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Chokmangmeepisarn P, Azmai MNA, Domingos JA, van Aerle R, Bass D, Prukbenjakul P, Senapin S, Rodkhum C. Genome Characterization and Phylogenetic Analysis of Scale Drop Disease Virus Isolated from Asian Seabass ( Lates calcarifer). Animals (Basel) 2024; 14:2097. [PMID: 39061559 PMCID: PMC11274154 DOI: 10.3390/ani14142097] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2024] [Revised: 07/07/2024] [Accepted: 07/16/2024] [Indexed: 07/28/2024] Open
Abstract
Scale drop disease virus (SDDV), a double-stranded DNA virus in the family Iridoviridae, has been reported widely in southeast Asian countries as a causative agent of scale drop syndrome (SDS) in Asian seabass. SDS has resulted in high mortality and significant economic losses to the aquaculture industry. This study demonstrated the use of metagenomic methods to investigate bacterial and viral communities present in infected fish tissues and recover a complete genome of the causative agent named SDDV TH7_2019. Characterization of the TH7_2019 genome revealed a genome size of 131 kb with 134 putative ORFs encoding viral proteins potentially associated with host apoptosis manipulation. A comparative genome analysis showed a high degree of amino acid identity across SDDV strains, with variations in number of repeat sequences and mutations within core genes. Phylogenetic analyses indicate a close relationship among SDDV genomes. This research enhances our understanding of the genetic diversity and evolutionary relationship of SDDV, contributing valuable insights for further development of effective control strategies of SDDV.
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Affiliation(s)
- Putita Chokmangmeepisarn
- Center of Excellence in Fish Infectious Diseases (CE FID), Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Mohammad Noor Amal Azmai
- Department of Biology, Faculty of Science, Universiti Putra Malaysia, UPM, Serdang 43400, Selangor, Malaysia;
- Aquatic Animal Health and Therapeutics Laboratory, Institute of Bioscience, Universiti Putra Malaysia, UPM, Serdang 43400, Selangor, Malaysia
| | - Jose A. Domingos
- Tropical Futures Institute, James Cook University, Singapore 387370, Singapore;
| | - Ronny van Aerle
- International Centre of Excellence for Aquatic Animal Health, Centre for Environment, Fisheries and Aquaculture Sciences (Cefas), Weymouth, Dorset DT4 8UB, UK; (R.v.A.); (D.B.)
- Centre for Sustainable Aquaculture Futures, University of Exeter, Stocker Road, Exeter EX4 4QY, UK
| | - David Bass
- International Centre of Excellence for Aquatic Animal Health, Centre for Environment, Fisheries and Aquaculture Sciences (Cefas), Weymouth, Dorset DT4 8UB, UK; (R.v.A.); (D.B.)
- Centre for Sustainable Aquaculture Futures, University of Exeter, Stocker Road, Exeter EX4 4QY, UK
- Department of Life Sciences, The Natural History Museum, London SW7 5BD, UK
| | - Pochara Prukbenjakul
- Center of Excellence in Fish Infectious Diseases (CE FID), Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Saengchan Senapin
- Tropical Futures Institute, James Cook University, Singapore 387370, Singapore;
- Fish Health Platform, Center of Excellence for Shrimp Molecular Biology and Biotechnology (Centex Shrimp), Faculty of Science, Mahidol University, Bangkok 10400, Thailand
- National Center for Genetic Engineering and Biotechnology (BIOTEC), National Science and Technology Development Agency (NSTDA), Khlong Nueng, Pathum Thani 12120, Thailand
| | - Channarong Rodkhum
- Center of Excellence in Fish Infectious Diseases (CE FID), Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
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Leiva-Rebollo R, Labella AM, Gémez-Mata J, Castro D, Borrego JJ. Fish Iridoviridae: infection, vaccination and immune response. Vet Res 2024; 55:88. [PMID: 39010235 PMCID: PMC11247874 DOI: 10.1186/s13567-024-01347-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2023] [Accepted: 05/31/2024] [Indexed: 07/17/2024] Open
Abstract
Each year, due to climate change, an increasing number of new pathogens are being discovered and studied, leading to an increase in the number of known diseases affecting various fish species in different regions of the world. Viruses from the family Iridoviridae, which consist of the genera Megalocytivirus, Lymphocystivirus, and Ranavirus, cause epizootic outbreaks in farmed and wild, marine, and freshwater fish species (including ornamental fish). Diseases caused by fish viruses of the family Iridoviridae have a significant economic impact, especially in the aquaculture sector. Consequently, vaccines have been developed in recent decades, and their administration methods have improved. To date, various types of vaccines are available to control and prevent Iridoviridae infections in fish populations. Notably, two vaccines, specifically targeting Red Sea bream iridoviral disease and iridoviruses (formalin-killed vaccine and AQUAVAC® IridoV, respectively), are commercially available. In addition to exploring these themes, this review examines the immune responses in fish following viral infections or vaccination procedures. In general, the evasion mechanisms observed in iridovirus infections are characterised by a systemic absence of inflammatory responses and a reduction in the expression of genes associated with the adaptive immune response. Finally, this review also explores prophylactic procedure trends in fish vaccination strategies, focusing on future advances in the field.
