Rapid detection of white sturgeon iridovirus (WSIV) using a polymerase chain reaction (PCR) assay

A polymerase chain reaction (PCR) assay was developed for detection of white sturgeon iridovirus (WSIV). The synthetic oligonucleotides WS 229F and WS 245R generate a 519 bp DNA amplicon from the WSIV genome that encodes the putative major capsid protein (MCP) gene. The WSIV PCR detected as little as 1 fg of plasmid DNA as mixed with 100 ng of host DNA. No amplicons were detected with the WSIV PCR assay upon testing of genomic DNA from uninfected white sturgeon spleen cell line (WSS-2), uninfected white sturgeon tissues, white sturgeon adenovirus (WSAV), Acipenserid herpesvirus 2 (AcHV-2), frog virus 3 (FV-3), epizootic haematopoietic necrosis virus (EHNV), and red sea bream iridovirus (RSIV). The newly developed PCR assay was also evaluated with groups of juvenile white sturgeon following experimental exposures to WSIV. An analysis of WSIV detection by PCR compared to current histological methods provided sensitivity estimates of 98% and 64% for PCR and histology, respectively. This new PCR assay provides a more rapid and sensitive approach for the detection of WSIV infections among juvenile white sturgeon than currently available diagnostic approaches including virus isolation and microscopic examinations of stained tissue sections.