1
|
Shavalier M, Faisal M, Loch TP, Fitzgerald SD, Thaiwong T, Kiupel M. Disease Progression in Lake Trout ( Salvelinus namaycush) Experimentally Infected With Epizootic Epitheliotropic Disease Virus (Salmonid Herpesvirus-3). Vet Pathol 2020; 57:687-699. [PMID: 32744164 DOI: 10.1177/0300985820941268] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Epizootic epitheliotropic disease virus (salmonid herpesvirus-3; EEDV) is responsible for the death of millions of hatchery-raised lake trout (Salvelinus namaycush) in the Laurentian Great Lakes Basin. However, little is known about its biology, pathology, tropism, and host interactions. In this study, the presence and disease progression of EEDV were evaluated following exposure of naïve juvenile lake trout to EEDV via bath immersion under controlled laboratory conditions (n = 84 infected; n = 44 control). Individual tissues (n = 10 per fish), collected over 6 weeks, were analyzed for viral load by quantitative polymerase chain reaction, gross and histopathologic changes, and virus cellular targets using in situ hybridization. Skin, fin, and ocular tissues were the earliest viral targets and yielded the highest viral loads throughout the course of infection. Early gross lesions included exophthalmia, ocular hemorrhage, fin congestion, and hyperemia of visceral blood vessels. Advanced disease was characterized by multifocal to coalescing erosions and ulcerations of the skin, and congestion of visceral organs. Microscopically, there was cellular degeneration and necrosis in the epidermis and spleen, and lymphohistiocytic perivasculitis of the dermis, omentum, and the epicardium. EEDV DNA was first detected by in situ hybridization in epithelial cells of the epidermis, with subsequent labeling in the epithelial lining of primary and secondary gill lamellae. During advanced disease, EEDV was detected in endothelial and dendritic cells as well as blood monocytes. This study characterized EEDV tissue tropism and associated pathologic features, to guide research aimed at understanding EEDV disease ecology and improving strategies for disease control.
Collapse
Affiliation(s)
- Megan Shavalier
- Comparative Medicine and Integrative Biology, College of Veterinary Medicine, 3078Michigan State University, East Lansing, MI, USA.,Department of Fisheries and Wildlife, College of Agriculture and Natural Resources, 3078Michigan State University, East Lansing, MI, USA
| | - Mohamed Faisal
- Department of Fisheries and Wildlife, College of Agriculture and Natural Resources, 3078Michigan State University, East Lansing, MI, USA.,Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine,3078Michigan State University, East Lansing, MI, USA
| | - Thomas P Loch
- Department of Fisheries and Wildlife, College of Agriculture and Natural Resources, 3078Michigan State University, East Lansing, MI, USA.,Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine,3078Michigan State University, East Lansing, MI, USA
| | - Scott D Fitzgerald
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine,3078Michigan State University, East Lansing, MI, USA.,Michigan State University Veterinary Diagnostic Laboratory, Lansing, MI, USA
| | - Tuddow Thaiwong
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine,3078Michigan State University, East Lansing, MI, USA.,Michigan State University Veterinary Diagnostic Laboratory, Lansing, MI, USA
| | - Matti Kiupel
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine,3078Michigan State University, East Lansing, MI, USA.,Michigan State University Veterinary Diagnostic Laboratory, Lansing, MI, USA
| |
Collapse
|
2
|
Faisal M, Loch TP, Shavalier M, VanDeuren MG, Standish I, Winters A, Glenney G, Aho J, Wolgamood M, VanAmberg J, Eisch E, Whelan GE. Resurgence of Salmonid Herpesvirus-3 Infection (Epizootic Epitheliotropic Disease) in Hatchery-Propagated Lake Trout in Michigan. J Aquat Anim Health 2019; 31:31-45. [PMID: 30681187 DOI: 10.1002/aah.10051] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 10/06/2018] [Indexed: 06/09/2023]
Abstract
