Abstract:

The clinical tissue samples collected from piglets died of suspected encephalomyocarditis were homogenated and the supernatant was inoculated into baby hamster kidney (BHK-21) cell lines to isolate encephalomyocarditis virus (EMCV). According to the cytopathic effect (CPE) and the results of RT-PCR and indirect fluorescent antibody test (IFA)，one strain of EMCV was successfully isolated and designated as GXLC strain. The 3D gene of GXLC strain was amplified by RT-PCR，cloned into pMD18-T vector，sequenced and analyzed. The sequence analysis showed that the 3D gene of GXLC strain consisted of 1380 nucleotides encoding 460 amino acids and contained 7 epitopes. The homology analysis indicated that the homology of 3D gene of GXLC strain and other EMCV strains available in GenBank were from 84.7% to 99.7% and from 96.1% to 99.6% based on the nucleotide and deduced amino acide sequences，respectively. The phylogenetic tree based on the 3D gene nucleotide sequences revealed that all the EMCV strains could be divided into two groups: group Ⅰ and group Ⅱ，and group Ⅰ could be subdivided into subgroup Ⅰa and subgroup Ⅰb. The strains from pig distributed in group I and group Ⅱ，while the strains from mouse distributed in group I and the strains from human distributed in group Ⅱ. GXLC strain，and other EMCV isolates from China belonged to subgroup Ⅰa.

Key words: swine; encephalomyocarditis virus; isolation; 3D gene; molecular characteristic