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Schaub GA. Interaction of Trypanosoma cruzi, Triatomines and the Microbiota of the Vectors-A Review. Microorganisms 2024; 12:855. [PMID: 38792688 PMCID: PMC11123833 DOI: 10.3390/microorganisms12050855] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Revised: 04/15/2024] [Accepted: 04/17/2024] [Indexed: 05/26/2024] Open
Abstract
This review summarizes the interactions between Trypanosoma cruzi, the etiologic agent of Chagas disease, its vectors, triatomines, and the diverse intestinal microbiota of triatomines, which includes mutualistic symbionts, and highlights open questions. T. cruzi strains show great biological heterogeneity in their development and their interactions. Triatomines differ from other important vectors of diseases in their ontogeny and the enzymes used to digest blood. Many different bacteria colonize the intestinal tract of triatomines, but only Actinomycetales have been identified as mutualistic symbionts. Effects of the vector on T. cruzi are indicated by differences in the ability of T. cruzi to establish in the triatomines and in colonization peculiarities, i.e., proliferation mainly in the posterior midgut and rectum and preferential transformation into infectious metacyclic trypomastigotes in the rectum. In addition, certain forms of T. cruzi develop after feeding and during starvation of triatomines. Negative effects of T. cruzi on the triatomine vectors appear to be particularly evident when the triatomines are stressed and depend on the T. cruzi strain. Effects on the intestinal immunity of the triatomines are induced by ingested blood-stage trypomastigotes of T. cruzi and affect the populations of many non-symbiotic intestinal bacteria, but not all and not the mutualistic symbionts. After the knockdown of antimicrobial peptides, the number of non-symbiotic bacteria increases and the number of T. cruzi decreases. Presumably, in long-term infections, intestinal immunity is suppressed, which supports the growth of specific bacteria, depending on the strain of T. cruzi. These interactions may provide an approach to disrupt T. cruzi transmission.
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Affiliation(s)
- Günter A Schaub
- Zoology/Parasitology, Ruhr-University Bochum, Universitätsstr. 150, 44780 Bochum, Germany
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Silvestrini MMA, Alessio GD, Frias BED, Sales Júnior PA, Araújo MSS, Silvestrini CMA, Brito Alvim de Melo GE, Martins-Filho OA, Teixeira-Carvalho A, Martins HR. New insights into Trypanosoma cruzi genetic diversity, and its influence on parasite biology and clinical outcomes. Front Immunol 2024; 15:1342431. [PMID: 38655255 PMCID: PMC11035809 DOI: 10.3389/fimmu.2024.1342431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2023] [Accepted: 02/26/2024] [Indexed: 04/26/2024] Open
Abstract
Chagas disease, caused by Trypanosoma cruzi, remains a serious public health problem worldwide. The parasite was subdivided into six distinct genetic groups, called "discrete typing units" (DTUs), from TcI to TcVI. Several studies have indicated that the heterogeneity of T. cruzi species directly affects the diversity of clinical manifestations of Chagas disease, control, diagnosis performance, and susceptibility to treatment. Thus, this review aims to describe how T. cruzi genetic diversity influences the biology of the parasite and/or clinical parameters in humans. Regarding the geographic dispersion of T. cruzi, evident differences were observed in the distribution of DTUs in distinct areas. For example, TcII is the main DTU detected in Brazilian patients from the central and southeastern regions, where there are also registers of TcVI as a secondary T. cruzi DTU. An important aspect observed in previous studies is that the genetic variability of T. cruzi can impact parasite infectivity, reproduction, and differentiation in the vectors. It has been proposed that T. cruzi DTU influences the host immune response and affects disease progression. Genetic aspects of the parasite play an important role in determining which host tissues will be infected, thus heavily influencing Chagas disease's pathogenesis. Several teams have investigated the correlation between T. cruzi DTU and the reactivation of Chagas disease. In agreement with these data, it is reasonable to suppose that the immunological condition of the patient, whether or not associated with the reactivation of the T. cruzi infection and the parasite strain, may have an important role in the pathogenesis of Chagas disease. In this context, understanding the genetics of T. cruzi and its biological and clinical implications will provide new knowledge that may contribute to additional strategies in the diagnosis and clinical outcome follow-up of patients with Chagas disease, in addition to the reactivation of immunocompromised patients infected with T. cruzi.
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Affiliation(s)
| | - Glaucia Diniz Alessio
- Integrated Biomarker Research Group, René Rachou Institute, Fiocruz Minas, Oswaldo Cruz Foundation, Belo Horizonte, Minas Gerais, Brazil
| | - Bruna Estefânia Diniz Frias
- Integrated Biomarker Research Group, René Rachou Institute, Fiocruz Minas, Oswaldo Cruz Foundation, Belo Horizonte, Minas Gerais, Brazil
| | - Policarpo Ademar Sales Júnior
- Integrated Biomarker Research Group, René Rachou Institute, Fiocruz Minas, Oswaldo Cruz Foundation, Belo Horizonte, Minas Gerais, Brazil
| | - Márcio Sobreira Silva Araújo
- Integrated Biomarker Research Group, René Rachou Institute, Fiocruz Minas, Oswaldo Cruz Foundation, Belo Horizonte, Minas Gerais, Brazil
| | | | | | - Olindo Assis Martins-Filho
- Integrated Biomarker Research Group, René Rachou Institute, Fiocruz Minas, Oswaldo Cruz Foundation, Belo Horizonte, Minas Gerais, Brazil
| | - Andréa Teixeira-Carvalho
- Integrated Biomarker Research Group, René Rachou Institute, Fiocruz Minas, Oswaldo Cruz Foundation, Belo Horizonte, Minas Gerais, Brazil
| | - Helen Rodrigues Martins
- Department of Pharmacy, Federal University of the Jequitinhonha and Mucuri Valleys, Diamantina, Minas Gerais, Brazil
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Discrete Typing Units of Trypanosoma cruzi Identified by Real-Time PCR in Peripheral Blood and Dejections of Triatoma infestans Used in Xenodiagnosis Descriptive Study. Pathogens 2022; 11:pathogens11070787. [PMID: 35890030 PMCID: PMC9317341 DOI: 10.3390/pathogens11070787] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2022] [Revised: 06/27/2022] [Accepted: 07/05/2022] [Indexed: 01/27/2023] Open
Abstract
Chagas disease (ChD) is a vector zoonosis native to the American continent caused by the protozoan parasite Trypanosoma cruzi; the biological vectors are multiple species of hematophagous insects of the family Triatominae. A relevant aspect in the host–parasite relationship is the identification of the various genotypes of T. cruzi called discrete typing units (DTU) that circulate in mammals and vectors. In Chile, it has been described that the DTUs TcI, TcII, TcV, and TcVI circulate in infected humans, vectors, and wild animals. Identifying DTUs has acquired clinical importance, since it has been suggested that different genotypes could cause distinct pathologies, circulate in different geographical areas, and present different sensitivities to trypanocidal drugs. In this study, circulating T. cruzi DTUs in peripheral blood and Triatoma infestans dejections used in xenodiagnosis (XD) were amplified by qPCR in 14 Chilean patients with chronic ChD from highly endemic areas. More positive samples were detected by XD compared to peripheral blood samples, and 64.28% of the cases were simple infections and 35.72% mixed, with a statistically significant difference in the frequency of TcV DTU. This study would suggest that T. infestans from Chile is more competent to amplify one DTU over others, probably due to a process of co-evolution.
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de Abreu AP, Lucas da Silva HF, Sarto MPM, Iunklaus GF, Trovo JV, de Souza Fernandes N, Teston APM, Toledo MJDO. Infection susceptibility and vector competence of Rhodnius robustus Larrousse, 1927 and R. pictipes Stal, 1872 (Hemiptera, Reduviidae, Triatominae) for strains of Trypanosoma cruzi (Chagas, 1909) (Kinetoplastida, Trypanosomatidae) I, II and IV. Parasit Vectors 2022; 15:239. [PMID: 35773725 PMCID: PMC9245265 DOI: 10.1186/s13071-022-05350-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2022] [Accepted: 05/31/2022] [Indexed: 11/23/2022] Open
Abstract
Background Rhodnius robustus and Rhodnius pictipes are vectors of Trypanosoma cruzi, the etiologic agent of Chagas disease (CD), that are found in the Brazilian Amazon region. Susceptibility to infection and vector competence depend on the parasite-vector relationship. Our objective was to evaluate the interaction between T. cruzi and these two triatomine vectors in pure and mixed experimental infections of T. cruzi strains from the same or different geographic regions. Methods Fifth-instar nymphs of R. robustus and R. pictipes were fed on mice infected with four T. cruzi strains, namely genotypes TcIAM, TcIMG, TcIIPR, and TcIVAM, respectively, from the Brazilian states of Amazonas, Minas Gerais and Paraná. Over a period of 120 days, excreta were examined every 20 days to assess vector competence, and intestinal contents (IC) were examined every 30 days to determine susceptibility to infection. Results The highest positive rate in the fresh examination (%+FE, 30.0%), the highest number of parasitic forms (PF, n = 1969) and the highest metacyclogenesis rate (%MC, 53.8%) in the excreta were recorded for R. robustus/TcIVAM. Examination of the IC of R. pictipes revealed a higher number of PF in infections with TcIAM (22,680 PF) and TcIIPR (19,845 PF) alone or in association (17,145 PF), as well as a %+FE of 75.0% with TcII, in comparison with the other genotypes. The highest %MC (100%) was recorded for the mixed infections of TcIAM with TcIIPR or TcIVAM in the IC of R. pictipes. Conclusions Overall, both species were found to be susceptible to the T. cruzi strains studied. Rhodnius robustus showed vector competence for genotypes TcIVAM and TcIAM+TcIVAM and R. pictipes for TcIAM+TcIVAM and TcIAM+TcIIPR; there was elimination of infective forms as early as at 20 days. Our results suggest that both the genetics of the parasite and its geographic origin influence the susceptibility to infection and vector competence, alone or in association. Graphical Abstract ![]()
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Affiliation(s)
- Ana Paula de Abreu
- Programa de Pós-Graduação Em Ciências da Saúde, Centro de Ciências da Saúde (CCS), Universidade Estadual de Maringá (UEM), Maringá, PR, 87020-900, Brazil.