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Affiliation(s)
- Rocío Leiva-Rebollo
- Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
- Department of Microbiology, Icahn School of Medicine at Mount Sinai, New York, NY, USA
- Global Health and Emerging Pathogens Institute, Icahn School of Medicine at Mount Sinai, New York, NY, USA
| | | | - Juan Gémez-Mata
- Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| | - Dolores Castro
- Departamento de Microbiología, Universidad de Málaga, Málaga, Spain
| | - Juan J Borrego
- Departamento de Microbiología, Universidad de Málaga, Málaga, Spain.
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Min JG, Kim GH, Kim CH, Kwon WJ, Jeong HD, Kim KI. Evaluation of Formalin-Inactivated Vaccine Efficacy against Red Seabream Iridovirus (RSIV) in Laboratory and Field Conditions. Vaccines (Basel) 2024; 12:680. [PMID: 38932409 PMCID: PMC11209460 DOI: 10.3390/vaccines12060680] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2024] [Revised: 06/13/2024] [Accepted: 06/16/2024] [Indexed: 06/28/2024] Open
Abstract
Red seabream iridovirus (RSIV) is a major cause of marine fish mortality in Korea, with no effective vaccine available since its first occurrence in the 1990s. This study evaluated the efficacy of a formalin-killed vaccine against RSIV in rock bream under laboratory and field conditions. For the field trial, a total of 103,200 rock bream from two commercial marine cage-cultured farms in Southern Korea were vaccinated. Farm A vaccinated 31,100 fish in July 2020 and monitored them for 18 weeks, while farm B vaccinated 30,700 fish in August 2020 and monitored them for 12 weeks. At farm A, where there was no RSIV infection, the vaccine efficacy was assessed in the lab, showing a relative percentage of survival (RPS) ranging from 40% to 80%. At farm B, where natural RSIV infections occurred, cumulative mortality rates were 36.43% in the vaccinated group and 80.32% in the control group, resulting in an RPS of 54.67%. The RSIV-infectious status and neutralizing antibody titers in serum mirrored the cumulative mortality results. This study demonstrates that the formalin-killed vaccine effectively prevents RSIV in cage-cultured rock bream under both laboratory and field conditions.
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Affiliation(s)
- Joon-Gyu Min
- Department of Aquatic Life Medicine, Pukyong National University, Busan 48513, Republic of Korea; (J.-G.M.); (G.-H.K.); (H.-D.J.)
| | - Guk-Hyun Kim
- Department of Aquatic Life Medicine, Pukyong National University, Busan 48513, Republic of Korea; (J.-G.M.); (G.-H.K.); (H.-D.J.)
| | - Chong-Han Kim
- Vaccine Research Institute, Woogene B&G Co., Ltd., Seoul 07299, Republic of Korea; (C.-H.K.); (W.-J.K.)
| | - Woo-Ju Kwon
- Vaccine Research Institute, Woogene B&G Co., Ltd., Seoul 07299, Republic of Korea; (C.-H.K.); (W.-J.K.)
| | - Hyun-Do Jeong
- Department of Aquatic Life Medicine, Pukyong National University, Busan 48513, Republic of Korea; (J.-G.M.); (G.-H.K.); (H.-D.J.)
| | - Kwang-Il Kim
- Department of Aquatic Life Medicine, Pukyong National University, Busan 48513, Republic of Korea; (J.-G.M.); (G.-H.K.); (H.-D.J.)
