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Ki Hong Kim - One of the best experts on this subject based on the ideXlab platform.
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changes in micrornas expression profile of olive flounder paralichthys olivaceus in response to viral Hemorrhagic Septicemia virus vhsv infection
Fish & Shellfish Immunology, 2016Co-Authors: Abdellaoui Najib, Min Sun Kim, Seung Hyuk Choi, Yue Jai Kang, Ki Hong KimAbstract:To know the effect of viral Hemorrhagic Septicemia virus (VHSV) infection on the cellular microRNA expression profile in olive flounder (Paralichthys olivaceus), fish were infected with VHSV, and cellular microRNAs expression was analyzed at 0 (control), 6, 12, 24, 48 and 72 h post-infection (h.p.i.) by the high-throughput sequencing. A total of 372 mature miRNAs were identified, and, among them, 63 miRNAs were differentially expressed during VHSV infection. The differentially expressed microRNAs number was greatly increased from 24 h.p.i. compared to the number at 6 and 12 h.p.i., suggesting that the alteration of microRNAs expression by VHSV infection may be related to the progression of VHSV disease. The target prediction analysis, the GO enrichment analysis, and the KEGG pathway analysis of the predicted target genes showed that various biological pathways could be affected by VHSV infection through the down-regulation or up-regulation of host miRNAs. The present results provide a basic information on the microRNAs related to VHSV infection in olive flounder. Considering broad effects of microRNAs on various biological pathways, data in this study can be used to interpret the mechanism of VHSV pathogenesis, which, vice versa, can be used to develop control measures against VHSV.
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the role of viral Hemorrhagic Septicemia virus vhsv nv gene in tnf α and vhsv infection mediated nf κb activation
Fish & Shellfish Immunology, 2013Co-Authors: Min Sun Kim, Ki Hong KimAbstract:The role of viral Hemorrhagic Septicemia virus (VHSV) NV gene in nuclear factor-κB (NF-κB) activation was investigated. Epithelioma papulosum cyprini (EPC) cells pre-treated with tumor necrosis factor (TNF)-α showed a strong resistance against VHSV infection, but cells treated with TNF-α after VHSV infection showed no resistance, suggesting that immediate early TNF-α-mediated responses inhibit VHSV replication. Activation of NF-κB is a key step in TNF-α-mediated immunomodulatory pathways. In this study, activation of NF-κB by TNF-α exposure was inhibited in EPC cells harboring NV gene expressing vectors, indicating that the NV gene of VHSV can suppress TNF-α-mediated NF-κB activation. Furthermore, the NV gene knock-out recombinant VHSV (rVHSV-ΔNV-EGFP) induced significantly higher NF-κB activity in EPC cells than wild-type VHSV, suggesting that VHSV adopted a strategy to suppress early activation of NF-κB in host cells through and NV gene.
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generation and characterization of nv gene knockout recombinant viral Hemorrhagic Septicemia virus vhsv genotype iva
Diseases of Aquatic Organisms, 2011Co-Authors: Min Sun Kim, Dongsoo Kim, Ki Hong KimAbstract:A recombinant viral Hemorrhagic Septicemia virus (rVHSV-deltaNV-EGFP) containing the enhanced green fluorescent protein (EGFP) gene instead of the NV gene was produced using the reverse-genetics method. For use as a positive control, another recombinant virus (rVHSV-wild) was also generated, which had an identical nucleotide sequence to the wild-type VHSV genome except for a few artificially replaced nucleotides. The rVHSVs were rescued using a system controlled by T7 RNA polymerase supplied by a retroviral vector. Generation of rVHSV-deltaNV-EGFP and rVHSV-wild was confirmed by sequencing of RT-PCR products, and rescue of infectious rVHSVs was confirmed by observation of plaque formation. Replication efficiency of rVHSV-wild was distinctly lower than that of wild-type VHSV, suggesting that the artificially replaced nucleotides, especially when immediately preceding the G or NV gene start codons, might affect the replication of the virus. Replication of rVHSV-deltaNV-EGFP was slightly lower than that of rVHSV-wild when epithelioma papulosum cyprini cells were infected with multiplicity of infection (MOI) 1.0, but much lower when cells were infected with MOI 0.00001. These results suggest that the NV gene plays an important role in VHSV replication through interactions with host-cell responses, and the lower replication ability of rVHSV-wild compared to wild-type VHSV might be caused by replaced nucleotides just before the NV gene open reading frame (ORF) rather than the G gene ORF. In olive flounder Paralichthys olivaceus, rVHSV-wild produced slower-progressing mortalities than wild-type VHSV, whereas rVHSV-deltaNV-EGFP pathogenesis was highly attenuated. These results suggest that the NV protein of VHSV may play an important role not only in viral replication but also in viral pathogenesis.
