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Nielsen SS, Alvarez J, Calistri P, Canali E, Drewe JA, Garin‐Bastuji B, Rojas JLG, Gortázar C, Herskin MS, Michel V, Miranda MÁ, Padalino B, Pasquali P, Roberts HC, Spoolder H, Ståhl K, Velarde A, Viltrop A, Winckler C, Bron J, Olesen NJ, Sindre H, Stone D, Vendramin N, Antoniou S, Kohnle L, Papanikolaou A, Karagianni A, Bicout DJ. Assessment of listing and categorisation of animal diseases within the framework of the Animal Health Law (Regulation (EU) No 2016/429): infectious pancreatic necrosis (IPN). EFSA J 2023; 21:e08028. [PMID: 37313317 PMCID: PMC10258726 DOI: 10.2903/j.efsa.2023.8028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/15/2023] Open
Abstract
Infectious pancreatic necrosis (IPN) was assessed according to the criteria of the Animal Health Law (AHL), in particular, the criteria of Article 7 on disease profile and impacts, Article 5 on its eligibility to be listed, Annex IV for its categorisation according to disease prevention and control rules as in Article 9, and Article 8 for listing animal species related to IPN. The assessment was performed following a methodology previously published. The outcome reported is the median of the probability ranges provided by the experts, which indicates whether each criterion is fulfilled (lower bound ≥ 66%) or not (upper bound ≤ 33%), or whether there is uncertainty about fulfilment. Reasoning points are reported for criteria with an uncertain outcome. According to the assessment here performed, it is uncertain whether IPN can be considered eligible to be listed for Union intervention according to Article 5 of the AHL (50-90% probability). According to the criteria in Annex IV, for the purpose of categorisation related to the level of prevention and control as in Article 9 of the AHL, the AHAW Panel concluded that IPN does not meet the criteria in Section 1 (Category A; 0-1% probability of meeting the criteria) and it is uncertain whether it meets the criteria in Sections 2, 3, 4 and 5 (Categories B, C, D and E; 33-66%, 33-66%, 50-90% and 50-99% probability of meeting the criteria, respectively). The animal species to be listed for IPN according to Article 8 criteria are provided.
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Maj-Paluch J, Wasiak M, Bocian Ł, Reichert M. Comparison of Selected Immune Parameters in a Single Infection and Co-Infection with Infectious Pancreatic Necrosis Virus with Other Viruses in Rainbow Trout. Pathogens 2022; 11:658. [PMID: 35745512 PMCID: PMC9231359 DOI: 10.3390/pathogens11060658] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 06/06/2022] [Accepted: 06/06/2022] [Indexed: 02/05/2023] Open
Abstract
Infectious pancreatic necrosis virus (IPNV) often occurs in an aquatic environment in co-infection with other viruses. In this study, we wanted to investigate the effect of this virus on the course of co-infection with other viruses in rainbow trout. For co-infection we used viral hemorrhagic septicemia virus (VHSV), infectious hematopoietic necrosis virus (IHNV) and salmonid alphavirus (SAV) field strains and infected rainbow trout divided into eight groups; I; IPNV, II; IHNV, III; VHSV, I; SAV, V; IPNV+IHNV, VI; IPNV+VHSV, VII; IPNV+SAV, and the control group. We assessed apoptosis in white blood cells and used a real time RT-PCR to analyze RNA obtained from the internal organs of the fish. During single infection and co-infection the level of expression of immune genes such as interferon and toll-like receptor 3 (TLR-3) was assessed. The highest mortality during the experiment was observed in group III infected by VHSV. The average percentage of apoptotic cells was higher in groups without co-infection, especially in groups II and III. Interferon expression was higher in singly infected groups, the highest being in the heart in group III, while expression of the TLR-3 gene was generally raised in all tested organs in all groups. We found that co-infection with IPNV had a positive impact on the course of infection with the viruses listed because it lowered mortality, reduced apoptosis in co-infected cells, and positively affected fish health.
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Affiliation(s)
- Joanna Maj-Paluch
- Department of Fish Diseases, National Veterinary Research Institute, 57 Partyzantow Avenue, 24-100 Pulawy, Poland;
| | - Magdalena Wasiak
- Department of Pathology, National Veterinary Research Institute, 57 Partyzantow Avenue, 24-100 Pulawy, Poland;
| | - Łukasz Bocian
- Department of Epidemiology and Risk Assessment, National Veterinary Research Institute, 57 Partyzantow Avenue, 24-100 Pulawy, Poland;
| | - Michał Reichert
- Department of Fish Diseases, National Veterinary Research Institute, 57 Partyzantow Avenue, 24-100 Pulawy, Poland;
- Department of Pathology, National Veterinary Research Institute, 57 Partyzantow Avenue, 24-100 Pulawy, Poland;
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Chen Y, Hua X, Ren X, Duan K, Gao S, Sun J, Feng Y, Zhou Y, Guan X, Li D, Wang N, Li J, Yang J, Xia D, Shi W, Liu M. Oral immunization with recombinant Lactobacillus casei displayed AHA1-CK6 and VP2 induces protection against infectious pancreatic necrosis in rainbow trout (Oncorhynchus mykiss). FISH & SHELLFISH IMMUNOLOGY 2020; 100:18-26. [PMID: 32142871 DOI: 10.1016/j.fsi.2020.03.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/16/2020] [Accepted: 03/02/2020] [Indexed: 06/10/2023]
Abstract
Infectious pancreatic necrosis virus (IPNV) primarily infects larvae and young salmonid with serious economic losses, which causes haemorrhage and putrescence of hepatopancreas. To develop a more effective oral vaccine against IPNV infection, the aeromonas hydrophila adhesion (AHA1) gene was used as a targeting molecule for intestinal epithelial cells. A genetically engineered Lactobacillus casei (pPG-612-AHA1-CK6-VP2/L. casei 393) was constructed to express the AHA1-CK6-VP2 fusion protein. The expression of interest protein was confirmed by western blotting and the immunogenicity of pPG-612-AHA1-CK6-VP2/L. casei 393 was evaluated. And the results showed that more pPG-612-AHA1-CK6-VP2/L. casei 393 were found in the intestinal mucosal surface of the immunized group. The Lactobacillus-derived AHA1-CK6-VP2 fusion protein could induce the production of serum IgM and skin mucus IgT specific for IPNV with neutralizing activity in rainbow trouts. The levels of IL-1β, IL-8 and TNF-α isolated from the lymphocytes stimulated by AHA1-CK6-EGFP produced were significantly higher than EGFP group. For transcription levels of IL-1β, IL-8, CK6, MHC-II, Mx and TNF-1α in the spleen, the result indicated that the adhesion and target chemokine recruit more immune cells to induce cellular immunity. The level of IPNV in the immunized group of pPG-612-AHA1-CK6-VP2/L. casei 393 was significantly lower than that in the control groups. These data indicated that the adhesion and target chemokine could enhance antigen delivery efficiency, which provides a valuable strategy for the development of IPNV recombination Lactobacillus casei oral vaccine in the future.
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Affiliation(s)
- Yaping Chen
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, PR China
| | - Xiaojing Hua
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, PR China
| | - Xuanyu Ren
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, PR China
| | - Kexin Duan
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, PR China
| | - Shuai Gao
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, PR China
| | - Jinhui Sun
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, PR China
| | - Ying Feng
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, PR China
| | - Ying Zhou
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, PR China
| | - Xin Guan
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, PR China
| | - Dechuan Li
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, PR China
| | - Na Wang
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, PR China
| | - Jiahui Li
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, PR China
| | - Jiawei Yang
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, PR China
| | - Dong Xia
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, PR China
| | - Wen Shi
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, PR China.
| | - Min Liu
- College of Animal Science and Technology, Northeast Agricultural University, Harbin, 150030, PR China.
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Chen J, Toh X, Ong J, Wang Y, Teo XH, Lee B, Wong PS, Khor D, Chong SM, Chee D, Wee A, Wang Y, Ng MK, Tan BH, Huangfu T. Detection and characterization of a novel marine birnavirus isolated from Asian seabass in Singapore. Virol J 2019; 16:71. [PMID: 31138237 PMCID: PMC6537170 DOI: 10.1186/s12985-019-1174-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2019] [Accepted: 05/03/2019] [Indexed: 11/11/2022] Open
Abstract
Background Lates calcarifer, known as seabass in Asia and barramundi in Australia, is a widely farmed species internationally and in Southeast Asia and any disease outbreak will have a great economic impact on the aquaculture industry. Through disease investigation of Asian seabass from a coastal fish farm in 2015 in Singapore, a novel birnavirus named Lates calcarifer Birnavirus (LCBV) was detected and we sought to isolate and characterize the virus through molecular and biochemical methods. Methods In order to propagate the novel birnavirus LCBV, the virus was inoculated into the Bluegill Fry (BF-2) cell line and similar clinical signs of disease were reproduced in an experimental fish challenge study using the virus isolate. Virus morphology was visualized using transmission electron microscopy (TEM). Biochemical analysis using chloroform and 5-Bromo-2′-deoxyuridine (BUDR) sensitivity assays were employed to characterize the virus. Next-Generation Sequencing (NGS) was also used to obtain the virus genome for genetic and phylogenetic analyses. Results The LCBV-infected BF-2 cell line showed cytopathic effects such as rounding and granulation of cells, localized cell death and detachment of cells observed at 3 to 5 days’ post-infection. The propagated virus, when injected intra-peritoneally into naïve Asian seabass under experimental conditions, induced lesions similar to fish naturally infected with LCBV. Morphology of LCBV, visualized under TEM, revealed icosahedral particles around 50 nm in diameter. Chloroform and BUDR sensitivity assays confirmed the virus to be a non-enveloped RNA virus. Further genome analysis using NGS identified the virus to be a birnavirus with two genome segments. Phylogenetic analyses revealed that LCBV is more closely related to the Blosnavirus genus than to the Aquabirnavirus genus within the Birnaviridae family. Conclusions These findings revealed the presence of a novel birnavirus that could be linked to the disease observed in the Asian seabass from the coastal fish farms in Singapore. This calls for more studies on disease transmission and enhanced surveillance programs to be carried out to understand pathogenicity and epidemiology of this novel virus. The gene sequences data obtained from the study can also pave way to the development of PCR-based diagnostic test methods that will enable quick and specific identification of the virus in future disease investigations.
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Affiliation(s)
- Jing Chen
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore, 259569, Singapore
| | - Xinyu Toh
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore, 259569, Singapore
| | - Jasmine Ong
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore, 259569, Singapore
| | - Yahui Wang
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore, 259569, Singapore
| | - Xuan-Hui Teo
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore, 259569, Singapore
| | - Bernett Lee
- Singapore Immunology Network, Agency for Science, Technology and Research (A*STAR), 8A Biomedical Grove, Singapore, 138648, Singapore
| | - Pui-San Wong
- DSO National Laboratories, 27 Medical Drive, Singapore, 117510, Singapore
| | - Denyse Khor
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore, 259569, Singapore
| | - Shin-Min Chong
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore, 259569, Singapore
| | - Diana Chee
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore, 259569, Singapore
| | - Alvin Wee
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore, 259569, Singapore
| | - Yifan Wang
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore, 259569, Singapore
| | - Mee-Keun Ng
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore, 259569, Singapore
| | - Boon-Huan Tan
- DSO National Laboratories, 27 Medical Drive, Singapore, 117510, Singapore
| | - Taoqi Huangfu
- Centre for Animal & Veterinary Sciences, Professional and Scientific Services, Animal and Veterinary Service, National Parks Board (NParks), 1 Cluny Road, Singapore, 259569, Singapore.