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Hsueh TC, Chen PH, Hong JR. ISKNV Triggers AMPK/mTOR-Mediated Autophagy Signaling through Oxidative Stress, Inducing Antioxidant Enzyme Expression and Enhancing Viral Replication in GF-1 Cells. Viruses 2024; 16:914. [PMID: 38932206 PMCID: PMC11209599 DOI: 10.3390/v16060914] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2024] [Revised: 05/25/2024] [Accepted: 06/01/2024] [Indexed: 06/28/2024] Open
Abstract
Infectious spleen and kidney necrosis virus (ISKNV) infections can induce the process of host cellular autophagy but have rarely been identified within the molecular autophagy signaling pathway. In the present study, we demonstrated that ISKNV induces ROS-mediated oxidative stress signals for the induction of 5'AMP-activated protein kinase/mechanistic target of rapamycin kinase (AMPK/mTOR)-mediated autophagy and upregulation of host antioxidant enzymes in fish GF-1 cells. We also examined ISKNV-induced oxidative stress, finding that reactive oxidative species (ROS) increased by 1.5-fold and 2.5-fold from day 2 to day 3, respectively, as assessed by the H2DCFDA assay for tracing hydrogen peroxide (H2O2), which was blocked by NAC treatment in fish GF-1 cells. Furthermore, ISKNV infection was shown to trigger oxidative stress/Nrf2 signaling from day 1 to day 3; this event was then correlated with the upregulation of antioxidant enzymes such as Cu/ZnSOD and MnSOD and was blocked by the antioxidant NAC. Using an MDC assay, TEM analysis and autophagy marker LC3-II/I ratio, we found that ROS stress can regulate autophagosome formation within the induction of autophagy, which was inhibited by NAC treatment in GF-1 cells. Through signal analysis, we found that AMPK/mTOR flux was modulated through inhibition of mTOR and activation of AMPK, indicating phosphorylation levels of mTOR Ser 2448 and AMPK Thr 172 from day 1 to day 3; however, this process was reversed by NAC treatment, which also caused a reduction in virus titer (TCID50%) of up to 1000 times by day 3 in GF-1 cells. Thus, ISKNV-induced oxidative stress signaling is blocked by antioxidant NAC, which can also either suppress mTOR/AMPK autophagic signals or reduce viral replication. These findings may provide the basis for the creation of DNA control and treatment strategies.
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Affiliation(s)
- Tsai-Ching Hsueh
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
| | - Pin-Han Chen
- Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan 701, Taiwan
| | - Jiann-Ruey Hong
- Laboratory of Molecular Virology and Biotechnology, Institute of Biotechnology, National Cheng Kung University, Tainan 701, Taiwan
- Department of Biotechnology and Bioindustry Sciences, National Cheng Kung University, Tainan 701, Taiwan
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Kim KH, Kang G, Woo WS, Sohn MY, Son HJ, Kim JW, Kong HJ, Kim YO, Park CI. Evaluation of the diagnostic assays detecting red sea bream iridovirus infection at different severity levels. J Virol Methods 2024; 326:114901. [PMID: 38367823 DOI: 10.1016/j.jviromet.2024.114901] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2023] [Revised: 01/31/2024] [Accepted: 02/14/2024] [Indexed: 02/19/2024]
Abstract
Red sea bream iridovirus (RSIV) is a highly contagious viral infection that affects various fish species and poses a significant threat to the global aquaculture industry. Thus, accurate and timely diagnosis is paramount for sustainable management of fish health. This study rigorously evaluated the diagnostic efficacy of various polymerase chain reaction (PCR) assays, focusing on those recommended by the World Organization for Animal Health (WOAH) and the assays newly proposed by WOAH's Aquatic Animals Health Standards Commission. Specifically, this study assessed conventional PCR, nested PCR, modified 1-F/1-R, and real-time PCR assays using a 95% limit of detection (LoD95%), as well as diagnostic sensitivity (DSe) and specificity (DSp) tests across different RSIV severity grades (G0-G4). In previous studies, the LoD95% for the 1-F/1-R and 4-F/4-R conventional assays were 225.81 and 328.7 copies/reaction, respectively. The modified 1-F/1-R exhibited a lower LoD95% of 51.32 copies/reaction. Notably, the nested PCR had an LoD95% of 11.23 copies/reaction, and the real-time PCR assay had an LoD95% of 12.02 copies/reaction. The DSe varied across RSIV severity grades, especially in the lower G0-G2 grades. The nested PCR and modified 1-F/1-R assays displayed the highest DSe, making them particularly useful for early-stage screening and detection of asymptomatic carriers. In addition, the PCR assays did not cross-react with any other aquatic pathogens except RSIV. Our findings significantly advanced the diagnostic capabilities of RSIVD by suggesting that nested PCR and modified 1-F/1-R assays are particularly promising for early detection. We propose their inclusion in future WOAH guidelines for a more comprehensive diagnostic framework.