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protection of olive flounder paralichthys olivaceus against viral Hemorrhagic Septicemia virus vhsv by immunization with nv gene knockout recombinant vhsv
Aquaculture, 2011Co-Authors: Min Sun Kim, Ki Hong KimAbstract:Abstract The potential of the NV gene-knockout recombinant viral Hemorrhagic Septicemia virus (rVHSV-ΔNV-EGFP) as a live attenuated vaccine was assessed. In an in vivo virulence experiment, olive flounder ( Paralichthys olivaceus ) intramuscularly (i.m.) injected with 10 3 and 10 5 PFU of rVHSV-ΔNV-EGFP showed no mortality. The rVHSV-ΔNV-EGFP had ability to spread and replicate in the internal organs of olive flounder reared at either 15 °C or 20 °C. In the vaccination experiment, the cumulative mortality rates of olive flounder i.m. immunized with 10 3 , 10 4 , and 10 5 PFU of rVHSV-ΔNV-EGFP were 40–50%, 10–30%, and 0–10%, respectively, at 4 weeks after the primary immunization. In the second challenge experiment conducted at 4 weeks after the boost immunization, the cumulative mortality in fish immunized with 10 3 PFU of rVHSV-ΔNV-EGFP was 10–30%. No mortality was recorded in fish immunized with 10 4 and 10 5 PFU of the recombinant virus. While the cumulative mortality of fish in control group was 90–100%. The serum neutralization titers were also proportional to the survival rates of vaccine groups. The present results suggest that the rVHSV-ΔNV-EGFP has a high potential to be used as a live vaccine in olive flounder farms.
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inhibition of viral Hemorrhagic Septicemia virus replication using a short hairpin rna targeting the g gene
Archives of Virology, 2011Co-Authors: Min Sun Kim, Ki Hong KimAbstract:RNA interference (RNAi), a mechanism for post-transcriptional silencing of homologous genes by double-stranded RNA (dsRNA), has emerged as an antiviral strategy in animals. In this study, the epithelioma papulosum cyprini (EPC) cell line, in combination with a fugu-U6-promoter-driven shRNA construct designed against G gene, was used to investigate whether short hairpin RNA (shRNA) could inhibit viral Hemorrhagic Septicemia virus (VHSV) proliferation by sequence-specific RNAi. The results showed that transfection with a shRNA-producing construct (shRNA-VG594) resulted in a sequence-specific knockdown of G gene mRNA in EPC cells. There were no significant differences in IFN-induced Mx1 gene expression among cells transfected with each shRNA vector including shRNA-VG594, -VG594sc (two nucleotides mismatch) and -EGFP (non-specific control), suggesting that knockdown of G gene expression was not due to an IFN response but instead by sequence-specific RNAi. Transfection of EPC cells with shRNA-VG594 conferred resistance to VHSV, and this anti-VHSV effect was not observed when using a two-nucleotide-mismatched shRNA-VG594sc or a shRNA targeting EGFP. Furthermore, shRNA-VG594 expressed in EPC cells did not confer protection against infectious hematopoietic necrosis virus (IHNV), suggesting sequence-specific RNAi-dependent suppression of viral replication.
Mohamed Faisal - One of the best experts on this subject based on the ideXlab platform.
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a dna vaccine encoding the viral Hemorrhagic Septicemia virus genotype ivb glycoprotein confers protection in muskellunge esox masquinongy rainbow trout oncorhynchus mykiss brown trout salmo trutta and lake trout salvelinus namaycush
Virology Journal, 2016Co-Authors: Isaac Standish, Travis O Brenden, Elena V. Millard, Mohamed FaisalAbstract:The viral Hemorrhagic Septicemia virus (VHSV) is one of the most serious fish pathogens. In 2003, a novel sublineage (genotype IVb) of this deadly virus emerged in the Great Lakes basin causing serious fish kills. We have previously demonstrated that a DNA plasmid (pcDNA), containing a cytomegalovirus (CMV) promoter and the viral Hemorrhagic Septicemia virus (VHSV) genotype IVb glycoprotein (G) gene insert (designated pVHSivb-G) confers moderate protection in muskellunge (Esox masquinongy), a highly susceptible species upon challenge. In order to achieve optimal protection, we investigated a number of factors including the incubation time [i.e. the number of degree days (° days)] before challenge, and viral challenge dose and route. Additionally, we tested if pVHSivb-G provides protection against VHSV-IVb to less susceptible salmonids such as rainbow trout (Oncorhynchus mykiss), brown trout (Salmo trutta) and lake trout (Salvelinus namaycush). An increase in the period lapsed between vaccination and challenge to 1880° days resulted in 95% relative percent protection (RPS) in muskellunge following a single administration of the pVHSivb-G plasmid and viral challenge. An RPS of 100% for muskellunge was achieved with a longer incubation period (2400° days) and in conjunction with a booster dose of the plasmid. The pVHSivb-G vaccine also elicited significant protection in all three salmonid species, reaching 100% RPS in lake trout following an incubation period of 1001° days prior to viral challenge. Vaccination with pVHSivb-G was also associated with the development of significant levels of circulating VHSV-binding antibodies in muskellunge as measured by indirect ELISA, which reached peak levels 6–7 weeks post-vaccination. Viral shedding in vaccinated survivors was minimal and of transient nature. The study shows that the pVHSivb-G plasmid can elicit a protective response against the wild virus strain in a range of species important in recreational and commercial Great Lakes fisheries.