| | - Hevillyn Fernanda Lucas da Silva
- Programa de Pós-Graduação Em Ciências da Saúde, Centro de Ciências da Saúde (CCS), Universidade Estadual de Maringá (UEM), Maringá, PR, 87020-900, Brazil
| | - Marcella Paula Mansano Sarto
- Programa de Pós-Graduação Em Ciências da Saúde, Centro de Ciências da Saúde (CCS), Universidade Estadual de Maringá (UEM), Maringá, PR, 87020-900, Brazil
| | - Giullia Ferreira Iunklaus
- Programa de Pós-Graduação Em Ciências da Saúde, Centro de Ciências da Saúde (CCS), Universidade Estadual de Maringá (UEM), Maringá, PR, 87020-900, Brazil
| | - João Vitor Trovo
- Programa de Pós-Graduação Em Ciências da Saúde, Centro de Ciências da Saúde (CCS), Universidade Estadual de Maringá (UEM), Maringá, PR, 87020-900, Brazil
| | - Nilma de Souza Fernandes
- Programa de Pós-Graduação Em Ciências Biológicas, Centro de Ciências Biológicas, UEM, Maringá, PR, 87020-900, Brazil
| | - Ana Paula Margioto Teston
- Departamento de Farmácia, Centro Universitario Uningá, Rodovia PR-317, Maringá, PR, 87035-510, Brazil
| | - Max Jean de Ornelas Toledo
- Programa de Pós-Graduação Em Ciências da Saúde, Centro de Ciências da Saúde (CCS), Universidade Estadual de Maringá (UEM), Maringá, PR, 87020-900, Brazil.,Programa de Pós-Graduação Em Ciências Biológicas, Centro de Ciências Biológicas, UEM, Maringá, PR, 87020-900, Brazil.,Departamento de Ciências Básicas da Saúde, CCS, UEM, Maringá, PR, 87020-900, Brazil
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Trypanosoma cruzi infection in the wild Chagas disease vector, Mepraia spinolai: Parasitic load, discrete typing units, and blood meal sources. Acta Trop 2022; 229:106365. [PMID: 35150641 DOI: 10.1016/j.actatropica.2022.106365] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2021] [Revised: 02/06/2022] [Accepted: 02/08/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND Mepraia spinolai, a wild vector of Trypanosoma cruzi in Chile, is an abundant triatomine species that is frequently infected by the parasite that causes Chagas disease. The aim of this study was to determine if the parasitic load of T. cruzi in M. spinolai is related to its blood meal source and the infecting DTUs of T. cruzi. METHODS The vector was captured in rural areas. In the laboratory, DNA was extracted from its abdomen and T. cruzi was quantified using qPCR. Real time PCR assays for four T. cruzi DTUs were performed. Blood meal sources were identified by real-time PCR amplification of vertebrate cytochrome b gene sequences coupled with high resolution melting (HRM). RESULTS Trypanosoma cruzi was detected in 735 M. spinolai; in 484 we identified one blood meal source, corresponding to human, sylvatic, and domestic species. From these, in 224 we were able to discriminate the infecting DTU. When comparing the parasitic loads between the unique blood meal sources, no significant differences were found, but infections with more than one DTU showed higher parasitic loads than single infections. DTU TcI was detected in a high proportion of the samples. CONCLUSIONS Higher parasitic loads are related to a greater number of T. cruzi DTUs infecting M. spinolai, and this triatomine seems to have a wide span of vertebrate species in its diet.
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Apt W, Carrasco D, Fuentealba C, Canals M, Muñoz G, Saavedra M, Castillo JP, Zulantay I. Chronic Chagas disease: Quantification of Trypanosoma cruzi in peripheral blood and dejections of Triatoma infestans fed by xenodiagnosis in patients with and without cardiopathy. Acta Trop 2019; 200:105167. [PMID: 31513762 DOI: 10.1016/j.actatropica.2019.105167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2019] [Revised: 08/30/2019] [Accepted: 09/07/2019] [Indexed: 01/27/2023]
Abstract
It is not currently known which individuals with chronic Chagas disease (ChD) will develop cardiopathy in a determined period and which will be maintained asymptomatic with normal routine laboratory tests all their lives. The parasite burden is a factor that could explain this different evolution. The objective of this study was to quantify Trypanosoma cruzi burden by real-time PCR in blood (qPCR-B) and dejections of triatomines fed by xenodiagnosis (qPCR-XD) in 90 individuals with chronic ChD untreated, classified according to XD results and the presence or absence of cardiopathy. All individuals came from hyperendemic areas of Chile and participated in the study under Informed Consent. The standard qPCR curves for qPCR-B and qPCR-XD were elaborated with a mixture of known concentrations of T. cruzi strains, performing DNA serial dilutions (1/10) with a dynamic range between 105 and 10-1 parasite equivalents/mL. The TaqManⓇ detection system was applied in a Stratagene Mx3000P thermocycler (Agilent Technologies, USA) with cruzi 1 and cruzi 2 satellite primers. 22.2% and 15.6% of cases with cardiopathy or without cardiopathy were XD positive. There was no significant difference between the groups. The positivity of qPCR-B and qPCR-XD in the positive XD group was 82.35% and 100%, respectively, while in the negative XD group was 55.26% and 42.10%, respectively. A superior qPCR value in chronic ChD patients with and without cardiopathy was determined for qPCR in cases with positive XD and positive qPCR-XD. The receiver operating characteristic (ROC) curve analyses show better accuracy for detecting parasite burden (area under the curve, AUC) for qPCR-XD in comparison to qPCR-B. That is to say, major performance in DNA samples obtained of positive XD (gold standard for viable T. cruzi) detected and quantified by qPCR-XD. A high percentage of cases with XD and qPCR-XD positive (80-100%) have result concordant with qPCR-B. In absence of XD, future challenges are especially related to the low parasitic load of chronic ChD patients treated with trypanocidal drugs and post-therapy parasitological evaluations by qPCR-B. Finally, no statistically significant differences were found between presence or absence of cardiopathy and XD, qPCR-B or qPCR-XD.
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Affiliation(s)
- Werner Apt
- Laboratorio de Parasitología Básico-Clínico, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Daniela Carrasco
- Laboratorio de Parasitología Básico-Clínico, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile; Escuela de Tecnología Médica, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Cristian Fuentealba
- Laboratorio de Parasitología Básico-Clínico, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile; Escuela de Tecnología Médica, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Mauricio Canals
- Escuela de Salud Pública, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Gabriela Muñoz
- Laboratorio de Parasitología Básico-Clínico, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Miguel Saavedra
- Laboratorio de Parasitología Básico-Clínico, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Juan-Paul Castillo
- Laboratorio de Parasitología Básico-Clínico, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Inés Zulantay
- Laboratorio de Parasitología Básico-Clínico, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
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de Fuentes-Vicente JA, Gutiérrez-Cabrera AE, Flores-Villegas AL, Lowenberger C, Benelli G, Salazar-Schettino PM, Córdoba-Aguilar A. What makes an effective Chagas disease vector? Factors underlying Trypanosoma cruzi-triatomine interactions. Acta Trop 2018; 183:23-31. [PMID: 29625091 DOI: 10.1016/j.actatropica.2018.04.008] [Citation(s) in RCA: 63] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 03/13/2018] [Accepted: 04/01/2018] [Indexed: 12/31/2022]
Abstract
The Chagas disease is caused by the parasite Trypanosoma cruzi, which infect blood-feeding triatomine bugs to finally reach mammal hosts. Chagas disease is endemic in Latin America, and is ranked among the 13 neglected tropical diseases worldwide. Currently, an estimate of 7 million people is infected by T. cruzi, leading to about 22 000 deaths per year throughout the Americas. As occurs with other vectors, a major question towards control programs is what makes a susceptible bug. In this review, we focus on findings linked to insect gut structure and microbiota, immunity, genetics, blood sources, abiotic factors (with special reference to ambient temperature and altitude) to understand the interactions occurring between T. cruzi and triatomine bugs, under a co-evolutionary scenario. These factors lead to varying fitness benefits and costs for bugs, explaining why infection in the insect takes place and how it varies in time and space. Our analysis highlights that major factors are gut components and microbiota, blood sources and temperature. Although their close interaction has never been clarified, knowledge reviewed here may help to boost the success of triatomine control programs, reducing the use of insecticides.
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Alessio GD, de Araújo FF, Sales Júnior PA, Gomes MDS, do Amaral LR, Pascoal Xavier MA, Teixeira-Carvalho A, de Lana M, Martins-Filho OA. Accomplishing the genotype-specific serodiagnosis of single and dual Trypanosoma cruzi infections by flow cytometry Chagas-Flow ATE-IgG2a. PLoS Negl Trop Dis 2018; 12:e0006140. [PMID: 29462135 PMCID: PMC5843347 DOI: 10.1371/journal.pntd.0006140] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 03/08/2018] [Accepted: 11/28/2017] [Indexed: 01/04/2023] Open
Abstract
The methods currently available for genotype-specific diagnosis of T. cruzi infection still present relevant limitations, especially to identify mixed infection. In the present investigation, we have evaluated the performance of Chagas-Flow ATE-IgG2a test for early and late differential diagnosis of single and dual genotype-specific T. cruzi infections. Serum samples from Swiss mice at early and late stages of T. cruzi infection were assayed in parallel batches for genotype-specific diagnosis of single (TcI, TcVI or TcII) and dual (TcI+TcVI, TcVI+TcII or TcII+TcI) infections. The intrinsic reactivity to TcI, TcVI and TcII target antigens, including amastigote (AI/AVI/AII), trypomastigote-(TI/TVI/TII) and epimastigote (EI/EVI/EII), at specific reverse of serum dilutions (500 to 64,000), was employed to provide reliable decision-trees for "early" vs "late", "single vs "dual" and "genotype-specific" serology. The results demonstrated that selective set of attributes "EII 500/EI 2,000/AII 500" were able to provide high-quality accuracy (81%) to segregate early and late stages of T. cruzi infection. The sets "TI 2,000/AI 1,000/EII 1,000" and "TI 8,000/AII 32,000" presented expressive scores to discriminate single from dual T. cruzi infections at early (85%) and late stages (84%), respectively. Moreover, the attributes "TI 4,000/TVI 500/TII 1,000", "TI 16,000/EI 2,000/EII 2,000/AI 500/TVI 500" showed good performance for genotype-specific diagnosis at early stage of single (72%) and dual (80%) T. cruzi infections, respectively. In addition, the attributes "TI 4,000/AII 1,000/EVI 1,000", "TI 64,000/AVI 500/AI 2,000/AII 1,000/EII 4,000" showed moderate performance for genotype-specific diagnosis at late stage of single (69%) and dual (76%) T. cruzi infections, respectively. The sets of decision-trees were assembled to construct a sequential algorithm with expressive accuracy (81%) for serological diagnosis of T. cruzi infection. These findings engender new perspectives for the application of Chagas-Flow ATE-IgG2a method for genotype-specific diagnosis in humans, with relevant contributions for epidemiological surveys as well as clinical and post-therapeutic monitoring of Chagas disease.