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Affiliation(s)
- Kyung-Ho Kim
- Department of Marine Biology and Aquaculture, College of Marine Science, Gyeongsang National University, Tongyeong 53064, South Korea
| | - Gyoungsik Kang
- Department of Marine Biology and Aquaculture, College of Marine Science, Gyeongsang National University, Tongyeong 53064, South Korea
| | - Won-Sik Woo
- Department of Marine Biology and Aquaculture, College of Marine Science, Gyeongsang National University, Tongyeong 53064, South Korea
| | - Min-Young Sohn
- Department of Marine Biology and Aquaculture, College of Marine Science, Gyeongsang National University, Tongyeong 53064, South Korea
| | - Ha-Jeong Son
- Department of Marine Biology and Aquaculture, College of Marine Science, Gyeongsang National University, Tongyeong 53064, South Korea
| | - Ju-Won Kim
- Biotechnology Research Division, National Institute of Fisheries Science, Busan 46083, South Korea
| | - Hee Jeong Kong
- Biotechnology Research Division, National Institute of Fisheries Science, Busan 46083, South Korea
| | - Young-Ok Kim
- Biotechnology Research Division, National Institute of Fisheries Science, Busan 46083, South Korea
| | - Chan-Il Park
- Department of Marine Biology and Aquaculture, College of Marine Science, Gyeongsang National University, Tongyeong 53064, South Korea.
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Kawato Y, Mizuno K, Harakawa S, Takada Y, Yoshihara Y, Kawakami H, Ito T. Risk assessment of wild fish as environmental sources of red sea bream iridovirus (RSIV) outbreaks in aquaculture. DISEASES OF AQUATIC ORGANISMS 2024; 158:65-74. [PMID: 38661138 DOI: 10.3354/dao03788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/26/2024]
Abstract
Red sea bream iridovirus (RSIV) causes substantial economic damage to aquaculture. In the present study, RSIV in wild fish near aquaculture installations was surveyed to evaluate the risk of wild fish being an infection source for RSIV outbreaks in cultured fish. In total, 1102 wild fish, consisting of 44 species, were captured from 2 aquaculture areas in western Japan using fishing, gill nets, and fishing baskets between 2019 and 2022. Eleven fish from 7 species were confirmed to harbor the RSIV genome using a probe-based real-time PCR assay. The mean viral load of the RSIV-positive wild fish was 101.1 ± 0.4 copies mg-1 DNA, which was significantly lower than that of seemingly healthy red sea bream Pagrus major in a net pen during an RSIV outbreak (103.3 ± 1.5 copies mg-1 DNA) that occurred in 2021. Sequencing analysis of a partial region of the major capsid protein gene demonstrated that the RSIV genome detected in the wild fish was identical to that of the diseased fish in a fish farm located in the same area in which the wild fish were captured. Based on the diagnostic records of RSIV in the sampled area, the RSIV-infected wild fish appeared during or after the RSIV outbreak in cultured fish, suggesting that RSIV detected in wild fish was derived from the RSIV outbreak in cultured fish. Therefore, wild fish populations near aquaculture installations may not be a significant risk factor for RSIV outbreaks in cultured fish.
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Affiliation(s)
- Yasuhiko Kawato
- Pathology Division, Nansei Field Station, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Mie 519-0193, Japan
| | - Kaori Mizuno
- Ehime Fisheries Research Center, Ehime 798-0087, Japan
| | | | - Yuzo Takada
- Pathology Division, Nansei Field Station, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Mie 519-0193, Japan
| | | | | | - Takafumi Ito
- Pathology Division, Nansei Field Station, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Mie 519-0193, Japan
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Simmelink B, Coolen JPM, Vogels W, Deijs M, van der Last-Kempkes JLM, Ng KS, Chang SF, Gevers K, Harkema L, van der Hoek L, de Groof A. Discovery, Pathogenesis, and Complete Genome Characterization of Lates calcarifer Herpesvirus. Genes (Basel) 2024; 15:264. [PMID: 38540323 PMCID: PMC10970581 DOI: 10.3390/genes15030264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/03/2024] [Accepted: 02/16/2024] [Indexed: 06/15/2024] Open
Abstract
In 2015 and 2016, two Barramundi (Lates calcarifer) farms in Singapore reported a disease outbreak characterized by lethargic behavior, pronounced inappetence, generalized skin lesions, erosions of the fins and tail, and ultimately high mortality in their fish. Next-generation sequencing and PCR confirmed presence of a novel virus belonging to the Alloherpesviridae family, Lates calcarifer herpesvirus (LCHV), which was subsequently isolated and cultured. We characterize, for the first time, the complete genome of two cultured LCHV isolates. The genome contains a long unique region of approximately 105,000 bp flanked by terminal repeats of approximately 24,800 bp, of which the first 8.2 kb do not show any similarity to described genomes in the Alloherpesviridae family. The two cultured isolates share 89% nucleotide identity, and their closest relatives are the viruses belonging to the genus Ictalurivirus. Experimental infections using one of the cultured LCHV isolates resulted in identical clinical signs as originally described in the index farm, both in intraperitoneal-injection infected fish and cohabitant fish, with mortality in both groups. Histopathological analysis showed pronounced abnormalities in the gills. Virus culture and PCR analysis confirmed the replication of LCHV in the infected fish, and thus Koch's postulates were fulfilled.
