Biology subjects

Barcellos, R. B.

Publications and source records attributed to Barcellos, R. B..

3 recordsLinked to original sources

bioRxiv2024

Simultaneous circulation and coinfection of Dengue clades and serotypes in Southern Brazil

Dengue is an arthropod-borne virus with worldwide urban transmission mediated by anthropophilic vectors of the genus Aedes. Currently, there is a substantial genotype diversity that belongs to at least four known serotypes. Tropical regions, where several serotypes cocirculate in the population, are hyperendemic, driving multiple outbreaks with variable disease manifestations. Notably, the Dengue virus burden is increasing in subtropical and temperate regions of the globe due to climatic changes associated with new outbreaks in naive and previously unaffected human populations. The introduction and endemic transmission of different clades and serotypes in these regions is highly concerning due to the known and still unknown consequences of Dengue infection on populations with diverse genetic backgrounds. Here, we characterized the coinfection of different Dengue clades and serotypes in Rio Grande do Sul, Brazils southernmost and subtropical state, by combining serotype-specific RT-PCR and deep sequencing. We found five coinfected patients in four municipalities where these clades and serotypes circulated simultaneously. Our data suggests that coinfection events account for a minority of total cases, but these findings may reflect the early transmission phases of some Dengue clades. Hence, close monitoring is warranted to evaluate coinfection rates and associated clinical consequences as clade prevalence changes.

genomics↗

bioRxiv2022

Incipient parallel evolution of SARS-CoV-2 Deltacron variant in South Brazil

With the coexistence of multiple lineages and increased international travel, recombination and gene flow are likely to become increasingly important in the adaptive evolution of SARS-CoV-2. This could result in the incipient parallel evolution of multiple recombinant lineages. However, identifying recombinant lineages is challenging, and the true extent of recombinant evolution in SARS-CoV-2 may be underestimated. This study describes the first SARS-CoV-2 Deltacron recombinant case identified in Brazil. We demonstrate that the recombination breakpoint is at the beginning of Spike gene (S). The 5' genome portion (circa 22 kb) resembles the AY.101 lineage (VOC Delta), and the 3' genome portion (circa 8 kb nucleotides) is most similar to the BA.1.1 lineage (VOC Omicron). Furthermore, evolutionary genomic analyses indicate that the new strain emerged after a single recombination event between lineages of diverse geographical locations in December 2021 in South Brazil. This Deltacron, named AYBA-RS, is one out of almost 30 recombinants described this year. The submission of only four sequences in the GISAID database suggests that this Brazilian lineage had a minor epidemiological impact. On the other hand, the recent emergence of this and various other Deltacron recombinant lineages (i.e., XD, XF, and XS) suggests that gene flow and recombination may play an increasingly important role in the COVID-19 pandemic. We explain the evolutionary and population genetic theory that support this assertion, and we conclude that this stresses the need for continued genomic and epidemiological surveillance. This is particularly important for countries where multiple variants are present, as well as for countries that receive significant inbound international travel.

evolutionary biology↗

bioRxiv2022

Chikungunya virus transmission in the Southernmost state of Brazil was characterized by self-limited cases (2017 to 2019) and a larger 2021 outbreak

Chikungunya is a reemerging arthropod-borne virus that has been causing large outbreaks in the Americas. In Brazil, Asian-Caribbean and ECSA genotypes have been detected and lead to large outbreaks in several states since 2014. In Rio Grande do Sul (RS), the southernmost State, the first autochthonous cases were reported in 2016. We employed genome sequencing and epidemiological investigation to characterize the increasing CHIKF burden in RS between 2017- 2021. Distinct lineages of the ECSA genotype were responsible for human infections between 2017-2021. Until 2020, CHIKV introductions were most travel associated and transmission was limited. Then, in 2021, the largest outbreak occurred in the state associated with the introduction of a new ECSA lineage. New CHIKV outbreaks are likely to occur in the near future due to abundant competent vectors and a susceptible population, exposing more than 11 million inhabitants to an increasing infection risk.

molecular biology↗