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detection and surveillance of viral Hemorrhagic Septicemia virus using real time rt pcr ii diagnostic evaluation of two protocols
Diseases of Aquatic Organisms, 2014Co-Authors: Janet V Warg, Mohamed Faisal, Geoffrey H Groocock, Travis Clement, Angela Cruz, Cem Giray, Andrew E Goodwin, Robert KimAbstract:Two real-time reverse transcription polymerase chain reaction (rRT-PCR) assays under consideration for deployment to multiple testing laboratories across the USA were evalu- ated for diagnostic sensitivity and specificity on tissue homogenates obtained from natural and experimental viral Hemorrhagic Septicemia (VHS)-infected fish. Estimates for diagnostic speci- ficity using virus isolation as the reference method were similar between laboratories regardless of the assay. Diagnostic sensitivity estimates of 0.96 (95% CI: 0.95, 0.97) for Jonstrup et al. (2013)'s assay (J Fish Dis 36:9�23) exceeded the diagnostic sensitivity of 0.85 (95% CI: 0.83, 0.87) for Phelps et al. (2012)'s assay (J Aquat Anim Health 24:238�243). The Jonstrup rRT-PCR assay is robust as demonstrated by high sensitivity and specificity estimates across laboratories and can be used as a valuable tool for targeted surveillance and for testing of suspect VHSV samples.
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detection and surveillance of viral Hemorrhagic Septicemia virus using real time rt pcr i initial comparison of four protocols
Diseases of Aquatic Organisms, 2014Co-Authors: Janet V Warg, Mohamed Faisal, Geoffrey H Groocock, Travis Clement, Angela Cruz, Cem Giray, Andrew E Goodwin, Robert KimAbstract:Eight laboratories worked collectively to evaluate 4 real-time RT-PCR (rRT-PCR) protocols targeting viral Hemorrhagic Septicemia virus (VHSV) being considered for deployment to a USA laboratory testing network. The protocols utilized previously published primers and probe sets developed for detection and surveillance of VHSV. All participating laboratories received and followed a standard operating protocol for extraction and for each of the rRT-PCR assays. Performance measures specifically evaluated included limit of detection (defined as the smallest amount of analyte in which 95% of the samples are classified as positive), analytical specificity, assay efficiency across genotype representatives, within- and between-plate variation within a laboratory, and variation between laboratories using the same platform, between platforms, and between software versions. This evaluation clearly demonstrated that the TaqMan®-based assay developed by Jonstrup et al. (2013; J Fish Dis 36:9-23) produced the most consistent analytical performance characteristics for detecting all genotypes of VHSV across the 8 participating laboratories.
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detection of viral Hemorrhagic Septicemia virus ivb antibodies in sera of muskellunge esox masquinongy using competitive elisa
Diseases of Aquatic Organisms, 2014Co-Authors: Elena V. Millard, Scott E. Lapatra, Travis O Brenden, Susan Marcquenski, Mohamed FaisalAbstract:: A competitive enzyme-linked immunosorbent assay (cELISA) was developed for the detection of antibodies to viral Hemorrhagic Septicemia virus genotype IVb (VHSV-IVb) in fish sera. Assay conditions were standardized using known negative and positive muskellunge Esox masquinongy. A positive-negative threshold of 14.6% inhibition was established based on analysis of sera of 60 muskellunge with no previous exposure to VHSV-IVb. The cELISA was then used to investigate immune responses of wild muskellunge sampled from 5 water bodies in Michigan and Wisconsin, USA, between 2005 and 2012. Antibodies were detected in fish from Lake St. Clair, Michigan, and Lower Fox River/Green Bay, Wisconsin. Both water systems were considered enzootic for VHSV-IVb. Additionally, antibodies were detected in muskellunge from Thornapple Lake, a Michigan inland lake previously considered negative for VHSV-IVb based on virus isolation methods. Muskellunge populations from Lake Hudson, Michigan, and Butternut Lake, Wisconsin, lacked evidence of an immune response to VHSV-IVb. When results of the cELISA were compared to the 50% plaque neutralization test for several groups of fish, there was 78.4% agreement between the tests for antibody presence. The cELISA is a rapid and efficient test for the detection of binding antibodies to VHSV-IVb and will be a useful non-lethal tool for monitoring the spread of this serious pathogen.