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Affiliation(s)
- Glaucia Diniz Alessio
- Laboratório de Doença de Chagas, Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Instituto de Ciências Exatas e Biológicas (ICEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, MG, Brazil
- Grupo Integrado de Pesquisas em Biomarcadores, Instituto René Rachou (FIOCRUZ-Minas), Belo Horizonte, MG, Brazil
| | - Fernanda Fortes de Araújo
- Grupo Integrado de Pesquisas em Biomarcadores, Instituto René Rachou (FIOCRUZ-Minas), Belo Horizonte, MG, Brazil
- Programa de Pós-graduação em Sanidade e Produção Animal nos Trópicos, Universidade de Uberaba, Uberaba, Brazil
| | - Policarpo Ademar Sales Júnior
- Grupo de Genômica Funcional e Proteômica de Leishmania spp e Trypanosoma cruzi, Instituto René Rachou (FIOCRUZ-Minas), Belo Horizonte, MG, Brazil
| | - Matheus de Souza Gomes
- Laboratório de Bioinformática e Análises Moleculares, Universidade Federal de Uberlândia, INGEB/FACOM, Campus Patos de Minas, Patos de Minas, MG, Brazil
| | - Laurence Rodrigues do Amaral
- Laboratório de Bioinformática e Análises Moleculares, Universidade Federal de Uberlândia, INGEB/FACOM, Campus Patos de Minas, Patos de Minas, MG, Brazil
| | - Marcelo Antônio Pascoal Xavier
- Grupo de Pesquisas Clínicas e Políticas Públicas em Doenças Infecciosas e Parasitárias, Instituto René Rachou (FIOCRUZ-Minas), Belo Horizonte, MG, Brazil
| | - Andréa Teixeira-Carvalho
- Grupo Integrado de Pesquisas em Biomarcadores, Instituto René Rachou (FIOCRUZ-Minas), Belo Horizonte, MG, Brazil
| | - Marta de Lana
- Laboratório de Doença de Chagas, Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Instituto de Ciências Exatas e Biológicas (ICEB), Universidade Federal de Ouro Preto (UFOP), Ouro Preto, MG, Brazil
| | - Olindo Assis Martins-Filho
- Grupo Integrado de Pesquisas em Biomarcadores, Instituto René Rachou (FIOCRUZ-Minas), Belo Horizonte, MG, Brazil
- * E-mail:
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Tomasini N, Ragone PG, Gourbière S, Aparicio JP, Diosque P. Epidemiological modeling of Trypanosoma cruzi: Low stercorarian transmission and failure of host adaptive immunity explain the frequency of mixed infections in humans. PLoS Comput Biol 2017; 13:e1005532. [PMID: 28481887 PMCID: PMC5440054 DOI: 10.1371/journal.pcbi.1005532] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 05/22/2017] [Accepted: 04/24/2017] [Indexed: 01/27/2023] Open
Abstract
People living in areas with active vector-borne transmission of Chagas disease have multiple contacts with its causative agent, Trypanosoma cruzi. Reinfections by T. cruzi are possible at least in animal models leading to lower or even hardly detectable parasitaemia. In humans, although reinfections are thought to have major public health implications by increasing the risk of chronic manifestations of the disease, there is little quantitative knowledge about their frequency and the timing of parasite re-inoculation in the course of the disease. Here, we implemented stochastic agent-based models i) to estimate the rate of re-inoculation in humans and ii) to assess how frequent are reinfections during the acute and chronic stages of the disease according to alternative hypotheses on the adaptive immune response following a primary infection. By using a hybrid genetic algorithm, the models were fitted to epidemiological data of Argentinean rural villages where mixed infections by different genotypes of T. cruzi reach 56% in humans. To explain this percentage, the best model predicted 0.032 (0.008-0.042) annual reinfections per individual with 98.4% of them occurring in the chronic phase. In addition, the parasite escapes to the adaptive immune response mounted after the primary infection in at least 20% of the events of re-inoculation. With these low annual rates, the risks of reinfection during the typically long chronic stage of the disease stand around 14% (4%-18%) and 60% (21%-70%) after 5 and 30 years, with most individuals being re-infected 1-3 times overall. These low rates are better explained by the weak efficiency of the stercorarian mode of transmission than a highly efficient adaptive immune response. Those estimates are of particular interest for vaccine development and for our understanding of the higher risk of chronic disease manifestations suffered by infected people living in endemic areas.
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Affiliation(s)
- Nicolás Tomasini
- Instituto de Patología Experimental, Facultad de Ciencias de la Salud, CONICET, Universidad Nacional de Salta, Salta, Argentina
| | - Paula Gabriela Ragone
- Instituto de Patología Experimental, Facultad de Ciencias de la Salud, CONICET, Universidad Nacional de Salta, Salta, Argentina
| | - Sébastien Gourbière
- UMR 228 ESPACE-DEV-IMAGES, ‘Institut de Modélisation et d'Analyses en Géo-Environnement et Santé’, Université de Perpignan Via Domitia, Perpignan, France
| | - Juan Pablo Aparicio
- Instituto de Investigaciones en Energía no Convencional, CONICET, Universidad Nacional de Salta, Salta, Argentina
| | - Patricio Diosque
- Instituto de Patología Experimental, Facultad de Ciencias de la Salud, CONICET, Universidad Nacional de Salta, Salta, Argentina
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10
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Brenière SF, Waleckx E, Barnabé C. Over Six Thousand Trypanosoma cruzi Strains Classified into Discrete Typing Units (DTUs): Attempt at an Inventory. PLoS Negl Trop Dis 2016; 10:e0004792. [PMID: 27571035 PMCID: PMC5003387 DOI: 10.1371/journal.pntd.0004792] [Citation(s) in RCA: 146] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 05/31/2016] [Indexed: 01/06/2023] Open
Abstract
Trypanosoma cruzi, the causative agent of Chagas disease, presents wide genetic diversity. Currently, six discrete typing units (DTUs), named TcI to TcVI, and a seventh one called TcBat are used for strain typing. Beyond the debate concerning this classification, this systematic review has attempted to provide an inventory by compiling the results of 137 articles that have used it. A total of 6,343 DTU identifications were analyzed according to the geographical and host origins. Ninety-one percent of the data available is linked to South America. This sample, although not free of potential bias, nevertheless provides today's picture of T. cruzi genetic diversity that is closest to reality. DTUs were genotyped from 158 species, including 42 vector species. Remarkably, TcI predominated in the overall sample (around 60%), in both sylvatic and domestic cycles. This DTU known to present a high genetic diversity, is very widely distributed geographically, compatible with a long-term evolution. The marsupial is thought to be its most ancestral host and the Gran Chaco region the place of its putative origin. TcII was rarely sampled (9.6%), absent, or extremely rare in North and Central America, and more frequently identified in domestic cycles than in sylvatic cycles. It has a low genetic diversity and has probably found refuge in some mammal species. It is thought to originate in the south-Amazon area. TcIII and TcIV were also rarely sampled. They showed substantial genetic diversity and are thought to be composed of possible polyphyletic subgroups. Even if they are mostly associated with sylvatic transmission cycles, a total of 150 human infections with these DTUs have been reported. TcV and TcVI are clearly associated with domestic transmission cycles. Less than 10% of these DTUs were identified together in sylvatic hosts. They are thought to originate in the Gran Chaco region, where they are predominant and where putative parents exist (TcII and TcIII). Trends in host-DTU specificities exist, but generally it seems that the complexity of the cycles and the participation of numerous vectors and mammal hosts in a shared area, maintains DTU diversity.
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Affiliation(s)
- Simone Frédérique Brenière
- IRD-CIRAD, INTERTRYP (Interactions hôtes-vecteurs-parasites-environnement dans les maladies tropicales négligées dues aux Trypanosomatidés), IRD Center, Montpellier, France
- Pontificia Universidad Católica del Ecuador, Centro de Investigación para la Salud en América Latina (CISeAL), Quito, Ecuador
- * E-mail:
| | - Etienne Waleckx
- Centro de Investigaciones Regionales “Hideyo Noguchi”, Universidad Autónoma de Yucatán, Mérida, Yucatán, México
| | - Christian Barnabé
- IRD-CIRAD, INTERTRYP (Interactions hôtes-vecteurs-parasites-environnement dans les maladies tropicales négligées dues aux Trypanosomatidés), IRD Center, Montpellier, France
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11
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Egaña C, Pinto R, Vergara F, Ortiz S, Campos R, Solari A. Fluctuations in Trypanosoma cruzi discrete typing unit composition in two naturally infected triatomines: Mepraia gajardoi and M. spinolai after laboratory feeding. Acta Trop 2016; 160:9-14. [PMID: 27109041 DOI: 10.1016/j.actatropica.2016.04.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Revised: 03/22/2016] [Accepted: 04/19/2016] [Indexed: 11/29/2022]
Abstract
Mepraia species are hematophagous insects and the most important wild vectors of Trypanosoma cruzi, the causative agent of Chagas disease in southeastern South America. Because the domestic Triatoma infestans is already controlled, the transmission of different T. cruzi discrete typing units (DTUs) by Mepraia species deserves attention. Our aim is to gather information on the diversity of T. cruzi DTUs circulating in natural insect populations. Two groups of naturally infected bugs 21 Mepraia gajardoi and 26 Mepraia spinolai were followed-up after two or more laboratory feedings by means of minicircle-PCR assays to evaluate the composition of four T. cruzi DTUs by hybridization tests. Fluctuations from positive T. cruzi detection to negative and the converse, as well as single to mixed infections with different T. cruzi DTUs and the opposite were frequent observations after laboratory feeding in both Mepraia species. Single and mixed infections with more than two T. cruzi DTUs were detected after the first feeding; however mainly mixed infections prevailed after the second feeding. Laboratory feeding on three or more occasions resulted in a decreasing trend of the parasite burden. In a comparison with 28 infected and fed M. gajardoi collected one year before from the same vector colony T. cruzi DTUs composition changed, indicating that temporal variations occur in T. cruzi. Natural populations of Mepraia species can transmit complex mixtures T. cruzi DTUs which fluctuate over time after feeding, with a tendency to eliminate the parasitism after prolonged feeding.
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Affiliation(s)
- Camila Egaña
- Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Raquel Pinto
- Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Fernanda Vergara
- Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Sylvia Ortiz
- Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Ricardo Campos
- Programa de Biología Celular y Molecular, ICBM, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Aldo Solari
- Instituto de Biología, Facultad de Ciencias, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile.
