Abstract

Two strains (isolates 890 and 992) of spring viraemia of carp virus (SVCV) were isolated separately from cultured koi (Cyprinus carpio koi) and common carp (C. carpio carpio) in Tianjin region of P.R. China in June 2003. The supernatant of a homogenate of pooled brain, spleen and kidney was inoculated into CO, FHM and EPC cells, and cytopathogenic effects (CPE) appeared in 48 hrs at 20ºC. A 714bp fragment was amplified from the viral RNA with reverse-transcription polymerase chain reaction (RT-PCR) using primers for the glycoprotein gene of SVCV. The fragments were cloned and sequenced. A phylogenetic tree was made based on the multiple sequence alignment of the 550 bp nucleotide region of the glycoprotein gene of SVCV isolates 890, 992, ATCC VR-1390 and UK isolates 980451 and 980528. The similarity between the 890 and 992 strains was 98%. The isolates 890 and 992 shared more than 98% nucleotide identity with 980451 and 980528, and less than 90% nucleotide identity with ATCC VR-1390. Phylogenetic analysis showed that the isolates 890 and 992 share evolutionary direction with UK isolates 980451, 980528 and 970469, and are different from 13 other SVCV isolates from European countries. This is the first confirmed identification of SVCV in China.