Publications by authors named "Christian Barnabe"

Background: Trypanosoma cruzi is mainly transmitted to mammals by vectors, but other transmission routes exist. Opossums can harbor the infectious form of the parasite in their anal glands, underscoring their potential role in non-vectorial transmission. In Mexico, Didelphis virginiana and D.

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Background: The presence of Aedes albopictus in Bolivia has been a subject of controversy, with a lack of concrete documentation.

Objectives: This study aimed to provide evidence of Ae. albopictus presence in Bolivia.

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The study focuses on identifying and understanding the ecological dynamics of Triatoma breyeri in Bolivia. Morphological identification and molecular analysis using gene fragments (COI, CytB and 16S) confirms T. breyeri's presence and its relation to other species.

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Background: Trypanosoma cruzi, the etiological agent of Chagas Disease, exhibits remarkable genetic diversity and is classified into different Discrete Typing Units (DTUs). Strain typing techniques are crucial for studying T. cruzi, because their DTUs have significant biological differences from one another.

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Chagas disease is a widespread neglected disease in Latin America. Trypanosoma cruzi, the causative agent of the disease, is currently subdivided into six DTUs (discrete typing units) named TcI-TcVI, and although no clear association has been found between parasite genetics and different clinical outcomes of the disease or different transmission cycles, genetic characterization of T. cruzi strains remains crucial for integrated epidemiological studies.

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Article Synopsis
  • A new deep learning method has been developed to identify and classify 20 species of Anopheles mosquitoes, including 13 that spread malaria.
  • The method achieved up to 100% accuracy for ten species, though it showed less accuracy for some others, especially those that are difficult to distinguish.
  • This tool is expected to improve malaria vector surveys and control measures, with potential applications for other diseases spread by arthropods in the future.
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The genus Triatoma contains numerous species, principal or secondary vectors of Chagas disease, which have been included in the three main lineages of Triatomini tribe based on morphological and biogeographical characteristics: North American, South American, and T. dispar complex. The three members of the T.

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Rhodnius ecuadoriensis is one of the most important vector species of Chagas disease in Ecuador. This species is distributed in the Central coast region and in the south Andean region, and an incipient speciation process between these geographical populations was previously proposed. The current population genetics study only focused on the Central coast region and analyzed 96 sylvatic specimens of R.

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Insects of the genus Rhodnius are broadly involved in Chagas disease transmission. In French Guiana, where the disease remains a public health problem, R. robustus and R.

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Background: For several years, the wild populations of Triatoma infestans, main vector of Trypanosoma cruzi causing Chagas disease, have been considered or suspected of being a source of reinfestation of villages. The number of sites reported for the presence of wild T. infestans, often close to human habitats, has greatly increased, but these data are scattered in several publications, and others obtained by our team in Bolivia have not been published yet.

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Arginase activity induction in macrophages is an escape mechanism developed by parasites to cope with the host's immune defense and benefit from increased host-derived growth factor production. We report that arginase expression and activity were induced in macrophages during mouse infection by , a natural parasite of this host. This induction was reproduced in vitro by excreted/secreted factors of the parasite.

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The Amazon region has recently been considered as endemic in Latin America. In Bolivia, the vast Amazon region is undergoing considerable human migrations and substantial anthropization of the environment, potentially renewing the danger of establishing the transmission of Chagas disease. The cases of human oral contamination occurring in 2010 in the town of Guayaramerín provided reasons to intensify research.

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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.

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Background: Chagas disease is a major public health problem in Latin America. Its etiologic agent, Trypanosoma cruzi, is mainly transmitted through the contaminated faeces of blood-sucking insects called triatomines. Triatoma infestans is the main vector in various countries in South America and recently, several foci of wild populations of this species have been described in Bolivia and other countries.

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It is generally acknowledged that Trypanosoma cruzi, responsible for Chagas disease, is structured into six or seven distinct discrete typing units (DTUs), and termed TcI through TcVI and TcBat for the seventh, by a collective of researchers. However, such structuring can be validated only when the species is analyzed over its entire distribution area with the same genetic markers. Many works have dealt with several DTUs in limited areas, generally one country, others have dealt with only one DTU over the endemic area, but no work has reported data of all DTUs over the entire endemic area.

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Article Synopsis
  • The research focuses on optimizing a Multilocus Sequence Typing (MLST) method for identifying genetic variations in Trypanosoma cruzi, the causative agent of Chagas disease, which is known for its significant genetic diversity.
  • By analyzing thirteen concatenated gene fragments from reference strains, the study achieved a robust classification of T. cruzi into its known Discrete Typing Units (DTUs) and found that a combination of seven specific gene fragments offers the best discrimination of genetic variations.
  • The proposed seven-fragment MLST scheme is suggested as a new gold standard for T. cruzi typing, providing a reliable comparison point for other typing methods, especially for simpler single locus techniques
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Background: Wild populations of Triatoma infestans are now believed to be the source of reinfestation of dwellings in some Andean areas and could impede the full achievement of vector control campaigns in this region. Given the poor knowledge of these populations in natural conditions, their basic biology traits, such as monthly demographic variations and movements of individuals, were explored.

Methods: A previously identified wild population of T.

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Trypanosoma cruzi, the causative agent of Chagas disease, is subdivided into six discrete typing units (DTUs; TcI-TcVI) of which TcI is ubiquitous and genetically highly variable. While clonality is the dominant mode of propagation, recombinant events play a significant evolutive role. Recently, foci of wild Triatoma infestans have been described in Bolivia, mainly infected by TcI.

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Triatoma infestans, the major vector of Chagas disease south of the Amazon in South America, has a large distribution of wild populations, contrary to what has previously been stated. These populations have been suspected of being the source of reinfestation of human habitats and could impede the full success of vector control campaigns. This study examined gene flow between intra-peridomestic populations and wild populations collected in the surround areas in three Andean localities in Bolivia.

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Article Synopsis
  • Trypanosoma cruzi, the causative agent of Chagas disease, consists of various Discrete Typing Units (DTUs), each characterized by genetic markers, with Ts factor being crucial for the parasite's virulence.
  • Research indicated that aggressive strains (TcII and TcVI) express more trans-sialidase (TS) genes compared to the less virulent TcI strains, which show an absence of a specific TS gene variant.
  • Sequencing of isolates across the Americas revealed consistent patterns in TS gene presence and absence among different DTUs, supporting existing evolutionary models of T. cruzi's genome and offering potential for genetic manipulation studies.
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