULTADOS Foram identificadas seis espécies de triatomíneos nas coletas realizadas em municípios do Estado da Bahia: Panstrongylus geniculatus (01), Triatoma melanocephala (11), T. lenti (94), T. pseudomaculata (02), T. sherlocki (26) e T. sordida (460), e duas no Estado do Rio Grande do Sul: T. circummaculata (11) e T. rubrovaria (115). Dos exemplares examinados, T. cruzi foi isolado de 28 triatomíneos pertencentes a quatro espécies: T. melanocephala (uma), T. lenti (uma), T. rubrovaria (16) e T. sordida (10). O índice de infecção natural de triatomíneos por T. cruzi foi de 6,4%. CONCLUSÕES O isolamento de cepas de T. cruzi em triatomíneos encontrados no intra e peridomicílio reflete o potencial risco de transmissão da doença de Chagas nos municípios estudados

Biological and molecular characterization of strains of Trypanosoma cruzi Chagas, 1909 (Kinetoplastida, Trypanosomatidae) isolated from Bahia, Rio Grande do Sul, Santa Catarina and São Paulo

Orientadores: João Aristeu da Rosa, Mário SteindelTese (doutorado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo: Trypanosoma cruzi, protozoário que faz parte da família Trypanosomatidae é o agente causador da doença de Chagas que afeta 6-8 milhões de pessoas na América Latina. A origem dessa família pode ser estudada por meio de técnicas moleculares, como a investigação da região V7V8 - SSUrRNA. Trypanosoma cruzi é subdividido em seis grupos independentes TcI-TcVI denominados Unidades Discretas de Tipagem (DTUs). A caracterização biológica e molecular de onze cepas de T. cruzi pertencentes aos grupos TcI (Bolívia; Tlenti; Tmelanocephala; SC90), TcII (Famema; SC96; SI8; Y) e TcIII (QMM3; QMM5; SI5) isoladas de cinco espécies de triatomíneos esclarece fatores biológicos por parâmetros como a cinética de crescimento, curva parasitêmica, taxa de infeção celular, caracterização molecular, ação de metaloproteinases, perfil protéico e sorologia. O objetivo do trabalho foi a caracterização biológica e molecular de cepas de T. cruzi isoladas de triatomíneos da Bahia, Rio Grande do Sul, Santa Catarina e São Paulo. O grupo TcII de T. cruzi mostrou maior capacidade multiplicativa em formas epimastigotas durante a cinética de crescimento, seguido por TcI e TcIII. A curva parasitêmica evidenciou variabilidade entre os camundongos Balb/c, contudo ao comparar os grupos TcI, TcII e TcIII de T. cruzi o perfil parasitêmico mostrou-se equivalente. Acrescentando os dados biológicos estudou-se a taxa de infecção de T. cruzi em linhagens celulares J774 e macrófagos peritoneais. O grupo TcI de T. cruzi apresentou maior taxa de infecção e menor tempo exigido para a multiplicação de formas amastigotas, assim como macrófagos peritoneias mostraram-se mais atrativos para T. cruzi. A caracterização molecular, por meio da região V7V8, mostrou que essas cepas pertencem às DTUs TcI, TcII e TcIII. A separação dos grupos torna-se evidente ao comparar o perfil protéico em formas epi e tripomastigotas de T. cruzi. O grupo TcI apresentou mais proteínas nos géis de acrilamida, particularidade que pode ser associada a intra-específicidade de TcI. A ação de metaloproteinases foi observada em formas epi e tripomastigotas sugerindo presença ativa e estável durante parte do ciclo do parasito. A reatividade sorológica foi comprovada nos grupos TcI, TcII e TcIII, por meio de ELISA em diluições de 1/100 até 1/12.800. A adição da técnica de Western Blotting aos ensaios por SDS-PAGE em soros de animais infectados após 50 dias mostrou o perfil protéico da cepa Y em membrana de nitrocelulose. Em conjunto, os resultados mostraram que as onze cepas de T. cruzi apresentaram diferenças entre os grupos do parasito. O