Dataset Information

Norovirus diversity in diarrheic children from an African-descendant settlement in Belem, Northern Brazil.

ABSTRACT: Norovirus (NoV), sapovirus (SaV) and human astrovirus (HAstV) are viral pathogens that are associated with outbreaks and sporadic cases of gastroenteritis. However, little is known about the occurrence of these pathogens in relatively isolated communities, such as the remnants of African-descendant villages ("Quilombola"). The objective of this study was the frequency determination of these viruses in children under 10 years, with and without gastroenteritis, from a "Quilombola" Community, Northern Brazil. A total of 159 stool samples were obtained from April/2008 to July/2010 and tested by an enzyme immunoassay (EIA) and reverse transcription-polymerase chain reaction (RT-PCR) to detect NoV, SaV and HAstV, and further molecular characterization was performed. These viruses were detected only in the diarrheic group. NoV was the most frequent viral agent detected (19.7%-16/81), followed by SaV (2.5%-2/81) and HAstV (1.2%-1/81). Of the 16 NoV-positive samples, 14 were sequenced with primers targeting the B region of the polymerase (ORF1) and the D region of the capsid (ORF2). The results showed a broad genetic diversity of NoV, with 12 strains being classified as GII-4 (5-41.7%), GII-6 (3-25%), GII-7 (2-16.7%), GII-17 (1-8.3%) and GI-2 (1-8.3%), as based on the polymerase region; 12 samples were classified, based on the capsid region, as GII-4 (6-50%, being 3-2006b variant and 3-2010 variant), GII-6 (3-25%), GII-17 (2-16.7%) and GII-20 (1-8.3%). One NoV-strain showed dual genotype specificity, based on the polymerase and capsid region (GII-7/GII-20). This study provides, for the first time, epidemiological and molecular information on the circulation of NoV, SaV and HAstV in African-descendant communities in Northern Brazil and identifies NoV genotypes that were different from those detected previously in studies conducted in the urban area of Belém. It remains to be determined why a broader NoV diversity was observed in such a semi-isolated community.

SUBMITTER: Aragao GC

PROVIDER: S-EPMC3574080 | biostudies-literature | 2013

REPOSITORIES: biostudies-literature

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Norovirus diversity in diarrheic children from an African-descendant settlement in Belém, Northern Brazil.

Aragão Glicélia Cruz GC Mascarenhas Joana D'Arc Pereira JD Kaiano Jane Haruko Lima JH de Lucena Maria Silvia Sousa MS Siqueira Jones Anderson Monteiro JA Fumian Túlio Machado TM Hernandez Juliana das Mercês Jd de Oliveira Consuelo Silva CS Oliveira Darleise de Souza Dde S Araújo Eliete da Cunha Eda C Soares Luana da Silva Lda S Linhares Alexandre Costa AC Gabbay Yvone Benchimol YB

PloS one 20130215 2

Norovirus (NoV), sapovirus (SaV) and human astrovirus (HAstV) are viral pathogens that are associated with outbreaks and sporadic cases of gastroenteritis. However, little is known about the occurrence of these pathogens in relatively isolated communities, such as the remnants of African-descendant villages ("Quilombola"). The objective of this study was the frequency determination of these viruses in children under 10 years, with and without gastroenteritis, from a "Quilombola" Community, North ...[more]

PMID: 23457593

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Project description:BackgroundCurrently, norovirus (NoV) is associated with one-fifth of all acute gastroenteritis (AGE) cases worldwide. The NoV GII.17_2014 variant has been associated with gastroenteritis outbreaks in several Asian countries, replacing the previously dominant Sydney 2012 variant. There is limited data about circulation of this new strain in Brazil. This study aimed to describe the phylogenetic and evolutionary characteristics of the GII.17_2014 strains in the Northern region of Brazil.MethodsNoV was detected by enzyme immunoassay (EIA) in 645 stool samples of AGE cases that were reported in Pará and Amazonas states during 2015-2016. All positive samples were tested for NoV GI and GII by reverse transcription polymerase chain reaction (RT-PCR) and the amplicons were subjected to genome sequencing. The GII.17-positive samples were retested by PCR using different sets of designed primers, which target a highly conserved capsid gene region. Next, the amplicons were sequenced and phylogenetically analyzed using Bayesian inferences.ResultsOf the 645 samples tested, 208 (32.2%) tested were positive for NoV by EIA, among which 95 (45.7%) were genotyped. Among the genotyped samples, 12 (12.6%) were characterized as GII.17_2014 with the first case detected in November 2015 (1/30, 3.3%) and the others in 2016 (11/65, 16.9%). All strains found in our study were clustered in clade D (epidemic strain). The uncorrelated log-normal model estimations calculated the rate of evolution for GII-17 strains as 1.95 × 10- 3 (1.28 × 10- 3-2.63 × 10- 3). In total, 36 nucleotide changes were observed after analyzing the VP1 sequence, among which 28 occurred in the P2 region.ConclusionsThese data demonstrate the evolutionary dynamics in NoV GII.17_2014 strains, which indicated high mutation rates with nucleotide substitutions and indels that are related to the elevated levels of antigenic diversity. This partly explains the increase in viral prevalence.

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Dataset Information

Norovirus diversity in diarrheic children from an African-descendant settlement in Belem, Northern Brazil.

Publications

Norovirus diversity in diarrheic children from an African-descendant settlement in Belém, Northern Brazil.

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