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Affiliation(s)
- Bartjan Simmelink
- Department Discovery & Technology, MSD Animal Health, Wim de Körverstraat 35, P.O. Box 31, 5830 AA Boxmeer, The Netherlands; (B.S.); (W.V.); (J.L.M.v.d.L.-K.); (K.G.)
| | - Jordy P. M. Coolen
- Department R&D-IT, MSD Animal Health, Wim de Körverstraat 35, P.O. Box 31, 5830 AA Boxmeer, The Netherlands;
| | - Wannes Vogels
- Department Discovery & Technology, MSD Animal Health, Wim de Körverstraat 35, P.O. Box 31, 5830 AA Boxmeer, The Netherlands; (B.S.); (W.V.); (J.L.M.v.d.L.-K.); (K.G.)
| | - Martin Deijs
- Laboratory of Experimental Virology, Department of Medical Microbiology and Infection Prevention, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (M.D.); (L.v.d.H.)
- Amsterdam Institute for Infection and Immunity, Postbus 22660, 1100 DD Amsterdam, The Netherlands
| | - Jessica L. M. van der Last-Kempkes
- Department Discovery & Technology, MSD Animal Health, Wim de Körverstraat 35, P.O. Box 31, 5830 AA Boxmeer, The Netherlands; (B.S.); (W.V.); (J.L.M.v.d.L.-K.); (K.G.)
| | - Kah Sing Ng
- MSD Animal Health Innovation Pte Ltd., 1 Perahu Road, Singapore 718847, Singapore; (K.S.N.); (S.F.C.)
| | - Siow Foong Chang
- MSD Animal Health Innovation Pte Ltd., 1 Perahu Road, Singapore 718847, Singapore; (K.S.N.); (S.F.C.)
| | - Koen Gevers
- Department Discovery & Technology, MSD Animal Health, Wim de Körverstraat 35, P.O. Box 31, 5830 AA Boxmeer, The Netherlands; (B.S.); (W.V.); (J.L.M.v.d.L.-K.); (K.G.)
| | - Liesbeth Harkema
- Department Animal Research & Pathology, MSD Animal Health, Wim de Körverstraat 35, P.O. Box 31, 5830 AA Boxmeer, The Netherlands;
| | - Lia van der Hoek
- Laboratory of Experimental Virology, Department of Medical Microbiology and Infection Prevention, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, The Netherlands; (M.D.); (L.v.d.H.)
- Amsterdam Institute for Infection and Immunity, Postbus 22660, 1100 DD Amsterdam, The Netherlands
| | - Ad de Groof
- Department Discovery & Technology, MSD Animal Health, Wim de Körverstraat 35, P.O. Box 31, 5830 AA Boxmeer, The Netherlands; (B.S.); (W.V.); (J.L.M.v.d.L.-K.); (K.G.)
