title: Recombination and evolutionary dynamics of human echovirus 6.
abstract: Enterovirus (EV) infections are associated with a wide array of often severe disease presentations including aseptic meningitis, encephalitis, and acute flaccid paralysis. Surveillance for polioviruses and other EVs is therefore important as a public health measure both for patient management and epidemiological studies. From 1988 to 2008, echovirus (E) 30 was the predominant genotype in Spain (33.7% of the total typed EVs). E6 was also endemic throughout this period although isolated less frequently (12.5%). In 2009, however, a substantial increase in the incidence of E6 was detected (60%), displacing E30 type (2%). To investigate the evolution and recombination in the epidemiology and transmission of E6 in Spain, a genetic analysis in VP1 and 3Dpol regions of 67 Spanish strains collected during the period 2004-2010 was performed. All VP1 sequences clustered monophyletically in the assigned genogroup C, subgroup 9, currently the predominant circulating strains identified in Europe and elsewhere in the last 10 years. 3Dpol sequences were interspersed with other species B EVs resulting from several recombination events that generated at least 12 different recombinant forms (RFs) among study samples. These showed typically minimal divergence in VP1. The co-circulation of different lineages of E6 in the same geographical area associated with its mainly endemic pattern of transmission may have contributed to the extremely short estimated half-life of E6 RFs (0.87 years). This pattern contrasts markedly with other species B EVs and EV71 where VP1 lineage expansion and extinction occurred in step with defined recombination events and periodic changes in incidence.
authors.affiliation: Enterovirus Unit, National Centre for Microbiology, Instituto de Salud Carlos III, Madrid, Spain.
authors.forename: María
authors.initials: M
authors.lastname: Cabrerizo
authors.forename: Gloria
authors.initials: G
authors.lastname: Trallero
authors.forename: Peter
authors.initials: P
authors.lastname: Simmonds
mesh_terms: D004458:Echovirus 6, Human / Q000235:genetics*; D004457:Echovirus Infections / Q000453:epidemiology* / Q000821:virology*; D019143:Evolution, Molecular; D005838:Genotype; D006801:Humans; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D011995:Recombination, Genetic; D017422:Sequence Analysis, DNA; D013030:Spain / Q000453:epidemiology; D014764:Viral Proteins / Q000235:genetics
chemical_list: D014764:Viral Proteins
keywords: 3Dpol gene; VP1 gene; enterovirus; phylogenetic analysis; recombinant forms