title: Cocirculation of two transmission lineages of echovirus 6 in jinan, china, as revealed by environmental surveillance and sequence analysis.
abstract: Enterovirus environmental surveillance on sewage from the city of Jinan, Shandong Province, China, was initiated in 2008. Thirty echovirus 6 (E6) strains-1 in 2008 and 29 in 2010-were isolated and identified. Most E6 isolates (n = 21) came from the sewage collected on August 2010, revealing high local E6 activity at that time. Interestingly, the VP1 sequences of most isolates, even from the same sewage, were not identical. Phylogenetic analysis of VP1 sequences revealed two lineages for these isolates, with 78.0 to 80.0% nucleotide identities with one another, 94.8 to 100.0% identity within the major lineage, and 92.7 to 98.5% identity within the minor one. The VP1 sequences of environmental isolates, clinical isolates from 1998 to 2010, and global E6 were subjected to evolutionary analysis using Bayesian phylodynamic methods. The inferred E6 VP1 ancestral sequence dated back to 1901 (range, 1873 to 1928) and evolved with 7.047 × 10(-3) substitutions per site per year. Shandong E6 segregated into three clusters, and the two environmental lineages belonged to clusters A and C, which originated in 2003 and 1992, respectively. The antigenicity analysis via neutralization assay confirmed great antigenic differences between Shandong isolates and a prototype strain. These findings underscore the value of continuous environmental surveillance and genetic analysis to monitor circulating enteroviruses in the population and give further insight into E6 evolution.
authors.affiliation: Shandong Center for Disease Control and Prevention, 16992 Jingshi Road, Jinan 250014, People's Republic of China. aqxuepi@163.com
authors.forename: Zexin
authors.initials: Z
authors.lastname: Tao
authors.forename: Haiyan
authors.initials: H
authors.lastname: Wang
authors.forename: Yan
authors.initials: Y
authors.lastname: Li
authors.forename: Aiqiang
authors.initials: A
authors.lastname: Xu
authors.forename: Yong
authors.initials: Y
authors.lastname: Zhang
authors.forename: Lizhi
authors.initials: L
authors.lastname: Song
authors.forename: Hiromu
authors.initials: H
authors.lastname: Yoshida
authors.forename: Qing
authors.initials: Q
authors.lastname: Xu
authors.forename: Jing
authors.initials: J
authors.lastname: Yang
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: Yao
authors.initials: Y
authors.lastname: Liu
authors.forename: Lei
authors.initials: L
authors.lastname: Feng
authors.forename: Wenbo
authors.initials: W
authors.lastname: Xu
mesh_terms: D057134:Antibodies, Neutralizing / Q000276:immunology; D002681:China / Q000453:epidemiology; D016000:Cluster Analysis; D004458:Echovirus 6, Human / Q000145:classification* / Q000235:genetics / Q000302:isolation & purification*; D004457:Echovirus Infections / Q000453:epidemiology* / Q000821:virology*; D005838:Genotype; D006801:Humans; D017720:Molecular Epidemiology; D008969:Molecular Sequence Data; D009500:Neutralization Tests; D012367:RNA, Viral / Q000235:genetics; D017422:Sequence Analysis, DNA; D012689:Sequence Homology, Nucleic Acid; D012703:Serotyping; D012722:Sewage / Q000821:virology*
chemical_list: D057134:Antibodies, Neutralizing; D012367:RNA, Viral; D012722:Sewage