The high numbers of COVID-19 cases and deaths in Brazil have made Latin America an epicentre of the pandemic. SARS-CoV-2 established sustained transmission in Brazil early in the pandemic, but important gaps remain in our understanding of virus transmission dynamics at a national scale. We use 17,135 near-complete genomes sampled from 27 Brazilian states and bordering country Paraguay. From March to November 2020, we detected co-circulation of multiple viral lineages that were linked to multiple importations (predominantly from Europe). After November 2020, we detected large, local transmission clusters within the country. In the absence of effective restriction measures, the epidemic progressed, and in January 2021 there was emergence and onward spread, both within and abroad, of variants of concern and variants under monitoring, including Gamma (P.1) and Zeta (P.2). We also characterized a genomic overview of the epidemic in Paraguay and detected evidence of importation of SARS-CoV-2 ancestor lineages and variants of concern from Brazil. Our findings show that genomic surveillance in Brazil enabled assessment of the real-time spread of emerging SARS-CoV-2 variants.

Brazil has experienced some of the highest numbers of COVID-19 infections and deaths globally and made Latin America a pandemic epicenter from May 2021. Although SARS-CoV-2 established sustained transmission in Brazil early in the pandemic, important gaps remain in our understanding of local virus transmission dynamics. Here, we describe the genomic epidemiology of SARS-CoV-2 using near-full genomes sampled from 27 Brazilian states and an adjacent country - Paraguay. We show that the early stage of the pandemic in Brazil was characterised by the co-circulation of multiple viral lineages, linked to multiple importations predominantly from Europe, and subsequently characterized by large local transmission clusters. As the epidemic progressed, the absence of effective restriction measures led to the local emergence and international spread of Variants of Concern (VOC) and under monitoring (VUM), including the Gamma (P.1) and Zeta (P.2) variants. In addition, we provide a preliminary genomic overview of the epidemic in Paraguay, showing evidence of importation from Brazil. These data reinforce the need for the implementation of widespread genomic surveillance in South America as a toolkit for pandemic monitoring and providing a means to follow the real-time spread of emerging SARS-CoV-2 variants with possible implications for public health and immunization strategies.

Introduction: Bovine papillomavirus (BPV) is the etiological agent of bovine papillomatosis, infectious and neoplastic disease, characterized by the presence of multiple papillomas that can regress spontaneously or to persist and progress to malignancies when in association with environmental cofactors. Although recognized that the BPV can induce DNA damages, the viral role following cancer initiation remains unresolved. Based on this, we stablished cell lines derived from cutaneous papilloma, fibropapilloma and esophageal carcinoma to study the BPV action on epithelial-mesenchymal transition (EMT). Our results showed strong evidences that the virus action can contribute to EMT and, therefore, metastasis. Aim: In this study, we analyzed the expression levels of the EMT markers (cytokeratin 10, STAT3 Y705, Oct-3/4 and vimentin) in paraffin-embed samples, using the same tissues that originated the cell lines previous studied, aiming to validate the results observed using cell lines. Material and Methods: Expression levels of these markers was analyzed by immunohistochemistry and the collagen composision by Picrosirius red staining. Results: We verified an overexpression of these markers in fibroblastoid cells present into the epidermis and ketarinocyte-like cells into the dermis present in dermo-epidermal junction. These data reinforce our previous results using cell cultures, validating both systems (cell culture and paraffin-embed tissues) as useful models to study the natural history of BPV-infected lesions. Conclusion: Altogether, the results from these systems indicate that the BPV promote the cancer progression and metastasis through the transdifferentiation of an epithelial to mesenchymal cells (EMT).