Genetic Characterization of Echovirus 11 Isolated from Acute Flaccid Paralysis Cases
This research firstly reported the molecular data of ECHO11(Echovirus type 11) in China.During 1999-2004,ECHO11 was the most frequently isolated non-polio enterovirus from AFP cases in Shandong Province.10 of the 11 ECHO11 strains isolated in 2003 were in July and December,distributing across the most parts of Shangdong Province.We sequenced the complete VP1 coding region of these 11 ECHO11 strains,and the results suggested that all these strains belong to a single transmission chain,the nucleotide sequence identity among them was 97.2%-100%,and that of the amino acid sequence was 99.6%-100.0%.There were 8-9 nucleotide differences among the strains isolated in July and in December,but the amino acid sequences were identical.Thess indicated that there were two ECHO11 epidemic in Shandong in 2003,in July and in December individually,but how these strains associated with AFP was yet uncertain.All the 11 ECHO11 strains belong to a new sub-genotype of genogroup A.The nucleotide and amino acid sequence identities among them and the other subgenotypes were 82.2%-84.7% and 94.8%-97.6% respectively.