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Spread of the emerging viral Hemorrhagic Septicemia virus strain, genotype IVb, in Michigan, USA.
Viruses, 2012Co-Authors: Mohamed Faisal, Carolyn A. Schulz, Robert Kim, Andrew D Winters, Elena V. Millard, Megan Shavalier, Michelle R. Gunn, Alaa Eldin Eissa, Michael V. Thomas, Martha WolgamoodAbstract: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.
Min Sun Kim - One of the best experts on this subject based on the ideXlab platform.
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changes in micrornas expression profile of olive flounder paralichthys olivaceus in response to viral Hemorrhagic Septicemia virus vhsv infection
Fish & Shellfish Immunology, 2016Co-Authors: Abdellaoui Najib, Min Sun Kim, Seung Hyuk Choi, Yue Jai Kang, Ki Hong KimAbstract:To know the effect of viral Hemorrhagic Septicemia virus (VHSV) infection on the cellular microRNA expression profile in olive flounder (Paralichthys olivaceus), fish were infected with VHSV, and cellular microRNAs expression was analyzed at 0 (control), 6, 12, 24, 48 and 72 h post-infection (h.p.i.) by the high-throughput sequencing. A total of 372 mature miRNAs were identified, and, among them, 63 miRNAs were differentially expressed during VHSV infection. The differentially expressed microRNAs number was greatly increased from 24 h.p.i. compared to the number at 6 and 12 h.p.i., suggesting that the alteration of microRNAs expression by VHSV infection may be related to the progression of VHSV disease. The target prediction analysis, the GO enrichment analysis, and the KEGG pathway analysis of the predicted target genes showed that various biological pathways could be affected by VHSV infection through the down-regulation or up-regulation of host miRNAs. The present results provide a basic information on the microRNAs related to VHSV infection in olive flounder. Considering broad effects of microRNAs on various biological pathways, data in this study can be used to interpret the mechanism of VHSV pathogenesis, which, vice versa, can be used to develop control measures against VHSV.
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the role of viral Hemorrhagic Septicemia virus vhsv nv gene in tnf α and vhsv infection mediated nf κb activation
Fish & Shellfish Immunology, 2013Co-Authors: Min Sun Kim, Ki Hong KimAbstract:The role of viral Hemorrhagic Septicemia virus (VHSV) NV gene in nuclear factor-κB (NF-κB) activation was investigated. Epithelioma papulosum cyprini (EPC) cells pre-treated with tumor necrosis factor (TNF)-α showed a strong resistance against VHSV infection, but cells treated with TNF-α after VHSV infection showed no resistance, suggesting that immediate early TNF-α-mediated responses inhibit VHSV replication. Activation of NF-κB is a key step in TNF-α-mediated immunomodulatory pathways. In this study, activation of NF-κB by TNF-α exposure was inhibited in EPC cells harboring NV gene expressing vectors, indicating that the NV gene of VHSV can suppress TNF-α-mediated NF-κB activation. Furthermore, the NV gene knock-out recombinant VHSV (rVHSV-ΔNV-EGFP) induced significantly higher NF-κB activity in EPC cells than wild-type VHSV, suggesting that VHSV adopted a strategy to suppress early activation of NF-κB in host cells through and NV gene.
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generation and characterization of nv gene knockout recombinant viral Hemorrhagic Septicemia virus vhsv genotype iva
Diseases of Aquatic Organisms, 2011Co-Authors: Min Sun Kim, Dongsoo Kim, Ki Hong KimAbstract:A recombinant viral Hemorrhagic Septicemia virus (rVHSV-deltaNV-EGFP) containing the enhanced green fluorescent protein (EGFP) gene instead of the NV gene was produced using the reverse-genetics method. For use as a positive control, another recombinant virus (rVHSV-wild) was also generated, which had an identical nucleotide sequence to the wild-type VHSV genome except for a few artificially replaced nucleotides. The rVHSVs were rescued using a system controlled by T7 RNA polymerase supplied by a retroviral vector. Generation of rVHSV-deltaNV-EGFP and rVHSV-wild was confirmed by sequencing of RT-PCR products, and rescue of infectious rVHSVs was confirmed by observation of plaque formation. Replication efficiency of rVHSV-wild was distinctly lower than that of wild-type VHSV, suggesting that the artificially replaced nucleotides, especially when immediately preceding the G or NV gene start codons, might affect the replication of the virus. Replication of rVHSV-deltaNV-EGFP was slightly lower than that of rVHSV-wild when epithelioma papulosum cyprini cells were infected with multiplicity of infection (MOI) 1.0, but much lower when cells were infected with MOI 0.00001. These results suggest that the NV gene plays an important role in VHSV replication through interactions with host-cell responses, and the lower replication ability of rVHSV-wild compared to wild-type VHSV might be caused by replaced nucleotides just before the NV gene open reading frame (ORF) rather than the G gene ORF. In olive flounder Paralichthys olivaceus, rVHSV-wild produced slower-progressing mortalities than wild-type VHSV, whereas rVHSV-deltaNV-EGFP pathogenesis was highly attenuated. These results suggest that the NV protein of VHSV may play an important role not only in viral replication but also in viral pathogenesis.
