title: Rotavirus A genotype P[4]G2: genetic diversity and reassortment events among strains circulating in Brazil between 2005 and 2009.
abstract: Group A rotaviruses (RV-A) are the leading cause of severe gastroenteritis in infants and young children worldwide. Due to the epidemiologic complexity of RV-A, especially in developing countries, it is important to determine which genotypes are circulating, principally after the introduction in March 2006 of the monovalent (P[8]G1) Rotarix® vaccine in Brazil by the National Immunization Program. In Phase III trials with Rotarix®, the prevalence of genotype P[4]G2 was extremely low, and therefore, evaluation of heterotypic immunization against this genotype was performed by meta-analysis statistics tests. Different studies have shown the re-emergence of genotype P[4]G2 in Brazil, since 2005, as well as in other countries, suggesting that it could be a continental phenomenon related to the temporal variability in the genotype's naturally occurring distribution. It is important to note that genotype P[4]G2 does not share VP4 or VP7 antigens with the vaccine strain. Therefore, we performed a phylogenetic analysis based on VP4 (VP8), VP7, VP6, and NSP4 genes of RV-A genotype P[4]G2 samples isolated from the five regions of Brazil between 2005 and 2009. This study revealed that different genetic variants of RV-A genotype P[4]G2 circulated in Brazil between 2005 and 2009, and that this variability is determined mainly by: occurrence of point mutations; reassortment events; and widespread global gene flow. The results obtained in this study are important to our understanding of the epidemiology and evolution of RV-A genotype P[4]G2 and demonstrate the importance of continuous monitoring and molecular characterization of RV-A strains circulating in human and animal populations.
authors.affiliation: Laboratory of Comparative and Environmental Virology, Oswaldo Cruz Institute-FIOCRUZ, Rio de Janeiro, RJ, Brazil.
authors.forename: Mariela Martínez
authors.initials: MM
authors.lastname: Gómez
authors.forename: Marcos César Lima
authors.initials: MC
authors.lastname: de Mendonça
authors.forename: Eduardo de Mello
authors.initials: Ede M
authors.lastname: Volotão
authors.forename: Luis Fernando López
authors.initials: LF
authors.lastname: Tort
authors.forename: Marcelle Figueira Marques
authors.initials: MF
authors.lastname: da Silva
authors.forename: Juan
authors.initials: J
authors.lastname: Cristina
authors.forename: Jose Paulo Gagliardi
authors.initials: JP
authors.lastname: Leite
mesh_terms: D000595:Amino Acid Sequence; D019943:Amino Acid Substitution; D001483:Base Sequence; D001938:Brazil / Q000453:epidemiology; D002675:Child, Preschool; D005759:Gastroenteritis / Q000453:epidemiology / Q000821:virology*; D051456:Gene Flow; D014644:Genetic Variation; D005838:Genotype; D006801:Humans; D007223:Infant; D008969:Molecular Sequence Data; D010802:Phylogeny; D012367:RNA, Viral / Q000235:genetics / Q000302:isolation & purification; D016865:Reassortant Viruses / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012401:Rotavirus / Q000145:classification / Q000235:genetics* / Q000302:isolation & purification; D012400:Rotavirus Infections / Q000453:epidemiology / Q000821:virology*; D016415:Sequence Alignment; D017422:Sequence Analysis, DNA; D014764:Viral Proteins / Q000235:genetics
chemical_list: D012367:RNA, Viral; D014764:Viral Proteins