Analysis of Genetic Diversity of Rabies Virus Isolates in China

Objective To analyze the genetic diversity of rabies virus(RV)isolates in China and provide a theoretical basis for prevention of rabies.Methods The N genes of 26 RV isolates were amplified by RT-PCR and sequenced,and the results were compared with those reported in GenBank,based on which a phylogenetic tree was plotted,and the genotype,genome as well as dynamic evolution in various times and spaces were analyzed.Results The available Chinese isolates of RV could be divided into two distinct clades,i.e.phylogroup clade Ⅰcomprising Chinese 1 ～ 4 groups and phylogroup clade Ⅱ comprising Chinese 5～8 groups.The intra-group homologies of nucleotides and amino acids were not less than 93.2% and not less than 94.3%,while the inter-group divergences were not less than 8.0% and not less than 1.7%,respectively.Bayesian Markov chain Monte Carlo(MCMC)analysis suggested that Chinese RV arose in 968 AD,and its annual mean nucleotide substitution rate for N gene was 1.4089 × 10-4 per site.Conclusion All the Chinese RV isolates are Lyssavirus genotype 1,which migrate among various regions and reservoir hosts.The isolates of phylogroup clade Ⅰ are in the same phylogenetic clades with those isolated in the countries in Southeast Asia,such as Thailand,Vietnam,Indonesia,Philippines and Malaysia,while those of phylogroup clade Ⅱ are found in many parts of the world.