Nested PCR detection of abalone shriveling syndrome-associated virus in China

Haliotis diversicolor (small abalone) is an economic seafood found off the Southern coast of China. Since 1999, the cultured abalone yields in China have been affected severely by continual outbreaks of a fatal epidemic disease caused by abalone shriveling syndrome associated virus (AbSV), a double-stranded DNA virus. Although the pathogenicity and genome of AbSV have been ascertained, the epidemiology of AbSV infection remains to be investigated. In the present study, four pairs of AbSV-specific primers were designed on the basis of open reading frame (ORF)24 and ORF25 sequences in the AbSV genome. Two nested PCR detection methods were established by optimization of the annealing temperatures of primers. The results showed that the specificity of primers for AbSV detection could not be interfered with by the host genome and other aquaculture species or viruses. The detection limits of the two methods were about 10 copies of recombinant plasmid containing AbSV genes in 20μL reaction mixture. The results of detection of the AbSV epidemic showed that AbSV was still present in juvenile abalones in some farms along the Southern coast of China (Fujian and Guangdong).