Study on the genetic characteristics and molecular epidemiology of Echovirus 11 strains isolated from patients with hand food and mouth disease in He-nan province, China
Objective To analyze the evolution and genetic characteristics of Echovirus 11 （Echo11） strains isolated from patients with hand food and mouth disease （ HFMD） in Henan province. Methods Enterovirus strains were isolated from stool samples of patients with HFMD from year 2010 to 2012.The sequences of VP1 region of all positive strains were amplified , sequenced and then analyzed by BLSAT to determine their genotypes .The entire VP1 coding regions of 10 Echo11 strains were amplified by RT-PCR, and the homology analysis was conducted among them and other Echo 11 strains published in Gen-Bank.A phylogenetic tree was constructed to evaluate the evolution of Henan isolates and the prevalence of different genotypes .Results From year 2010 to 2012 , 184 non-Enterovirus 71 （ EV71 ） strains and non-Coxsakievirus A16 （CA16） strains causing HFMD were isolated, 10 （5.43%） of with were Echo11 strains. There were 876 nucleotides （ nt） in the complete VP1 gene sequence , encoding 292 amino acids （ aa） .The 10 Echo11 strains shared 93.1%-100% homologies in nt sequences and 97.3%-100% in aa sequences. The homology analysis indicated that Henan strains and prototype strains were highly similar but different with the homology of 77.8%-78.8% in nt and 90.8%-91.8% in aa, respectively.Conclusion Echo11 was one of the pathogens causing HFMD in He-nan province and genotype A was the dominant genotype . 
 
Key words: 
HFMD; Echovirus 11; Genetic characteristics