Temporal and spatial population dynamics of rabies virus isolates in China / 病毒学报

In order to study phylogeography, population dynamics and molecular evolution of rabies viruses (RABVs) isolates from China, especially spatio-temporal dynamics, the timescale of RABVs evolution and its pattern of migration, we performed an extensive comparative analysis of RABV N gene sequence data, representing 167 isolates sampled from 20 provinces in a 78-year period (from 1931 through 2009). The available Chinese isolates could be divided into two distinct clades:Phylogroup clades I comprised Chinese group 1-4; Phylogroup clades II contained Chinese group 5-8. We found no evidence for positive selection (dN/dS>1) acting at any codon and found strong selective constraints for N gene. Bayesian Markov Chain Monte Carlo (MCMC) analysis suggested that the Chinese rabies viruses originated within the last 2000 years and the mean rates of nucleotide substitution for the N gene were approximately 4 x 10(-4) substitutions per site per year. The analyses of the spatial and spatio-temporal evolution indicated that RABV isolates from China migrated among different Provinces.

Sequencing and analyses on glycoprotein gene of rabies viruses isolated in Zhejiang province,China / 中华流行病学杂志

Objective Based on sequencing the genomes of glycoprotein (GP) gene of rabies viruses isolated in Zhejiang, we analyzed the properties of rabies viruses genetic variation in molecular level, and to compare with those of other representative vaccine strains and street virus strains, get the information about rabies viruses variation. Methods Suckling mice against rabies virus were selected. Overlapped fragments were amplified by RT-PCR and full-length genomes were assembled to analyze the nucleotide and deduced protein similarities and phylogenetic analyses of the GP genes. Results The fourteen full-length genomes were completely sequenced and they had the same genetic structure with 1575 nts and deduced protein with 524 aa. Genetic analysis revealed that the nucleotide and amino acid homologies of GP gene from Zhejiang strains and other vaccine strains or street virus strains were 82.3%-99.9% and 85.1%-99.8%. The fourteen strains were genotype 1 according to the phylogenetic analyses. The GP amino acids of Zhejiang strains rabies virus strains without any recombination occurred in GP and no larger variation appeared in the major antigenic sites. Conclusion The comprehensive analysis based on the first-level structure of GP demonstrated that it was possible that some advantageous antigenic epitopes existed in certain areas and potential antigenic determinants. It was evident that the GP gene of Zhejiang strains appear to be stable and their sequence similarity with the representative strains of street virus in China were higher than those of other vaccine strains. Some differences showed in the genetic structure and evolution relationship among Zhejiang strains, other street strains in other regions and vaccine strains.

Sequencing and analysis of complete genome of rabies viruses isolated from Chinese Ferret-Badger and dog in Zhejiang province / 病毒学报

Based on sequencing the full-length genomes of four Chinese Ferret-Badger and dog, we analyze the properties of rabies viruses genetic variation in molecular level, get the information about rabies viruses prevalence and variation in Zhejiang, and enrich the genome database of rabies viruses street strains isolated from China. Rabies viruses in suckling mice were isolated, overlapped fragments were amplified by RT-PCR and full-length genomes were assembled to analyze the nucleotide and deduced protein similarities and phylogenetic analyses from Chinese Ferret-Badger, dog, sika deer, vole, used vaccine strain were determined. The four full-length genomes were sequenced completely and had the same genetic structure with the length of 11, 923 nts or 11, 925 nts including 58 nts-Leader, 1353 nts-NP, 894 nts-PP, 609 nts-MP, 1575 nts-GP, 6386 nts-LP, and 2, 5, 5 nts- intergenic regions(IGRs), 423 nts-Pseudogene-like sequence (psi), 70 nts-Trailer. The four full-length genomes were in accordance with the properties of Rhabdoviridae Lyssa virus by BLAST and multi-sequence alignment. The nucleotide and amino acid sequences among Chinese strains had the highest similarity, especially among animals of the same species. Of the four full-length genomes, the similarity in amino acid level was dramatically higher than that in nucleotide level, so the nucleotide mutations happened in these four genomes were most synonymous mutations. Compared with the reference rabies viruses, the lengths of the five protein coding regions had no change, no recombination, only with a few point mutations. It was evident that the five proteins appeared to be stable. The variation sites and types of the four genomes were similar to the reference vaccine or street strains. And the four strains were genotype 1 according to the multi-sequence and phylogenetic analyses, which possessed the distinct district characteristics of China. Therefore, these four rabies viruses are likely to be street viruses already existing in the natural world.

Molecular Epidemiology and Sequencing of the G-L Intergenic Region of Rabies Viruses Isolated in China / 中国病毒学

A group of 25 rabies viruses (RABVs),recovered from 24 dogs and one human case,were collected from various areas in China between 2004 and 2006.Genetic and phylogenetic analyses of the G-L intergenic region were carried out in 25 street RABV isolates and CTN vaccine strains of 7 generations.The study was based on the comparison of a 519 bp nucleotide sequence,encompassing the G-L intergenic region.The nucleotide sequence homologies of Chinese street strains were from 95.5% to 100%.The phylogenetic analysis showed that all Chinese isolates clearly supported the placement of all Chinese viruses in Lyssavirus genotype 1 and they were distributed according to their geographical origins.All of the Chinese strains were closely related but they could still be divided into two groups:group of street strains and group of CTN strains.This study presents details about the molecular epidemiology of rabies viruses based on the sequences of the G-L Intergenic region.