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12
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Saavedra M, Zulantay I, Apt W, Castillo J, Araya E, Martínez G, Rodríguez J. Quantification by real-time PCR of Trypanosoma cruzi DNA in samples of Triatoma infestans used in xenodiagnosis of chronic Chagas disease patients. Parasit Vectors 2016; 9:382. [PMID: 27377063 PMCID: PMC4932745 DOI: 10.1186/s13071-016-1664-5] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 06/23/2016] [Indexed: 01/22/2023] Open
Abstract
BACKGROUND Trypanosoma cruzi multiplies and differentiates in the digestive tract of triatomine insects. Xenodiagnosis (XD) is a parasitological tool in which the insect vectors acts as a biological culture medium to amplify and detect T. cruzi infection in mammals. The sensitivity of XD has been overcome by the application of PCR in fecal samples (FS) of XD (PCR-XD). In this study, T. cruzi amplified in Triatoma infestans fed by XD on individuals with chronic Chagas disease (CChD) is quantified by real-time PCR (qPCR-XD). FINDINGS Under informed consent, 100 individuals were evaluated. In 21 of them XD, PCR-XD and qPCR-XD were positive. For the contrary, 79 were negative XD. In 58 (73.4 %) and 66 cases (83.5 %) of them, PCR-XD (Fisher's exact test P = 0.005) and qPCR-XD (Fisher's exact test: P = 0.037) respectively, were positive. In cases with positive XD, qPCR-XD allowed to establish that in 9/21 cases (42.9 %) the parasite burden fluctuated between 100 and 1,000 par. eq./ml. Otherwise, in 32/79 (40.5 %) cases with negative XD, a parasite burden between 1 and 10 par. eq./ml was determined. All samples showed amplification of exogenous internal control (X12, Ct average: 31.8), so problems in the DNA extraction (excess or loss of genetic material), unspecific amplification and/or inhibition in qPCR-XD reactions were ruled out. Additionally, in all the patients qPCR in blood (qPCR-B) was performed. In the cases with positive XD, the concordance between the positivity of qPCR-XD and qPCR-B was 100 %, nevertheless, the parasite burden in blood was lower and different than XD (Chi-square test: χ (2) = 91.82, df = 5, P = 0.0001). In the cases with negative XD the ranges of qPCR-XD and qPCR-B were similar (Chi-square test: χ (2) = 6.71, df = 5, P = 0.1520). CONCLUSIONS This study allowed the detection and quantification of T. cruzi by qPCR-XD in FS of Tr. infestans fed on patients with CChD. The highest parasite burden was observed in positive XD cases. qPCR-XD could be used in different studies related with the complex T. cruzi-vector-host interactions.
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Affiliation(s)
- Miguel Saavedra
- />Laboratorio de Parasitología Básico-Clínico, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Inés Zulantay
- />Laboratorio de Parasitología Básico-Clínico, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Werner Apt
- />Laboratorio de Parasitología Básico-Clínico, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Juan Castillo
- />Laboratorio de Parasitología Básico-Clínico, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Eduardo Araya
- />Laboratorio de Parasitología Básico-Clínico, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Gabriela Martínez
- />Laboratorio de Parasitología Básico-Clínico, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Jorge Rodríguez
- />Escuela de Salud Pública, Facultad de Medicina, Universidad de Chile, Santiago, Chile
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13
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Messenger LA, Miles MA, Bern C. Between a bug and a hard place: Trypanosoma cruzi genetic diversity and the clinical outcomes of Chagas disease. Expert Rev Anti Infect Ther 2015; 13:995-1029. [PMID: 26162928 PMCID: PMC4784490 DOI: 10.1586/14787210.2015.1056158] [Citation(s) in RCA: 134] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Over the last 30 years, concomitant with successful transnational disease control programs across Latin America, Chagas disease has expanded from a neglected, endemic parasitic infection of the rural poor to an urbanized chronic disease, and now a potentially emergent global health problem. Trypanosoma cruzi infection has a highly variable clinical course, ranging from complete absence of symptoms to severe and often fatal cardiovascular and/or gastrointestinal manifestations. To date, few correlates of clinical disease progression have been identified. Elucidating a putative role for T. cruzi strain diversity in Chagas disease pathogenesis is complicated by the scarcity of parasites in clinical specimens and the limitations of our contemporary genotyping techniques. This article systematically reviews the historical literature, given our current understanding of parasite genetic diversity, to evaluate the evidence for any association between T. cruzi genotype and chronic clinical outcome, risk of congenital transmission or reactivation and orally transmitted outbreaks.
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Affiliation(s)
- Louisa A Messenger
- Department of Pathogen Molecular Biology, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Michael A Miles
- Department of Pathogen Molecular Biology, Faculty of Infectious Tropical Diseases, London School of Hygiene and Tropical Medicine, London, UK
| | - Caryn Bern
- Global Health Sciences, Department of Epidemiology and Biostatistics, School of Medicine, University of California San Francisco, San Francisco, CA, USA
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14
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Dutra WO, Menezes CAS, Magalhães LMD, Gollob KJ. Immunoregulatory networks in human Chagas disease. Parasite Immunol 2014; 36:377-87. [PMID: 24611805 DOI: 10.1111/pim.12107] [Citation(s) in RCA: 104] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2013] [Accepted: 02/19/2014] [Indexed: 01/11/2023]
Abstract
Chagas disease, caused by the infection with Trypanosoma cruzi, is endemic in all Latin America. Due to the increase in population migration, Chagas disease has spread worldwide and is now considered a health issue not only in endemic countries. While most chronically infected individuals remain asymptomatic, approximately 30% of the patients develop a potentially deadly cardiomyopathy. The exact mechanisms that underlie the establishment and maintenance of the cardiac pathology are not clear. However, there is consistent evidence that immunoregulatory cytokines are critical for orchestrating the immune response and thus influence disease development or control. While the asymptomatic (indeterminate) form represents a state of balance between the host and the parasite, the establishment of the cardiac form represents the loss of this balance. Analysis of data obtained from several studies has led to the hypothesis that the indeterminate form is associated with an anti-inflammatory cytokine profile, represented by high expression of IL-10, while cardiac form is associated with a high production of IFN-gamma and TNF-alpha in relation to IL-10, leading to an inflammatory profile. Here, we discuss the immunoregulatory events that might influence disease outcome, as well as the mechanisms that influence the establishment of these complex immunoregulatory networks.
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Affiliation(s)
- W O Dutra
- Laboratório de Biologia das Interações Celulares, Departamento de Morfologia, Instituto de Ciências Biológicas, Belo Horizonte, MG, Brazil; Instituto Nacional de Ciência e Tecnologia - Doenças Tropicais - INCT-DT, Belo Horizonte, MG, Brazil
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15
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Ortiz S, Zulantay I, Apt W, Saavedra M, Solari A. Transferability of Trypanosoma cruzi from mixed human host infection to Triatoma infestans and from insects to axenic culture. Parasitol Int 2014; 64:33-6. [PMID: 25240699 DOI: 10.1016/j.parint.2014.09.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 08/21/2014] [Accepted: 09/11/2014] [Indexed: 10/24/2022]
Abstract
The etiologic agent of Chagas disease is Trypanosoma cruzi, a protozoan whose life cycle involves obligatory passage through vertebrate and invertebrate hosts in a series of stages. The aim of this study was to explore the transferability of mixed discrete typing units (DTUs) of T. cruzi present in chronic chagasic patients when passed through an invertebrate host during xenodiagnosis (XD) and then when transferred to axenic cultures to obtain T. cruzi isolates. DTUs of T. cruzi present in these two hosts and axenic cultures were identified by kDNA PCR amplification and subsequent hybridization with DTU-specific probes. Mixtures of Tc I, Tc II, Tc V and Tc VI DTUs were detected in blood samples. However as a result of XD and axenic cultures it was possible to identify mostly Tc V. We conclude that the transferability of an isolate of T.cruzi derived from mixed DTUs present in human blood depends upon the starved invertebrate host used for xenodiagnosis.
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Affiliation(s)
- Sylvia Ortiz
- Laboratorio de Biología Molecular de Parásitos, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Inés Zulantay
- Laboratorio de Parasitología Básico-Clínico, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Werner Apt
- Laboratorio de Parasitología Básico-Clínico, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Miguel Saavedra
- Laboratorio de Parasitología Básico-Clínico, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile
| | - Aldo Solari
- Laboratorio de Biología Molecular de Parásitos, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago, Chile.
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16
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Arnaud-Haond S, Moalic Y, Barnabé C, Ayala FJ, Tibayrenc M. Discriminating micropathogen lineages and their reticulate evolution through graph theory-based network analysis: the case of Trypanosoma cruzi, the agent of Chagas disease. PLoS One 2014; 9:e103213. [PMID: 25148574 PMCID: PMC4141739 DOI: 10.1371/journal.pone.0103213] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 06/28/2014] [Indexed: 12/02/2022] Open
Abstract
Micropathogens (viruses, bacteria, fungi, parasitic protozoa) share a common trait, which is partial clonality, with wide variance in the respective influence of clonality and sexual recombination on the dynamics and evolution of taxa. The discrimination of distinct lineages and the reconstruction of their phylogenetic history are key information to infer their biomedical properties. However, the phylogenetic picture is often clouded by occasional events of recombination across divergent lineages, limiting the relevance of classical phylogenetic analysis and dichotomic trees. We have applied a network analysis based on graph theory to illustrate the relationships among genotypes of Trypanosoma cruzi, the parasitic protozoan responsible for Chagas disease, to identify major lineages and to unravel their past history of divergence and possible recombination events. At the scale of T. cruzi subspecific diversity, graph theory-based networks applied to 22 isoenzyme loci (262 distinct Multi-Locus-Enzyme-Electrophoresis -MLEE) and 19 microsatellite loci (66 Multi-Locus-Genotypes -MLG) fully confirms the high clustering of genotypes into major lineages or "near-clades". The release of the dichotomic constraint associated with phylogenetic reconstruction usually applied to Multilocus data allows identifying putative hybrids and their parental lineages. Reticulate topology suggests a slightly different history for some of the main "near-clades", and a possibly more complex origin for the putative hybrids than hitherto proposed. Finally the sub-network of the near-clade T. cruzi I (28 MLG) shows a clustering subdivision into three differentiated lesser near-clades ("Russian doll pattern"), which confirms the hypothesis recently proposed by other investigators. The present study broadens and clarifies the hypotheses previously obtained from classical markers on the same sets of data, which demonstrates the added value of this approach. This underlines the potential of graph theory-based network analysis for describing the nature and relationships of major pathogens, thereby opening stimulating prospects to unravel the organization, dynamics and history of major micropathogen lineages.
