Browsing by Autor "Eugenia Fuentes-Luppichini"

Filter results by typing the first few letters
Now showing 1 - 2 of 2
  • Thumbnail Image
    Item type: Item ,
    Multiplex RT-qPCR strategy for SARS-CoV-2 variants detection in developing countries without ngs: The Bolivian experience
    (Cambridge University Press, 2025) Rudy Parrado; Carolina X Cuba-Grandy; Eugenia Fuentes-Luppichini; Nattaly Grecia Torrico Villarroel; Yercin Mamani Ortiz; Javier Méndez; Betty Melgarejo; Irenice Coronado-Arrázola; Nair A. Montaño; Leonardo I. Almonacid
    The rapid evolution of SARS-CoV-2 has led to the emergence of variants of concern (VOCs) characterized by increased transmissibility, pathogenicity, and resistance to neutralizing antibodies. Identifying these variants is essential for guiding public health efforts to control COVID-19. Although whole genome sequencing (WGS) is the gold standard for variant identification, its implementation is often limited in developing countries due to resource constraints. In Bolivia, genomic surveillance is a challenge due to its limited technological infrastructure and resources. An RT-qPCR-based strategy was designed to address these limitations and detect the mutations associated with VOCs and variants of interest (VOIs). The multiplex RT-qPCR commercial kits Allplex<sup>TM</sup> Master and Variants I (Seegene®) and the ValuPanel<sup>TM</sup> (Biosearch®) were used to target mutations such as HV69/70del, E484K, N501Y, P681H, and K417N/T. They are characteristic of the Alpha (B.1.1.7), Beta (B.1.531), Gamma (P.1), Omicron (B.1.1.529), Mu (B.1.621), and Zeta (P.2) variants. A total of 157 samples collected in Cochabamba from January to November 2021 were evaluated, identifying 44 Gamma, 2 Zeta, 20 Mu, and 10 Omicron were identified. The strategy's effectiveness was validated against WGS data generated with Oxford Nanopore<sup>TM</sup> technology, showing a concordance rate of 0.96. This highlights the value of the RT-qPCR strategy in guiding the selection of samples for WGS, enabling broader detection of new variants that cannot be identified by RT-qPCR alone.
  • Thumbnail Image
    Item type: Item ,
    New Andes virus isolate haplotype obtained during prospective close contacts follow-up of an Hantavirus cardiopulmonary syndrome fatal case, Chile
    (Elsevier BV, 2025) Aldo Barrera; Hade Ramos; Eugenia Fuentes-Luppichini; Constanza Martínez-Valdebenito; Javiera Pradenas; C. Rogers; Carlos Palma; Campillo Sáinz C; Maritza Navarrete; Nicole Le Corre
    Andes virus (ANDV) is a zoonotic orthohantavirus that causes hantavirus cardiopulmonary syndrome. Transmission occurs mainly through contact with infected rodent excreta and, less frequently, between humans. Viral isolation from human samples is rare; in Chile, only one strain (CHI-7913, 2002) has been reported. The limited number of isolates reflects the challenge of obtaining samples during early viremia before antibodies appear, and maintaining long-term production of infectious particles in culture. We investigated an asymptomatic case from a family cluster, sampled during early infection. The absence of anti-ANDV antibodies in sera was confirmed by ELISA. Blood fractions were used to infect Vero E6 cells for six weeks, with infectivity monitored by RT-qPCR and Immunofluorescence. We obtained a replication-stable isolate from the buffy-coat fraction, achieving high viral loads at early passages. Whole-genome sequencing revealed a novel haplotype with mutations that reverted during non-human cell culture adaptation. This isolate, designated CHI-Hu13724, represents a new human-derived ANDV strain first reported in over two decades in Chile. It provides a valuable tool to study viral replication, infectivity, and pathogenicity.