Phylogenetic analysis of human P[8]G9 rotavirus strains circulating in Brazil reveals the presence of a novel genetic variant.
BACKGROUND
Group A rotavirus (RV-A) genotype P[8]G9 has emerged as one of the leading causes of gastroenteritis in children worldwide and currently is recognized as one of the five most common genotypes detected in humans. High intragenotype diversity in G9 RV-A has been observed, and nowadays, based on the genetic variability of the VP7 gene, six different phylogenetic lineages and eleven sublineages were described.


OBJECTIVE
To study the degree of genetic variation and evolution of Brazilian P[8]G9 RV-A strains.


METHODS
Phylogenetic analysis of 19 P[8]G9 RV-A strains isolated from 2004 to 2007 in five different Brazilian states was conducted using the NSP1, NSP3, NSP5, VP4 and VP7 genes. For the VP4 and VP7 genes, 3D protein structure predictions were generated to analyze the spatial distribution of amino acid substitutions observed in Brazilian strains.


RESULTS
Based on the phylogenetic analyses, all Brazilian strains clustered within lineage G9-III and P[8]-3 for VP7 and VP4, respectively, and were classified as genotype A1, T1 and H1 for the NSP1, NSP3 and NSP5 genes, respectively. Interestingly, all the strains isolated in Acre State (Northern Brazil) formed a closely related cluster clearly separated from the other Brazilian and prototype strains with regard to the five genes studied. Unique amino acid substitutions were observed in Acre strains in comparison with the prototype and Brazilian strains.


CONCLUSIONS
Inclusion of Acre strains in the phylogenetic analysis revealed the presence of a novel genetic variant and demonstrated a diversification of P[8]G9 rotaviruses in Brazil.
Tort
Luis Fernando López
LF
Laboratory of Comparative and Environmental Virology, Oswaldo Cruz Institute - FIOCRUZ, Av. Brasil 4365, Manguinhos, 21040-360 Rio de Janeiro, RJ, Brazil.
Volotão
Eduardo de Mello
Ede M
de Mendonça
Marcos César Lima
MC
da Silva
Marcelle Figueira Marques
MF
Siqueira
Alessandra A
AA
Assis
Rosane Maria Santos
RM
Moratorio
Gonzalo
G
Cristina
Juan
J
Leite
José Paulo G
JP
D001938:Brazil; D002675:Child, Preschool; D016000:Cluster Analysis; D005838:Genotype; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008969:Molecular Sequence Data; D010802:Phylogeny; D011110:Polymorphism, Genetic; D012367:RNA, Viral / Q000235:genetics*; D012401:Rotavirus / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D012400:Rotavirus Infections / Q000821:virology*; D017422:Sequence Analysis, DNA; D014764:Viral Proteins / Q000235:genetics*
D012367:RNA, Viral; D014764:Viral Proteins