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Affiliation(s)
- Sophie Arnaud-Haond
- IFREMER (Institut Français de Recherche pour l'Exploitation de la Mer) - Département Ecosystèmes Marins Exploités, Sète, France
| | - Yann Moalic
- IFREMER (Institut Français de Recherche pour l'Exploitation de la Mer) - Département Ecosystèmes Marins Exploités, Sète, France
| | - Christian Barnabé
- Interactions hôte-vecteur-parasite dans les maladies dues aux Trypanosomatidés, INTERTRYP (IRD-CIRAD), Montpellier, France
| | - Francisco José Ayala
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, California, United States of America
| | - Michel Tibayrenc
- Maladies Infectieuses et Vecteurs Ecologie, Génétique, Evolution et Contrôle, MIVEGEC (IRD 224-CNRS 5290-UM1-UM2), Montpellier, France
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17
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Machin A, Telleria J, Brizard JP, Demettre E, Séveno M, Ayala FJ, Tibayrenc M. Trypanosoma cruzi: gene expression surveyed by proteomic analysis reveals interaction between different genotypes in mixed in vitro cultures. PLoS One 2014; 9:e95442. [PMID: 24748035 PMCID: PMC3991653 DOI: 10.1371/journal.pone.0095442] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2013] [Accepted: 03/26/2014] [Indexed: 11/30/2022] Open
Abstract
We have analyzed the comportment in in vitro culture of 2 different genotypes of Trypanosoma cruzi, the agent of Chagas disease, pertaining to 2 major genetic subdivisions (near-clades) of this parasite. One of the stocks was a fast-growing one, highly virulent in mice, while the other one was slow- growing, mildly virulent in mice. The working hypothesis was that mixtures of genotypes interact, a pattern that has been observed by us in empirical experimental studies. Genotype mixtures were followed every 7 days and characterized by the DIGE technology of proteomic analysis. Proteic spots of interest were characterized by the SAMESPOT software. Patterns were compared to those of pure genotypes that were also evaluated every 7 days. One hundred and three spots exhibited changes in time by comparison with T = 0. The major part of these spots (58%) exhibited an under-expression pattern by comparison with the pure genotypes. 32% of the spots wereover-expressed; 10% of spots were not different from those of pure genotypes. Interestingly, interaction started a few minutes after the mixtures were performed. We have retained 43 different proteins that clearly exhibited either under- or over-expression. Proteins showing interaction were characterized by mass spectrometry (MALDI-TOF). Close to 50% of them were either tubulins or heat shock proteins. This study confirms that mixed genotypes of T. cruzi interact at the molecular level. This is of great interest because mixtures of genotypes are very frequent in Chagas natural cycles, both in insect vectors and in mammalian hosts, and may play an important role in the transmission and severity of Chagas disease. The methodology proposed here is potentially applicable to any micropathogen, including fungi, bacteria and viruses. It should be of great interest in the case of bacteria, for which the epidemiological and clinical consequences of mixed infections could be underestimated.
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Affiliation(s)
- Alexandre Machin
- Unité Mixte de Recherche, Institut de Recherche pour le Développement/Centre National de la Recherche Scientifique/Universités Montpellier 1 and 2, Génétique et Evolution des Maladies Infectieuses, n° 5290, Maladies Infectieuses et Vecteurs Ecologie, Génétique, Evolution et Contrôle (MIVEGEC) Institut de Recherche pour le Développement, Montpellier, France
| | - Jenny Telleria
- Unité Mixte de Recherche, Institut de Recherche pour le Développement/Centre National de la Recherche Scientifique/Universités Montpellier 1 and 2, Génétique et Evolution des Maladies Infectieuses, n° 5290, Maladies Infectieuses et Vecteurs Ecologie, Génétique, Evolution et Contrôle (MIVEGEC) Institut de Recherche pour le Développement, Montpellier, France
| | - Jean-Paul Brizard
- Unité Mixte de Recherche, Institut de Recherche pour le Développement/Centre National de la Recherche Scientifique, n° 5096, Centre Institut de Recherche pour le Développement, Montpellier, France
| | - Edith Demettre
- Plate-forme de Proteomique Fonctionnelle, c/o Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique Unité Mixte de Recherche 5203, Institut National de la Santé et de la Recherche Médicales, Unité 661, Université Montpellier I et II, Montpellier, France
| | - Martial Séveno
- Plate-forme de Proteomique Fonctionnelle, c/o Institut de Génomique Fonctionnelle, Centre National de la Recherche Scientifique Unité Mixte de Recherche 5203, Institut National de la Santé et de la Recherche Médicales, Unité 661, Université Montpellier I et II, Montpellier, France
| | - Francisco José Ayala
- Department of Ecology and Evolutionary Biology, University of California Irvine, Irvine, California, United States of America
| | - Michel Tibayrenc
- Unité Mixte de Recherche, Institut de Recherche pour le Développement/Centre National de la Recherche Scientifique/Universités Montpellier 1 and 2, Génétique et Evolution des Maladies Infectieuses, n° 5290, Maladies Infectieuses et Vecteurs Ecologie, Génétique, Evolution et Contrôle (MIVEGEC) Institut de Recherche pour le Développement, Montpellier, France
- * E-mail:
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18
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Araújo CAC, Waniek PJ, Jansen AM. TcI/TcII co-infection can enhance Trypanosoma cruzi growth in Rhodnius prolixus. Parasit Vectors 2014; 7:94. [PMID: 24593987 PMCID: PMC4015778 DOI: 10.1186/1756-3305-7-94] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2013] [Accepted: 02/22/2014] [Indexed: 11/13/2022] Open
Abstract
Background Rhodnius prolixus is an obligate haematophagous insect and one of the most important vectors of Trypanosoma cruzi, the causative agent of Chagas disease in the Americas. T. cruzi is a highly variable parasite which is not transmitted in the same efficiency by the different triatomine vectors. Because different T. cruzi genotypes are aetiopathologically divergent, further elucidation of the transmission abilities of different Chagas disease vectors is extremely important. Findings In the present study, the growth behaviour of two T. cruzi isolates, MDID/BR/1993/C45 (TcI) and TBRA/BR/1999/JCA3 (TcII), sharing the same microhabitat (intestinal tract) in single and mixed infections, was examined. The distribution patterns and parasite population densities were evaluated at 7, 14 and 21 days after feeding (daf) by quantification of parasites using Neubauer haemocytometric measurements and mini-exon PCR to identify TcI and TcII subpopulations. Parasitic colonization in the small intestine was more successful in the mixed infection model than the single infection models at 21 daf. In the rectal lumen and wall, the growth behaviour of the mixed infection was similar to that of the TcI group, although the total parasite number was lower. In the TcII group, no metacyclic trypomastigote forms were found. PCR analysis of the contents of each dissected region showed different genotype fractions in the mixed infection model, in which TcI seemed to be the predominant isolate. Conclusion The different growth behaviour of the TcI and TcII isolates in single and mixed infection models demonstrated that possibly an intraspecific factor modulates parasitic development in the intestine of R. prolixus.
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Affiliation(s)
- Catarina A C Araújo
- Laboratório de Biologia de Tripanosomatídeos, Instituto Oswaldo Cruz - IOC/FIOCRUZ, Av, Brasil 4365, 21045-900 Rio de Janeiro, Brazil.
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19
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Ragone PG, Pérez Brandán C, Padilla AM, Monje Rumi M, Lauthier JJ, Alberti D’Amato AM, Tomasini N, Cimino RO, Romero NM, Portelli M, Nasser JR, Basombrío MA, Diosque P. Biological behavior of different Trypanosoma cruzi isolates circulating in an endemic area for Chagas disease in the Gran Chaco region of Argentina. Acta Trop 2012; 123:196-201. [PMID: 22643298 DOI: 10.1016/j.actatropica.2012.05.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2011] [Revised: 05/08/2012] [Accepted: 05/14/2012] [Indexed: 10/28/2022]
Abstract
The biological behavior of the different Trypanosoma cruzi strains is still unclear and the importance of exploring the relevance of these differences in natural isolates is of great significance. Herein we describe the biological behavior of four T. cruzi isolates circulating sympatrically in a restricted geographic area in Argentina endemic for Chagas Disease. These isolates were characterized as belonging to the Discrete Typing Units (DTUs) TcI, TcIII, TcV and TcVI as shown by Multilocus Enzyme Electrophoresis and Multilocus Sequence Typing. In order to study the natural behavior of the different isolates and to preserve their natural properties, we developed a vector transmission model that allows their maintenance in the laboratory. The model consisted of serial passages of these parasites between insect vectors and mice. Vector-derived parasite forms were then inoculated in C57BL/6J mice and number of parasite in peripheral blood, serological response and histological damage in acute and chronic phases of the infection were measured. Parasites from DTUs TcI, TcIII and TcVI were detected by direct fresh blood examination, while TcV parasites could only be detected by Polimerase Chain Reaction. No significant difference in the anti-T. cruzi antibody response was found during the chronic phase of infection, except for mice infected with TcV parasites where no antibodies could be detected. Histological sections showed that TcI isolate produced more damage in skeletal muscle while TcVI induced more inflammation in the heart. This work shows differential biological behavior among different parasite isolates obtained from the same cycle of transmission, permitting the opportunity to formulate future hypotheses of clinical and epidemiological importance.
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Bacigalupo A, Segovia V, García A, Botto-Mahan C, Ortiz S, Solari A, Acuna-Retamar M, Torres-Pérez F, Cattan PE. Differential pattern of infection of sylvatic nymphs and domiciliary adults of Triatoma infestans with Trypanosoma cruzi genotypes in Chile. Am J Trop Med Hyg 2012; 87:473-80. [PMID: 22802439 PMCID: PMC3435350 DOI: 10.4269/ajtmh.2012.11-0237] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2011] [Accepted: 05/03/2012] [Indexed: 11/07/2022] Open
Abstract
In Chile, the main vector of Chagas disease, Triatoma infestans, is under control after insecticide spraying. However, it has been found colonizing wild habitats. This study evaluated Trypanosoma cruzi infection of sylvatic and domiciliary T. infestans and identified their parasite genotypes. The sample studied was composed mainly of T. infestans sylvatic nymphs and domiciliary adults from a semi-urban area with human dwellings under vector control surveillance. Results showed prevalences of 57.7% in nymphs and 68.6% in adults. Hybridization tests showed a major T. cruzi lineage (TcI) circulating in sylvatic (93.3%) and domiciliary (100%) T. infestans. TcII, TcV, and TcVI were also detected, mainly in nymphs, suggesting differential adaptation of T. cruzi lineages among instars. We also discuss the origin of domiciliary individuals of T. infestans and the risk of human infection by triatomines of sylvatic foci that invade houses despite vector control programs.