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Chavan SG, Yagati AK, Mohammadniaei M, Min J, Lee MH. Robust Bioengineered Apoferritin Nanoprobes for Ultrasensitive Detection of Infectious Pancreatic Necrosis Virus. Anal Chem 2019; 91:5841-5849. [PMID: 30938982 DOI: 10.1021/acs.analchem.9b00187] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Infectious pancreatic necrosis virus (IPNV) has been identified as a viral pathogen for many fish diseases that have become a huge hurdle for the growing fishing industry. Thus, in this work, we report a label-free impedance biosensor to quantify IPNV in real fish samples at point-of-care (POC) level. High specificity IPNV sensor with a detection limit of 2.69 TCID50/mL was achieved by conjugating IPNV antibodies to portable Au disk electrode chips using human heavy chain apoferritin (H-AFN) nanoprobes as a binding agent. H-AFN probes were bioengineered through PCR by incorporating pET-28b(+) resulting in 24 subunits of 6 × his-tag and protein-G units on its outer surface to increase the sensitivity of the IPNV detection. The biosensor surface modifications were characterized by differential pulse voltammetry (DPV) and EIS methods for each modification step. The proposed nanoprobe based sensor showed three-fold enhancement in charge transfer resistance toward IPNV detection in comparison with the traditional linker approach when measured in a group of similar virus molecules. The portable sensor exhibited a linear range of 100-10000 TCID50/mL and sensitivity of 5.40 × 10-4 TCID50/mL in real-fish samples. The performance of the proposed IPNV sensor was fully validated using an enzyme-linked immunosorbent assay (ELISA) technique with a sensitivity of 3.02 × 10-4 TCID50/mL. Results from H-AFN nanoprobe based IPNV sensor indicated high selectivity, sensitivity, and stability could be a promising platform for the detection of similar fish viruses and other biological molecules of interest.
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Affiliation(s)
- Sachin Ganpat Chavan
- School of Integrative Engineering , Chung-Ang University , Heuseok-dong , Dongjak-Gu, Seoul 06974 , South Korea
| | - Ajay Kumar Yagati
- School of Integrative Engineering , Chung-Ang University , Heuseok-dong , Dongjak-Gu, Seoul 06974 , South Korea
| | - Mohsen Mohammadniaei
- School of Integrative Engineering , Chung-Ang University , Heuseok-dong , Dongjak-Gu, Seoul 06974 , South Korea
| | - Junhong Min
- School of Integrative Engineering , Chung-Ang University , Heuseok-dong , Dongjak-Gu, Seoul 06974 , South Korea
| | - Min-Ho Lee
- School of Integrative Engineering , Chung-Ang University , Heuseok-dong , Dongjak-Gu, Seoul 06974 , South Korea
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Investigation of nervous necrosis virus (NNV) replication in vitro using RNA in situ hybridization. Virus Res 2018; 260:78-85. [PMID: 30472093 DOI: 10.1016/j.virusres.2018.11.011] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2018] [Revised: 11/15/2018] [Accepted: 11/21/2018] [Indexed: 12/16/2022]
Abstract
Nervous necrosis virus (NNV) belongs to the genus Betanodavirus of family Nodaviridae. Its genome consists of two RNA segments, RNA1 and RNA2. Several studies have investigated NNV detection by in situ hybridization (ISH), but these have typically focused on the detection of the RNA2 gene. In this study, we localized both RNA1 and RNA2 NNV segments in viral-infected cells by ISH, using labeled RNA probes (RNA-ISH). Also, immunocytochemistry (ICC) assay was carried out for localization of viral particle by targeting the coat protein. Further, viral quantification assays were performed by quantitative RT-PCR and viral infectivity (TCID50) in SSN-1 cells. Viral segments were observed by RNA-ISH at 6 h post infection (hpi), while NNV particles were detected at 24 hpi by ICC. Use of double labeling RNA-ISH revealed the co-expression of the two viral segments in the same area of the cells, while RNA1 was also detected separately. Comparison of the level of viral genomic segments and viral infectivity revealed significantly more copies of RNA1 at each time points than copies of RNA2 and greater NNV titers. The results suggest that RNA1 might be expressed in the early stages of replication, with RNA2 expressed later. The virions then assemble through initially expressed viral genomic segments. Even though infectious particles displayed very efficient packaging, the RNA1 segment was still over-produced.
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Escobar-Dodero J, Kinsley A, Perez AM, Ibarra R, Tello A, Monti G, Mardones FO. Risk factors for infectious pancreatic necrosis in farmed Chilean Atlantic salmon (Salmo salar L.) from 2010 to 2013. Prev Vet Med 2018; 167:182-189. [PMID: 29891102 DOI: 10.1016/j.prevetmed.2018.04.016] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2017] [Revised: 04/20/2018] [Accepted: 04/24/2018] [Indexed: 10/17/2022]
Abstract
Infectious pancreatic necrosis (IPN) is a widespread and economically devastating fish disease caused by infection with a virus referred to as IPN virus (IPNv). In Chile, the disease is endemic and prevalent in both fresh- and salt-water farms affecting cultured salmonids, mainly Atlantic salmon. Here, we present the results of a retrospective cohort study of Atlantic salmon farms stocked between 2010 and 2013, aimed at quantifying the extent to which certain epidemiological factors influence the time interval between stocking and onset of IPN mortality (time to mortality, ttm) in marine farms. Six variables were retained in a final multivariable Cox proportional hazard model. Compared to the 2010 stocking year, ttm was shorter for salmon stocked in years 2012 (HR = 2.1; p = 0.005) and 2013 (HR = 4.3; p = 0.01). The number of salmon farms within a 10-km radius (HR = 1.07; p = 0.002), positive report of IPN in the previous production cycle (HR = 1.95; p = 0.006), three or more smolt batches (HR = 2.27; p < 0.001), and positive report of mortality attributable to BKD (HR = 2.02; p < 0.001) were also associated with low ttm; conversely, ttm was longer for farms that stocked heavier fish (HR = 0.94; p = 0.001). The results presented here were consistent with early studies of IPN epidemiology in Norway and Scotland. Some of the risk factors identified in this study also influenced the risk for other diseases, such as infectious salmon anemia, suggesting that implementation of selected management practices may help to mitigate the burden of important infectious diseases of salmon in Chile.
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Affiliation(s)
- J Escobar-Dodero
- Escuela de Medicina Veterinaria, Facultad de Ecología y Recursos Naturales, Universidad Andres Bello (UNAB), Republica 440, Santiago 8370251, Chile
| | - A Kinsley
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota Saint Paul, MN, USA
| | - A M Perez
- Department of Veterinary Population Medicine, College of Veterinary Medicine, University of Minnesota Saint Paul, MN, USA
| | - R Ibarra
- SalmonChile, Department of Fish Health, Instituto Tecnológico del Salmón, Av. Juan Soler Manfredini 41, OF 1802, Puerto Montt, Chile
| | - A Tello
- SalmonChile, Department of Fish Health, Instituto Tecnológico del Salmón, Av. Juan Soler Manfredini 41, OF 1802, Puerto Montt, Chile
| | - G Monti
- Instituto de Medicina Preventiva Veterinaria, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, P.O. Box 567, Valdivia, Chile
| | - F O Mardones
- Escuela de Medicina Veterinaria, Facultad de Ecología y Recursos Naturales, Universidad Andres Bello (UNAB), Republica 440, Santiago 8370251, Chile.
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8
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VP2 (PTA motif) encoding DNA vaccine confers protection against lethal challenge with infectious pancreatic necrosis virus (IPNV) in trout. Mol Immunol 2017; 94:61-67. [PMID: 29274924 DOI: 10.1016/j.molimm.2017.12.015] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2017] [Revised: 12/12/2017] [Accepted: 12/18/2017] [Indexed: 12/26/2022]
Abstract
IPNV in Atlantic salmon is represented by various strains with different virulence and immunogenicity linked to various motifs of the VP2 capsid. IPNV variant with P217, T221, A247 (PTA) motif is found to be avirulent in Atlantic salmon, but virulent in rainbow trout, and other salmonid species. This study describes a DNA vaccine delivered intramuscularly encoding the VP2 protein of infectious pancreatic necrosis virus (IPNV) with PTA motif that confers high protection in rainbow trout (Oncorhynchus mykiss). Intramuscular injection of 2, 5 and 10 μg of DNA (pcDNA3.1-VP2) in rainbow trout fry (4-5 g), confers relative protection of 75-83% in the different vaccine groups at 30 days post vaccination (450° days). The VP2 gene is expressed in spleen, kidney, muscle and liver at day 30 post-vaccination (RT-PCR), and IFN-1 and Mx-1 mRNA are upregulated at early time post vaccination, and so also for IgM, IgT, CD4 and CD8 in the head kidney of vaccinated fish compared to controls, 15 and 30 days post vaccination. Significant increase of serum anti-IPNV antibodies was found 30-90 days post-vaccination that was correlated with protection levels. Mortality corresponded with viral VP4 gene expression were significantly decreased in vaccinated and challenged fish. This shows for the first time that a VP2-encoding DNA vaccine delivered intramuscularly elicits a high level of protection alongside with high levels of circulating antibodies in rainbow trout and a lowered viral replication.
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9
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Dopazo CP, Moreno P, Olveira JG, Borrego JJ. The theoretical reliability of PCR-based fish viral diagnostic methods is critically affected when they are applied to fish populations with low prevalence and virus loads. J Appl Microbiol 2017; 124:977-989. [PMID: 28915317 DOI: 10.1111/jam.13586] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2017] [Revised: 09/06/2017] [Accepted: 09/06/2017] [Indexed: 11/30/2022]
Abstract
AIMS The reliability of polymerase chain reaction (PCR) techniques is an important issue in viral diagnosis, and it is even crucial when they must be applied for detection of viruses in asymptomatic carriers. The problems will arise when the aim is to study wild fish populations, where the viral loads and prevalence values are extremely low. We have evaluated several PCR procedures employed by two laboratories for monitoring fish captured in several oceanographic campaigns performed in the Gulf of Cádiz. METHODS AND RESULTS To evaluate the reliability of different diagnostics test used, we have re-analysed fish samples that had been previously subjected to diagnosis for a surveillance of viruses performed in 2010-2011 in wild fish populations. The following parameters were employed: the clinical sensitivity (Ss), the clinical specificity (Sp), the predictive positive value, the predictive negative value, and the positive and negative likelihood ratio (LR+ and LR- ). For viral nervous necrosis virus, a RT-PCR procedure supplemented by nested PCR showed the highest values (100%) for all the parameters. For viral haemorrhagic septicaemia virus, the highest values were provided by RT-PCR supplemented by dot-blot hybridization. In the case of infectious pancreatic necrosis virus, none of the procedures yielded 100% for any parameter. CONCLUSIONS The results obtained for viral prevalence indicate: (i) that the conservation of the samples at -80°C did not affect to the capacity of detection of the virus in the tissues, and (ii) that the reproducibility of the diagnosis can be affected by factors including the staff experience and/or the materials employed. Finally, the use of a combination of procedures in advised to ensure the maximum reliability of the diagnosis when it is applied to asymptomatic fish populations. SIGNIFICANCE AND IMPACT OF THE STUDY This paper describes a strategy of combining diagnostic tests for the surveillance and monitoring of wild fish populations to reduce underestimation of the prevalence of viruses this type of populations.