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Kim SJ, Cheon J, Cho MY, Jung SJ, Jung MH. Abnormalities in red blood cell production and pathogenesis of anemia in the progression of rock bream iridovirus (RBIV). Virus Res 2024; 339:199278. [PMID: 37984754 PMCID: PMC10709172 DOI: 10.1016/j.virusres.2023.199278] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2023] [Revised: 11/15/2023] [Accepted: 11/17/2023] [Indexed: 11/22/2023]
Abstract
Rock bream iridovirus (RBIV), belonging to Megalocytivirus, causes severe mortality in rock bream. Almost all deaths associated with RBIV are accompanied by splenic enlargement and anemia. Although red blood cells (RBCs) are involved in the immune response against viral infections, their involvement in rock bream has not yet been studied in terms of the immune response against RBIV. In this study, the viral replication patterns, blood characteristics and anemia-related factors were evaluated in rock bream post RBIV infection. The virus-infected RBCs of rock bream demonstrated similarities in the expression levels of hemoglobins (HGB) (α and β), cytokine-dependent hematopoietic cell linker (CLNK) and hematopoietic transcription factor GATA (GATA), with significantly decreasing levels from 4 days post infection (dpi) to 17 (dpi), when the viral replication was at its peak. This suggests that the expression of blood-related genes is inadequate for HGB synthesis and RBC production, thereby causing anemia leading to death. Moreover, the levels of complete blood cell count (CBC) indicators, such as RBCs, HGB and hematocrit (HCT), significantly decreased from 10 to 17 dpi. This phenomenon suggests that blood-related gene expression and/or RBC-, HGB- and HCT-related levels are critical factors in RBIV-induced anemia and disease progression. These results highlight the significance of blood-mediated immune responses against RBIV infection in rock bream. Understanding blood-related gene levels to identify blood-related immune response interactions in rock bream will be useful for development of future strategies in controlling RBIV diseases in rock bream.
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Affiliation(s)
- Soo-Jin Kim
- Pathology Division, National Institute of Fisheries Science, Republic of Korea
| | - Jayeon Cheon
- Department of MarineBio and Medical Sciences, Hanseo University, Republic of Korea
| | - Mi Young Cho
- Pathology Division, National Institute of Fisheries Science, Republic of Korea
| | - Sung-Ju Jung
- Department of Aqualife Medicine, Chonnam National University, Republic of Korea
| | - Myung-Hwa Jung
- Department of MarineBio and Medical Sciences, Hanseo University, Republic of Korea.
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Liao J, Kang S, Zhang L, Zhang D, Xu Z, Qin Q, Wei J. Isolation and identification of a megalocytivirus strain (SKIV-TJ) from cultured spotted knifejaw (Oplegnathus punctatus) in China and its pathogenicity analysis. FISH & SHELLFISH IMMUNOLOGY 2023; 141:109034. [PMID: 37640124 DOI: 10.1016/j.fsi.2023.109034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 04/26/2023] [Accepted: 08/25/2023] [Indexed: 08/31/2023]
Abstract
The spotted knifejaw (Oplegnathus punctatus) has recently emerged as a highly economically significant farmed fish in China. However, due to increasing environmental pollution and breeding density, a range of infectious diseases, including the iridovirus pathogen, have begun to spread widely. In this study, we isolated and identified a strain of Megalocytivirus, SKIV-TJ, from cultured spotted knifejaw in Tianjin, China. We observed significant cytopathic effects (CPE) in SKIV-TJ-infected spotted knifejaw brain (SKB) cells, and electron microscopy showed numerous virus particles in the cytoplasm of SKB cells 6 days post-infection. The annotated complete genome of SKIV-TJ (GenBank accession number ON075463) contained 112,489 bp and 132 open reading frames. Based on the multigene association evolutionary tree using 26 iridovirus core genes, SKIV-TJ was found to be most closely related to Rock bream iridovirus (RBIV). Cumulative mortality of spotted knifejaw infected with SKIV-TJ reached 100% by day 9. A transcriptomic analysis were conducted and a total of 5517 differentially expressed genes were identified, including 2757 upregulated genes and 2760 downregulated genes. The upregulated genes were associated with viral infection and immune signaling pathways. Our findings provide a valuable genetic resource and a deeper understanding of the immune response to SKIV infection in spotted knifejaw.
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Affiliation(s)
- Jiaming Liao
- College of Marine Sciences, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Shaozhu Kang
- College of Marine Sciences, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Luhao Zhang
- College of Marine Sciences, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Dongzhuo Zhang
- Guangdong Winsun Biological Pharmaceutical Co., Ltd., Guangzhou, 511356, China
| | - Zhuqing Xu
- College of Marine Sciences, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Qiwei Qin
- College of Marine Sciences, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China; Laboratory for Marine Biology and Biotechnology, Pilot National Laboratory for Marine Science and Technology (Qingdao), Qingdao, 266000, China.
| | - Jingguang Wei
- College of Marine Sciences, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China; Department of Biological Sciences, National University of Singapore, Singapore, 117543, Singapore.