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Affiliation(s)
| | | | | | | | | | | | | | | | - Pedro E. Cattan
- Departamento de Ciencias Biológicas Animales, Facultad de Ciencias Veterinarias y Pecuarias, Unidad de Parasitología, Facultad de Medicina Occidente, Departamento de Ciencias Ecológicas, Facultad de Ciencias, Programa de Biología Celular y Molecular, Instituto de Ciencias Biomédicas, Facultad de Medicina Norte, Departamento de Patología Animal, Facultad de Ciencias Veterinarias y Pecuarias, Universidad de Chile, Santiago, Chile; Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
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Valadares HMS, Pimenta JR, Segatto M, Veloso VM, Gomes ML, Chiari E, Gollob KJ, Bahia MT, de Lana M, Franco GR, Machado CR, Pena SDJ, Macedo AM. Unequivocal identification of subpopulations in putative multiclonal Trypanosoma cruzi strains by FACs single cell sorting and genotyping. PLoS Negl Trop Dis 2012; 6:e1722. [PMID: 22802979 PMCID: PMC3393670 DOI: 10.1371/journal.pntd.0001722] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2012] [Accepted: 05/22/2012] [Indexed: 11/18/2022] Open
Abstract
Trypanosoma cruzi, the etiological agent of Chagas disease, is a polymorphic species. Evidence suggests that the majority of the T. cruzi populations isolated from afflicted humans, reservoir animals, or vectors are multiclonal. However, the extent and the complexity of multiclonality remain to be established, since aneuploidy cannot be excluded and current conventional cloning methods cannot identify all the representative clones in an infection. To answer this question, we adapted a methodology originally described for analyzing single spermatozoids, to isolate and study single T. cruzi parasites. Accordingly, the cloning apparatus of a Fluorescence-Activated Cell Sorter (FACS) was used to sort single T. cruzi cells directly into 96-wells microplates. Cells were then genotyped using two polymorphic genomic markers and four microsatellite loci. We validated this methodology by testing four T. cruzi populations: one control artificial mixture composed of two monoclonal populations--Silvio X10 cl1 (TcI) and Esmeraldo cl3 (TcII)--and three naturally occurring strains, one isolated from a vector (A316A R7) and two others derived from the first reported human case of Chagas disease. Using this innovative approach, we were able to successfully describe the whole complexity of these natural strains, revealing their multiclonal status. In addition, our results demonstrate that these T. cruzi populations are formed of more clones than originally expected. The method also permitted estimating of the proportion of each subpopulation of the tested strains. The single-cell genotyping approach allowed analysis of intrapopulation diversity at a level of detail not achieved previously, and may thus improve our comprehension of population structure and dynamics of T. cruzi. Finally, this methodology is capable to settle once and for all controversies on the issue of multiclonality.
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Affiliation(s)
- Helder Magno Silva Valadares
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- Universidade Federal de São João del-Rey, Campus Centro-Oeste Dona Lindu, Divinópolis, Minas Gerais, Brazil
| | - Juliana Ramos Pimenta
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Marcela Segatto
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Vanja Maria Veloso
- Departamento de Análises Clínicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Mônica Lúcia Gomes
- Departamento de Ciências Básicas da Saúde, Universidade Estadual de Maringá, Maringá, Paraná, Brazil
| | - Egler Chiari
- Departamento de Parasitologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Kenneth John Gollob
- Instituto de Ensino e Pesquisa da Santa Casa de Belo Horizonte, Belo Horizonte, Minas Gerais, Brazil
| | - Maria Terezinha Bahia
- Departamento de Ciências Biológicas, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Marta de Lana
- Departamento de Análises Clínicas, Escola de Farmácia, Universidade Federal de Ouro Preto, Ouro Preto, Minas Gerais, Brazil
| | - Glória Regina Franco
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Carlos Renato Machado
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Sérgio Danilo Junho Pena
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
| | - Andréa Mara Macedo
- Departamento de Bioquímica e Imunologia, Instituto de Ciências Biológicas, Universidade Federal de Minas Gerais, Belo Horizonte, Minas Gerais, Brazil
- * E-mail:
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Zingales B, Miles MA, Campbell DA, Tibayrenc M, Macedo AM, Teixeira MMG, Schijman AG, Llewellyn MS, Lages-Silva E, Machado CR, Andrade SG, Sturm NR. The revised Trypanosoma cruzi subspecific nomenclature: rationale, epidemiological relevance and research applications. INFECTION GENETICS AND EVOLUTION 2011; 12:240-53. [PMID: 22226704 DOI: 10.1016/j.meegid.2011.12.009] [Citation(s) in RCA: 610] [Impact Index Per Article: 46.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Accepted: 12/16/2011] [Indexed: 10/14/2022]
Abstract
The protozoan Trypanosoma cruzi, its mammalian reservoirs, and vectors have existed in nature for millions of years. The human infection, named Chagas disease, is a major public health problem for Latin America. T. cruzi is genetically highly diverse and the understanding of the population structure of this parasite is critical because of the links to transmission cycles and disease. At present, T. cruzi is partitioned into six discrete typing units (DTUs), TcI-TcVI. Here we focus on the current status of taxonomy-related areas such as population structure, phylogeographical and eco-epidemiological features, and the correlation of DTU with natural and experimental infection. We also summarize methods for DTU genotyping, available for widespread use in endemic areas. For the immediate future multilocus sequence typing is likely to be the gold standard for population studies. We conclude that greater advances in our knowledge on pathogenic and epidemiological features of these parasites are expected in the coming decade through the comparative analysis of the genomes from isolates of various DTUs.
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Affiliation(s)
- Bianca Zingales
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, Avenida Professor Lineu Prestes 748, 05508-000 São Paulo, SP, Brazil.
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23
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Modelling the Transmission of Trypanosoma cruzi: The Need for an Integrated Genetic Epidemiological and Population Genomics Approach. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2010; 673:200-11. [DOI: 10.1007/978-1-4419-6064-1_14] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/19/2023]
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24
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Britto CC. Usefulness of PCR-based assays to assess drug efficacy in Chagas disease chemotherapy: value and limitations. Mem Inst Oswaldo Cruz 2009; 104 Suppl 1:122-35. [DOI: 10.1590/s0074-02762009000900018] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Accepted: 06/01/2009] [Indexed: 11/21/2022] Open
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Mejía-Jaramillo AM, Peña VH, Triana-Chávez O. Trypanosoma cruzi: Biological characterization of lineages I and II supports the predominance of lineage I in Colombia. Exp Parasitol 2009; 121:83-91. [DOI: 10.1016/j.exppara.2008.10.002] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2008] [Revised: 09/10/2008] [Accepted: 10/01/2008] [Indexed: 11/29/2022]
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26
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Martins HR, Silva RM, Valadares HMS, Toledo MJO, Veloso VM, Vitelli-Avelar DM, Carneiro CM, Machado-Coelho GLL, Bahia MT, Martins-Filho OA, Macedo AM, Lana M. Impact of dual infections on chemotherapeutic efficacy in BALB/c mice infected with major genotypes of Trypanosoma cruzi. Antimicrob Agents Chemother 2007; 51:3282-9. [PMID: 17638698 PMCID: PMC2043214 DOI: 10.1128/aac.01590-06] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The aim of this work was to investigate the impact of dual infections with stocks of Trypanosoma cruzi major genotypes on benznidazole (BZ) treatment efficacy. For this purpose, T. cruzi stocks representative of the genetic T. cruzi lineages, displaying different susceptibilities to BZ, belonging to the major T. cruzi genotypes broadly dispersed in North and South America and important in Chagas' disease epidemiology were used. Therapeutic efficacy was observed in 27.8% of the animals treated. Following BZ susceptibility classification, significant differences were observed in dual infections on the major genotype level, demonstrating that combinations of genotypes 19+39 and genotypes 19+32 led to a shift in the expected BZ susceptibility profile toward the resistance pattern. Analysis on the T. cruzi stock level demonstrated that 9 out of 24 dual infections shifted the expected BZ susceptibility profile compared with the respective single infections, including shifts toward lower and higher BZ susceptibilities. Microsatellite identification was able to identify a mixture of T. cruzi stocks in 7.7% of the T. cruzi isolates from infected and untreated mice (6.9%) and infected and treated but not cured mice (9.0%), revealing in some mixtures of BZ-susceptible and -resistant stocks that the T. cruzi stock identified after BZ treatment was previously susceptible in single infections. Considering the clonal structure and evolution of T. cruzi, an unexpected result was the identification of parasite subpopulations with distinct microsatellite alleles in relation to the original stocks observed in 12.2% of the isolates. Taken together, the data suggest that mixed infections, already verified in nature, may have an important impact on the efficacy of chemotherapy.
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Affiliation(s)
- H R Martins
- Núcleo de Pesquisas em Ciências Biológicas, Instituto de Ciências Exatas e Biológicas, Universidade Federal de Ouro Preto, Campus Universitário, Morro do Cruzeiro, 35400-000 Ouro Preto, MG, Brazil.
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27
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Araújo CAC, Cabello PH, Jansen AM. Growth behaviour of two Trypanosoma cruzi strains in single and mixed infections: In vitro and in the intestinal tract of the blood-sucking bug, Triatoma brasiliensis. Acta Trop 2007; 101:225-31. [PMID: 17374352 DOI: 10.1016/j.actatropica.2007.02.004] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2006] [Revised: 10/16/2006] [Accepted: 02/13/2007] [Indexed: 10/23/2022]
Abstract
Competition and cooperation are well-recognized biological phenomena, even among parasites. Co-infection of parasites in a single host leads to several outcomes, one being competition for a limited resource. Here, the behaviour of mixed infection was evaluated using two isolates of Trypanosoma cruzi, previously typed as belonging to genotypes TcI and TcII. The growth in vitro and in the different compartments of the gut of Triatoma brasiliensis was studied. In vitro growth showed that MDID/BR/1999/M1 (TcI) has a doubling time of 19.5h and MIDID/BR/1999/JCPD4 (TcII) of 9.6h, while the mixed infection group presented a doubling time of 13.9h. In vivo, three groups of infection were done: M1/TcI, JCPD4/TcII and mixed infection (50% of each strain), respectively. All comparisons among the groups were done using the Kruskal-Wallis non-parametric test. The data showed that the in vitro culture of mixed populations has a similar pattern to the growth of M1/TcI, apparently suggesting a positively selection for M1/TcI strain, in axenic culture. In the gut of the insects, M1/TcI isolate and mixed infections colonized predominantly the rectal wall and rectal lumen, in contrast to the JCPD4/TcII isolate, which was found mainly colonizing the small intestine. According to the isolates investigated, it could be concluded that the doubling time was not determinant factor for the final composition of a co-infection. Moreover, mixed infections resulted in a homogenous distribution of the parasites, comparing to the isolates studied separately. Apparently, in the gut of the bugs, the simultaneous presence of JCPD4/TcII isolate resulted in an improvement of the number of parasites from M1/TcI.
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Affiliation(s)
- Catarina A C Araújo
- Departamento de Protozoologia, Instituto Oswaldo Cruz, FIOCRUZ, Avenida Brasil, 4365 Manguinhos, RJ, Brazil
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Garcia ES, Ratcliffe NA, Whitten MM, Gonzalez MS, Azambuja P. Exploring the role of insect host factors in the dynamics of Trypanosoma cruzi-Rhodnius prolixus interactions. JOURNAL OF INSECT PHYSIOLOGY 2007; 53:11-21. [PMID: 17141801 DOI: 10.1016/j.jinsphys.2006.10.006] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2006] [Revised: 10/11/2006] [Accepted: 10/16/2006] [Indexed: 05/12/2023]
Abstract
Members of the subfamily Triatominae, family Reduviidae, comprise a large number of insect species of which some are vectors of Trypanosoma cruzi, the causative agent of Chagas' disease. This article outlines research on the process of transformation and the dynamics of developmental stages of Trypanosoma cruzi in the triatomine insect hosts. Special attention is given to the interactions of parasites with gut molecules, and the gut environment, and with host developmental physiology and intestinal organization. The vector insect's permissiveness to Trypanosoma cruzi, which develops in the vector gut, largely depends on the host nutritional state, the parasite strain, trypanolytic compounds, digestive enzymes, lectins, resident bacteria in the gut and the endocrine system of the insect vector. Finally, the mechanisms of these interactions and their significance for Trypanosoma cruzi transmission are discussed.