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protection of olive flounder paralichthys olivaceus against viral Hemorrhagic Septicemia virus vhsv by immunization with nv gene knockout recombinant vhsv
Aquaculture, 2011Co-Authors: Min Sun Kim, Ki Hong KimAbstract:Abstract The potential of the NV gene-knockout recombinant viral Hemorrhagic Septicemia virus (rVHSV-ΔNV-EGFP) as a live attenuated vaccine was assessed. In an in vivo virulence experiment, olive flounder ( Paralichthys olivaceus ) intramuscularly (i.m.) injected with 10 3 and 10 5 PFU of rVHSV-ΔNV-EGFP showed no mortality. The rVHSV-ΔNV-EGFP had ability to spread and replicate in the internal organs of olive flounder reared at either 15 °C or 20 °C. In the vaccination experiment, the cumulative mortality rates of olive flounder i.m. immunized with 10 3 , 10 4 , and 10 5 PFU of rVHSV-ΔNV-EGFP were 40–50%, 10–30%, and 0–10%, respectively, at 4 weeks after the primary immunization. In the second challenge experiment conducted at 4 weeks after the boost immunization, the cumulative mortality in fish immunized with 10 3 PFU of rVHSV-ΔNV-EGFP was 10–30%. No mortality was recorded in fish immunized with 10 4 and 10 5 PFU of the recombinant virus. While the cumulative mortality of fish in control group was 90–100%. The serum neutralization titers were also proportional to the survival rates of vaccine groups. The present results suggest that the rVHSV-ΔNV-EGFP has a high potential to be used as a live vaccine in olive flounder farms.
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inhibition of viral Hemorrhagic Septicemia virus replication using a short hairpin rna targeting the g gene
Archives of Virology, 2011Co-Authors: Min Sun Kim, Ki Hong KimAbstract:RNA interference (RNAi), a mechanism for post-transcriptional silencing of homologous genes by double-stranded RNA (dsRNA), has emerged as an antiviral strategy in animals. In this study, the epithelioma papulosum cyprini (EPC) cell line, in combination with a fugu-U6-promoter-driven shRNA construct designed against G gene, was used to investigate whether short hairpin RNA (shRNA) could inhibit viral Hemorrhagic Septicemia virus (VHSV) proliferation by sequence-specific RNAi. The results showed that transfection with a shRNA-producing construct (shRNA-VG594) resulted in a sequence-specific knockdown of G gene mRNA in EPC cells. There were no significant differences in IFN-induced Mx1 gene expression among cells transfected with each shRNA vector including shRNA-VG594, -VG594sc (two nucleotides mismatch) and -EGFP (non-specific control), suggesting that knockdown of G gene expression was not due to an IFN response but instead by sequence-specific RNAi. Transfection of EPC cells with shRNA-VG594 conferred resistance to VHSV, and this anti-VHSV effect was not observed when using a two-nucleotide-mismatched shRNA-VG594sc or a shRNA targeting EGFP. Furthermore, shRNA-VG594 expressed in EPC cells did not confer protection against infectious hematopoietic necrosis virus (IHNV), suggesting sequence-specific RNAi-dependent suppression of viral replication.
Paul K Hershberger - One of the best experts on this subject based on the ideXlab platform.
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Optimization of a Plaque Neutralization Test (PNT) to Identify the Exposure History of Pacific Herring to Viral Hemorrhagic Septicemia Virus (VHSV).
Journal of aquatic animal health, 2017Co-Authors: Lucas M. Hart, Maureen K. Purcell, Ashley Mackenzie, Rachel L. Powers, Paul K HershbergerAbstract: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 mostly restored by the addition of exogenous complement from specific-pathogen-free Pacific Herring. Optimal methods included the overnight incubation of VHSV aliquots in serial dilutions (starting at 1:16) of whole test plasma containing endogenous complement. The resulting viral titers were then enumerated using a viral plaque assay in 96-well microplates. Serum neutralizing activity was virus-specific as plasma from viral Hemorrhagic Septicemia (VHS) survivors demonstrated only negligible reactivity to infectious hematopoietic necrosis virus, a closely related rhabdovirus. Among Pacific Herring that survived VHSV exposure, neutralizing activity was detected in the plasma as early as 37 d postexposure and peaked at approximately 64 d postexposure. The onset of neutralizing activity was slightly delayed in fish reared at 7.4°C relative to those in warmer temperatures (9.9°C and 13.1°C); however, neutralizing activity persisted for at least 345 d postexposure in all temperature treatments. It is anticipated that this novel ability to assess VHSV neutralizing activity in Pacific Herring will enable retrospective comparisons between prior VHS infections and year-class recruitment failures. Additionally, the optimized PNT could be employed as a forecasting tool capable of identifying the potential for future VHS epizootics in wild Pacific Herring populations. Received November 7, 2016; accepted January 14, 2017.