grupo TcI mostrou maior taxa de infecção em células; TcII, os maiores valores para a cinética de crescimento e TcIII filogenéticamente próximo a TcV, grupo híbrido. A associação parasito-hospedeiro pode explicar diferenças biológicas e moleculares em cepas de T. cruzi, neste sentido o estudo de onze cepas isoladas de diferentes hospedeiros pode agregar informações a literatura e esclarecer alguns aspectos biológicos desse patógenoAbstract: Trypanosoma cruzi, a protozoan from the family Trypanosomatidae, is responsible for Chagas disease which affects about 6 to 8 million people in Latin America. The origin of this family can be studied through molecular techniques, for instance the investigation of the region V7V8 ¿ SSurRNA. The protozoan is subdivided in six independents groups TcI-TcVI known as Discrete Typing of Units (DTUs). The biological and molecular characterization of eleven strains of T. cruzi from the group TcI (Bolivia; Tlenti; Tmelanocephala; SC90), TcII (Famema; SC96; SI8; Y) and TcIII (QMM3; QMM5; SI5) isolated from five different species of triatomine are able to elucidate biological factors through the kinetic growth, parasitemic curve, cell infection rate, molecular characterization, metalloproteinase action, proteic and serological profile. This investigation was conducted to provide a biological and molecular characterization of T. cruzi isolated from specimens of triatomines. The group TcII of T. cruzi demonstrated higher replicative capacity in epimastigotes forms during the kinetic growth curve, followed by TcI and TcIII. The parasitemic curve demonstrated variability between Balb/c mice; however, the groups TcI, TcII and TcIII showed equivalent parasitemic profile. Furthermore, the cell infection rate in J774 cellular lineages and peritoneal macrophages was used to corroborate the biological data. The group TcI of T. cruzi demonstrated higher infection rate and less time to amastigotes forms multiplication and the peritoneal macrophages showed more attractive to T. cruzi. The molecular characterization through the V7V8 region indicated that these strains belong to DTUs TcI, TcII and TcIII. The groups segregation is important to compare the proteic profile of epimastigotes and tripomastigotes forms of T. cruzi. The groups TcI presented more proteins in acrylamide gels, which can be associated with intra-specif of TcI. The metalloproteinase action was observed in epimastigotes and tripomastigotes forms, demonstrating active and stable presence at the parasite life cycle. The serological reactivity was proven in the groups TcI, TcII and TcIII through ELISA dilutions of 1/100 to 1/12.800. Moreover, the Western Blotting technique was added to SDS-PAGE experiments in infected animals¿ serum after 50 dias and the proteic profile of Y strain was observed in nitrocellulose membrane. The results demonstrated that these eleven strains of T. cruzi have differences between the groups of the parasite. The group TcI showed higher infection rate in cells; TcII, higher value for kinetic growth and TcIII is phylogenetically closer to TcV, which is a hybrid group. The association between parasite and host is able to explain the biological and molecular differences in T. cruzi strains; for this reason, the study of eleven strains isolated from different hosts can add information to the literature and clarify some of the biological aspects of the parasiteDoutoradoParasitologiaDoutora em Parasitologi

Morphological, biological and molecular characterization of three Trypanosoma cruzi Chagas, 1909 (Kinetoplastida, Trypanosomatidae) stains isolated of Triatoma sordida Stal 1859 (Hemiptera, Reduviidae) specimens