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Affiliation(s)
- Eloi S Garcia
- Department of Biochemistry and Molecular Biology, Instituto Oswaldo Cruz, Fundação Oswaldo Cruz, Av. Brasil 4365, Rio de Janeiro 21045-900, RJ, Brazil
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29
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Pérez Brandán C, Padilla AM, Diosque P, Basombrío MA. Trypanosoma cruzi: Infectivity modulation of a clone after passages through different hosts. Exp Parasitol 2006; 114:89-93. [PMID: 16564526 DOI: 10.1016/j.exppara.2006.02.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2005] [Revised: 01/24/2006] [Accepted: 02/16/2006] [Indexed: 10/24/2022]
Abstract
Although Trypanosoma cruzi virulence can be modified through passages in vivo or long-term in vitro culture, the mechanisms involved are poorly understood. Here we report modifications in the infectivity of a T. cruzi clone after passages in different hosts without detectable changes in parasite genetic patterns. A clone was obtained from a T. cruzi IIe isolate and showed to be less virulent than the original isolate (p<0.05). This clone was enzymatically similar to the original isolate as shown by multilocus enzyme electrophoresis. Infection of this clone was compared by successive passages in mice and guinea pigs. The mouse-passaged subline became more virulent for both host species compared to the guinea pig-passaged subline (p<0.05). The clone line displayed similar random amplified polymorphic DNA patterns before and after passages in different hosts suggesting that alterations in virulence could be a result of a differential expression of virulence factors.
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Affiliation(s)
- Cecilia Pérez Brandán
- Instituto de Patología Experimental, Facultad de Ciencias de la Salud, Universidad Nacional de Salta, Avda. Bolivia 5150, CP 4400 Salta, Argentina.
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Abstract
Insects comprise the largest species composition in the entire animal kingdom and possess a vast undiscovered genetic diversity and gene pool that can be better explored using molecular marker techniques. Current trends of application of DNA marker techniques in diverse domains of insect ecological studies show that mitochondrial DNA (mtDNA), microsatellites, random amplified polymorphic DNA (RAPD), expressed sequence tags (EST) and amplified fragment length polymorphism (AFLP) markers have contributed significantly for progresses towards understanding genetic basis of insect diversity and for mapping medically and agriculturally important genes and quantitative trait loci in insect pests. Apart from these popular marker systems, other novel approaches including transposon display, sequence-specific amplification polymorphism (S-SAP), repeat-associated polymerase chain reaction (PCR) markers have been identified as alternate marker systems in insect studies. Besides, whole genome microarray and single nucleotide polymorphism (SNP) assays are becoming more popular to screen genome-wide polymorphisms in fast and cost effective manner. However, use of such methodologies has not gained widespread popularity in entomological studies. The current study highlights the recent trends of applications of molecular markers in insect studies and explores the technological advancements in molecular marker tools and modern high throughput genotyping methodologies that may be applied in entomological researches for better understanding of insect ecology at molecular level.
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Affiliation(s)
- Susanta K Behura
- Department of Entomology, 505 S Goodwin Avenue, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA.
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31
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Martins HR, Toledo MJO, Veloso VM, Carneiro CM, Machado-Coelho GLL, Tafuri WL, Bahia MT, Valadares HM, Macedo AM, Lana M. Trypanosoma cruzi: Impact of dual-clone infections on parasite biological properties in BALB/c mice. Exp Parasitol 2006; 112:237-46. [PMID: 16406355 DOI: 10.1016/j.exppara.2005.11.006] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2005] [Revised: 11/08/2005] [Accepted: 11/10/2005] [Indexed: 10/25/2022]
Abstract
Herein, we have analyzed major biological properties following dual-clone Trypanosoma cruzi infections in BALB/c mice. Eight T. cruzi clonal stocks, two of each principal genotype, including genotype 19 and 20 (T. cruzi I), hybrid genotype 39 (T. cruzi) and 32 (T. cruzi II) were combined into 24 different dual-clone infections. Special attention was given to characterize biological parameters assayed including: prepatent period, patent period, maximum of parasitemia, day of maximum parasitemia, area under the parasitemia curve, infectivity, mortality, and hemoculture positivity. Our findings clearly demonstrated that features resultant of dual-clone infections of T. cruzi clonal stocks did not display either the characteristics of the corresponding monoclonal infections or the theoretical mixture based on the respective monoclonal infections. Significant changes in the expected values were observed in 4.2-79.2% of the mixtures considering the eight biological parameters studied. A lower frequency of significant differences was found for mixtures composed by phylogenetically distant clonal stocks. Altogether, our data support our hypothesis that mixed T. cruzi infections have a great impact on the biological properties of the parasite in the host and re-emphasizes the importance of considering the possible occurrence of natural mixed infections in humans and their consequences on the biological aspects of ongoing Chagas' disease.
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Affiliation(s)
- H R Martins
- Núcleo de Pesquisas em Ciências Biológicas (NUPEB), Instituto de Ciências Exatas e Biológicas (ICEB), UFOP, MG, Brazil
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32
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Oury B, Tarrieu F, Monte-Alegre A, Ouaissi A. Trypanosoma cruzi: Sequence polymorphism of the gene encoding the Tc52 immunoregulatory-released factor in relation to the phylogenetic diversity of the species. Exp Parasitol 2005; 111:198-206. [PMID: 16199037 DOI: 10.1016/j.exppara.2005.07.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2004] [Revised: 07/04/2005] [Accepted: 07/15/2005] [Indexed: 10/25/2022]
Abstract
We have previously identified a Trypanosoma cruzi gene encoding a protein named Tc52 sharing structural and functional properties with the thioredoxin and glutaredoxin family involved in thiol-disulfide redox reactions. Gene targeting strategy and immunological studies allowed showing that Tc52 is among T. cruzi virulence factors. Taking into account that T. cruzi has a genetic variability that might be important determinant that governs the different behaviour of T. cruzi clones in vitro and in vivo, we thought it was of interest to analyse the sequence polymorphism of Tc52 gene in several reference clones. The DNA sequences of 12 clones which represent the whole genetic diversity of T. cruzi allowed showing that 40 amino-acid positions over 400 analysed are targets for mutations. A number of residues corresponding to putative amino-acids playing a role in GSH binding and/or enzymatic function and others located nearby are subject to mutations. Although the immunological analysis showed that Tc52 is present in parasite extracts from different clones, it is possible that the amino-acid differences could affect the enzymatic and/or the immunomodulatory function of Tc52 variants and therefore the parasite phenotype.
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Affiliation(s)
- Bruno Oury
- Institut de Recherche pour le Développement (IRD), Unité de Recherche no 8 Pathogénie des Trypanosomatidae, Montpellier, France.
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Tibayrenc M. Genetic subdivisions within Trypanosoma cruzi (Discrete Typing Units) and their relevance for molecular epidemiology and experimental evolution. KINETOPLASTID BIOLOGY AND DISEASE 2003; 2:12. [PMID: 14613498 PMCID: PMC270070 DOI: 10.1186/1475-9292-2-12] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/18/2003] [Accepted: 10/28/2003] [Indexed: 11/10/2022]
Abstract
Background This paper summarizes the main results obtained on Trypanosoma cruzi genetic diversity and population structure since this parasite became the theme of many genetic and molecular studies in the early seventies. Results T. cruzi exibits a paradigmatic pattern of long-term, clonal evolution, which has structured its natural populations into several discrete genetic subdivisions or "Discrete Typing Units" (DTU). Rare hybridization events are nevertheless detectable in natural populations and have been recently obtained in the laboratory. Conclusions The DTUs and natural clones of T. cruzi constitute relevant units for molecular epidemiology and experimental evolution. Experimental mating opens the way to an in-depth knowledge of this parasite's formal genetics.
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Affiliation(s)
- Michel Tibayrenc
- UR62 "Genetics of Infectious Diseases", UMR CNRS/IRD 9926, IRD Centre, BP 64501, 34394 Montpellier Cedex 5, France.
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34
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Brisse S, Verhoef J, Tibayrenc M. Characterisation of large and small subunit rRNA and mini-exon genes further supports the distinction of six Trypanosoma cruzi lineages. Int J Parasitol 2001; 31:1218-26. [PMID: 11513891 DOI: 10.1016/s0020-7519(01)00238-7] [Citation(s) in RCA: 163] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
It has been proposed that isolates of Trypanosoma cruzi, the agent of American trypanosomiasis, can be ordered into two primary phylogenetic lineages, first based on multilocus enzyme electrophoresis and random amplified polymorphic DNA, and subsequently based on the 24Salpha rRNA and mini-exon genes. Recent multilocus enzyme electrophoresis and random amplified polymorphic DNA data have additionally shown that the major multilocus enzyme electrophoresis/random amplified polymorphic DNA lineage II is further subdivided into five smaller lineages, designated IIa-IIe. In this study, the precise correspondence between the multilocus enzyme electrophoresis/random amplified polymorphic DNA and rRNA/mini-exon lineages was investigated. Using the 24Salpha rRNA and mini-exon markers in combination, five sets of strains were distinguished, corresponding to the multilocus enzyme electrophoresis/random amplified polymorphic DNA lineages I, IIa, IIc, IId and to lineages IIb/IIe together, respectively. The previous categorisation into only two primary lineages based on 24Salpha rRNA and mini-exon characterisation is explained, in part, by the lack of representativeness of the breadth of T. cruzi diversity in earlier study samples. Additionally, a PCR assay based on a length-variable region of the 18S rRNA gene distinguished lineage IIe from lineage IIb. Thus, the six multilocus enzyme electrophoresis/random amplified polymorphic DNA lineages could be readily identified by combining data from the 24Salpha rRNA, mini-exon and 18S rRNA characterisation assays, further supporting the relevance of these genetic units for T. cruzi strain classification and subspecific nomenclature. The recently proposed groups T. cruzi I and T. cruzi II correspond to multilocus enzyme electrophoresis/random amplified polymorphic DNA lineages I and IIb, respectively. Our findings show that T. cruzi lineage characterisation based on a single marker (either mini-exon or 24Salpha rRNA) has insufficient resolution, and leads to important reinterpretations of recent epidemiological and evolutionary studies based on the oversimplified rRNA/mini-exon dichotomic classification of T. cruzi isolates.
