[Genetic characteristics of mumps virus in China from 2006 to 2008]

To analyze genetic characteristics of mumps virus in China from 2006 to 2008.

In the study, the fragments containing 316 nucleotides of SH genes from 7 mumps virus isolates in China from 2007 to 2008 were amplified by RT-PCR method, the PCR products were directly sequenced and analyzed with other 7 mumps virus sequences in China in 2006 and WHO mumps reference strains downloaded from Genbank together.

The results of homology and phylogenetic analyses based on 316 nucleotides showed that all 14 Chinese mumps virus strains in 2006-2008 belong to a distinguish branch of F genotype, but there were some differences between these 14 mumps virus strains. The mumps virus sequences in different provinces or different years showed dispersed distributions in phylogenetic tree, which was no obvious tendency of the distribution for years and geography. Otherwise, with the analyses of genetic distance between and within mumps virus strains groups in 2006, 2007 and 2008, it was found that the mumps sequences in 2006-2008 were no obvious regular variation, which were similar with the results of homology and phylogenetic analyses.

It suggested that F genotype of mumps virus was the predominant genotype in 2006-2008, and the mumps prevailed in recent years was mainly caused by F genotype mumps viruses with multi-transmission routes. However, the mumps viruses circulated during 2006 to 2008 were different from those in 1995,these mumps virus occured genetics evolution in some extent during 14-year period from to 2008. Furthermore, comparing with other genotype mumps strains from other countries, there were 5 shared nucleotides mutations (C(Nt65),C(Nt105), G(Nt137), C(Nt192), C(Nt239)) in SH gene in all Chinese F genotype mumps viruses. However, these mutations were not found in the other genotype of mumps virus.