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Affiliation(s)
- C P Dopazo
- Unidad de Ictiopatología-Patologia Viral, Departamento de Microbiología y Parasitologia, Instituto de Acuicultura, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - P Moreno
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Malaga, Malaga, Spain
| | - J G Olveira
- Unidad de Ictiopatología-Patologia Viral, Departamento de Microbiología y Parasitologia, Instituto de Acuicultura, Universidade de Santiago de Compostela, Santiago de Compostela, Spain
| | - J J Borrego
- Departamento de Microbiología, Facultad de Ciencias, Universidad de Malaga, Malaga, Spain
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Molecular characterisation of infectious pancreatic necrosis viruses isolated from farmed fish in Finland. Arch Virol 2017; 162:3459-3471. [PMID: 28795226 PMCID: PMC5640752 DOI: 10.1007/s00705-017-3525-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Accepted: 07/20/2017] [Indexed: 11/18/2022]
Abstract
Infectious pancreatic necrosis virus (IPNV) has been isolated annually since 1987 from salmonids without clinical signs at coastal fish farms in Finland. In the inland area, viral isolations were rare until 2012, when IPNV was detected at several freshwater fish farms. Between 2013 and 2015, the infection spread and IPNV was continuously isolated from several farms, both inland and on the coast. The aim of this study was to genetically characterise the IPNV isolates collected from Finnish coastal and inland fish farms over the last 15 years, and to detect genetic changes that may have occurred in the virus populations during the study period. The partial VP2 gene sequence from 88 isolates was analysed. In addition, a complete genomic coding sequence was obtained from 11 isolates. Based on the genetic analyses, Finnish IPNV isolates belong to three genogroups: 2, 5 and 6. The genetic properties of the isolates appear to vary between inland farms producing juveniles and food fish farms in the coastal region: the inland farms harboured genogroup 2 isolates, whereas at coastal farms, all three genogroups were detected. Little genetic variation was observed within the Finnish genogroup 2 and 5 isolates, whereas among the genogroup 6 isolates, two subgroups were detected. All isolates studied demonstrated amino acid patterns in the viral VP2 gene previously associated with avirulence. However, increased mortality was detected at some of the farms, indicating that more research is needed to clarify the relationship between the pathogenicity and genetic properties of IPNV isolates from different genogroups.
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11
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A novel "in-feed" delivery platform applied for oral DNA vaccination against IPNV enables high protection in Atlantic salmon (Salmon salar). Vaccine 2016; 35:626-632. [PMID: 28012776 DOI: 10.1016/j.vaccine.2016.12.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Revised: 12/01/2016] [Accepted: 12/02/2016] [Indexed: 11/23/2022]
Abstract
BACKGROUND DNA vaccination has emerged as a promising tool against infectious diseases of farmed fish. Oral delivery allows stress-free administration that is ideal for mass immunization and of paramount importance for infectious pancreatic necrosis (IPN) and other viral disease that affect young salmonids and cause economic losses in aquaculture worldwide. METHODS We describe the development and in vivo assessment of an "in-feed" formulation strategy for oral immunization with liposomal DNA vaccines, by delivering a vaccine construct coding for an immunogenic region of the VP2 capsid protein. A challenge against IPNV was carried out to determine the vaccine efficacy, by comparing the mortality of pre-smolt Atlantic salmons immunized and non-immunized with the oral vaccine. The antibody response (ELISA) and hematological parameters after immunization were examined, as well as the vaccine effect on the growth and internal structures of fry salmons (histological analysis). The vaccine distribution in the experimental tank after oral administration was investigated by HPLC and PCR amplification. RESULTS The oral vaccine induced detectable levels of VP2-specific antibodies and conferred significant protection following IPNV challenge, with relative percent survivals (RPS) of 58.2%, for single dose (1mgpDNA/kgfish⋅d), and 66% for double dose (2mgpDNA/kgfish⋅d). We further provide evidence in favour of the vaccine safety to fish and demonstrated absence of pDNA in the tank water, but presence of vaccine residues in faeces and unconsumed feed sediments (solid wastes). CONCLUSION The delivery platform for liposomal DNA vaccination via feed was successfully proved against IPNV in Atlantic salmon, showing the oral vaccine to be immunogenic and safe for fish, and providing significant protection after oral administration. The "in-feed" technology for oral DNA vaccination holds potential to be applied against IPNV and other pathogens that currently threaten the aquaculture worldwide.
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Eriksson-Kallio AM, Holopainen R, Viljamaa-Dirks S, Vennerström P, Kuukka-Anttila H, Koski P, Gadd T. Infectious pancreatic necrosis virus (IPNV) strain with genetic properties associated with low pathogenicity at Finnish fish farms. DISEASES OF AQUATIC ORGANISMS 2016; 118:21-30. [PMID: 26865232 DOI: 10.3354/dao02951] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Infectious pancreatic necrosis (IPN) is a contagious viral disease of fish that causes economic losses in aquaculture worldwide. In Finland, IPN virus (IPNV) has been isolated since 1987 from adult fish showing no signs of clinical disease at fish farms located in the coastal areas of the Baltic Sea. The inland area of Finland, however, remained free of IPN until 2012, when fish on several rainbow trout farms were diagnosed IPNV-positive. The fish mortalities detected at the farms were low, but clinical signs and histopathological changes typical for IPNV infection were seen in juvenile salmonids. IPNV was isolated at high water temperatures up to 22°C. In 2013 and 2014, IPNV detections continued at inland farms, indicating that infections have spread. The aim of this study was to describe the epidemiology of the outbreak and to characterise the Finnish inland IPNV isolates using histopathological, immunohistochemical and genetic approaches. In order to determine the epidemiological origin of the inland IPNV infections, the partial viral capsid protein (VP2) gene sequences of the inland IPNV isolates were compared with the sequences of the isolates from the coastal farms. Based on the genetic analysis, the inland isolates belong to IPNV Genogroup 2 (Serotype A3/Ab), and the origin of the isolates appears to be one or several coastal fish farms.
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Affiliation(s)
- Anna Maria Eriksson-Kallio
- Finnish Food Safety Authority Evira, Research and Laboratory Department, Production Animal and Wildlife Health Research Unit, Mustialankatu 3, 00790 Helsinki, Finland
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McCowan C, Motha J, Crane MSJ, Moody NJG, Crameri S, Hyatt AD, Bradley T. Isolation of a novel aquatic birnavirus from rainbow trout Oncorhynchus mykiss in Australia. DISEASES OF AQUATIC ORGANISMS 2015; 114:117-125. [PMID: 25993886 DOI: 10.3354/dao02858] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
In November 2010, a rainbow trout (Oncorhynchus mykiss) hatchery in Victoria reported increased mortality rates in diploid and triploid female fingerlings. Live and moribund fish were submitted for laboratory investigation. All fish showed hyperpigmentation of the cranial half of the body. Histological lesions were seen in all areas of skin examined despite the localised nature of the gross lesions. There was irregular hyperplasia and spongiosis, alternating with areas of thinning and architectural disturbance. Occasionally, particularly in superficial layers of epithelium, cells showed large, eosinophilic inclusions that obscured other cellular detail. A small number of fish had necrosis in dermis, subcutis and superficial muscles. Bacteriological culture of skin and gills was negative for all bacterial pathogens, including Flavibacterium columnare, the agent of columnaris disease. Attempts at virus isolation from the skin of affected fish resulted in the development of a cytopathic effect in RTG-2 cell cultures suggestive of the presence of a virus. Negative contrast electron microscopy of cell culture supernatant demonstrated the presence of viral particles with the typical morphology of birnaviruses. Preliminary molecular characterisation identified an aquabirnavirus that differed from both the Tasmanian aquabirnavirus (TABV) and other aquabirnaviruses exotic to Australia. Previous isolates of aquabirnaviruses in Australia and New Zealand have been from healthy fish in a marine environment. This is the first report of an aquabirnavirus isolated from young salmonids at a freshwater hatchery in Australia. The role of the virus in the mortality event on the farm is uncertain as no further deaths attributable to this virus have occurred in the 4 yr since its initial discovery. The virus has been provisionally named Victorian trout aquabirnavirus (VTAB).
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Affiliation(s)
- Christina McCowan
- Victorian Department of Economic Development, Jobs, Transport and Resources, Agriculture Productivity Division, 5 Ring Road, Bundoora, Victoria 3083, Australia
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Nácher-Vázquez M, Ballesteros N, Canales Á, Rodríguez Saint-Jean S, Pérez-Prieto SI, Prieto A, Aznar R, López P. Dextrans produced by lactic acid bacteria exhibit antiviral and immunomodulatory activity against salmonid viruses. Carbohydr Polym 2015; 124:292-301. [PMID: 25839823 DOI: 10.1016/j.carbpol.2015.02.020] [Citation(s) in RCA: 71] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 02/01/2015] [Accepted: 02/06/2015] [Indexed: 11/24/2022]
Abstract
Viral infections in the aquaculture of salmonids can lead to high mortality and substantial economic losses. Thus, there is industrial interest in new molecules active against these viruses. Here we describe the production, purification, and the physicochemical and structural characterization of high molecular weight dextrans synthesized by Lactobacillus sakei MN1 and Leuconostoc mesenteroides RTF10. The purified dextrans, and commercial dextrans with molecular weights ranging from 10 to 2000kDa, were assayed in infected BF-2 and EPC fish cell-line monolayers for antiviral activity. Only T2000 and dextrans from MN1 and RTF10 had significant antiviral activity. This was similar to results obtained against infectious pancreatic necrosis virus. However the dextran from MN1 showed ten-fold higher activity against hematopoietic necrosis virus than T2000. In vivo assays using the MN1 polymer confirmed the in vitro results and revealed immunomodulatory activity. These results together with the high levels of dextran production (2gL(-1)) by Lb. sakei MN1, indicate the compounds potential utility as an antiviral agent in aquaculture.
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Affiliation(s)
| | - Natalia Ballesteros
- Centro de Investigaciones Biológicas, C.S.I.C., Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Ángeles Canales
- Centro de Investigaciones Biológicas, C.S.I.C., Ramiro de Maeztu 9, 28040 Madrid, Spain
| | | | | | - Alicia Prieto
- Centro de Investigaciones Biológicas, C.S.I.C., Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Rosa Aznar
- Instituto de Agroquímica y Tecnología de los Alimentos, C.S.I.C., Agustín Escardino 7, Paterna, 46980 Valencia, Spain; Departamento de Microbiología y Ecología, Universidad de Valencia, Doctor Moliner 50, Burjassot, 46100 Valencia, Spain
| | - Paloma López
- Centro de Investigaciones Biológicas, C.S.I.C., Ramiro de Maeztu 9, 28040 Madrid, Spain.
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15
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Reyes-Cerpa S, Reyes-López F, Toro-Ascuy D, Montero R, Maisey K, Acuña-Castillo C, Sunyer JO, Parra D, Sandino AM, Imarai M. Induction of anti-inflammatory cytokine expression by IPNV in persistent infection. FISH & SHELLFISH IMMUNOLOGY 2014; 41:172-182. [PMID: 25193394 DOI: 10.1016/j.fsi.2014.08.029] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/02/2014] [Revised: 08/18/2014] [Accepted: 08/25/2014] [Indexed: 06/03/2023]
Abstract
Infectious Pancreatic Necrosis Virus (IPNV) is the agent of a well-characterized acute disease that produces a systemic infection and high mortality in farmed fish species but also persistent infection in surviving fish after outbreaks. Because viral persistence of susceptible mammal hosts appears to be associated with the modulation of anti-inflammatory cytokine expression, in this study we examined the expression levels of key pro- and anti-inflammatory cytokines in kidney and spleen of trout, as well as humoral immune response (IgM and IgT) during experimental persistent viral infection and in the acute phase of infection as a comparison. IPNV infection in rainbow trout resulted in a distinct profile of cytokine expression depending on the type of infection, acute or persistent. Levels of early pro-inflammatory cytokines, IL-1β and IL-8, did not increase in the head kidney of the fish with persistent asymptomatic infection but increased in some of the symptomatic infected fish. The antiviral cytokine IFNα was not significantly induced in any of the infected fish groups. The level of expression of the Th1-related cytokine IL-12 was significantly higher in trout with persistent asymptomatic infection than in symptomatic fish. This was also accompanied by an increase in IFNγ. The anti-inflammatory cytokines IL-10 and TGF-β1 had distinct expression profiles. While IL-10 expression increased in all infected fish, TGF-β1 was only up-regulated in fish with persistent infection. All infected fish had significantly lower total IgM levels than the non-infected fish whereas IgT levels did not change. Specific and neutralizing antibodies against IPNV were not observed in acute and persistent infection except in the group of fish with the lowest degree of clinical signs. Interestingly, the lack of humoral immune response could be associated with the high expression of anti-inflammatory cytokines, which might inhibit antibody production. The balance between pro-inflammatory Th1 type cytokines and the regulatory cytokines could explain the high percentage of survival and the resolution of the inflammatory response in the IPNV-infected fish but also the establishment of viral persistence.
