Biology subjects

Nunes, M. R. T.

Publications and source records attributed to Nunes, M. R. T..

3 recordsLinked to original sources

bioRxiv2021

FECAL MICROBIOME OF CHILDREN WITH NOROVIRUS GASTROENTERITIS

The human fecal microbiome is composed of endogenous bacteria, eukaryotic viruses, bacteriophages and retroviruses. Several pathological conditions, including gastroenteritis, may be characterized by imbalance of gastrointestinal functions, with alteration in the diversity and composition of the fecal microbiota. Were analyzed twenty-seven fecal microbiome in children hospitalized with gastroenteritis (norovirus positive) from northern region of Brazil. After sequencing, was verified the presence of the domains Bacteria (95%) and Eukaryota (3.1%), the viruses represented 1.9%. Among the pathogenic viruses were found in addition to noroviruses the picornaviruses, enterovirus and parechovirus. The bacteriophages detected were of Caudovirales order, families Siphoviridae, Podoviridae and Myoviridae. In 22.2% (6/27) of the samples was observed co-infection between norovirus, enterovirus B and echovirus. As for the others components of the microbiome, we can highlight the presence of the taxonomic groups: Terrabacteria (50.2%), composed mainly of Actinobacteria and Firmicutes; Proteobacteria (34.5%) represented by the Enterobacteriaceae family; and FCB group (22%) whose most abundant microorganisms were those of the phylum Bacterioidetes. We performed a metagenomic approach to analyze the fecal microbiota of children with viral gastroenteritis, it was observed that the bacterias (Enterobacteriaceae) deserve attention in a possible association with noroviruses, as they were found in large quantities in infections. In addition, other enteric viruses were observed, such as enteroviruses.

microbiology↗

bioRxiv2018

Chikungunya virus outbreak in the Amazon region: replacement of the Asian genotype by an ECSA lineage

BackgroundSince its first detection in the Caribbean in late 2013, chikungunya virus (CHIKV) has affected 51 countries in the Americas. The CHIKV epidemic in the Americas was caused by the CHIKV-Asian genotype. In August 2014, local transmission of the CHIKV-Asian genotype was detected in the Brazilian Amazon region. However, a distinct lineage, the CHIKV-East-Central-South-America (ECSA)-genotype, was detected nearly simultaneously in Feira de Santana, Bahia state, northeast Brazil. The genomic diversity and the dynamics of CHIKV in the Brazilian Amazon region remains poorly understood despite its importance to better understand the epidemiological spread and public health impact of CHIKV in the country.\n\nMethodology/Principal FindingsWe report a large CHIKV outbreak (5,928 notified cases between August 2014 and August 2018) in Boa vista municipality, capital city of Roraimas state, located in the Brazilian Amazon region. In just 48 hours, we generated 20 novel CHIKV-ECSA genomes from the Brazilian Amazon region using MinION portable genome sequencing. Phylogenetic analyses revealed that despite an early introduction of the Asian genotype in 2015 in Roraima, the large CHIKV outbreak in 2017 in Boa Vista was caused by an ECSA-lineage most likely introduced from northeastern Brazil.\n\nEpidemiological analyses suggest a basic reproductive number of R0 of 1.66, which translates in an estimated 39 (95% CI: 36 to 45) % of Roraimas population infected with CHIKV-ECSA. Finally, we find a strong association between Google search activity and the local laboratory-confirmed CHIKV cases in Roraima.\n\nConclusions/SignificanceThis study highlights the potential of combining traditional surveillance with portable genome sequencing technologies and digital epidemiology to inform public health surveillance in the Amazon region. Our data reveal a large CHIKV-ECSA outbreak in Boa Vista, limited potential for future CHIKV outbreaks, and indicate a replacement of the Asian genotype by the ECSA genotype in the Amazon region.\n\nAuthor SummaryUntil the end of 2017, Brazil notified the highest number of infections caused by chikungunya virus (CHIKV) in the Americas. We investigated a large CHIKV outbreak in Boa vista municipality in the Brazilian Amazon region. Rapid portable genome sequencing of 20 novel isolates and subsequent genetic analysis revealed that ECSA lineage was introduced from northeastern Brazil to Roraima around July 2016. Epidemiological analyses suggest a basic reproductive number of R0 of 1.66, which suggests that approximately 39% of Roraimas population was infected with CHIKV-ECSA. Given the dominance of the CHIKV-Asian genotype in the Americas, our data highlights the rapid spread of a less understood and poorly characterized CHIKV-ECSA genotype in Brazil. Investigations on potential associations between public health impact of CHIKV and genetic diversity of circulating strains are warranted to better evaluate its impact in Brazil and beyond.

epidemiology↗

bioRxiv2018

Whole-genome sequencing of parvoviruses from wild and domestic animals in Brazil provides new insights into parvovirus distribution and diversity

AbstractParvoviruses (family Parvoviridae) are small, single-stranded DNA viruses. Many parvoviral pathogens of medical, veterinary and ecological importance have been identified. In this study, we used high-throughput sequencing (HTS) to investigate the diversity of parvoviruses infecting wild and domestic animals in Brazil. We identified 21 parvovirus sequences (including twelve nearly complete genomes and nine partial genomes) in samples derived from rodents, bats, opossums, birds and cattle in Pernambuco, Sao Paulo, Parana and Rio Grande do Sul states. These sequences were investigated using phylogenetic and distance-based approaches, and were thereby classified into eight parvovirus species (six of which have not been described previously), representing six distinct genera in the subfamily Parvovirinae. Our findings extend the known biogeographic range of previously characterized parvovirus species, and the known host range of three parvovirus genera (Dependovirus, Aveparvovirus, and Tetraparvovirus). Moreover, our investigation provides a window into the ecological dynamics of parvovirus infections in vertebrates, revealing that many parvovirus genera contain well-defined sub-lineages that circulate widely throughout the world within particular taxonomic groups of hosts.

microbiology↗