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virulence of viral Hemorrhagic Septicemia virus vhsv genotypes ia iva ivb and ivc in five fish species
Diseases of Aquatic Organisms, 2013Co-Authors: Eveline J Emmenegger, Paul K Hershberger, Chang Hoon Moon, Gael KurathAbstract:The susceptibility of yellow perch Perca flavescens, rainbow trout Oncorhynchus mykiss, Chinook salmon O. tshawytscha, koi Cyprinus carpio koi, and Pacific herring Clupea pal- lasii to 4 strains of viral Hemorrhagic Septicemia virus (VHSV) was assessed. Fish were challenged via intraperitoneal injection with high (1 × 10 6 plaque-forming units, PFU) and low (1 × 10 3 PFU) doses of a European strain (genotype Ia), and North American strains from the West coast (geno- type IVa), Great Lakes (genotype IVb), and the East coast (genotype IVc). Pacific herring were exposed to the same VHSV strains, but at a single dose of 5 × 10 3 PFU ml �1 by immersion in static seawater. Overall, yellow perch were the most susceptible, with cumulative percent mortality (CPM) ranging from 84 to 100%, and 30 to 93% in fish injected with high or low doses of virus, respectively. Rainbow trout and Chinook salmon experienced higher mortalities (47 to 98% CPM) after exposure to strain Ia than to the other virus genotypes. Pacific herring were most susceptible to strain IVa with an average CPM of 80% and moderately susceptible (42 to 52% CPM) to the other genotypes. Koi had very low susceptibility (≤5.0% CPM) to all 4 VHSV strains. Fish tested at 7 d post challenge were positive for all virus strains, with yellow perch having the highest prevalence and concentrations of virus, and koi the lowest. While genotype Ia had higher viru- lence in salmonid species, there was little difference in virulence or host-specificity between iso- lates from subtypes IVa, IVb, and IVc.
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Influence of temperature on viral Hemorrhagic Septicemia (Genogroup IVa) in Pacific herring, Clupea pallasii Valenciennes☆
Journal of Experimental Marine Biology and Ecology, 2013Co-Authors: Paul K Hershberger, Maureen K. Purcell, Lucas M. Hart, Rachel L. Thompson, Kyle A. Garver, James R. WintonAbstract:Abstract An inverse relationship between water temperature and susceptibility of Pacific herring ( Clupea pallasii ) to viral Hemorrhagic Septicemia, genogroup IVa (VHS) was indicated by controlled exposure studies where cumulative mortalities, viral shedding rates, and viral persistence in survivors were greatest at the coolest exposure temperatures. Among groups of specific pathogen-free (SPF) Pacific herring maintained at 8, 11, and 15 °C, cumulative mortalities after waterborne exposure to viral Hemorrhagic Septicemia virus (VHSV) were 78%, 40%, and 13%, respectively. The prevalence of survivors with VHSV-positive tissues 25 d post-exposure was 64%, 16%, and 0% (at 8, 11 and 15 °C, respectively) with viral prevalence typically higher in brain tissues than in kidney/spleen tissue pools at each temperature. Similarly, geometric mean viral titers in brain tissues and kidney/spleen tissue pools decreased at higher temperatures, and kidney/spleen titers were generally 10-fold lower than those in brain tissues at each temperature. This inverse relationship between temperature and VHS severity was likely mediated by an enhanced immune response at the warmer temperatures, where a robust type I interferon response was indicated by rapid and significant upregulation of the herring Mx gene. The effect of relatively small temperature differences on the susceptibility of a natural host to VHS provides insights into conditions that preface periodic VHSV epizootics in wild populations throughout the NE Pacific.
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Viral tropism and pathology associated with viral Hemorrhagic Septicemia in larval and juvenile Pacific herring.
