Taura syndrome virus from Venezuela is a new genetic variant

In early 2005, the Aquaculture Pathology Laboratory of the University of Arizona received samples of diseased shrimp, Penaeus vannamei, from a Taura syndrome (TS) outbreak in the Lake Maracaibo region of Venezuela. Histopathology and in situ hybridization (ISH) were performed and the results confirmed the presence of Taura syndrome virus (TSV). The viral isolate was sequenced and presented a 93% similarity with the TSV reference strain from Hawaii (TSV-HI94). Immunohistochemistry (IHC), dot blot immunoassay and bioassays were also performed. While processed samples reacted only faintly with the TSV monoclonal antibody MAb 1A1, the virus in its native state reacted strongly with the antibody. In bioassay, the Venezuelan isolate of TSV (TSV-VE05) presented mortality comparable to TSV-HI94 in P. vannamei SPF Kona stock. These data indicate that a new variant of the virus was responsible for the outbreak of TS in Venezuela.