Rachel Powers
Science and Products
Dataset: Molecular testing of adult Pacific salmon and trout (Oncorhynchus spp.) for several RNA viruses demonstrates widespread distribution of piscine orthoreovirus (PRV) in Alaska and Washington
Dataset for the publication 'Molecular testing of adult Pacific salmon and trout (Oncorhynchus spp.) for several RNA viruses demonstrates widespread distribution of piscine orthoreovirus (PRV) in Alaska and Washington'. This research was initiated in conjunction with a systematic, multi-agency surveillance effort in the United States (U.S.) in response to reported findings of in
Consequences of Piscine orthoreovirus genotype 1 (PRV‐1) infections in Chinook salmon (Oncorhynchus tshawytscha ), coho salmon (O. kisutch ) and rainbow trout (O. mykiss )
Piscine orthoreovirus genotype 1 (PRV‐1) is the causative agent of heart and skeletal muscle inflammation (HSMI) in farmed Atlantic salmon (Salmo salar L.). The virus has also been found in Pacific salmonids in western North America, raising concerns about the risk to native salmon and trout. Here, we report the results of...
Purcell, Maureen K.; Powers, Rachel L.; Taksdal, Torunn; Mckenney, Douglas; Conway, Carla M.; Elliott, Diane G.; Polinski, Mark; Garver, Kyle A.; Winton, James Mortality of endangered juvenile Lost River Suckers associated with cyanobacteria blooms in mesocosms in Upper Klamath Lake, Oregon
Unsustainably high mortality within the first 2 years of life prevents endangered Lost River Suckers Deltistes luxatus in Upper Klamath Lake, Oregon, from recruiting to spawning populations. Massive blooms of the cyanobacterium Aphanizomenon flos‐aquae and their subsequent death and decay in the lake (bloom‐crashes) are...
Burdick, Summer M.; Hereford, Danielle M; Conway, Carla M.; Banet, Nathan V; Powers, Rachel L.; Martin, Barbara A.; Elliott, Diane G. Complete genome sequences of the index isolates of two genotypes of Pacific salmon paramyxovirus
We report here the genome sequences of two index strains of Pacific salmon paramyxovirus isolated in 1982 and 1983 from adult salmon in Oregon. The isolates are most closely related to Atlantic salmon paramyxovirus, the type species of the genus Aquaparamyxovirus, but are sufficiently distinct to be considered two genotypes of a novel species.
Winton, James; Batts, William N.; Powers, Rachel L.; Purcell, Maureen K. Broad-spectrum antiviral JL122 blocks infection and inhibits transmission of aquatic rhabdoviruses
The aquaculture industry is growing rapidly to meet the needs for global protein consumption. Viral diseases in aquaculture are quite challenging due to lack of treatment options as well as limited injection-delivery vaccines, which are costly. Thus, water-immersion antiviral treatments are highly desirable. This study focused on broad-...
Balmer, Bethany F.; Getchell, Rodman G.; Powers, Rachel L.; Lee, Jihye; Zhang, Tinghu; Jung, Michael E.; Purcell, Maureen K.; Snekvik, Kevin; Aguilar, Hector C. Molecular testing of adult Pacific salmon and trout (Oncorhynchus spp.) for several RNA viruses demonstrates widespread distribution of piscine orthoreovirus in Alaska and Washington
This research was initiated in conjunction with a systematic, multiagency surveillance effort in the United States (U.S.) in response to reported findings of infectious salmon anaemia virus (ISAV) RNA in British Columbia, Canada. In the systematic surveillance study reported in a companion paper, tissues from various salmonids taken from...
Purcell, Maureen K.; Thompson, Rachel L.; Evered, Joy; Kerwin, John; Meyers, Ted R.; Stewart, Bruce; Winton, James Detection of Nanophyetus salmincola in water, snails, and fish tissues by quantitative polymerase chain reaction
We report the development and validation of two quantitative PCR (qPCR) assays to detect Nanophyetus salmincola DNA in water samples and in fish and snail tissues. Analytical and diagnostic validation demonstrated good sensitivity, specificity, and repeatability of both qPCR assays. The N. salmincola DNA copy number in kidney...