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Affiliation(s)
- S Brisse
- Eijkman-Winkler Institute, University Medical Centre Utrecht, AZU G04.614, Heidelberglaan 100, 3584 CX Utrecht, The Netherlands.
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Brisse S, Dujardin JC, Tibayrenc M. Identification of six Trypanosoma cruzi lineages by sequence-characterised amplified region markers. Mol Biochem Parasitol 2000; 111:95-105. [PMID: 11087920 DOI: 10.1016/s0166-6851(00)00302-9] [Citation(s) in RCA: 114] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Six discrete phylogenetic lineages were recently identified in Trypanosoma cruzi, on the basis of multilocus enzyme electrophoresis and random amplified polymorphic DNA (RAPD) characterisation. The objective of the present study was to develop specific PCR-based markers for the identification of each of the six lineages. Eighty-seven T. cruzi stocks representative of all the lineages were characterised by RAPD with three primers, resulting in the identification of three fragments that were specifically amplified in the given sets of lineages. After cloning and sequencing these fragments, three pairs of sequence-characterised amplified region (SCAR) primers were designed. After PCR amplification using the SCAR primers, the initial polymorphism was retained either as the presence or absence of amplification, or as size variation between the PCR products. Although most PCR products, taken individually, were distributed across several lineages, the combination of the three SCAR markers resulted in characteristic patterns that were distinct in the six lineages. Furthermore, T. cruzi lineages were distinguished from Trypanosoma rangeli, T. cruzi marinkellei and T. cruzi-like organisms. The excellent correspondence of these new PCR markers with the phylogenetic lineages, allied with their sensitivity, makes them reliable tools for lineage identification and strain characterisation in T. cruzi. The approach described here could be generalised to any species of microorganism harbouring clear-cut phylogenetic subdivisions.
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Affiliation(s)
- S Brisse
- Centre d'Etudes sur le Polymorphisme des Microorganismes, UMR CNRS/IRD 9926, IRD, 911 avenue Agropolis, BP 5045, 34 032 Montpellier Cedex, France.
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de Lana M, da Silviera Pinto A, Bastrenta B, Barnabé C, Noël S, Tibayrenc M. Trypanosoma cruzi: infectivity of clonal genotype infections in acute and chronic phases in mice. Exp Parasitol 2000; 96:61-6. [PMID: 11052864 DOI: 10.1006/expr.2000.4552] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Eight Trypanosoma cruzi stocks pertaining to the clonal genotypes 19/20, 32, and 39 have been characterized for three experimental parameters of infectivity in Balb/c mice: (i) percentage of mice with a patent parasitemia (% MPP), (ii) maximum parasitemia (MP), and (iii) percentage of mice with positive hemoculture (% MPH). By order of decreasing values, the values recorded for the clonal genotypes ranked as follows: 19/20, 32, and 39, except for the % MPP parameter, for which 19/20 and 32 were not statistically different. The rate of successful reisolation after infection in mice, analyzed by multilocus enzyme electrophoresis and random amplified polymorphic DNA typing, was statistically different according to the clonal genotype and was different for uniclonal infections and for mixed infections by two different clonal genotypes. These results confirm that T. cruzi clonal genotypes differ significantly in their infectivity in mice.
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Affiliation(s)
- M de Lana
- Centre d'Etudes sur le Polymorphisme des Microorganismes (CEPM), Unité Mixte de Recherche no. 9926 Centre National de la Recherche Scientifique (CNRS)/Institut de Recherche pour le Développement (IRD), B.P. 5045, 34032 Montpellier Cedex 1, France
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Bosseno MF, Yacsik N, Vargas F, Brenière SF. Selection of Trypanosoma cruzi clonal genotypes (clonet 20 and 39) isolated from Bolivian triatomines following subculture in liquid medium. Mem Inst Oswaldo Cruz 2000; 95:601-7. [PMID: 10998206 DOI: 10.1590/s0074-02762000000500002] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/17/2023] Open
Abstract
Previous studies showed that two groups of Trypanosoma cruzi clonal genotypes named clonet 20 and clonet 39 were predominant in Triatoma infestans, the unique vector of Chagas disease in Bolivia. These groups of clones correspond to distinct genetic clusters. These clonets were detected in T. infestans and Rhodnius pictipes fecal samples before isolation and after culture by kDNA PCR (polymerase chain reaction) and hybridization of the amplified products with clonet specific kDNA probes named 20 and 39 as previously reported. Forty eight T. infestans and three R. pictipes infected insects captured at random in different Bolivian departments were proceeded. As previously reported the direct identification of the two major clonets in fecal samples allowed the detection of abundant mixed infections: 41% in the original sample, however after culture, only 6% of mixed infections were detected. Among the 21 parasite stocks isolated from digestive tracts where mixed infections were initially detected (clonet 20 + 39) clonet 20 alone was detected in 81% of them. This result clearly showed that the culture step selected clonet 20 parasites over those belonging to clonet 39. The taxonomic status of the isolated stocks was also confirmed by isoenzyme typing, and correlation was observed between clustering topology and hybridization patterns with the probes 20 and 39.
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Kollien AH, Schaub GA. The development of Trypanosoma cruzi in triatominae. PARASITOLOGY TODAY (PERSONAL ED.) 2000; 16:381-7. [PMID: 10951597 DOI: 10.1016/s0169-4758(00)01724-5] [Citation(s) in RCA: 209] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Trypanosoma cruzi multiplies and differentiates in the digestive tract of triatomine insects. These insects ingest an enormous amount of blood, with ingestion followed very rapidly by a strong diuresis, slow digestion and occasionally long periods of starvation. Resulting changes in the intestinal environment induce the development of dominant stages of T. cruzi--epimastigotes and metacyclic trypomastigotes--and can be correlated with the appearance of specific developmental stages--spheromastigotes and giant cells--which otherwise are only rarely seen. Here, Astrid Kollien and Günter Schaub outline recent research on these developmental steps of T. cruzi in the vector, and the effects of different compounds acting against the parasite in the vector.
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Affiliation(s)
- A H Kollien
- Department of Special Zoology, Ruhr-University Bochum, D-44780 Bochum, Germany.
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Abstract
Due to the increase of human migrations, the appearance of emerging and reemerging endemies, growing antibiotic resistance, and climatic changes, infectious diseases most probably constitute the major challenge for medicine in the next century. The advent of molecular methods of pathogen characterization has considerably improved our knowledge of the epidemiology of these diseases. However, the use of concepts of evolutionary genetics for interpreting "molecular epidemiology" data remains limited, although the application of such methods would broaden considerably the scope of this field of research, and allow epidemiologic and taxonomic approaches to be ascertained on a much firmer basis. In turn, pathogens, hosts, and vectors provide fascinating models for basic research. The artificial character of the border between "basic" and "applied" research is especially apparent with regard to the "integrated genetic epidemiology of infectious diseases" concept. The goal of this chapter is to evaluate the respective impact, on the transmission and pathogenicity of infectious diseases, of the host's, the pathogen's, and the vector's (for vector-borne diseases) genetic diversity, and the interactions between these three parameters (coevolution phenomena).
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Affiliation(s)
- M Tibayrenc
- Centre d'Etudes sur le Polymorphisme des Microorganismes (CEPM), Centre IRD de Montpellier, France.
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Brisse S, Barnabé C, Tibayrenc M. Identification of six Trypanosoma cruzi phylogenetic lineages by random amplified polymorphic DNA and multilocus enzyme electrophoresis. Int J Parasitol 2000; 30:35-44. [PMID: 10675742 DOI: 10.1016/s0020-7519(99)00168-x] [Citation(s) in RCA: 230] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Genetic characterisation of Trypanosoma cruzi variants is of foremost importance, due to considerable genetic and biological heterogeneity in the parasite populations. Two major phylogenetic lineages, each highly heterogeneous, have been previously described within this species. Here we characterised a geographically and ecologically diverse sample of stocks representative of the breadth of the known clonal diversity of each major lineage, using random amplified polymorphic DNA with 20 primers and multilocus enzyme electrophoresis at 22 loci. Molecular hybridisation experiments were performed to control the homology of randomly amplified DNA markers. Both sets of data were highly consistent and supported the existence of two major lineages. Additionally, we found that lineage 2 appeared further partitioned into five sharply delineated phylogenetic clusters, each comprising one of the following reference strains: CanIII cl1 (Z3 reference), M5631 cl5, Esmeraldo cl3 (Z2 reference), CL Brener, and MN cl2. The two first clusters were found mainly in sylvatic environments, whereas the three latter were restricted to domestic transmission cycles and were only collected South to the Amazon Basin. In contrast, lineage 1, which included Miles' Z1 reference strain X10 cl1, was not further subdivided and was encountered across the entire endemic area, in both domestic and sylvatic cycles. Thus, T. cruzi appeared to be subdivided into six discrete typing units, or DTUs, exhibiting distinct geographic and ecological ranges. Reliable diagnostic markers for the two major lineages and the five smaller DTUs of lineage 2 are described, and correspondence with previous classifications of T. cruzi genotypes is given in order to help communication on T. cruzi phylogenetic diversity.
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Affiliation(s)
- S Brisse
- Centre d'Etudes sur le Polymorphisme des Microorganismes (CEPM,) UMR No. 9926 Centre National de la Recherche Scientifique/Institut de Recherche pour le Développement, IRD, 911 avenue Agropolis, BP 5045, 34 032, Montpellier, France.
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Abstract
We review recent advances in the study of population structure and phylogenetic diversity of parasites belonging to the genera Trypanosoma and Leishmania. In all species properly analyzed, these parasites exhibit a basically clonal population structure, with occasional bouts of genetic exchange or hybridization, and a strong structuration of their populations into discrete evolutionary lineages. On an evolutionary scale, the impact of sex appears to be greater in African than in American trypanosomes. The taxonomic status of some Leishmania 'species' is questionable.
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Affiliation(s)
- M Tibayrenc
- Centre d'Etudes sur le Polymorphisme des Microorganismes (CEPM), UMR CNRS/IRD 9926, IRD, BP 5045, 34032 Montpellier, France
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Abstract
Genetic typing of pathogenic agents and of vectors has known impressive developments in the last 10 years, thanks to the progresses of molecular biology, and to the contribution of the concepts of evolutionary genetics. Moreover, we know more and more on the genetic susceptibility of man to infectious diseases. I propose here to settle a new, synthetic field of research, which I call 'integrated genetic epidemiology of infectious diseases' (IGEID). I aim at evaluating, by an evolutionary genetic approach, the respective impact, on the transmission and pathogenicity of infectious diseases, of the host's, the pathogen's and the vector's genetic diversity, and their possible interactions (co-evolution phenomena). Chagas' disease constitutes a fine model to develop the IGEID methodology, by both field and experimental studies.
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Affiliation(s)
- M Tibayrenc
- Centre d'Etudes sur le Polymorphisme des Microorganismes (CEPM), UMR CNRS/ORSTOM 9926, Monptellier, France.
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