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listelement.badge.dso-type Item , SARS-CoV-2 Rapid Antigen Test Based on a New Anti-Nucleocapsid Protein Monoclonal Antibody: development and real-time validation(Universidade Federal de Minas Gerais, 2023) Fabiana Fioravante Coelho; Miriam Aparecida da Silva; Thiciany Blener Lopes; Juliana Moutinho Polatto; Natália Salazar de Castro; Luís Adan Flores Andrade; Karine Lima Lourenço; Hugo Itaru Sato; Alex Fiorini de Carvalho; Helena Perez Coelho; Flávia Fonseca Bagno; Daniela Luz; Vicente Luís Viala; Pedro Queiroz Cattony; Bruna de Sousa Melo; Ana Maria Moro; Wagner Quintílio; Ana Paula Barbosa; Camila Gasque Bomfim; Camila Pereira Soares; Cristiane Rodrigues Guzzo; Flávio Guimarães Fonseca; Edison Luiz Durigon; Ricardo Tostes Gazzinelli; Santuza Maria Ribeiro Teixeira; Roxane Maria Fontes Piazza; Ana Paula FernandesSARS-CoV-2 diagnostic tests have become an important tool for pandemic control. Among the alternatives for COVID-19 diagnosis, antigen rapid diagnostic tests (Ag-RDT) are very convenient and widely used. However, as SARS-CoV-2 variants may continuously emerge, the replacement of tests and reagents may be required to maintain the sensitivity of Ag-RDTs. Here, we describe the development and validation of an Ag-RDT during an outbreak of the Omicron variant, including the characterization of a new monoclonal antibody (anti-DTC-N 1B3 mAb) that recognizes the Nucleocapsid protein (N). The anti-DTC-N 1B3 mAb recognized the sequence TFPPTEPKKDKKK located at the C-terminus of the N protein of main SARS-CoV-2 variants of concern. Accordingly, the Ag-RDT prototypes using the anti-DTC-N 1B3 mAB detected all the SARS-CoV-2 variants—Wuhan, Alpha, Gamma, Delta, P2 and Omicron. The performance of the best prototype (sensitivity of 95.2% for samples with Ct ≤ 25; specificity of 98.3% and overall accuracy of 85.0%) met the WHO recommendations. Moreover, results from a patients’ follow-up study indicated that, if performed within the first three days after onset of symptoms, the Ag-RDT displayed 100% sensitivity. Thus, the new mAb and the Ag-RDT developed herein may constitute alternative tools for COVID-19 point-of-care diagnosis and epidemiological surveillance.listelement.badge.dso-type Item , A case study of incorporating variable recovery and specific energy in long-term open pit mining(Universidade Federal de Minas Gerais)listelement.badge.dso-type Item , Disruption of multiple copies of the Prostaglandin F2alpha synthase gene affects oxidative stress response and infectivity in Trypanosoma cruzi(Universidade Federal de Minas Gerais, 2022) Ana Maria Murta Santi; Juliana Martins Ribeiro; João Luís Reis-Cunha; Gabriela de Assis Burle-Caldas; Isabel Fernandes Martins Santos; Paula Alves Silva; Daniela de Melo Resende; Daniella Castanheira Bartolomeu; Santuza Maria Ribeiro Teixeira; Silvane Maria Fonseca MurtaChagas disease, caused by the protozoan Trypanosoma cruzi, is a serious chronic parasitic disease, currently treated with Nifurtimox (NFX) and Benznidazole (BZ). In addition to high toxicity, these drugs have low healing efficacy, especially in the chronic phase of the disease. The existence of drug-resistant T. cruzi strains and the occurrence of cross-resistance between BZ and NFX have also been described. In this context, it is urgent to study the metabolism of these drugs in T. cruzi, to better understand the mechanisms of resistance. Prostaglandin F2α synthase (PGFS) is an enzyme that has been correlated with parasite resistance to BZ, but the mechanism by which resistance occurs is still unclear. Our results show that the genome of the CL Brener clone of T. cruzi, contains five PGFS sequences and three potential pseudogenes. Using CRISPR/Cas9 we generated knockout cell lines in which all PGFS sequences were disrupted, as shown by PCR and western blotting analyses. The PGFS deletion did not alter the growth of the parasites or their susceptibility to BZ and NFX when compared to wild-type (WT) parasites. Interestingly, NTR-1 transcripts were shown to be upregulated in ΔPGFS mutants. Furthermore, the ΔPGFS parasites were 1.6 to 1.7-fold less tolerant to oxidative stress generated by menadione, presented lower levels of lipid bodies than the control parasites during the stationary phase, and were less infective than control parasites.listelement.badge.dso-type Item , Genomics and functional genomics in Leishmania and Trypanosoma cruzi: statuses, challenges and perspectives(Universidade Federal de Minas Gerais, 2021) Daniella Castanheira Bartholomeu; Santuza Maria Ribeiro Teixeira; Angela Kaysel CruzThe availability of Trypanosomatid genomic data in public databases has opened myriad experimental possibilities that have contributed to a more comprehensive understanding of the biology of these parasites and their interactions with hosts. In this review, after brief remarks on the history of the Trypanosoma cruzi and Leishmania genome initiatives, we present an overview of the relevant contributions of genomics, transcriptomics and functional genomics, discussing the primary obstacles, challenges, relevant achievements and future perspectives of these technologies.listelement.badge.dso-type Item , Repeat-Driven Generation of Antigenic Diversity in a Major Human Pathogen, Trypanosoma cruzi(Universidade Federal de Minas Gerais, 2021) Carlos Talavera López; Louisa Alexandra Messenger; Michael Lewis; Matthew Yeo; João Luís Reis Cunha; Gabriel Machado Matos; Daniella Bartholomeu; José Eduardo Calzada; Azael Saldaña; Juan David Ramírez; Felipe Guhl; Sofía Ocaña-Mayorga; Jaime Costales; Rodion Gorchakov; Kathryn Marie Jones; Melissa Nolan; Santuza Maria Ribeiro Teixeira; Hernán José Carrasco; Maria Elena Bottazzi; Peter Jay Hotez; Kristy Murray; Mario Grijalva; Barbara Burleigh; Edmundo Carlos Grisard; Michael Alexander Miles; Björn AnderssonTrypanosoma cruzi, a zoonotic kinetoplastid protozoan parasite, is the causative agent of American trypanosomiasis (Chagas disease). Having a very plastic, repetitive and complex genome, the parasite displays a highly diverse repertoire of surface molecules, with pivotal roles in cell invasion, immune evasion and pathogenesis. Before 2016, the complexity of the genomic regions containing these genes impaired the assembly of a genome at chromosomal level, making it impossible to study the structure and function of the several thousand repetitive genes encoding the surface molecules of the parasite. We here describe the genome assembly of the Sylvio X10/1 genome sequence, which since 2016 has been used as a reference genome sequence for T. cruzi clade I (TcI), produced using high coverage PacBio single-molecule sequencing. It was used to analyze deep Illumina sequence data from 34 T. cruzi TcI isolates and clones from different geographic locations, sample sources and clinical outcomes. Resolution of the surface molecule gene distribution showed the unusual duality in the organization of the parasite genome, a synteny of the core genomic region with related protozoa flanked by unique and highly plastic multigene family clusters encoding surface antigens. The presence of abundant interspersed retrotransposons in these multigene family clusters suggests that these elements are involved in a recombination mechanism for the generation of antigenic variation and evasion of the host immune response on these TcI strains. The comparative genomic analysis of the cohort of TcI strains revealed multiple cases of such recombination events involving surface molecule genes and has provided new insights into T. cruzi population structure.