犬瘟热病毒YD株的分离鉴定及其H基因序列分析

从疑似犬瘟热(CD)病犬的脏器中分离到1株病毒,经间接免疫荧光试验、RT-PCR鉴定、红细胞凝集试验和对不同动物致病性试验,证实该病毒为犬瘟热病毒(CDV)强毒株,命名为CDV YD株.对H基因序列的测定和分析表明,YD株H基因与国内强毒株更接近,核苷酸同源性为98.4％～99.7％,氨基酸同源性为97.8％～99.7...

Isolation and identification of caine distemper virus strain YD and sequence analysis of its H gene

A strain of virus was isolated from the organs of a dog suspected with canine distemper(CD).The virulent virus,designated as YD,was identified as canine distemper virus(CDV)by indirect immunofluorescence assay,RT-PCR,haemagglutination and pathogenesis in different animals.Analysis of the H gene derived from the virulent strain revealed that the YD strain had 98.4%-99.7%nucleotide sequence homology and 97.8%-99.7% homology in putative amino acid sequences,especially sharing a high degree of homology with the Chinese virulent strain;but,compared with the existing vaccine strains,the homologies of YD strain were 91.2%-91.5% in the nucleotide sequence and 90.3%-91.2% in the amino acid sequence.Nine potential sites for N-linked glycosylation which might be related to virus neutralization by antibodies and replication in vitro were identified in the H protein of the YD strain.In addition,twelve conservative cysteine residues known to be important for the secondary structure of the H protein were also found in its predicted amino acid sequences.Phylogenetic analysis of the N and H genes showed that the YD strain belonged with the Asia-1 group,the predominant genotype in China.This study offered a basis for a better understanding of genetic variation of CDV in China and for development of CD vaccine.