Veterinary Microbiology, 2012Co-Authors: Jan Lovy, Paul K Hershberger, T. R. Meyers, Nicole L. Lewis, W. Bennett, Kyle A. GarverAbstract:Abstract Viral Hemorrhagic Septicemia virus (VHSV) genotype IVa causes mass mortality in wild Pacific herring, a species of economic value, in the Northeast Pacific Ocean. Young of the year herring are particularly susceptible and can be carriers of the virus. To understand its pathogenesis, tissue and cellular tropisms of VHSV in larval and juvenile Pacific herring were investigated with immunohistochemistry, transmission electron microscopy, and viral tissue titer. In larval herring, early viral tropism for epithelial tissues (6 d post-exposure) was indicated by foci of epidermal thickening that contained heavy concentrations of virus. This was followed by a cellular tropism for fibroblasts within the fin bases and the dermis, but expanded to cells of the kidney, liver, pancreas, gastrointestinal tract and meninges in the brain. Among wild juvenile herring that underwent a VHS epizootic in the laboratory, the disease was characterized by acute and chronic phases of death. Fish that died during the acute phase had systemic infections in tissues including the submucosa of the gastrointestinal tract, spleen, kidney, liver, and meninges. The disease then transitioned into a chronic phase that was characterized by the appearance of neurological signs including erratic and corkscrew swimming and darkening of the dorsal skin. During the chronic phase viral persistence occurred in nervous tissues including meninges and brain parenchymal cells and in one case in peripheral nerves, while virus was mostly cleared from the other tissues. The results demonstrate the varying VHSV tropisms dependent on the timing of infection and the importance of neural tissues for the persistence and perpetuation of chronic infections in Pacific herring.
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induction of anti viral genes during acute infection with viral Hemorrhagic Septicemia virus vhsv genogroup iva in pacific herring clupea pallasii
Fish & Shellfish Immunology, 2012Co-Authors: J D L Hansen, Paul K Hershberger, Jacob L Gregg, C A Grady, James C. Woodson, Maureen K. PurcellAbstract:Infection with the aquatic rhabdovirus Viral Hemorrhagic Septicemia virus (VHSV) genogroup IVa results in high mortality in Pacific herring (Clupea pallasii) and is hypothesized to be a potential limiting factor for herring recovery. To investigate anti-viral immunity in the Pacific herring, four immune response genes were identified: the myxovirus resistance (Clpa-Mx), a major histocompatibility complex IB (named Clpa-UAA.001), the inducible immunoproteosome subunit 9 (Clpa-PSMB9) and the neutrophil chemotactic factor (Clpa-LECT2). Reverse transcriptase quantitative PCR (RT-qPCR) assays were developed based on these gene sequences to investigate the host immune response to acute VHSV infection following both injection and immersion challenge. Virus levels were measured by both plaque assay and RT-qPCR and peaked at day 6 during the 10-day exposure period for both groups of fish. The interferon stimulated genes (Clpa-Mx, −UAA.001, and −PSMB9) were significantly up-regulated in response to VHSV infection at both 6 and 10 days post-infection in both spleen and fin. Results from this study indicate that Pacific herring mount a robust, early antiviral response in both fin and spleen tissues. The immunological tools developed in this study will be useful for future studies to investigate antiviral immunity in Pacific herring.
James R. Winton - One of the best experts on this subject based on the ideXlab platform.
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Influence of temperature on viral Hemorrhagic Septicemia (Genogroup IVa) in Pacific herring, Clupea pallasii Valenciennes☆
Journal of Experimental Marine Biology and Ecology, 2013Co-Authors: Paul K Hershberger, Maureen K. Purcell, Lucas M. Hart, Rachel L. Thompson, Kyle A. Garver, James R. WintonAbstract:Abstract An inverse relationship between water temperature and susceptibility of Pacific herring ( Clupea pallasii ) to viral Hemorrhagic Septicemia, genogroup IVa (VHS) was indicated by controlled exposure studies where cumulative mortalities, viral shedding rates, and viral persistence in survivors were greatest at the coolest exposure temperatures. Among groups of specific pathogen-free (SPF) Pacific herring maintained at 8, 11, and 15 °C, cumulative mortalities after waterborne exposure to viral Hemorrhagic Septicemia virus (VHSV) were 78%, 40%, and 13%, respectively. The prevalence of survivors with VHSV-positive tissues 25 d post-exposure was 64%, 16%, and 0% (at 8, 11 and 15 °C, respectively) with viral prevalence typically higher in brain tissues than in kidney/spleen tissue pools at each temperature. Similarly, geometric mean viral titers in brain tissues and kidney/spleen tissue pools decreased at higher temperatures, and kidney/spleen titers were generally 10-fold lower than those in brain tissues at each temperature. This inverse relationship between temperature and VHS severity was likely mediated by an enhanced immune response at the warmer temperatures, where a robust type I interferon response was indicated by rapid and significant upregulation of the herring Mx gene. The effect of relatively small temperature differences on the susceptibility of a natural host to VHS provides insights into conditions that preface periodic VHSV epizootics in wild populations throughout the NE Pacific.