Orientador: João Aristeu da RosaDissertação (mestrado) - Universidade Estadual de Campinas, Instituto de BiologiaResumo : A doenca de Chagas, assim como seu agente etiologico Trypanosoma cruzi, foram descritos por Carlos Ribeiro Justiniano das Chagas. T. cruzi e transmitido por hemipteros sendo os generos Panstrongylus, Rhodnius e Triatoma os mais importantes. Com resultados bastante satisfatorios em relacao ao controle do principal vetor, T. infestans, outros triatomineos de importancia secundaria, coletados no peridomicilio, passaram a assumir maior relevancia, dentre essas especies, T. sordida. As populacoes de T. cruzi apresentam grande variabilidade intraespecifica evidenciada por diferencas na morfologia, na virulencia e patogenicidade, na habilidade de evasao a resposta imune do hospedeiro e na constituicao antigenica. Essa diversidade pode estar associada a sua adaptacao e sobrevivencia em diferentes hospedeiros. As diferentes formas de manifestacao clinica da doenca no homem podem ser associadas com cepas especificas ou com marcadores geneticos do hospedeiro, embora ambos possam influenciar o curso da infeccao. Este trabalho objetivou a caracterizacao biologica, morfologica e molecular de tres cepas de T. cruzi (SI5, SI8 e SIGR3) isoladas de T. sordida coletadas em Santo Inacio, Bahia. Desse modo, o estudo biologico indicou que as cepas isoladas de Santo Inacio, pertencem ao Biodema III e Zimodema I. Os resultados das mensuracoes das cepas SI5, SI8 e SIGR3 mostraram polimorfismo das formas tripomastigotas sanguineas, embora com predominancia de formas intermediarias para largura do corpo e curtas para comprimento total do corpo no decurso da infeccao experimental. Foram avaliados para as formas epimastigotas, parametros como comprimento total do corpo, largura e indice nuclear e observamos para as cepas SI5, SI8 e SIGR3 respectivamente, formas intermediaria/intermediaria/baixo, curto/intermediario/baixo e curta/larga/baixo para os parametros descritos acima. O significado geral desse polimorfismo ainda nao foi suficientemente investigado, desconhecendo-se se ele expressa um diferente comportamento biologico das cepas ou se reflete apenas a existencia de um "complexo" morfologico. A caracterizacao molecular das cepas SI5, SI8 e SIGR3, as enquadram no grupo II, o que indica, que nesse local circula uma mesma linhagem de T. cruzi, apesar das mesmas terem sido isoladas de hospedeiros e epocas distintas.Abstract: Chagas disease and its causative agent Trypanosoma cruzi were described by Carlos Ribeiro Justiniano das Chagas. T. cruzi is transmitted by blood-sucking hemipterous and Panstrongylus, Rhodnius and Triatoma are the most important genera. Satisfactory results were achieved to the control of the main vector, T. infestans. However, other bugs of secondary importance, like Triatoma sordida collected around the houses began to assume greater epidemiological importance. The populations of T. cruzi show great variability among individuals demonstrated by differences in morphology, virulence and pathogenicity, ability to evade the host immune response and antigenic constitution. Such diversity may be associated with their adaptation and survival in different hosts. The course of the infection in human may be associated with specific strains or host genetic markers, although both can influence. This aim of this study was the biological, morphological and molecular characterization of three strains of T. cruzi (SI5, and SI8 SIGR3) isolated from T. sordida collected in Santo Inacio, Bahia. The biological study indicated that the isolates from Santo Inacio, belong to Biodeme III Zimodeme I. The results of measurements of the strains SI5, SI8 SIGR3 showed polymorphism of blood trypomastigotes, with a predominance of intermediate forms to body width and short length for total body in the course of experimental infection. Parameters such as: total body length, width and nuclear index were evaluated for epimastigotes, and observed for strains SI5, SI8 and SIGR3 respectively, forms na intermediate / middle / low, short / intermediate / low, short / wide / low for the parameters described above. The general meaning of this polymorphism has not been sufficiently investigated. It is not known if such poliymorphism expresses a different biologic behavior of the strains or merely is a result of a "complex" morphology. According to the molecular characterization the strains SI5, SI8 SIGR3 are in group II, which indicates that in this site it occurs the same lineage of T. cruzi, despite their different sources (isolated from different hosts and different times).MestradoParasitologiaMestre em Parasitologi

