Classification and evolution of rabies virus in Guizhou and neighboring provinces and cities

Abstract

Objective To understand the classification and evolution of rabies virus (RABV) in Guizhou and its neighboring provinces and cities, as well as molecular genetic differences of rabies vaccine strains and epidemic strains, so as to provide guidance for the prevention and control of rabies epidemic situation in Guizhou. Methods Epidemic strains with clear information of time, location and host from Guizhou and its 5 neighboring provinces and cities were searched in GenBank, then the glycoprotein (G) gene complete sequences were summarized. Combining with G gene complete sequences of epidemic and vaccine stains obtained from our laboratory, the phylogenetic analysis and evolutionary time analysis were conducted by MEGA and BEAST software, respectively. Results The analysis indicated that 79 RABV strains from Guizhou and its neighboring provinces and cities belonged to Genotype 1. All epidemic strains could be classified as 9 different geographical groups which had obvious regional characteristics, and 11 vaccine strains were classified as 2 groups. The nucleotide and amino acid homology of G gene for epidemic and vaccine strains were 0.827-0.999 and 0.713-0.998, respectively. It was estimated that time to the most recent common ancestor (TMRCA) of RABV strains from Guizhou and its neighboring provinces and cities was detected about 150 year ago. Conclusions RABV genotype 1 is predominant in Guizhou and its neighboring provinces and cities. However, the strain has differentiated after years of evolution. It is necessary to further reassess the consistency and effectiveness of the RABV epidemic strains and vaccine strains. Key words: Rabies virus; Glycoprotein gene; Phylogeny; Molecular evolution