Purcell, Maureen K.; Powers, Rachel L.; Besijn, Bonnie; Hershberger, Paul K. Optimization of a Plaque Neutralization Test (PNT) to identify the exposure history of Pacific Herring to viral hemorrhagic septicemia virus (VHSV)
Methods for a plaque neutralization test (PNT) were optimized for the detection and quantification of viral hemorrhagic septicemia virus (VHSV) neutralizing activity in the plasma of Pacific Herring Clupea pallasii. The PNT was complement dependent, as neutralizing activity was attenuated by heat inactivation; further, neutralizing activity was...
Hart, Lucas; Mackenzie, Ashley; Purcell, Maureen K.; Thompson, Rachel L.; Hershberger, Paul Inhibition of an aquatic rhabdovirus demonstrates promise of a broad-spectrum antiviral for use in aquaculture
Many enveloped viruses cause devastating disease in aquaculture, resulting in significant economic impact. LJ001 is a broad-spectrum antiviral compound that inhibits enveloped virus infections by specifically targeting phospholipids in the lipid bilayer via the production of singlet oxygen (1O2). This stabilizes positive curvature and decreases...
Balmer, Bethany F.; Powers, Rachel L.; Zhang, Ting-Hu; Lee, Jihye; Vigant, Frederic; Lee, Benhur; Jung, Michael E.; Purcell, Maureen K.; Snekvik, Kevin; Aguilar, Hector C. Identification of the major capsid protein of erythrocytic necrosis virus (ENV) and development of quantitative real-time PCR assays for quantification of ENV DNA
Viral erythrocytic necrosis (VEN) is a disease of marine and anadromous fish that is caused by the erythrocytic necrosis virus (ENV), which was recently identified as a novel member of family Iridoviridae by next-generation sequencing. Phylogenetic analysis of the ENV DNA polymerase grouped ENV with other erythrocytic iridoviruses from...
Purcell, Maureen K.; Pearman-Gillman, Schuyler; Thompson, Rachel L.; Gregg, Jacob L.; Hart, Lucas M.; Winton, James R.; Emmenegger, Eveline J.; Hershberger, Paul K. Ichthyophonus parasite phylogeny based on ITS rDNA structure prediction and alignment identifies six clades, with a single dominant marine type
Despite their widespread, global impact in both wild and cultured fishes, little is known of the diversity, transmission patterns, and phylogeography of parasites generally identified as Ichthyophonus. This study constructed a phylogeny based on the structural alignment of internal transcribed spacer (ITS) rDNA sequences to compare Ichthyophonus...
Gregg, Jacob; Thompson, Rachel L.; Purcell, Maureen K.; Friedman, Carolyn S.; Hershberger, Paul Piscine reovirus, but not Jaundice Syndrome, was transmissible to Chinook Salmon, Oncorhynchus tshawytscha (Walbaum), Sockeye Salmon, Oncorhynchus nerka (Walbaum), and Atlantic Salmon, Salmo salar L.
A Jaundice Syndrome occurs sporadically among sea-pen-farmed Chinook Salmon in British Columbia, the westernmost province of Canada. Affected salmon are easily identified by a distinctive yellow discolouration of the abdominal and periorbital regions. Through traditional diagnostics, no bacterial or viral agents were cultured from tissues of...
Garver, Kyle A.; Marty, Gary D.; Cockburn, Sarah N.; Richard, Jon; Hawley, Laura M.; Müller, Anita; Thompson, Rachel L.; Purcell, Maureen K.; Saksida, Sonja M. Distribution and transmission of the highly pathogenic parasite Ichthyophonus in marine fishes of Alaska
A combination of field surveys, molecular typing, and laboratory experiments were used to improve our understanding of the distribution and transmission mechanisms of fish parasites in the genus Ichthyophonus. Ichthyophonus spp. infections were detected from the Bering Sea to the coast of Oregon in 10 of 13 host species surveyed. Sequences of rDNA...
Gregg, Jacob L.; Grady, Courtney A.; Thompson, Rachel L.; Purcell, Maureen K.; Friedman, Carolyn S.; Hershberger, Paul K.