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Affiliation(s)
- Sebastián Reyes-Cerpa
- Laboratorio de Inmunología, Centro de Biotecnología Acuícola (CBA), Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile.
| | - Felipe Reyes-López
- Laboratorio de Inmunología, Centro de Biotecnología Acuícola (CBA), Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - Daniela Toro-Ascuy
- Laboratorio de Inmunología, Centro de Biotecnología Acuícola (CBA), Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - Ruth Montero
- Laboratorio de Inmunología, Centro de Biotecnología Acuícola (CBA), Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - Kevin Maisey
- Laboratorio de Inmunología, Centro de Biotecnología Acuícola (CBA), Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - Claudio Acuña-Castillo
- Laboratorio de Inmunoterapia, Centro de Biotecnología Acuícola (CBA), Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - J Oriol Sunyer
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - David Parra
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Ana María Sandino
- Laboratorio de Virología, Centro de Biotecnología Acuícola (CBA), Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile
| | - Mónica Imarai
- Laboratorio de Inmunología, Centro de Biotecnología Acuícola (CBA), Facultad de Química y Biología, Universidad de Santiago de Chile, Santiago, Chile.
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Kung HC, Evensen Ø, Hong JR, Kuo CY, Tso CH, Ngou FH, Lu MW, Wu JL. Interferon regulatory factor-1 (IRF-1) is involved in the induction of phosphatidylserine receptor (PSR) in response to dsRNA virus infection and contributes to apoptotic cell clearance in CHSE-214 cell. Int J Mol Sci 2014; 15:19281-306. [PMID: 25342322 PMCID: PMC4227274 DOI: 10.3390/ijms151019281] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 10/13/2014] [Accepted: 10/14/2014] [Indexed: 11/16/2022] Open
Abstract
The phosphatidylserine receptor (PSR) recognizes a surface marker on apoptotic cells and initiates engulfment. This receptor is important for effective apoptotic cell clearance and maintains normal tissue homeostasis and regulation of the immune response. However, the regulation of PSR expression remains poorly understood. In this study, we determined that interferon regulatory factor-1 (IRF-1) was dramatically upregulated upon viral infection in the fish cell. We observed apoptosis in virus-infected cells and found that both PSR and IRF-1 increased simultaneously. Based on a bioinformatics promoter assay, IRF-1 binding sites were identified in the PSR promoter. Compared to normal viral infection, we found that PSR expression was delayed, viral replication was increased and virus-induced apoptosis was inhibited following IRF-1 suppression with morpholino oligonucleotides. A luciferase assay to analyze promoter activity revealed a decreasing trend after the deletion of the IRF-1 binding site on PSR promoter. The results of this study indicated that infectious pancreatic necrosis virus (IPNV) infection induced both the apoptotic and interferon (IFN) pathways, and IRF-1 was involved in regulating PSR expression to induce anti-viral effects. Therefore, this work suggests that PSR expression in salmonid cells during IPNV infection is activated when IRF-1 binds the PSR promoter. This is the first report to show the potential role of IRF-1 in triggering the induction of apoptotic cell clearance-related genes during viral infection and demonstrates the extensive crosstalk between the apoptotic and innate immune response pathways.
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Affiliation(s)
- Hsin-Chia Kung
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11574, Taiwan.
| | - Øystein Evensen
- Department of Basic Sciences and Aquatic Medicine, Norwegian University of Life Sciences, Oslo 0454, Norway.
| | - Jiann-Ruey Hong
- Institute of Biotechnology, National Cheng-Kung University, Tainan 70101, Taiwan.
| | - Chia-Yu Kuo
- Department of Aquaculture, National Taiwan Ocean University, Keelung 20224, Taiwan.
| | - Chun-Hsi Tso
- Department of Aquaculture, National Taiwan Ocean University, Keelung 20224, Taiwan.
| | - Fang-Huar Ngou
- Department of Aquaculture, National Taiwan Ocean University, Keelung 20224, Taiwan.
| | - Ming-Wei Lu
- Department of Aquaculture, National Taiwan Ocean University, Keelung 20224, Taiwan.
| | - Jen-Leih Wu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11574, Taiwan.
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17
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Surveillance of viruses in wild fish populations in areas around the Gulf of Cadiz (South Atlantic Iberian Peninsula). Appl Environ Microbiol 2014; 80:6560-71. [PMID: 25128341 DOI: 10.1128/aem.02090-14] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
This report describes a viral epidemiological study of wild fish around the Gulf of Cadiz (southwestern Iberian Peninsula) and is focused on infectious pancreatic necrosis virus (IPNV), viral hemorrhagic septicemia virus (VHSV), and viral nervous necrosis virus (VNNV). One fish species (Chelon labrosus) was sampled inside the gulf, at the mouth of the San Pedro River. Another 29 were sampled, in three oceanographic campaigns, at sites around the Bay of Cadiz. The fish were processed individually and subjected to isolation in cell culture and molecular diagnosis. VHSV was not isolated from any species. Thirteen IPNV-type isolates were obtained from barracuda (Sphyraena sphyraena), axillary seabream (Pagellus acarne), common two-banded seabream (Diplodus vulgaris), common pandora (P. erythrinus), Senegal seabream (D. bellottii), and surmullet (Mullus surmuletus). Six VNNV isolates were obtained from axillary seabream, common pandora, black seabream (Spondyliosoma cantharus), red mullet (Mullet barbatus), Lusitanian toadfish (Halobatrachus didactylus), and tub gurnard (Chelidonichtys lucerna). In the river mouth, viruses were detected only after reamplification, obtaining prevalence percentages of IPNV and VNNV (44.4 and 63.0%, respectively) much higher than those observed in the oceanographic campaigns (25.7 and 19.6%, respectively). The opposite results were obtained in the case of VHSV after reamplification: 11.1% in the river mouth and 43.6% in the oceanic locations. Analyzing the results with respect to the proximity of the sampling sites to the coast, an anthropogenic influence on wild fish is suggested and discussed. The type of viruses and the presence of natural reassortants are also discussed.
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18
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Ballesteros NA, Rodriguez Saint-Jean S, Perez-Prieto SI. Food pellets as an effective delivery method for a DNA vaccine against infectious pancreatic necrosis virus in rainbow trout (Oncorhynchus mykiss, Walbaum). FISH & SHELLFISH IMMUNOLOGY 2014; 37:220-228. [PMID: 24561129 DOI: 10.1016/j.fsi.2014.02.003] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2013] [Revised: 02/07/2014] [Accepted: 02/09/2014] [Indexed: 06/03/2023]
Abstract
A DNA vaccine based on the VP2 gene of infectious pancreatic necrosis virus (IPNV) was incorporated into feed to evaluate the effectiveness of this oral delivery method in rainbow trout. Lyophilized alginate-plasmid complexes were added to feed dissolved in water and the mixture was then lyophilized again. We compared rainbow trout that were fed for 3 consecutive days with vaccine pellets with fish that received the empty plasmid or a commercial pellet. VP2 gene expression could be detected in tissues of different organs in the rainbow trout that received the pcDNA-VP2 coated feed (kidney, spleen, gut and gill) throughout the 15 day time-course of the experiments. This pcDNA-VP2 vaccine clearly induced an innate and specific immune-response, significantly up-regulating IFN-1, IFN-γ, Mx-1, IL8, IL12, IgM and IgT expression. Strong protection, with relative survival rates of 78%-85.9% were recorded in the vaccinated trout, which produced detectable levels of anti-IPNV neutralizing antibodies during 90 days at least. Indeed, IPNV replication was significantly down-regulated in the vaccinated fish 45 days pi.
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Affiliation(s)
- Natalia A Ballesteros
- Dept. Microbiología Molecular y Biología de las infecciones, Centro de Investigaciones Biológicas (CSIC), C/Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Sylvia Rodriguez Saint-Jean
- Dept. Microbiología Molecular y Biología de las infecciones, Centro de Investigaciones Biológicas (CSIC), C/Ramiro de Maeztu 9, 28040 Madrid, Spain
| | - Sara I Perez-Prieto
- Dept. Microbiología Molecular y Biología de las infecciones, Centro de Investigaciones Biológicas (CSIC), C/Ramiro de Maeztu 9, 28040 Madrid, Spain.
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Salgado-Miranda C, Rojas-Anaya E, García-Espinosa G, Loza-Rubio E. Molecular characterization of the VP2 gene of infectious pancreatic necrosis virus (IPNV) isolates from Mexico. JOURNAL OF AQUATIC ANIMAL HEALTH 2014; 26:43-51. [PMID: 24689957 DOI: 10.1080/08997659.2013.860060] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Infectious pancreatic necrosis virus (IPNV) is one of the most important viruses in the Pacific salmon Oncorhynchus spp., Atlantic Salmon Salmo salar, and Rainbow Trout O. mykiss industry. This virus has been shown to produce high mortality among salmonid fry and juveniles, and survivors might become carriers. Since 2000, IPNV has affected Mexican Rainbow Trout culture, resulting in considerable economic losses. In the current study, molecular characterization of the VP2 gene of a number of Mexican IPNV isolates was done and the virus's phylogenetic relationships to IPNV reference strains were investigated. The phylogenetic analysis indicated that Mexican IPNV isolates are closely related to strains from the United States and Canada and that all Mexican IPNV isolates belong to genogroup 1. Furthermore, low genetic diversity was found between the Mexican isolates (identity, 95.8-99.8% nucleotides and 95.8-99.6% amino acids). The result of the analysis of the amino acid residues found at positions 217, 221, and 247 (alanine, threonine, and glutamic acid, respectively) could be associated with virulence, although the expression of virulence factors is more complex and may be influenced by the agent and host factors. The high percentage of identity among the VP2 genes from geographically distant IPNV isolates and the evidence of wide distribution in the country might have been facilitated by carrier trout. This hypothesis is supported by the identification of the amino acid threonine at position 221 in all Mexican isolates, a factor related to the carrier state for IPNV, as reported by other studies.
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Affiliation(s)
- Celene Salgado-Miranda
- a Facultad de Medicina Veterinaria y Zootecnia , Universidad Nacional Autónoma de México , México , D.F. , 04510 , Mexico
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20
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Hirayama T, Imajoh M, Oshima SI. Quantification of Aquabirnaviruses Isolated from Different Host Species by Real-Time RT-PCR. Microbiol Immunol 2013; 49:361-71. [PMID: 15840962 DOI: 10.1111/j.1348-0421.2005.tb03741.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Real-time reverse transcription (RT)-PCR was developed to detect and quantify successfully aquatic birnaviruses (ABVs) from fish tissue and seawater samples. This method detected marine birnavirus (MABV) RNA in several samples, and the detection was specific for ABVs. Monitoring the MABV strain Y-6 RNA quantification by real-time RT-PCR showed replication kinetics of MABV after experimental infection in vitro. We found the quantity of ABVs isolated from different host species by using combined virus absorption in cell culture and real-time RT-PCR. Although all specimens showed no symptoms of viral infection, ABVs were detected regardless of host species. In conclusion, real-time RT-PCR was shown to be a sensitive and reliable tool to detect and quantify ABVs in cultured fish. This method is useful procedure to show details of horizontal or vertical infections by ABVs in the breeding water of aquatic animals.
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Affiliation(s)
- Takeshi Hirayama
- Laboratory of Cell Structure and Function, Division of Marine Bioresource Science, Graduate School of Kuroshio Science, Kochi University, Nankoku, Kochi 783-8502, Japan
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21
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Salgado-Miranda C, Loza-Rubio E, Rojas-Anaya E, García-Espinosa G. Viral vaccines for bony fish: past, present and future. Expert Rev Vaccines 2013; 12:567-78. [PMID: 23659303 DOI: 10.1586/erv.13.38] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Since 1970, aquaculture production has grown. In 2010, it had an annual average rate of 6.3% with 59.9 million tons of product and soon could exceed capture fisheries as a source of fishery products. However, the occurrence of viral diseases continues to be a significant limiting factor and its control is important for the development of this sector. In aquaculture farms, fish are reared under intensive culture conditions, and the use of viral vaccines has enabled an increase in production. Several types of vaccines and strategies of vaccination have been developed; however, this approach has not reached the expected goals in the most susceptible stage (fingerlings). Currently, there are inactivated and recombinant commercial vaccines, mainly for salmonids and cyprinids. In addition, updated genomic and proteomic technology has expedited the research and expansion of new vaccine models, such as those comprised of subunits or DNA. The objective of this review is to cover the various types of viral vaccines that have been developed and are available for bony fishes, as well as the advantages and challenges that DNA vaccines present for massive administration in a growing aquaculture, possible risks for the environment, the controversy regarding genetically modified organisms and possible acceptance by consumers.
