Genetic characteristic analysis of echovirus 11
Objective To study echovirus 11 ( ECHO11 ) sequences genetic variability of the VP1 gene of 82 isolates from 15 countries and 2 provinces in China.Methods The VP1 sequences of 82 strains of echovirus 11 were downloaded from the GenBank,and their nucleotide and amino acid diversity were calculated and phylogenetic tree was constructed using Mega software.Results 82 echovirus 11 strains were divided into 4 genotypes( A-D),Genotype A is further divided into 7 subgenotyps and genotype D into 7 subgenotyps.The prototype strain Gregory is the sole member of genotype B.Genotype C is divided into 3 genotypes.The sequence diversity between echovirus 11 strains is 21.7%-24.1% (AA diversity:6.0%-12.1% ).Conclusion Our results show that most genotypes contain isolates that have circulated over a wide geographical(several countries from different continents) and temporal range.Several genotypes were also shown to co-circulate in a region during the same period of time,showing that the epidemic of echovirus 11 has typical time and geographical characters. 
 
Key words: 
Echovirus 11 ;  Genetic characteristics