Maureen K Purcell

Survival and viral load of chinook salmon, sockeye salmon, and steelhead trout exposed to 4 genogroups of infectious hematopoietic necrosis virus (IHNV)

Theory of the evolution of pathogen specialization suggests that a specialist pathogen gains high fitness in one host, but this comes with fitness loss in other hosts. By contrast, a generalist pathogen does not achieve high fitness in any host, but gains ecological fitness by exploiting different hosts, and has higher fitness than specialists in non-specialized hosts. As a result, specialist pathogens are predicted to have greater variation in fitness across hosts, and generalists would have lower fitness variation across hosts. We test these hypotheses by measuring pathogen replicative fitness as within-host viral loads from the onset of infection to the beginning of virus clearance, using the rhabdovirus infectious...

Categories: Data; Tags: Aquatic Biology, Ecology, Pacific Northwest, RNA viruses, USGS Science Data Catalog (SDC), All tags... Wildlife Disease, farming, generalism, pathogen, replication, salmonids, specialization, tradeoffs, viral load, Fewer tags

Spatial and temporal survey of waterborne myxozoan parasites in the Lake Sammamish watershed, Washington, from 2019 - 2020

There is a fundamental knowledge gap on the distribution, prevalence, intensity, and ecology of salmonid myxozoan parasites in the Lake Sammamish watershed, Washington. To address this knowledge gap, we tested water samples for Ceratonova shasta, Parvicapsula minibicornis and Tetracapsuloides bryosalmonae DNA from 84 sites distributed throughout the Lake Sammamish watershed in fall 2019 and 74 sites in spring 2020. Our surveillance identified zones with high waterborne parasite loads and provides a proof of concept for this approach that could be expanded throughout the larger Lake Washington watershed.

Categories: Data; Tags: Aquatic Biology, Ceratonova shasta, Ecology, Parvicapsula minibicornis, Puget Sound, All tags... Tetracapsuloides bryosalmonae, USGS Science Data Catalog (SDC), Washington, Wildlife Disease, biota, environment, fishes, inlandWaters, parasites, Fewer tags

Laboratory exposure of Chinook salmon (Oncorhynchus tshawytscha), coho salmon (O. kisutch) and rainbow trout (O. mykiss) to a Pacific Canadian strain of piscine orthoreovirus genotype one (PRV-1)

Piscine orthoreovirus genotype one (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 laboratory challenges using juvenile Chinook salmon, coho salmon, and rainbow trout injected with tissue homogenates from Atlantic salmon testing positive for PRV-1 or with control material. Fish were sampled at intervals to assess viral RNA transcript levels, hematocrit, erythrocytic inclusions, and histopathology. While PRV-1 replicated to high loads in all species, there was negligible mortality...

Categories: Data; Tags: Pacific Northwest, USGS Science Data Catalog (SDC), Wildlife Disease, environment

Survival, viral load and neutralizing antibodies in steelhead trout and cell cultures exposed to infectious hematopoietic necrosis virus (IHNV) at 3 temperatures

Environmental variation has important effects on host-pathogen interactions, affecting large-scale ecological processes such as the severity and frequency of epidemics. However, less is known about how the environment modulates viral fitness traits and within host infection processes. Viral genetic variation, fish host immune response and environmental parameters such as temperature have been reported to strongly influence the replication and clearance of infectious hematopoietic necrosis virus (IHNV), a significant pathogen of salmon and trout. Here, we quantified the effect of water temperature on probability of infection across time following exposure of steelhead (Oncorhynchus mykiss) to a field isolate of IHNV....

Categories: Data; Tags: Aquatic Biology, Pacific Northwest, USGS Science Data Catalog (SDC), Wildlife Disease, aquaculture water use, All tags... climate change, farming, fish, health and disease, migratory species, Fewer tags

Detection of Nanophyetus salmincola in water, snails and fish tissues by quantitative PCR

The data are used to support the development and validation of two quantitative polymerase chain reaction (qPCR) assays to detect the parasite Nanophyetus salmincola DNA in water samples and fish and snail tissues. The data link to a series of experiments that are described in the publications. Experiment 1 defines the linearity and detection limits of the assays. Experiment 2 assesses the utility of the assays to detect N. salminicola waterborne cercaria in one liter volumes of water. Experiment 4 assesses the detection of N. salminicola waterborne cercaria in small volumes (50 microliters). Experiments 5 and 6 assesses the within and between run repeatability of the assays. Experiment 7 assesses the diagnostic...

Categories: Data; Tags: DNA probe analysis, Disease research, USGS Science Data Catalog (SDC), Washington