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Affiliation(s)
- Celene Salgado-Miranda
- Centro de Investigación y Estudios Avanzados en Salud Animal, Facultad de Medicina Veterinaria y Zootecnia, Universidad Autónoma del Estado de Mexico, Toluca, 50200, Mexico.
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22
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Dadar M, Peyghan R, Memari HR, Shapouri MRSA, Hasanzadeh R, Goudarzi LM, Vakharia VN. Sequence analysis of infectious pancreatic necrosis virus isolated from Iranian reared rainbow trout (Oncorhynchus mykiss) in 2012. Virus Genes 2013; 47:574-8. [PMID: 24048887 DOI: 10.1007/s11262-013-0981-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2013] [Accepted: 09/10/2013] [Indexed: 11/30/2022]
Abstract
Infectious pancreatic necrosis virus (IPNV) is the causal agent of a highly contagious disease that affects many species of fish and shellfish. This virus causes economically significant diseases of farmed rainbow trout, Oncorhynchus mykiss (Walbaum), in Iran, which is often associated with the transmission of pathogens from European resources. In this study, moribund rainbow trout fry samples were collected during an outbreak of IPNV in three different fish farms in north and west provinces of Iran in 2012; and we investigated the full genome sequence of Iranian IPNV and compared it with previously identified IPNV sequences. The sequences of different structural and nonstructural-protein genes were compared to those of other aquatic birnaviruses sequenced to date. Our results show that the Iranian isolate falls within genogroup 5, serotype A2 strain SP, having 99% identity with the strain 1146 from Spain. These results suggest that the Iranian isolate may have originated from Europe.
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Affiliation(s)
- Maryam Dadar
- Department of Aquatic Health, College of Veterinary Medicine, Shahid Chamran University, Ahvaz, Iran,
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Ahmadi N, Oryan A, Akhlaghi M, Hosseini A. Tissue distribution of infectious pancreatic necrosis virus serotype Sp in naturally infected cultured rainbow trout, Oncorhynchus mykiss (Walbaum): an immunohistochemical and nested-PCR study. JOURNAL OF FISH DISEASES 2013; 36:629-637. [PMID: 23293847 DOI: 10.1111/jfd.12072] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Revised: 10/29/2012] [Accepted: 10/30/2012] [Indexed: 06/01/2023]
Abstract
This study investigates the occurrence and distribution pattern of infectious pancreatic necrosis virus (IPNV) within the pancreas, liver, kidney and spleen of naturally infected cultured rainbow trout, Oncorhynchus mykiss (Walbaum), using immunohistochemistry (IHC). A nested PCR was also employed to confirm the presence of the virus in the pooled tissues of the specimens. All the examined tissues except spleen were immunohistochemically positive for IPNV, but staining intensity and distribution pattern varied. The kidney tubules had the most intense and widespread staining by IHC, indicating a specific tissue tropism at least for this particular serotype. The nucleotide sequence had the greatest identity with the Sp serotype confirming the presence of the nucleic acid of IPNV in the pooled tissues. Based on the present findings, it could be concluded that the absence of lesions consistent with infectious pancreatic necrosis (IPN) disease in the H&E-stained sections cannot rule out the presence of the IPNV, and the use of an alternative rapid confirmatory method such as IHC with formalin-fixed, paraffin-embedded tissue sections is helpful for the final diagnosis of IPN in rainbow trout.
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Affiliation(s)
- N Ahmadi
- Department of Pathobiology, School of Veterinary Medicine, Shiraz University, Shiraz, Iran.
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Cano I, Valverde EJ, Garcia-Rosado E, Alonso MC, Lopez-Jimena B, Ortiz-Delgado JB, Borrego JJ, Sarasquete C, Castro D. Transmission of lymphocystis disease virus to cultured gilthead seabream, Sparus aurata L., larvae. JOURNAL OF FISH DISEASES 2013; 36:569-576. [PMID: 23163555 DOI: 10.1111/jfd.12011] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2012] [Revised: 08/23/2012] [Accepted: 08/24/2012] [Indexed: 06/01/2023]
Abstract
The transmission of lymphocystis disease virus (LCDV) to gilthead seabream, Sparus aurata L., larvae was investigated using fertilized eggs from a farm with previous reports of lymphocystis disease. LCDV genome was detected by PCR-hybridization in blood samples from 17.5% of the asymptomatic gilthead seabream broodstock analysed. Using the same methodology, eggs spawned from these animals were LCDV positive, as well as larvae hatched from them. The presence of infective viral particles was confirmed by cytopathic effects development on SAF-1 cells. Whole-mount in situ hybridization (ISH) and immunohistochemistry (IHC) showed the presence of LCDV in the epidermis of larvae hatched from LCDV-positive eggs. When fertilized eggs were disinfected with iodine, no viral DNA was detected either in eggs (analysed by PCR-hybridization) or in larvae (PCR-hybridization and ISH). These results suggest the vertical transmission of LCDV, the virus being transmitted on the egg surface. Larvae hatched from disinfected eggs remain LCDV negative during the endotrophic phase, as showed by PCR-hybridization, ISH and IHC. After feeding on LCDV-positive rotifers, viral antigens were observed in the digestive tract, which suggests that viral entry could be achieved via the alimentary canal, and that rotifers can act as a vector in LCDV transmission to gilthead seabream larvae.
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Affiliation(s)
- I Cano
- Instituto de Ciencias Marinas de Andalucía-ICMAN, CSIC, Puerto Real, Cádiz, Spain.
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Alvarez-Torres D, Garcia-Rosado E, Fernandez-Trujillo MA, Bejar J, Alvarez MC, Borrego JJ, Alonso MC. Antiviral specificity of the Solea senegalensis Mx protein constitutively expressed in CHSE-214 cells. MARINE BIOTECHNOLOGY (NEW YORK, N.Y.) 2013; 15:125-132. [PMID: 22886190 DOI: 10.1007/s10126-012-9478-8] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2012] [Accepted: 07/14/2012] [Indexed: 06/01/2023]
Abstract
Interferons play a key role in fish resistance to viral infections by inducing the expression of antiviral proteins, such as Mx. The aim of the present study was to test the antiviral activity of the Senegalese sole Mx protein (SsMx) against RNA and DNA viruses pathogenic to fish, i.e. the infectious pancreatic necrosis virus (IPNV, dsRNA), the viral haemorrhagic septicaemia virus (VHSV, ssRNA), and the European sheatfish virus (ESV, dsDNA), using a CHSE-214 cell clone expressing this antiviral protein. A strong inhibition of IPNV and VHSV replication was recorded in SsMx-expressing cells, as has been shown by the virus yield reduction and the decrease in the synthesis of the viral RNA encoding the polyprotein (for IPNV) and the nucleoprotein (for VHSV). The titres of these viruses replicating on SsMx-expressing cells were 100 times lower than those recorded on non-transfected cells. In contrast, SsMx did not inhibit ESV replication since no significant differences were observed regarding the virus yield or the major capsid protein gene transcription in transfected and non-transfected cells.
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Affiliation(s)
- Daniel Alvarez-Torres
- Department of Microbiology, Faculty of Sciences, University of Malaga, Campus Teatinos, 29071 Malaga, Spain
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Bahar MW, Sarin LP, Graham SC, Pang J, Bamford DH, Stuart DI, Grimes JM. Structure of a VP1-VP3 complex suggests how birnaviruses package the VP1 polymerase. J Virol 2013; 87:3229-36. [PMID: 23283942 PMCID: PMC3592137 DOI: 10.1128/jvi.02939-12] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2012] [Accepted: 12/27/2012] [Indexed: 11/20/2022] Open
Abstract
Infectious pancreatic necrosis virus (IPNV), a member of the family Birnaviridae, infects young salmon, with a severe impact on the commercial sea farming industry. Of the five mature proteins encoded by the IPNV genome, the multifunctional VP3 has an essential role in morphogenesis; interacting with the capsid protein VP2, the viral double-stranded RNA (dsRNA) genome and the RNA-dependent RNA polymerase VP1. Here we investigate one of these VP3 functions and present the crystal structure of the C-terminal 12 residues of VP3 bound to the VP1 polymerase. This interaction, visualized for the first time, reveals the precise molecular determinants used by VP3 to bind the polymerase. Competition binding studies confirm that this region of VP3 is necessary and sufficient for VP1 binding, while biochemical experiments show that VP3 attachment has no effect on polymerase activity. These results indicate how VP3 recruits the polymerase into birnavirus capsids during morphogenesis.
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Affiliation(s)
- Mohammad W. Bahar
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - L. Peter Sarin
- Institute of Biotechnology and Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - Stephen C. Graham
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Cambridge Institute for Medical Research and Department of Clinical Biochemistry, University of Cambridge, Addenbrooke's Hospital, Cambridge, United Kingdom
| | - Jances Pang
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Dennis H. Bamford
- Institute of Biotechnology and Department of Biosciences, University of Helsinki, Helsinki, Finland
| | - David I. Stuart
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Science Division, Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, United Kingdom
| | - Jonathan M. Grimes
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- Science Division, Diamond Light Source Ltd., Diamond House, Harwell Science and Innovation Campus, Didcot, Oxfordshire, United Kingdom
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Lima PC, Harris JO, Cook M. Exploring RNAi as a therapeutic strategy for controlling disease in aquaculture. FISH & SHELLFISH IMMUNOLOGY 2013; 34:729-743. [PMID: 23276883 DOI: 10.1016/j.fsi.2012.11.037] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2012] [Revised: 11/21/2012] [Accepted: 11/30/2012] [Indexed: 06/01/2023]
Abstract
Aquatic animal diseases are one of the most significant constraints to the development and management of aquaculture worldwide. As a result, measures to combat diseases of fish and shellfish have assumed a high priority in many aquaculture-producing countries. RNA interference (RNAi), a natural mechanism for post-transcriptional silencing of homologous genes by double-stranded RNA (dsRNA), has emerged as a powerful tool not only to investigate the function of specific genes, but also to suppress infection or replication of many pathogens that cause severe economic losses in aquaculture. However, despite the enormous potential as a novel therapeutical approach, many obstacles must still be overcome before RNAi therapy finds practical application in aquaculture, largely due to the potential for off-target effects and the difficulties in providing safe and effective delivery of RNAi molecules in vivo. In the present review, we discuss the current knowledge of RNAi as an experimental tool, as well as the concerns and challenges ahead for the application of such technology to combat infectious disease of farmed aquatic animals.
