title: Ten years of global evolution of the human respiratory syncytial virus BA genotype with a 60-nucleotide duplication in the G protein gene.
abstract: The emergence of natural isolates of human respiratory syncytial virus group B (HRSV-B) with a 60-nucleotide (nt) duplication in the G protein gene in Buenos Aires, Argentina, in 1999 (A. Trento et al., J. Gen. Virol. 84:3115-3120, 2003) and their dissemination worldwide allowed us to use the duplicated segment as a natural tag to examine in detail the evolution of HRSV during propagation in its natural host. Viruses with the duplicated segment were all clustered in a new genotype, named BA (A. Trento et al., J. Virol. 80:975-984, 2006). To obtain information about the prevalence of these viruses in Spain, we tested for the presence of the duplicated segment in positive HRSV-B clinical samples collected at the Severo Ochoa Hospital (Madrid) during 12 consecutive epidemics (1996-1997 to 2007-2008). Viruses with the 60-nt duplication were found in 61 samples, with a high prevalence relative to the rest of B genotypes in the most recent seasons. Global phylogenetic and demographic analysis of all G sequences containing the duplication, collected across five continents up until April 2009, revealed that the prevalence of the BA genotype increased gradually until 2004-2005, despite its rapid dissemination worldwide. After that date and coinciding with a bottleneck effect on the population size, a relatively new BA lineage (BA-IV) replaced all other group B viruses, suggesting further adaptation of the BA genotype to its natural host.
authors.affiliation: Unidad de Biología Viral, Centro Nacional de Microbiología, Instituto de Salud Carlos III, Majadahonda, Madrid, Spain. altrento@isciii.es
authors.forename: Alfonsina
authors.initials: A
authors.lastname: Trento
authors.forename: Inmaculada
authors.initials: I
authors.lastname: Casas
authors.forename: Ana
authors.initials: A
authors.lastname: Calderón
authors.forename: Maria L
authors.initials: ML
authors.lastname: Garcia-Garcia
authors.forename: Cristina
authors.initials: C
authors.lastname: Calvo
authors.forename: Pilar
authors.initials: P
authors.lastname: Perez-Breña
authors.forename: José A
authors.initials: JA
authors.lastname: Melero
mesh_terms: D016000:Cluster Analysis; D019143:Evolution, Molecular; D005838:Genotype; D006801:Humans; D017720:Molecular Epidemiology; D015995:Prevalence; D011995:Recombination, Genetic; D018357:Respiratory Syncytial Virus Infections / Q000453:epidemiology / Q000821:virology*; D018113:Respiratory Syncytial Virus, Human / Q000235:genetics* / Q000302:isolation & purification; D017422:Sequence Analysis, DNA; D013030:Spain / Q000453:epidemiology; D014759:Viral Envelope Proteins / Q000235:genetics
chemical_list: D014759:Viral Envelope Proteins; C116204:attachment protein G