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10
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Kawato Y, Takada Y, Mizuno K, Harakawa S, Yoshihara Y, Nakagawa Y, Kurobe T, Kawakami H, Ito T. Assessing the transmission risk of red sea bream iridovirus (RSIV) in environmental water: insights from fish farms and experimental settings. Microbiol Spectr 2023; 11:e0156723. [PMID: 37737592 PMCID: PMC10580957 DOI: 10.1128/spectrum.01567-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2023] [Accepted: 08/07/2023] [Indexed: 09/23/2023] Open
Abstract
Aquatic animal viruses are considered to be transmitted via environmental water between fish farms. This study aimed to understand the actual transmission risk of red sea bream iridovirus (RSIV) through environmental water among fish farms. An environmental DNA (eDNA) method using iron-based flocculation coupled with large-pore filtration was used to monitor RSIV DNA copies in seawater from fish farms and from an experimental infection model. RSIV dispersion in seawater from a net pen where the disease outbreak occurred was visualized by the inverse distance weighting method using multiple-sampling data sets from a fish farm. The analysis demonstrated that the center of the net pen had a high viral load, and RSIV seemed to be quickly diluted by the tidal current. To evaluate the transmission risk of RSIV in environmental water, the red sea bream Pagrus major (approximately 10 g) was exposed to RSIV-contained seawater (103, 104, 105, 106, and 107 copies/L) for 3 days, which mimicked field exposure. A probit analysis of the challenge test indicated that the inferred infection rates of seawater containing 105.9 copies/L and 103.1 copies/L of RSIV were 50% and 0.0001%, respectively. In the surveillance for 3 years at 10 fixed points (n = 306), there were only seven samples in which the viral load exceeded 104 copies/L in seawater. These results suggest that the transmission of RSIV among fish farms via seawater is highly associated with the distance between the net pens, and the environmental water is not always an infection source for the transmission of RSIV between fish farms. IMPORTANCE Our surveillance of viral loads for red sea bream iridovirus (RSIV) by monitoring environmental DNA in fish farms suggested that the viral loads in the seawater were low, except for the net pens where RSIV outbreaks occurred. Furthermore, our experimental infection model indicated that the infection risk of RSIV-contained seawater with less than 103 copies/L was extremely low. The limited risk of environmental water for transmission of RSIV gives an insight that RSIV could be partly transmitted between fish farms due to the movement of equipment and/or humans from the fish farm where the disease outbreaks. Since our data suggest that seawater can function as a potential wall to reduce the transmission of RSIV, biosecurity management, such as disinfection of equipment associated with fish farms could be effective, even in the semi-open system aquaculture that the environmental water can be freely transferred, to reduce the risk of RSIV outbreaks.
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Affiliation(s)
- Yasuhiko Kawato
- Pathology Division, Nansei Field Station, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Mie, Japan
| | - Yuzo Takada
- Pathology Division, Nansei Field Station, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Mie, Japan
| | | | | | | | - Yukihiro Nakagawa
- Pathology Division, Tamaki Field Station, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Mie, Japan
| | - Tomofumi Kurobe
- Pathology Division, Nansei Field Station, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Mie, Japan
| | | | - Takafumi Ito
- Pathology Division, Nansei Field Station, Fisheries Technology Institute, Japan Fisheries Research and Education Agency, Mie, Japan
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Fu W, Li Y, Fu Y, Zhang W, Luo P, Sun Q, Yu F, Weng S, Li W, He J, Dong C. The Inactivated ISKNV-I Vaccine Confers Highly Effective Cross-Protection against Epidemic RSIV-I and RSIV-II from Cultured Spotted Sea Bass Lateolabrax maculatus. Microbiol Spectr 2023; 11:e0449522. [PMID: 37222626 PMCID: PMC10269448 DOI: 10.1128/spectrum.04495-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2022] [Accepted: 05/02/2023] [Indexed: 05/25/2023] Open
Abstract
The genus Megalocytivirus of the family Iridoviridae is composed of two distinct species, namely, infectious spleen and kidney necrosis virus (ISKNV) and scale drop disease virus (SDDV), and both are important causative agents in a variety of bony fish worldwide. Of them, the ISKNV species is subdivided into three genotypes, namely, red seabream iridovirus (RSIV), ISKNV, and turbot reddish body iridovirus (TRBIV), and a further six subgenotypes, RSIV-I, RSIV-II, ISKNV-I, ISKNV-II, TRBIV-I, and TRBIV-II. Commercial vaccines derived from RSIV-I , RSIV-II and ISKNV-I have been available to several fish species. However, studies regarding the cross-protection effect among different genotype or subgenotype isolates have not been fully elucidated. In this study, RSIV-I and RSIV-II were demonstrated as the causative agents in cultured spotted seabass, Lateolabrax