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Affiliation(s)
- Paula C Lima
- CSIRO Marine and Atmospheric Research, C/-CSIRO Livestock Industries, QBP, 306 Carmody Rd, St Lucia, QLD 4067, Australia
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Ballesteros NA, Saint-Jean SSR, Perez-Prieto SI, Coll JM. Trout oral VP2 DNA vaccination mimics transcriptional responses occurring after infection with infectious pancreatic necrosis virus (IPNV). FISH & SHELLFISH IMMUNOLOGY 2012; 33:1249-57. [PMID: 23041507 DOI: 10.1016/j.fsi.2012.09.004] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2012] [Revised: 08/26/2012] [Accepted: 09/04/2012] [Indexed: 05/12/2023]
Abstract
Time-course and organ transcriptional response profiles in rainbow trout Oncorhynchus mykiss were studied after oral DNA-vaccination with the VP2 gene of the infectious pancreatic necrosis virus (IPNV) encapsulated in alginates. The profiles were also compared with those obtained after infection with IPNV. A group of immune-related genes (stat1, ifn1, ifng, mx1, mx3, il8, il10, il11, il12b, tnf2, mhc1uda, igm and igt) previously selected from microarray analysis of successful oral vaccination of rainbow trout, were used for the RTqPCR analysis. The results showed that oral VP2-vaccination qualitatively mimicked both the time-course and organ (head kidney, spleen, intestine, pyloric ceca, and thymus) transcriptional profiles obtained after IPNV-infection. Highest transcriptional differential expression levels after oral vaccination were obtained in thymus, suggesting those might be important for subsequent protection against IPNV challenges. However, transcriptional differential expression levels of most of the genes mentioned above were lower in VP2-vaccinated than in IPNV-infected trout, except for ifn1 which were similar. Together all the results suggest that the oral-alginate VP2-vaccination procedure immunizes trout against IPNV in a similar way as IPNV-infection does while there is still room for additional improvements in the oral vaccination procedure. Some of the genes described here could be used as markers to further optimize the oral immunization method.
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Affiliation(s)
- Natalia A Ballesteros
- Centro de Investigaciones Biológicas-CSIC, Dpto. Microbiología Molecular y Biología de la Infección, c/Ramiro de Maeztu 9, 28040 Madrid, Spain
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van Beurden SJ, Engelsma MY, Roozenburg I, Voorbergen-Laarman MA, van Tulden PW, Kerkhoff S, van Nieuwstadt AP, Davidse A, Haenen OLM. Viral diseases of wild and farmed European eel Anguilla anguilla with particular reference to the Netherlands. DISEASES OF AQUATIC ORGANISMS 2012; 101:69-86. [PMID: 23047193 DOI: 10.3354/dao02501] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
Diseases are an important cause of losses and decreased production rates in freshwater eel farming, and have been suggested to play a contributory role in the worldwide decline in wild freshwater eel stocks. Three commonly detected pathogenic viruses of European eel Anguilla anguilla are the aquabirnavirus eel virus European (EVE), the rhabdovirus eel virus European X (EVEX), and the alloherpesvirus anguillid herpesvirus 1 (AngHV1). In general, all 3 viruses cause a nonspecific haemorrhagic disease with increased mortality rates. This review provides an overview of the current knowledge on the aetiology, prevalence, clinical signs and gross pathology of these 3 viruses. Reported experimental infections showed the temperature dependency and potential pathogenicity of these viruses for eels and other fish species. In addition to the published literature, an overview of the isolation of pathogenic viruses from wild and farmed A. anguilla in the Netherlands during the past 2 decades is given. A total of 249 wild A. anguilla, 39 batches of glass eels intended for farming purposes, and 239 batches of farmed European eels were necropsied and examined virologically. AngHV1 was isolated from wild yellow and silver A. anguilla from the Netherlands from 1998 until the present, while EVEX was only found sporadically, and EVE was never isolated. In farmed A. anguilla AngHV1 was also the most commonly isolated virus, followed by EVE and EVEX.
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Affiliation(s)
- Steven J van Beurden
- Central Veterinary Institute, Wageningen UR, PO Box 65, 8200 AB Lelystad, The Netherlands
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Ørpetveit I, Küntziger T, Sindre H, Rimstad E, Dannevig BH. Infectious pancreatic necrosis virus (IPNV) from salmonid fish enters, but does not replicate in, mammalian cells. Virol J 2012; 9:228. [PMID: 23039240 PMCID: PMC3566970 DOI: 10.1186/1743-422x-9-228] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Accepted: 10/03/2012] [Indexed: 11/19/2022] Open
Abstract
Background The aquatic birnavirus infectious pancreatic necrosis virus (IPNV) causes infectious pancreatic necrosis (IPN), a severe disease in farmed salmonid fish. IPNV has a very broad host range and infects many different species of fish as well as molluscs and crustaceans. Investigation of the host reservoir of a virus may reveal important molecular mechanisms governing the infection processes such as receptors and entry mechanisms. In the present work we have studied whether IPNV is able to infect cells with different mammalian origin. Results IPNV bound in a specific manner to a membrane protein of the rabbit kidney cell line RK-13 as shown by the use of a virus overlay protein binding assay (VOPBA). Six different mammalian cell lines were inoculated with IPNV and incubated in parallels at different temperatures. At 7 days post inoculation (dpi), IPNV was detected by indirect immunofluorescent antibody test (IFAT) in all the cell lines. Confocal microscopy confirmed intracellular presence of the virus. No apparent cytopathic effect (cpe) was observed in any of the cultures, and no viral replication was demonstrated with real-time RT-PCR. Conclusion Our results show that IPNV is able to enter into a wide range of mammalian cells, and virus entry is most likely receptor mediated. We found no indication of IPNV replication in any of the mammalian cell lines tested.
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Affiliation(s)
- Irene Ørpetveit
- Norwegian Veterinary Institute, PO Box 0750, Sentrum, Oslo, NO 0106, Norway.
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Ballesteros NA, Saint-Jean SSR, Encinas PA, Perez-Prieto SI, Coll JM. Oral immunization of rainbow trout to infectious pancreatic necrosis virus (Ipnv) induces different immune gene expression profiles in head kidney and pyloric ceca. FISH & SHELLFISH IMMUNOLOGY 2012; 33:174-185. [PMID: 22521628 DOI: 10.1016/j.fsi.2012.03.016] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/25/2012] [Revised: 03/14/2012] [Accepted: 03/15/2012] [Indexed: 05/31/2023]
Abstract
Induction of neutralizing antibodies and protection by oral vaccination with DNA-alginates of rainbow trout Oncorhynchus mykiss against infectious pancreatic necrosis virus (IPNV) was recently reported. Because orally induced immune response transcript gene profiles had not been described yet neither in fish, nor after IPNV vaccination, we studied them in head kidney (an immune response internal organ) and a vaccine entry tissue (pyloric ceca). By using an oligo microarray enriched in immune-related genes validated by RTqPCR, the number of increased transcripts in head kidney was higher than in pyloric ceca while the number of decreased transcripts was higher in pyloric ceca than in head kidney. Confirming previous reports on intramuscular DNA vaccination or viral infection, mx genes increased their transcription in head kidney. Other transcript responses such as those corresponding to interferons, their receptors and induced proteins (n=91 genes), VHSV-induced genes (n=25), macrophage-related genes (n=125), complement component genes (n=176), toll-like receptors (n=31), tumor necrosis factors (n=32), chemokines and their receptors (n=121), interleukines and their receptors (n=119), antimicrobial peptides (n=59), and cluster differentiation antigens (n=58) showed a contrasting and often complementary behavior when head kidney and pyloric ceca were compared. For instance, classical complement component transcripts increased in head kidney while only alternative pathway transcripts increased in pyloric ceca, different β-defensins increased in head kidney but remained constant in pyloric ceca. The identification of new gene markers on head kidney/pyloric ceca could be used to follow up and/or to improve immunity during fish oral vaccination.
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Affiliation(s)
- Natalia A Ballesteros
- Centro de Investigaciones Biologicas, CSIC, C/Ramiro de Maeztu 9, 28040 Madrid, Spain
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Calleja F, Godoy MG, Cárcamo JG, Bandín I, Yáñez AJ, Dopazo CP, Kibenge FS, Avendaño-Herrera R. Use of reverse transcription-real time polymerase chain reaction (real time RT-PCR) assays with Universal Probe Library (UPL) probes for the detection and genotyping of infectious pancreatic necrosis virus strains isolated in Chile. J Virol Methods 2012; 183:80-5. [DOI: 10.1016/j.jviromet.2012.03.022] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2011] [Revised: 03/15/2012] [Accepted: 03/21/2012] [Indexed: 11/25/2022]
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Reyes-Cerpa S, Reyes-López FE, Toro-Ascuy D, Ibañez J, Maisey K, Sandino AM, Imarai M. IPNV modulation of pro and anti-inflammatory cytokine expression in Atlantic salmon might help the establishment of infection and persistence. FISH & SHELLFISH IMMUNOLOGY 2012; 32:291-300. [PMID: 22142704 DOI: 10.1016/j.fsi.2011.11.018] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2011] [Revised: 11/15/2011] [Accepted: 11/20/2011] [Indexed: 05/20/2023]
Abstract
IPNV is the agent of a well-characterized acute disease that produces a systemic infection and high mortality in farmed fish species and persistent infection in surviving fish after outbreaks. Because modulation of the host expression of pro and anti-inflammatory cytokines can help establish persistence, in this study, we examined the expression of IL-1β, IL-8, IFNα1 and IL-10 during acute and persistent IPNV infection of Atlantic salmon. Results showed that IPNV infection induces an increase of the IFNα1 and IL-10 mRNA levels in the spleen and head kidney (HK) of fish after acute experimental infection. Levels of the pro-inflammatory cytokines IL-1β and IL-8 did not rise in the spleen although an increase of IL-1β, but not of IL-8, was observed in head kidney. In carrier asymptomatic salmon, cytokine gene expression of IFNα1 in the spleen and IL-10 in head kidney were also significantly higher than expression in non-carrier fish. Interestingly, a decrease of IL-8 expression was also observed. IPNV infection of SHK-1, which is a macrophage-like cell line of salmon, also induced an increase of expression of the anti-inflammatory cytokine IL-10 with no effects on the expression of IL-1β and IL-8. The effects are induced by an unknown mechanism during viral infection because poly I:C and the viral genomic dsRNA showed the opposite effects on cytokine expression in SHK-1 cells. In summary, IPNV always induces up-regulation of the anti-inflammatory cytokine IL-10 in Atlantic salmon. As this is accompanied by a lack of induction of the pro-inflammatory cytokines IL-1β and IL-8, the anti-inflammatory milieu may explain the high frequency, prevalence and persistence of IPNV in salmon. Effects might be part of the viral mechanisms of immune evasion.
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Affiliation(s)
- Sebastián Reyes-Cerpa
- Laboratorio de Inmunología, Centro de Biotecnología Acuícola, Facultad de Química y Biología, Universidad de Santiago de Chile, Chile
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Fridholm H, Everitt E. Virion glycosylation governs integrity and infectivity of infectious pancreatic necrosis virus. JOURNAL OF FISH DISEASES 2011; 34:663-75. [PMID: 21838710 PMCID: PMC7197461 DOI: 10.1111/j.1365-2761.2011.01280.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Revised: 02/09/2011] [Accepted: 03/24/2011] [Indexed: 05/05/2023]
Abstract
The possible importance of the O-linked glycosylation in virion stability and infectivity of infectious pancreatic necrosis virus (IPNV) was analysed. Enzymatic treatment with O-glycosidase of radiolabelled virions under different ionic conditions, to allow for possible alternative exposure of glycosidic enzyme cleavage sites, did not alter the specific infectivity of virions re-isolated after rate-zonal centrifugation in glycerol gradients. As an alternative method to assess the significance of carbohydrates in IPNV integrity, periodate oxidation in the presence of an aldehyde quencher was chosen. Following re-isolation of viruses, a 3-5 (10)log-unit reduction in specific infectivity was revealed and, at higher concentrations, a total disruption or virion aggregation was observed. The loss of infectivity of intact virions was not because of a lack of attachment to cells. Additionally, re-evaluation of reading values from UV-spectra of purified IPNV yielded a specific infectivity of 3 × 10(11) TCID(50)-units mg(-1) of protein and a ratio of 40 virions per TCID(50)-unit in the CHSE-214 cell system.
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Affiliation(s)
- H Fridholm
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PEI, Canada.