Over the past century, populations of Lake Trout Salvelinus namaycush have declined throughout the Great Lakes basin due to overfishing, habitat destruction, introduction of invasive species, and associated recruitment issues from high thiaminase, as well as emerging infectious diseases. To combat these declines, state and federal fishery management agencies undertook substantial stock enhancement efforts, including more stringent regulation of sport and commercial catch limits and increasing hatchery propagation of Lake Trout stocked into Great Lakes basin waterways. One state fish hatchery involved in these rehabilitation efforts experienced mass mortality events in 2012 and 2017. In 2012, following a period of abnormally heavy rain, hatchery staff observed abnormal behavior followed by increased mortalities in two strains of Lake Trout fingerlings, reaching upwards of 20% mortality and totaling a loss of approximately 100,000 fish. In 2017, following another heavy-rain season, 6-8% of 2-year-old Lake Trout experienced morbidity and mortality similar to that observed in 2012. During the 2012 event, Brook Trout Salvelinus fontinalis and splake (Lake Trout × Brook Trout hybrid) reared in flow-through systems receiving water from diseased Lake Trout remained clinically unaffected. Molecular analyses revealed all lots of affected Lake Trout were infected with the salmonid herpesvirus-3 (epizootic epitheliotropic disease virus [EEDV]), a disease that caused complete depopulation of this hatchery in the late 1980s and until 2012 was never again detected in this hatchery or in Michigan. Further sampling detected EEDV in apparently healthy 5-year-old Lake Trout and in wild Mottled Sculpin Cottus bairdii collected in the hatchery source water. The ability of the virus to replicate in tissues of infected fish was verified by exposing naïve Lake Trout to the filtered tissue homogenates of infected fish resulting in similar disease signs. Despite the virus going undetected for many years, these two EEDV episodes clearly demonstrate the continued presence of this deadly herpesvirus in the Great Lakes basin.
Collapse
Affiliation(s)
- Mohamed Faisal
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, 1129 Farm Lane, Room 177K, East Lansing, Michigan, 48824, USA
- Department of Fisheries and Wildlife, College of Agriculture and Natural Resources, Michigan State University, 1129 Farm Lane, Room 177K, East Lansing, Michigan, 48824, USA
| | - Thomas P Loch
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, 1129 Farm Lane, Room 177K, East Lansing, Michigan, 48824, USA
- Department of Fisheries and Wildlife, College of Agriculture and Natural Resources, Michigan State University, 1129 Farm Lane, Room 177K, East Lansing, Michigan, 48824, USA
| | - Megan Shavalier
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, 1129 Farm Lane, Room 177K, East Lansing, Michigan, 48824, USA
| | - Michelle Gunn VanDeuren
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, 1129 Farm Lane, Room 177K, East Lansing, Michigan, 48824, USA
| | - Isaac Standish
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, 1129 Farm Lane, Room 177K, East Lansing, Michigan, 48824, USA
| | - Andrew Winters
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, 1129 Farm Lane, Room 177K, East Lansing, Michigan, 48824, USA
| | - Gavin Glenney
- U.S. Fish and Wildlife Service, Lamar Fish Health Center, Post Office Box 155, Lamar, Pennsylvania, 16848, USA
| | - James Aho
- Michigan Department of Natural Resources, Marquette State Fish Hatchery, 488 Cherry Creek Road, Marquette, Michigan, 49855, USA
| | - Martha Wolgamood
- Michigan Department of Natural Resources, Wolf Lake State Fish Hatchery, 34270 County Road 652, Mattawan, Michigan, 49071, USA
| | - Jan VanAmberg
- Michigan Department of Natural Resources, Thompson State Fish Hatchery, 944 South State Highway M149, Manistique, Michigan, 49854, USA
| | - Edward Eisch
- Michigan Department of Natural Resources, Fisheries Division, 2122 South M-37, Traverse City, Michigan, 49685, USA
| | - Gary E Whelan
- Michigan Department of Natural Resources, Fisheries Division, Post Office Box 30446, Lansing, Michigan, 48909, USA
| |
Collapse
|
3
|
Zhang Q, Shavalier M, Standish I, Glenney GW, Loch TP, Faisal M. Development of a loop-mediated isothermal amplification assay for the detection and quantification of epizootic epitheliotropic disease virus (salmonid herpesvirus-3). J Virol Methods 2018; 264:44-50. [PMID: 30444983 PMCID: PMC7119762 DOI: 10.1016/j.jviromet.2018.11.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2018] [Revised: 10/02/2018] [Accepted: 11/12/2018] [Indexed: 11/25/2022]
Abstract
A quantitative LAMP method for identification of EEDV has been developed. Analytical sensitivity of the qLAMP is as low as 78 pg extracted DNA from tissue. The method is highly specific for EEDV. The EEDV qLAMP method was evaluated against the qPCR method.
