Isolates of viral hemorrhagic septicemia virus from North America and Europe can be detected and distinguished by DNA probes

Abstract

Biotinylated DNA probes were constructed to hybndize with speclfic sequences within the messenger RNA (mRNA) of the nucleoprotein (N) gene of vlral hemorrhagic septicemia virus (VHSV) reference strains from Europe (07-71) and North Arnenca (Makah) Probes were synthesized that were complementary to (1) a 29-nucleotide sequence near the center of the N gene conlmon to both the 07-71 and Makah reference strains of the virus (2) a unique 28-nucleotide sequence that followed the open r e a d n g frame of the Makah N gene mRNA most of which was absent In the 07-71 strain, and (3) a 22-nucleobde sequence w t h i n the 07-71 N gene that had 6 nllsmatches \nth the Makah straln Sixteen dlverse isolates of VHSV from North Amenca and Europe were tested by dot blot hybridization The first probe reacted with all isolates of the virus the second probe reacted with only the North Amencan isolates (includng those from Pacific cod), and the third probe reacted with only the European isolates, Including those from rainbow trout brown trout and Atlantic cod The probes did not react with mRNA extracted from uninfected cells or from cells infected with infectious hematopoletic necrosls vlrus (IHNV) a related fish rhabdovlrus The results showed that VHSV isolates from North Amenca and Europe formed 2 genetically distlnct strains of the virus in which isolates from different years or species of flsh on each continent were more related to each other than to isolates from the other continent The results of this and other studies indicate that the North Amencan straln of VHSV is enzootic in the North Pacific Ocean and IS not a result of a recent importation of fish from Europe When used In conlunchon with a biotinylated probe that recognizes all isolates of IHNV, these reagents p r o m s e to slrnphfy the detechon of salmonid rhabdoviruses KEY WORDS: DNA probe . Rhabdovirus . VHSV Viral hemorrhagic septicemia (VHS) is the most important viral disease of trout in Europe (Wolf 1988). Caused by a rhabdovirus (VHSV), the disease is responsible for killing millions of rainbow troutOnco~.hynchus mykiss each year at hatcheries throughout much of Europe. Regulations in the United States and Canada have been enacted to prevent the introduction of VHSV into North America. In 1988, routine examinations of adult chinook 0. tshawytscha and coho 0. kisutch salmon returning to hatcheries in western 'Washington State, USA, produced the first isolates of VHSV from North America (Brunson et al. 1989, Hopper 1989. Serological analyses using polyclonal and monoclonal antisera were not able to distinguish the novel isolates from the typical European reference strains (F1 or 07-71) of the virus . Initially, VHSV was feared to have been imported from Europe, perhaps by commercial aquaculture interests, which had been increasing the numbers of Atlantic salmon Salmo salar cultured in net pens in the Puget Sound area of western Washington. Existing fish health policies of the State of Washington and the U.S. Fish and Wildlife Service mandated the destruct...

Isolation of viral hemorrhagic septicemia virus from Greenland halibut Reinhardtius hippoglossoides caught at the Flemish Cap

“…Nevertheless, more data (e.g. molecular comparison with continental pathogenic strains) is necessary to confirm this hypothesis.It has been reported that VHSV isolates from North America and Europe constituted 2 genetically distinct groups of the virus (Batts et al 1993, Basurco et al 1995, Einer-Jensen et al 1995, Benmansour et al 1997). Further analysis is necessary to determine the relatedness between the Greenland halibut isolates and the European and/or North American strains.…”

“…Previous studies using antisera against that strain (4 neutralizing MAbs against the viral glycoprotein and 1 polyclonal antisera) have demonstrated antigenic diversity among European isolates of VHSV, establishing 3 reaction patterns but only 1 major serotype (Olesen et al 1993). Although distinguishable from the European strains by genotyping with molecular techniques (Batts et al 1993, Einer-Jensen et al 1995, Benmansour et al 1997, Snow et al 1999, all North American isolates of VHSV isolated in the Pacific coast, from either salmonids or marine fishes, have been identified as Type F1 strains using the plaque neutralization test and IFAT with a polyclonal antisera (Meyers et al 1992, Meyers & Winton 1995. Therefore, having regard to the location of the area where the fish were caught, and the serological techniques used, most of the Greenland halibut VHSV isolates would be expected to be of the F1 type.…”

Molecular epidemiology of viral haemorrhagic septicaemia virus (VHSV) in British Columbia, Canada, reveals transmission from wild to farmed fish

“…If CPE were observed, a second passage from the affected cell culture was performed to confirm CPE. Initial virus identity for isolates prior to 1998 was determined using a DNA probe (Batts et al 1993), while isolations post 1998 were confirmed via VHSV-specific reverse transcriptase polymerase chain reaction (RT-PCR) as described below. All BC VHSV isolates listed herein were cultured with the exception of the Pa cific Hake isolate which was detected via quantitative RT-PCR (RT-qPCR) (Garver et al 2011) and RT-PCR.…”

Genetic comparison of viral hemorrhagic septicemia virus isolates from North America and Europe

“…Further surveillance is needed to determine the extent of VHSV in differed by about 13%. Similarly, Batts et al (1993) these species, and studies to determine the virulence showed that a DNA probe designed to hybridize with a of both strains of the virus for marine fishes seem unique sequence in the N gene of the Makah isolate warranted. reacted with all North American and none of the Many RNA viruses, including rhabdoviruses, are European isolates tested, while a probe designed to capable of accumulating high numbers of mutations recognize a sequence in the 07-71 isolate reacted with in the RNA genome (Holland et al 1982).…”