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Skjesol A, Skjæveland I, Elnæs M, Timmerhaus G, Fredriksen BN, Jørgensen SM, Krasnov A, Jørgensen JB. IPNV with high and low virulence: host immune responses and viral mutations during infection. Virol J 2011; 8:396. [PMID: 21827718 PMCID: PMC3169513 DOI: 10.1186/1743-422x-8-396] [Citation(s) in RCA: 68] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2011] [Accepted: 08/10/2011] [Indexed: 01/10/2023] Open
Abstract
Background Infectious pancreatic necrosis virus (IPNV) is an aquatic member of the Birnaviridae family that causes widespread disease in salmonids. IPNV is represented by multiple strains with markedly different virulence. Comparison of isolates reveals hyper variable regions (HVR), which are presumably associated with pathogenicity. However little is known about the rates and modes of sequence divergence and molecular mechanisms that determine virulence. Also how the host response may influence IPNV virulence is poorly described. Methods In this study we compared two field isolates of IPNV (NFH-Ar and NFH-El). The sequence changes, replication and mortality were assessed following experimental challenge of Atlantic salmon. Gene expression analyses with qPCR and microarray were applied to examine the immune responses in head kidney. Results Significant differences in mortality were observed between the two isolates, and viral load in the pancreas at 13 days post infection (d p.i.) was more than 4 orders of magnitude greater for NFH-Ar in comparison with NFH-El. Sequence comparison of five viral genes from the IPNV isolates revealed different mutation rates and Ka/Ks ratios. A strong tendency towards non-synonymous mutations was found in the HRV of VP2 and in VP3. All mutations in VP5 produced precocious stop codons. Prior to the challenge, NFH-Ar and NFH-El possessed high and low virulence motifs in VP2, respectively. Nucleotide substitutions were noticed already during passage of viruses in CHSE-214 cells and their accumulation continued in the challenged fish. The sequence changes were notably directed towards low virulence. Co-ordinated activation of anti-viral genes with diverse functions (IFN-a1 and c, sensors - Rig-I, MDA-5, TLR8 and 9, signal transducers - Srk2, MyD88, effectors - Mx, galectin 9, galectin binding protein, antigen presentation - b2-microglobulin) was observed at 13 d p.i. (NFH-Ar) and 29 d p.i. (both isolates). Conclusions Mortality and expression levels of the immune genes were directly related to the rate of viral replication, which was in turn associated with sequences of viral genes. Rapid changes in the viral genome that dramatically reduced virus proliferation might indicate a higher susceptibility to protective mechanism employed by the host. Disease outbreak and mortality depend on a delicate balance between host defence, regulation of signalling cascades and virus genomic properties.
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Affiliation(s)
- Astrid Skjesol
- Norwegian College of Fishery Sciences, University of Tromsø, N- 9037 Tromsø, Norway
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Graham SC, Sarin LP, Bahar MW, Myers RA, Stuart DI, Bamford DH, Grimes JM. The N-terminus of the RNA polymerase from infectious pancreatic necrosis virus is the determinant of genome attachment. PLoS Pathog 2011; 7:e1002085. [PMID: 21731487 PMCID: PMC3121795 DOI: 10.1371/journal.ppat.1002085] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2010] [Accepted: 04/11/2011] [Indexed: 12/30/2022] Open
Abstract
The RNA-dependent RNA polymerase VP1 of infectious pancreatic necrosis virus (IPNV) is a single polypeptide responsible for both viral RNA transcription and genome replication. Sequence analysis identifies IPNV VP1 as having an unusual active site topology. We have purified, crystallized and solved the structure of IPNV VP1 to 2.3 Å resolution in its apo form and at 2.2 Å resolution bound to the catalytically-activating metal magnesium. We find that recombinantly-expressed VP1 is highly active for RNA transcription and replication, yielding both free and polymerase-attached RNA products. IPNV VP1 also possesses terminal (deoxy)nucleotide transferase, RNA-dependent DNA polymerase (reverse transcriptase) and template-independent self-guanylylation activity. The N-terminus of VP1 interacts with the active-site cleft and we show that the N-terminal serine residue is required for formation of covalent RNA∶polymerase complexes, providing a mechanism for the genesis of viral genome∶polymerase complexes observed in vivo. Infectious pancreatic necrosis virus (IPNV) is highly contagious and causes severe disease in fish. As a result of intensive rearing conditions it has become a serious problem for the salmon and trout farming industries. IPNV, like many other viruses, replicates its genome using a protein (a ‘polymerase’) that is itself encoded by the viral genome. Unusually, in infectious IPNV particles the polymerase is found chemically linked to the viral genome. We have determined the atomic structure of IPNV polymerase using X-ray crystallography, revealing some significant differences in the fold of the protein chain compared to other well-characterized viral polymerases. By mutating an amino acid residue at the beginning of the protein we show how the chemical linkage to the viral genome can be disrupted. This provides an elegant mechanism for the attachment of the viral genome to the polymerase observed in vivo.
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Affiliation(s)
- Stephen C. Graham
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - L. Peter Sarin
- Institute of Biotechnology and Department of Biosciences, University of Helsinki, Biocenter 2, Helsinki, Finland
| | - Mohammad W. Bahar
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Reg A. Myers
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - David I. Stuart
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
| | - Dennis H. Bamford
- Institute of Biotechnology and Department of Biosciences, University of Helsinki, Biocenter 2, Helsinki, Finland
- * E-mail: (DHB); (JMG)
| | - Jonathan M. Grimes
- Division of Structural Biology, Wellcome Trust Centre for Human Genetics, University of Oxford, Oxford, United Kingdom
- * E-mail: (DHB); (JMG)
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Gomez-Casado E, Estepa A, Coll J. A comparative review on European-farmed finfish RNA viruses and their vaccines. Vaccine 2011; 29:2657-71. [DOI: 10.1016/j.vaccine.2011.01.097] [Citation(s) in RCA: 127] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Revised: 12/09/2010] [Accepted: 01/30/2011] [Indexed: 11/29/2022]
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Biacchesi S. The reverse genetics applied to fish RNA viruses. Vet Res 2011; 42:12. [PMID: 21314978 PMCID: PMC3037892 DOI: 10.1186/1297-9716-42-12] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2010] [Accepted: 11/18/2010] [Indexed: 02/05/2023] Open
Abstract
Aquaculture has expanded rapidly to become a major economic and food-producing sector worldwide these last 30 years. In parallel, viral diseases have emerged and rapidly spread from farm to farm causing enormous economic losses. The most problematic viruses encountered in the field are mainly, but not exclusively, RNA viruses belonging to the Novirhabdovirus, Aquabirnavirus, Alphavirus and Betanodavirus genera. The recent establishment of reverse genetics systems to recover infectious fish RNA viruses entirely from cDNA has made possible to genetically manipulate the viral genome. These systems have provided powerful tools to study all aspects of the virus biology and virus-host interactions but also gave the opportunity to use these viruses as live vaccines or as gene vectors. This review provides an overview on the recent breakthroughs achieved by using these reverse genetics systems in terms of viral protein function, virulence and host-specificity factor, vaccine development and vector design.
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Affiliation(s)
- Stéphane Biacchesi
- Unité de Virologie et Immunologie Moléculaires, INRA, CRJ, 78352 Jouy-en-Josas, France.
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Espinoza JC, Kuznar J. Visualization of the infectious pancreatic necrosis virus replication cycle by labeling viral intermediates with a TUNEL assay. Vet Microbiol 2010; 143:101-5. [DOI: 10.1016/j.vetmic.2009.11.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2009] [Revised: 11/03/2009] [Accepted: 11/09/2009] [Indexed: 10/20/2022]
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Lopez-Jimena B, Garcia-Rosado E, Infante C, Cano I, Manchado M, Castro D, Borrego JJ, Alonso MC. Detection of infectious pancreatic necrosis virus (IPNV) from asymptomatic redbanded seabream, Pagrus auriga Valenciennes, and common seabream, Pagrus pagrus (L.), using a non-destructive procedure. JOURNAL OF FISH DISEASES 2010; 33:311-319. [PMID: 20059634 DOI: 10.1111/j.1365-2761.2009.01123.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
A non-destructive procedure based on nested RT-PCR and dot-blot hybridization has been developed for the detection of asymptomatic IPNV-carrier fish. The pair of primers designed for RT-PCR amplified a 599-bp fragment of the pVP2 region within the polyprotein gene, resulting in the detection of IPNV genotype III.1. The use of a nested RT-PCR allowed the amplification of IPNV genotypes III.1 and I.2. In addition, a 191-bp probe was designed for hybridization studies used in combination with the nested RT-PCR. The application of the nested RT-PCR to analyse blood samples from asymptomatic redbanded seabream, Pagrus auriga, and common seabream, P. pagrus, specimens showed a 53.1% and 77.8% prevalence of IPNV-carriers, respectively. The combination of nested RT-PCR and dot-blot hybridization increased the detection rates up to 100% for redbanded seabream and 94.4% for common seabream. Therefore, the protocol described in this study is highly sensitive and specific for the detection of IPNV in asymptomatic carrier fish, and, in addition, the results demonstrate the carrier state in two newly cultured sparid species in southern Spain.
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Affiliation(s)
- B Lopez-Jimena
- Departamento de Microbiologia, Facultad de Ciencias, Universidad de Malaga, 29071 Malaga, Spain
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42
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Rodríguez Saint-Jean S, de Las Heras AI, Pérez Prieto SI. The persistence of infectious pancreatic necrosis virus and its influence on the early immune response. Vet Immunol Immunopathol 2010; 136:81-91. [PMID: 20334936 DOI: 10.1016/j.vetimm.2010.02.015] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2009] [Revised: 02/22/2010] [Accepted: 02/23/2010] [Indexed: 02/07/2023]
Abstract
Persistent infection by IPNV was induced in RTG-2 and RTG-P1 cells in vitro and the influence of this phenomenon on viral infectivity, viral antigen expression and interference with homologous and heterologous viruses was characterized over successive passages. The induction of IFN was also assessed, as was the sequence of the VP2 viral capsid protein, the region believed to be responsible for virulence, attenuation or persistence. Viral antigen expression was recorded in cells with no evidence of cytopathic effects and in these conditions, flow cytometry was more sensitive than RT-PCR to demonstrate the presence of a non-lytic virus. Interference of homologous viral infection could be detected in cross-infection experiments and in RTG-P1 cells persistently infected with IPNV, the Mx1 promoter could still be activated for at least 5 successive passages. Indeed, although over-induction of luciferase was not observed by re-infection with homologous or heterologous viruses, a significant increase in luciferase was induced by poly I:C. IFN transcripts could be quantified by qRT-PCR in the persistent cells at several passages, suggesting that IFN plays a role in maintaining IPNV persistence. In addition, we observed the same determinants in the VP2 sequences from the persistent virus as those described previously for IPNV adaptation and persistence in cell culture.
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Affiliation(s)
- Sylvia Rodríguez Saint-Jean
- Centro de Investigaciones Biológicas (CIB), Consejo Superior de Investigaciones Científicas (CSIC), Departamento de Microbiología Molecular, C/Ramiro de Maeztu 9, 28040 Madrid, Spain
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43
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Modak B, Sandino AM, Arata L, Cárdenas-Jirón G, Torres R. Inhibitory effect of aromatic geranyl derivatives isolated from Heliotropium filifolium on infectious pancreatic necrosis virus replication. Vet Microbiol 2010; 141:53-8. [DOI: 10.1016/j.vetmic.2009.09.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Revised: 08/12/2009] [Accepted: 09/04/2009] [Indexed: 11/30/2022]
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44
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de Las Heras AI, Pérez Prieto SI, Rodríguez Saint-Jean S. In vitro and in vivo immune responses induced by a DNA vaccine encoding the VP2 gene of the infectious pancreatic necrosis virus. FISH & SHELLFISH IMMUNOLOGY 2009; 27:120-129. [PMID: 19121400 DOI: 10.1016/j.fsi.2008.11.021] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Revised: 11/21/2008] [Accepted: 11/27/2008] [Indexed: 05/27/2023]
Abstract
The work presented here describes the construction of a plasmid encoding the VP2 gene of the infectious pancreatic necrosis virus (IPNV), its expression in BF-2 cells and an evaluation of its activity in brown trout (Salmo trutta L) soon after injection. Preliminary experiments to evaluate the potential of the plasmid to induce neutralizing antibodies were also performed. We established a BF-2 cell line that expresses VP2 constitutively and we examined the infection of these VP2-transfected BF-2 cells with homologous and heterologous viruses. The expression kinetics of IFN, and of the IFN-induced genes Mx and ISG15, was also evaluated in brown trout over a 15 day interval, and quantified by real-time or semi-quantitative PCR. Type I IFN and Mx are markers of the non-specific innate immune response to viruses and they are involved in antiviral defences. Our results demonstrate that expression of the IPNV VP2 protein in BF-2 cells induces an antiviral state against IPNV and against the infectious haematopoietic necrosis virus (IHNV). In BF-2 infected cells, VP2 inhibited both the IPNV and IHNV-induced cytopathic effect to some extent, as well as the virus yield. In vivo, VP2 was expressed in haematopoietic tissues such as the head kidney of 7 month-old trout. In addition, it induced early immune responses and specific immunity 30 days after injection. IFN mRNA expression increased sharply on the 1st and 15th day post-injection and expression of other IFN-induced genes as Mx and ISG15 was also detected soon after vaccination of brown trout. Moreover, specific antibodies were detected 30 days after vaccination. These results suggest that the VP2 gene is a good candidate for the design of IPNV-DNA vaccines and to investigate the use of cytokines as co-stimulatory molecules.