Epizootic Epitheliotropic Disease Virus (EEDV; Salmonid Herpesvirus-3) causes a serious disease hatchery-reared lake trout (Salvelinus namaycush), threatening restoration efforts of this species in North America. The current inability to replicate EEDV in vitro necessitates the search for a reproducible, sensitive, and specific assay that allows for its detection and quantitation in a time- and cost-effective manner. Herein, we describe a loop-mediated isothermal amplification (LAMP) assay that was developed for the quantitative detection of EEDV in infected fish tissues. The newly developed LAMP reaction was optimized in the presence of calcein, and the best results were produced using 2 mM MgCl2, 1.8 mM dNTPs and at an incubation temperature of 67.1 °C. This method was highly specific to EEDV, as it showed no cross-reactivity with several fish viruses, including Salmonid Herpesvirus-1, -2, -4, and -5, Infectious Pancreatic Necrosis Virus, Spring Viremia of Carp Virus, Infectious Hematopoietic Necrosis Virus, Golden Shiner Reovirus, Fathead Minnow Nidovirus, and Viral Hemorrhagic Septicemia Virus. The analytical sensitivity of the EEDV-LAMP method was estimated to be as low as 16 copies of plasmid per reaction. When infected fish tissue was used, a positive reaction could be obtained when an infected gill tissue sample that contained 430 viral copies/μg was diluted up to five orders of magnitude. The sensitivity and specificity of the newly developed LAMP assay compared to the SYBR Green qPCR assay were 84.3% and 93.3%, respectively. The quantitative LAMP for EEDV had a correlation coefficient (R2 = 0.980), and did not differ significantly from the SYBR Green quantitative PCR assay (p > 0.05). Given its cost- and time-effectiveness, this quantitative LAMP assay is suitable for screening lake trout populations and for the initial diagnosis of clinical cases.
Collapse
Affiliation(s)
- Qingli Zhang
- Function Laboratory for Marine Fisheries Science and Food Production Processes, Qingdao National Laboratory for Marine Science and Technology, Yellow Sea Fisheries Research Institute, Chinese Academy of Fishery Sciences, Qingdao, 266071, China; Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Megan Shavalier
- Comparative Medicine and Integrative Biology, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA
| | - Isaac Standish
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI, 48824, USA
| | - Gavin W Glenney
- U.S. Fish and Wildlife Service, Lamar Fish Health Center, Lamar, PA 16848, USA
| | - Thomas P Loch
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI, 48824, USA; Department of Fisheries and Wildlife, College of Agriculture and Natural Resources,Michigan State University, East Lansing, MI 48824, USA
| | - Mohamed Faisal
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI, 48824, USA; Comparative Medicine and Integrative Biology, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; Department of Fisheries and Wildlife, College of Agriculture and Natural Resources,Michigan State University, East Lansing, MI 48824, USA.