Response to different benznidazole doses in animal models of chronic phase Chagas disease: a critical review

Abstract Chagas disease is a protozoan infection that was identified over a century ago. No drugs are available to treat the indeterminate and determinate chronic phases of the disease. Success of a drug design is dependent on correct biological evaluation. Concerning new drug designs for Chagas disease, it is essential to first identify the most effective, existing, experimental chronic protocols that can be used for comparison purposes. Here, we present a literature review regarding experimental models with chronic Chagas disease to evaluate the efficacy of benznidazole (BZN). We searched literature published in PubMed and Web of Science databases, using these keywords: animal model, BZN, Chagas disease, T. cruzi, and chronic phase, with no timeframe limitations. We excluded articles involving acute phase animal models and/or those without BZN treatment. The selected studies were conducted using different BZN concentrations (10mg-100mg) involving several different periods (5-70 days). Concentrations and durations of use are directly related to side effects, but do not prevent chronic tissue lesions. BZN use during the late/chronic phases of Chagas disease is unable to eliminate amastigote forms present in infected tissues. This study suggests the administration of a lower BZN concentration (<100mg/kg/day) during the chronic phase of the animal model, as this had been reported to result in fewer side effects

Trypanosoma cruzi isolated from a triatomine found in one of the biggest metropolitan areas of Latin America

Abstract: INTRODUCTION: To characterize Trypanosoma cruzi (TcI) isolated from a Panstrongylus megistus specimen found in one of the biggest metropolitan areas of Latin America, the relationship between the TcI group of T. cruzi and the transmission cycle in the urban environment was studied. METHODS: The T. cruzi strain, Pm, was isolated in a culture medium from the evolutionary forms present in the hindgut of a live male specimen of P. megistus found in the Jabaquara subway in São Paulo City. The sample from the triatomine showed trypomastigote forms of Trypanosomatidae, which were inoculated in the peritoneum of Balb/c mice. The sample was then inoculated in Liver Infusion Tryptose medium and J774 cells for the molecular identification and characterization of the parasite. The Pm strain of T. cruzi was identified by isolation in axenic culture medium, and based on the morphology, cell infection, growth kinetics, and molecular characterization. RESULTS: After isolation, the protozoan was identified as T. cruzi. No parasites were detected in the peripheral blood of the animal, which can be a characteristic inherent to the strain of T. cruzi that was isolated. Cell invasion assays were performed in triplicate in the J774 cell line to confirm the invasive ability of the Pm strain and revealed amastigote forms of the parasite within macrophages. CONCLUSIONS: Our biological and molecular characterizations helped understand parasite-host interactions and their evolutionary history in context of the associations between vectors, ecotopes, hosts, and groups of the parasite

Spermathecae: morphofunctional features and correlation with fat bodies and trachea in six species of vectors of Chagas disease