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Affiliation(s)
- Ana I de Las Heras
- Centro de Investigaciones Biológicas, Consejo Superior de Investigaciones Científicas, Departamento de Microbiología Molecular, C/Ramiro de Maeztu 9, 28040 Madrid, Spain
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Sundh H, Olsen RE, Fridell F, Gadan K, Evensen Ø, Glette J, Taranger GL, Myklebust R, Sundell K. The effect of hyperoxygenation and reduced flow in fresh water and subsequent infectious pancreatic necrosis virus challenge in sea water, on the intestinal barrier integrity in Atlantic salmon, Salmo salar L. JOURNAL OF FISH DISEASES 2009; 32:687-698. [PMID: 19500205 DOI: 10.1111/j.1365-2761.2009.01047.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
In high intensive fish production systems, hyperoxygenation and reduced flow are often used to save water and increase the holding capacity. This commonly used husbandry practice has been shown to be stressful to fish and increase mortality after infectious pancreatic necrosis virus (IPNV) challenge, but the cause and effect relationship is not known. Salmonids are particularly sensitive to stress during smoltification and the first weeks after seawater (SW) transfer. This work aimed at investigating the impact of hyperoxygenation combined with reduced flow in fresh water (FW), on the intestinal barrier in FW as well as during later life stages in SW. It further aims at investigating the role of the intestinal barrier during IPNV challenge and possible secondary infections. Hyperoxygenation in FW acted as a stressor as shown by significantly elevated plasma cortisol levels. This stressful husbandry condition tended to increase paracellular permeability (P(app)) as well as translocation of Aeromonas salmonicida in the posterior intestine of Atlantic salmon. After transfer to SW and subsequent IPNV challenge, intestinal permeability, as shown by P(app), and translocation rate of A. salmonicida increased in the anterior intestine, concomitant with further elevation in plasma cortisol levels. In the anterior intestine, four of five fish displayed alterations in intestinal appearance. In two of five fish, IPNV caused massive necrosis with significant loss of cell material and in a further two fish, IPNV caused increased infiltration of lymphocytes into the epithelium and granulocytes in the lamina propria. Hyperoxygenation and reduced flow in the FW stage may serve as stressors with impact mainly during later stages of development. Fish with an early history of hyperoxygenation showed a higher stress response concomitant with a disturbed intestinal barrier function, which may be a cause for the increased susceptibility to IPNV infection and increased susceptibility to secondary infections.
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Affiliation(s)
- H Sundh
- Fish Endocrinology Laboratory, Department of Zoology/Zoophysiology, University of Gothenburg, Sweden.
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46
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de las Heras AI, Rodríguez Saint-Jean S, Pérez-Prieto SI. Salmonid fish viruses and cell interactions at early steps of the infective cycle. JOURNAL OF FISH DISEASES 2008; 31:535-546. [PMID: 18482382 DOI: 10.1111/j.1365-2761.2008.00931.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
A flow cytometric virus-binding assay that directly visualizes the binding and entry of infectious pancreatic necrosis virus (IPNV), infectious haematopoietic necrosis virus (IHNV) and virus haemorrhagic septicaemia virus (VHSV) to several cell lines was established. The highest efficiency of binding was shown by the BF-2 cell line and this was used to study, at the attachment level, the interactions of these cells with salmonid fish viruses in coinfections, and to further determine if the earliest stage of the viral growth cycle could explain the previously described loss of infectivity of IHNV when IPNV is present. Our results demonstrated that IPNV binds to around 88% of cells either in single or dual infections, whereas IHNV attachment always decreased in the presence of any of the other viruses. VHSV binding was not affected by IPNV, but coinfection with IHNV reduced the percentage of virus-binding cells, which suggests competition for viral receptors or co-receptors. Internalization of the adsorbed IHNV was not decreased by coinfection with IPNV, so the hypothetical competence could be restricted to the binding step. Treatment of the cells with antiviral agents, such as amantadine or chloroquine, did not affect the binding of IPNV and VHSV, but reduced IHNV binding by more than 30%. Tributylamine affected viral binding of the three viruses to different degrees and inhibited IPNV or IHNV entry in a large percentage of cells treated for 30 min. Tributylamine also inhibited IHNV cytopathic effects in a dose-dependent manner, decreasing the virus yield by 4 log of the 50% endpoint titre, at 10 mm concentration. IPNV was also inhibited, but at a lower level. The results of this study support the hypothesis that IHNV, in contrast to VHSV or IPNV, is less efficient at completing its growth cycle in cells with a simultaneous infection with IPNV. It can be affected at several stages of viral infection and is more sensitive to the action of antiviral compounds.
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Affiliation(s)
- A I de las Heras
- Departamento de Microbiología Molecular, Consejo Superior de Investigaciones Científicas, Centro de Investigaciones Biológicas, Laboratorio de Virología, Madrid, Spain
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47
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Isolation, characterization and genome sequence of a birnavirus strain from flounder Paralichthys olivaceus in China. Arch Virol 2008; 153:1143-8. [PMID: 18398563 DOI: 10.1007/s00705-008-0075-0] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2007] [Accepted: 02/26/2008] [Indexed: 10/22/2022]
Abstract
A birnavirus strain, Paralichthys olivaceus birnavirus (POBV), was isolated and characterized from cultured flounder in China, and its complete genomic sequence was subsequently determined. The virus could induce cytopathic effects (CPE) in four of seven fish cell lines and was resistant to chloroform, 5-iodo-2'-deoxyuridine, acid and alkaline pH, and heat treatment. Purified virus particles had a typical icosahedral shape, with a diameter of approximately 55-60 nm. The genomic segments A and B of POBV were 3,091 and 2,780 bp in length and shared many of the features of the members of the family Birnaviridae. Segment A contained two partially overlapping ORFs encoding a polyprotein, pVP2-VP4-VP3, and a nonstructural protein, VP5, while segment B had only one ORF encoding for the VP1, a viral RNA-dependent RNA polymerase (RdRp). This is the first report about a birnavirus strain from a new non-salmonid host in China and its complete genome sequence.
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Fernandez-Trujillo A, Ferro P, Garcia-Rosado E, Infante C, Alonso MC, Bejar J, Borrego JJ, Manchado M. Poly I:C induces Mx transcription and promotes an antiviral state against sole aquabirnavirus in the flatfish Senegalese sole (Solea senegalensis Kaup). FISH & SHELLFISH IMMUNOLOGY 2008; 24:279-285. [PMID: 18191581 DOI: 10.1016/j.fsi.2007.11.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/27/2007] [Revised: 11/15/2007] [Accepted: 11/18/2007] [Indexed: 05/25/2023]
Abstract
Mx is an interferon-induced protein that protects against viral infections. In this study the absolute number of Mx transcripts after poly I:C injection (a synthetic dsRNA) or sole aquabirnavirus (solevirus) inoculation in Senegalese sole (Solea senegalensis Kaup) has been quantified. Mx expression profiles differed clearly in both experimental conditions; the induction response was faster and more intense after poly I:C injection than after solevirus inoculation. Moreover, pre-injection of soles with poly I:C prior to solevirus infection eliminated the induction of Mx expression associated with this virus. To evaluate the possible interference of poly I:C treatments on solevirus replication, the mRNA levels of the virus capsid protein (VP2) were determined by RT-PCR. VP2 transcripts were hardly detected in poly I:C pre-injected animals from 12 to 72 h after solevirus inoculation. All these data suggest that poly I:C is able to induce an antiviral state that interferes with solevirus replication, and support the suitability of Mx expression analysis as a marker to study the defensive response against solevirus.
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Affiliation(s)
- A Fernandez-Trujillo
- Department of Genetics, Faculty of Sciences, University of Málaga, 29071 Málaga, Spain
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Pedersen T, Skjesol A, Jørgensen JB. VP3, a structural protein of infectious pancreatic necrosis virus, interacts with RNA-dependent RNA polymerase VP1 and with double-stranded RNA. J Virol 2007; 81:6652-63. [PMID: 17428850 PMCID: PMC1900092 DOI: 10.1128/jvi.02831-06] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Infectious pancreatic necrosis virus (IPNV) is a bisegmented, double-stranded RNA (dsRNA) virus of the Birnaviridae family that causes widespread disease in salmonids. Its two genomic segments are encapsulated together with the viral RNA-dependent RNA polymerase, VP1, and the assumed internal protein, VP3, in a single-shell capsid composed of VP2. Major aspects of the molecular biology of IPNV, such as particle assembly and interference with host macromolecules, are as yet poorly understood. To understand the infection process, analysis of viral protein interactions is of crucial importance. In this study, we focus on the interaction properties of VP3, the suggested key organizer of particle assembly in birnaviruses. By applying the yeast two-hybrid system in combination with coimmunoprecipitation, VP3 was proven to bind to VP1 and to self-associate strongly. In addition, VP3 was shown to specifically bind to dsRNA in a sequence-independent manner by in vitro pull-down experiments. The binding between VP3 and VP1 was not dependent on the presence of dsRNA. Deletion analyses mapped the VP3 self-interaction domain within the 101 N-terminal amino acids and the VP1 interaction domain within the 62 C-terminal amino acids of VP3. The C-terminal end was also crucial but not sufficient for the dsRNA binding capacity of VP3. For VP1, the 90 C-terminal amino acids constituted the only dispensable part for maintaining VP3-binding ability. Kinetic analysis revealed the presence of VP1-VP3 complexes prior to the formation of mature virions in IPNV-infected CHSE-214 cells, which indicates a role in promoting the assembly process.
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Affiliation(s)
- Torunn Pedersen
- Department of Marine Biotechnology, Norwegian College of Fishery Sciences, University of Tromsø, N-9037 Tromsø, Norway
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50
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Osorio M, Espinoza JC, Kuznar J. Visualization of infectious pancreatic necrosis virus (IPNV) particles labeled with fluorescent probes. J Virol Methods 2005; 130:140-4. [PMID: 16046003 DOI: 10.1016/j.jviromet.2005.06.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2005] [Revised: 06/09/2005] [Accepted: 06/14/2005] [Indexed: 10/25/2022]
Abstract
Infectious pancreatic necrosis virus (IPNV) particles were labeled with SYBR Green I or a monoclonal antibody and FITC-conjugated secondary antibody and examined in a fluorescence microscope. Labeled viral particles were visualized in a narrow range of pixels. Comparing IPNV particles with fluorescent phage T4 virions, the former, as expected, were seen smaller in size. The method allows the rapid and accurate counting of viral particles both on filters and bound to the cell surface. In addition, IPNV particles can be specifically enumerated in the presence of other virions and the ratio between physical particles and virus infectivity can be easily calculated as well.
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Affiliation(s)
- Manuel Osorio
- Laboratorio de Bioquímica y Virología, Instituto de Ciencias Biológicas y Químicas, Facultad de Ciencias, Universidad de Valparaíso, Casilla 50 30, Valparaíso, Chile
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