Isolation and molecular analysis of porcine encephalomyocarditis virus strain BD2 from northern China

Encephalomyocarditis virus (EMCV) can cause acute myocarditis in young pigs or reproductive failure in sows. In this study, an EMCV strain (BD2) was isolated from the suspected piglets with EMCV in China. It was identified by an indirect immunofluorescence assay and reverse-transcription polymerase chain reaction. The virus could reproduce on BHK-21 cells and reach a peak titer by 16 hpi with maximum titers of 108.22 TCID50/0.1 ml. Phylogenetic analyses of open reading frame and the VP3/VP1 genes using neighbor-joining method revealed that EMCV isolates fell into two clusters: groups I and II. The BD2 isolate belonged to group I, along with strains NJ08, HB1, BJC3, CBNU, K3, K11, BEL-2887A, GX0601, GXLC, pEC9, and PV21, whereas four strains (D variant, EMCV-B, EMCV-D, and PV2) belonged to group II.