Since spermatheca is able to transport spermatozoa and maintain a specific microenvironment for the storage of viable sperm cells for long periods of time, specific morphofunctional features must be involved in this capacity, and an efficient nutritional and oxygen supply must be required. In this study, we investigated the histological features of spermathecae and fat bodies in six species of three genera of epidemiological importance for Chagas' disease. The association of the reproductive system with the fat bodies and tracheal system was also focused in these species. The reproductive system, tracheae and fat bodies were fixed in 4% formaldehyde, and embedded in glycol methacrylate. The sections were stained with H.E., picrosirius red and Periodic-Acid Schiff methods for morphological analyses. Paraffin-embedded spermatheca sections were submitted to immunofluorescence for detection of V-ATPase. In P. lignarius, R. montenegrensis and R. prolixus, the spermatheca contains a slightly dilated tubular distal portion. In P. megistus and T. tibiamaculata, the spermatheca shows a large bulbous distal portion, and in T. infestans, a large oval-shaped distal portion. In all species, this portion was surrounded by a thin muscular layer, and the epithelial height varied according to the shape of this terminal portion. All spermathecal proximal portions showed simple columnar epithelium surrounded by a thick muscular layer. The epithelial cells of spermathecae showed PAS-positive cytoplasm and V-ATPase immunofluorescence in the apical surface. Tracheoles and polysaccharide-rich fat body cells were found next or in close contact to the oviduct or spermathecal tissues. The results indicate that the spermatheca proximal portion is related to contraction and sperm transport, whose oxygen and energy supply is guaranteed by the associated tracheal branches and fat bodies. In the storage portion, fat bodies and tracheae seem to be crucial for the maintenance of an optimal spermathecal microenvironment and storage of viable sperm cells. The participation of V-ATPase in the spermathecae epithelial cells may contribute for the maintenance of an optimal luminal milieu to spermatozoa, by alkalinization and/or acidification of lumen, similarly to the other epithelial cell types in insects. Further studies are necessary to clarify the role of this proton pump in the spermathecal epithelial cells197CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorFAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulosem informação2012/23845-3; 2017/19829-

Trypanosoma cruzi strains from triatomine collected in Bahia and Rio Grande do Sul, Brazil

OBJECTIVE: Collection of triatomines in domestic, peridomestic and sylvatic environments in states of Bahia and Rio Grande do Sul, Northeastern and Southern Brazil respectively, and isolation of Trypanosoma cruzi strains.METHODS: First, the captured triatomines were identified using insect identification keys, then their intestinal content was examined by abdominal compression, and the samples containing trypanosomatid forms were inoculated in LIT medium and Swiss mice.RESULTS: Six triatomine species were collected in cities in Bahia, namely Panstrongylus geniculatus (01), Triatoma melanocephala (11), T. lenti (94), T. pseudomaculata (02), T. sherlocki (26) and T. sordida (460), and two in cities in Rio Grande do Sul, namely T. circummaculata (11) and T. rubrovaria (115). Out of the specimens examined, T. cruzi was isolated from 28 triatomine divided into four different species: T. melanocephala (one), T. lenti (one), T. rubrovaria (16) and T. sordida (10). Their index of natural infection by T. cruzi was 6.4%.CONCLUSIONS: The isolation of T. cruzi strains from triatomines found in domestic and peridomestic areas shows the potential risk of transmission of Chagas disease in the studied cities. The maintenance of those T. cruzi strains in laboratory is intended to promote studies that facilitate the understanding of the parasite-vector-host relationship.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES

Structural Differences in Translation Initiation between Pathogenic Trypanosomatids and Their Mammalian Hosts

International audienceLa traduction canonique de l’ARNm chez les eucaryotes commence par la formation du complexe de pré-initiation (PIC) 43S. Son assemblage nécessite la liaison de l’initiateur Met-TRNAjeRencontrèrent et plusieurs facteurs d’initiation eucaryotes (eIF) à la petite sous-unité ribosomique (40S). Par rapport à leurs hôtes mammifères, les trypanosomatidés présentent des différences structurelles significatives dans leurs 40S, suggérant une variabilité substantielle dans l’initiation de la traduction. Ici, nous déterminons la structure du PIC 43S de Trypanosoma cruzi, le parasite responsable de la maladie de Chagas. Notre structure présente de nombreuses caractéristiques spécifiques, telles que la variante eIF3 et ses interactions uniques avec les grands segments d’expansion de l’ARNr (ES) 9S, 7S, et 6S, et l’association d’une hélicase de type DDX60 spécifique au kinétoplaste. Il révèle également le site de liaison 40S du domaine eIF5 C-terminal et les structures des queues terminales clés de plusieurs eIF conservés sous-jacentes à leurs activités au sein du PIC. Nos résultats sont corroborés par des essais de traction de glutathion S-transférase (GST) dans les données humaines et T. cruzi et la spectrométrie de masse