Genetic characteristics of echovirus 11 among healthy children in Shifang city, Sichuan province

Objective To analyze the genetic characteristics of echovirus 11 (E11) in Shifang city, Sichuan province. Methods Stool specimens were collected from the healthy children in one urban kindergarten of Shifang city. Enterovirus (EV) nucleic acid detection, virus isolation and sequencing of full length VP1 gene were carried out. Phylogenetic tree was constructed and genogroup/subgenogroup was identified according to phylogenetic clustering. Results Of the 69 stool specimens detected, 32 were EV nucleic acid positive. Twenty stool specimens (Ct≤33) were selected for virus isolation, and 14 strains were harvested, including eight E11 strains. The identities of VP1 gene sequences and deduced amino acid sequences among E11 strains were ≥99.4% and ≥98.9%, respectively. Phylogenetic analysis showed all Shifang E11 were clustered with reference strains of subgenogroup D5. Conclusions The E11 strains isolated from healthy children in Shifang city belonged to subgenogroup D5 and was different from previously reported circulating genogroups (A and C) in China. The E11 strains of subgenogroup D5 may cause encephalitis, meningitis, hand, foot, and mouth disease and other diseases. The surveillance is needed concerning the extent and duration of its circulation. Key words: Healthy children; Echovirus 11; VP1 sequencing; Genetic characteristics