OBJECTIVE: To analyze the evolution and genetic characterization of echovirus 11 (Echo11) from the acute flaccid paralysis (AFP) cases in Shandong province. METHODS: Isolation of Enterovirus was performed from stool samples of AFP cases from 1994 to 2009. All positive strains were sero-typed by neutralization test. Entire VP1 coding region from 27 strains typed as Echo11 was amplified by reverse transcription-polymerase chain reaction (RT-PCR), and subsequently phylogenetic analyse on VP1 sequences from these strains and others published in GenBank were conducted. RESULTS: From 1994 to 2009, altogether 915 non-polio enterovirus (NPEV) strains were isolated with 79 (8.6%) isolates serotyped as Echo11. There were 876 nucleotides (nt) in the complete VP1 genes, encoding 292 amino acids (aa). The nt identities were 76.4% - 100.0% among those Echo11 Shandong strains with the aa identities as 91.4% - 100.0%. The nt and aa identities were 77.7% - 80.7% and 90.7% - 94.8% between Shandong strains and prototype strains, respectively. CONCLUSION: All Echo11 strains could be divided into four genotypes. Shandong strains that forming three (A1, A2 and C1) new sub-genotypes, with every sub-genotype had several brands. Sub-genotype A1 appeared to be the lately circulating one.
OBJECTIVE: To analyze the evolution and genetic characterization of echovirus 11 (Echo11) from the acute flaccid paralysis (AFP) cases in Shandong province. METHODS: Isolation of Enterovirus was performed from stool samples of AFP cases from 1994 to 2009. All positive strains were sero-typed by neutralization test. Entire VP1 coding region from 27 strains typed as Echo11 was amplified by reverse transcription-polymerase chain reaction (RT-PCR), and subsequently phylogenetic analyse on VP1 sequences from these strains and others published in GenBank were conducted. RESULTS: From 1994 to 2009, altogether 915 non-polio enterovirus (NPEV) strains were isolated with 79 (8.6%) isolates serotyped as Echo11. There were 876 nucleotides (nt) in the complete VP1 genes, encoding 292 amino acids (aa). The nt identities were 76.4% - 100.0% among those Echo11 Shandong strains with the aa identities as 91.4% - 100.0%. The nt and aa identities were 77.7% - 80.7% and 90.7% - 94.8% between Shandong strains and prototype strains, respectively. CONCLUSION: All Echo11 strains could be divided into four genotypes. Shandong strains that forming three (A1, A2 and C1) new sub-genotypes, with every sub-genotype had several brands. Sub-genotype A1 appeared to be the lately circulating one.