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Susceptibility of pacific herring to viral Hemorrhagic Septicemia is influenced by diet
Journal of aquatic animal health, 2012Co-Authors: J. Beaulaurier, C A Grady, James R. Winton, Nathaniel A Bickford, A. L. Gannam, Paul K HershbergerAbstract:Abstract Groups of specific-pathogen-free Pacific herring Clupea pallasii were highly susceptible to infection by viral Hemorrhagic Septicemia virus (VHSV); however, the level of mortality was influenced by diet during the 40–71 d before, during, and after the first exposure to the virus. Cumulative mortality was highest among the herring maintained on an experimental soy-based pellet, intermediate among those maintained on a commercially available fish-meal-based pellet, and lowest among those maintained on a second commercially available fish-meal-based pellet containing β-glucans. Additionally, the herring maintained on the experimental soy-based feed demonstrated less growth than those on the commercially available feeds. The results indicate the importance of standardizing diet during empirical determinations of disease susceptibility and provide insights into the risk factors affecting VHS susceptibility in wild populations. Received August 26, 2011; accepted November 4, 2011
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detection of viral Hemorrhagic Septicemia virus by quantitative reverse transcription polymerase chain reaction from two fish species at two sites in lake superior
Journal of Aquatic Animal Health, 2011Co-Authors: Emily R Cornwell, James R. Winton, Rodman G Getchell, Geoffrey H Groocock, Geofrey E. Eckerlin, Tarin M. Thompson, William N. Batts, Gael Kurath, Rufina N. Casey, Paul R BowserAbstract:Abstract Viral Hemorrhagic Septicemia virus (VHSV) was first detected in the Laurentian Great Lakes in 2005 during a mortality event in the Bay of Quinte, Lake Ontario. Subsequent analysis of archived samples determined that the first known isolation of VHSV in the Laurentian Great Lakes was from a muskellunge Esox masquinongy collected in Lake St. Clair in 2003. By the end of 2008, mortality events and viral isolations had occurred in all of the Laurentian Great Lakes except Lake Superior. In 2009, a focused disease surveillance program was designed to determine whether VHSV was also present in Lake Superior. In this survey, 874 fish from 7 sites along the U.S. shoreline of Lake Superior were collected during June 2009. Collections were focused on nearshore species known to be susceptible to VHSV. All fish were dissected individually by using aseptic techniques and were tested for the presence of VHSV genetic material by use of a quantitative reverse transcription (qRT) polymerase chain reaction (PCR) ta...
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Passive Immunization of Pacific Herring against Viral Hemorrhagic Septicemia
Journal of aquatic animal health, 2011Co-Authors: Paul K Hershberger, Jacob L Gregg, C A Grady, Scott E. Lapatra, James R. WintonAbstract:Abstract The plasma of Pacific herring Clupea pallasii that survived laboratory-induced viral Hemorrhagic Septicemia (VHS) epizootics contained humoral substances that, when injected into naive animals, conferred passive immunity against the disease. Among groups exposed to viral Hemorrhagic Septicemia virus (VHSV), injection of donor plasma from VHS survivors resulted in significantly greater survival (50%) and significantly lower tissue titers (1.5 × 105 plaque-forming units [PFU]/g) than the injection of plasma from VHSV-naive donors (6% survival; 3.7 × 106 PFU/g). Additionally, the magnitude of the protective immune response increased during the postexposure period; plasma that was collected from survivors at 123 d postexposure (931 degree-days) provided greater protection than plasma collected from survivors at 60 d postexposure (409 degree-days). These results provide proof of concept that the VHSV exposure history of Pacific herring populations can be determined post hoc; furthermore, the results c...
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Chronic and persistent viral Hemorrhagic Septicemia virus infections in Pacific herring.
Diseases of aquatic organisms, 2010Co-Authors: Paul K Hershberger, C A Grady, L. Taylor, James R. WintonAbstract:Chronic viral Hemorrhagic Septicemia virus (VHSV) infections were established in a lab- oratory stock of Pacific herring Clupea pallasii held in a large-volume tank supplied with pathogen- free seawater at temperatures ranging from 6.8 to 11.6°C. The infections were characterized by viral persistence for extended periods and near-background levels of host mortality. Infectious virus was recovered from mortalities occurring up to 167 d post-exposure and was detected in normal-appear- ing herring for as long as 224 d following initial challenge. Geometric mean viral titers were gener- ally as high as or higher in brain tissues than in pools of kidney and spleen tissues, with overall preva- lence of infection being higher in the brain. Upon re-exposure to VHSV in a standard laboratory challenge, negligible mortality occurred among groups of herring that were either chronically infected or fully recovered, indicating that survival from chronic manifestations conferred protection against future disease. However, some survivors of chronic VHS infections were capable of replicat- ing virus upon re-exposure. Demonstration of a chronic manifestation of VHSV infection among Pacific herring maintained at ambient seawater temperatures provides insights into the mechanisms by which the virus is maintained among populations of endemic hosts.