Genetic Characteristics Of The Chinese Isolates Of Rabies Virus

Objectives To analyze the genetic characteristics of the isolates of rabies virus in the main epidemic-stricken area of China, to study the relatedness amongst them and RV vaccine strain 3aG, CTN, PV, ERA and other vaccine strains, and to offer some evidences to effective control of rabies.Methods IFA, ELISA, RT-nestedPCR were used to detect 1074 canine brains, feline brains and other samples collected from Henan, Jiangsu, Hunan, Guangxi, Guizhou provinces. The suspensions of positive samples were inoculated to suckling mice and then amplified the nucleoprotein (N), glycoprotein (G) gene and pseudogene (ψ) from the brains of dying mice. The 3 segments were subsequently cloned, sequenced and analyzed by DNAStar and MEGA.Results 20 genotype 1 RV street isolates were obtained. Sequence comparison revealed that 6 representative isolates were diverged from all of the vaccine strains used in China in both genes and deduced proteins. The most homogeneous vaccine strains related Chinese isolates of rabies virus was CTN. Phylogeny analysis manifested the Chinese isolates and Southeast Asia strains isolated from Indonesia, Thailand and Malaysia were in the same branch in Phylogenetic tree, and the relatedness amongst them was more closer than amongst other strains.Conclusions The rabies virus carrying rate of the host animals in the main epidemic-stricken area in our country was 2.1%～5.1%. The Chinese isolates of rabies virus were still genotype 1, and they can be divided into 3 subgenotypes. The Chinese isolates of rabies virus were diverged from the vaccines in both genes and deduced proteins. These divergences may result in the inefficiency of the vaccines.