| |
Collapse
|
4
|
Faisal M, Shavalier M, Kim RK, Millard EV, Gunn MR, Winters AD, Schulz CA, Eissa A, Thomas MV, Wolgamood M, Whelan GE, Winton J. Spread of the emerging viral hemorrhagic septicemia virus strain, genotype IVb, in Michigan, USA. Viruses 2012; 4:734-60. [PMID: 22754647 PMCID: PMC3386630 DOI: 10.3390/v4050734] [Citation(s) in RCA: 55] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Revised: 04/11/2012] [Accepted: 04/13/2012] [Indexed: 11/16/2022] Open
Abstract
In 2003, viral hemorrhagic septicemia virus (VHSV) emerged in the Laurentian Great Lakes causing serious losses in a number of ecologically and recreationally important fish species. Within six years, despite concerted managerial preventive measures, the virus spread into the five Great Lakes and to a number of inland waterbodies. In response to this emerging threat, cooperative efforts between the Michigan Department of Natural Resources (MI DNR), the Michigan State University Aquatic Animal Health Laboratory (MSU-AAHL), and the United States Department of Agriculture-Animal and Plant Health Inspection Services (USDA-APHIS) were focused on performing a series of general and VHSV-targeted surveillances to determine the extent of virus trafficking in the State of Michigan. Herein we describe six years (2005-2010) of testing, covering hundreds of sites throughout Michigan's Upper and Lower Peninsulas. A total of 96,228 fish representing 73 species were checked for lesions suggestive of VHSV and their internal organs tested for the presence of VHSV using susceptible cell lines. Of the 1,823 cases tested, 30 cases from 19 fish species tested positive for VHSV by tissue culture and were confirmed by reverse transcriptase polymerase chain reaction (RT-PCR). Gene sequence analyses of all VHSV isolates retrieved in Michigan demonstrated that they belong to the emerging sublineage "b" of the North American VHSV genotype IV. These findings underscore the complexity of VHSV ecology in the Great Lakes basin and the critical need for rigorous legislation and regulatory guidelines in order to reduce the virus spread within and outside of the Laurentian Great Lakes watershed.
Collapse
Affiliation(s)
- Mohamed Faisal
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (M.S.); (R.K.K.); (E.V.M.); (M.R.G.)
- Department of Fisheries and Wildlife, College of Agriculture and Natural Resources, Michigan State University, East Lansing, MI 48824, USA; (A.D.W.); (C.A.S.)
- Author to whom correspondence should be addressed; ; Tel.: +1-517-884-2019; Fax: +1-517-432-2310
| | - Megan Shavalier
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (M.S.); (R.K.K.); (E.V.M.); (M.R.G.)
| | - Robert K. Kim
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (M.S.); (R.K.K.); (E.V.M.); (M.R.G.)
| | - Elena V. Millard
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (M.S.); (R.K.K.); (E.V.M.); (M.R.G.)
| | - Michelle R. Gunn
- Department of Pathobiology and Diagnostic Investigation, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (M.S.); (R.K.K.); (E.V.M.); (M.R.G.)
| | - Andrew D. Winters
- Department of Fisheries and Wildlife, College of Agriculture and Natural Resources, Michigan State University, East Lansing, MI 48824, USA; (A.D.W.); (C.A.S.)
| | - Carolyn A. Schulz
- Department of Fisheries and Wildlife, College of Agriculture and Natural Resources, Michigan State University, East Lansing, MI 48824, USA; (A.D.W.); (C.A.S.)
| | - Alaa Eissa
- Department of Fish Diseases and Management, Cairo University, Cairo, Egypt;
| | - Michael V. Thomas
- Michigan Department of Natural Resources, State of Michigan Government, Lansing, MI 48909, USA; (M.V.T.); (M.W.); (G.E.W.)
| | - Martha Wolgamood
- Michigan Department of Natural Resources, State of Michigan Government, Lansing, MI 48909, USA; (M.V.T.); (M.W.); (G.E.W.)
| | - Gary E. Whelan
- Michigan Department of Natural Resources, State of Michigan Government, Lansing, MI 48909, USA; (M.V.T.); (M.W.); (G.E.W.)
| | - James Winton
- United States Geological Survey-Western Fisheries Research Center, Seattle, WA 98115, USA;
| |
Collapse
|