maculatus, through serial robust evidence, including cell culture-based viral isolation, whole-genome determination and phylogeny analysis, artificial challenge, histopathology, immunohistochemistry, and immunofluorescence as well as transmission electron microscope observation. Thereafter, a formalin-killed cell (FKC) vaccine generated from an ISKNV-I isolate was prepared to evaluate the protective effects against two spotted seabass original RSIV-I and RSIV-II. The result showed that the ISKNV-I-based FKC vaccine conferred almost complete cross-protection against RSIV-I and RSIV-II as well as ISKNV-I itself. No serotype difference was observed among RSIV-I, RSIV-II, and ISKNV-I. Additionally, the mandarin fish Siniperca chuatsi is proposed as an ideal infection and vaccination fish species for the study of various megalocytiviral isolates. IMPORTANCE Red seabream iridovirus (RSIV) infects a wide mariculture bony fish and has resulted in significant annual economic loss worldwide. Previous studies showed that the phenotypic diversity of infectious RSIV isolates would lead to different virulence characteristics, viral antigenicity, and vaccine efficacy as well as host range. Importantly, it is still doubted whether a universal vaccine could confer the same highly protective effect against various genotypic isolates. Our study here presented enough experimental evidence that a water in oil (w/o) formation of inactivated ISKNV-I vaccine could confer almost complete protection against RSIV-I and RSIV-II as well as ISKNV-I itself. Our study provides valuable data for better understanding the differential infection and immunity among different genotypes of ISKNV and RSIV isolates in the genus Megalocytivirus.
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Affiliation(s)
- Weixuan Fu
- State Key Laboratory of Biocontrol (Guangzhou, SYSU)/Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai, SMST-GDL), School of Life Sciences of Sun Yat-sen University, Guangzhou, China
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Yong Li
- Zhuhai Modern Agriculture Development Center, Zhuhai, China
| | - Yuting Fu
- State Key Laboratory of Biocontrol (Guangzhou, SYSU)/Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai, SMST-GDL), School of Life Sciences of Sun Yat-sen University, Guangzhou, China
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, People’s Republic of China
- School of Marine Sciences, Sun Yat-sen University, Zhuhai, Guangdong, China
| | - Wenfeng Zhang
- State Key Laboratory of Biocontrol (Guangzhou, SYSU)/Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai, SMST-GDL), School of Life Sciences of Sun Yat-sen University, Guangzhou, China
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Panpan Luo
- State Key Laboratory of Biocontrol (Guangzhou, SYSU)/Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai, SMST-GDL), School of Life Sciences of Sun Yat-sen University, Guangzhou, China
| | - Qianqian Sun
- State Key Laboratory of Biocontrol (Guangzhou, SYSU)/Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai, SMST-GDL), School of Life Sciences of Sun Yat-sen University, Guangzhou, China
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Fangzhao Yu
- Zhuhai Modern Agriculture Development Center, Zhuhai, China
| | - Shaoping Weng
- State Key Laboratory of Biocontrol (Guangzhou, SYSU)/Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai, SMST-GDL), School of Life Sciences of Sun Yat-sen University, Guangzhou, China
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, People’s Republic of China
| | - Wangdong Li
- Zhuhai Modern Agriculture Development Center, Zhuhai, China
| | - Jianguo He
- State Key Laboratory of Biocontrol (Guangzhou, SYSU)/Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai, SMST-GDL), School of Life Sciences of Sun Yat-sen University, Guangzhou, China
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, People’s Republic of China
- School of Marine Sciences, Sun Yat-sen University, Zhuhai, Guangdong, China
| | - Chuanfu Dong
- State Key Laboratory of Biocontrol (Guangzhou, SYSU)/Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai, SMST-GDL), School of Life Sciences of Sun Yat-sen University, Guangzhou, China
- Institute of Aquatic Economic Animals and Guangdong Province Key Laboratory for Aquatic Economic Animals, Sun Yat-sen University, Guangzhou, People’s Republic of China
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12
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Qin P, Munang'andu HM, Xu C, Xie J. Megalocytivirus and Other Members of the Family Iridoviridae in Finfish: A Review of the Etiology, Epidemiology, Diagnosis, Prevention and Control. Viruses 2023; 15:1359. [PMID: 37376659 DOI: 10.3390/v15061359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/06/2023] [Accepted: 06/11/2023] [Indexed: 06/29/2023] Open
Abstract
Aquaculture has expanded to become the fastest growing food-producing sector in the world. However, its expansion has come under threat due to an increase in diseases caused by pathogens such as iridoviruses commonly found in aquatic environments used for fish farming. Of the seven members belonging to the family Iridoviridae, the three genera causing diseases in fish comprise ranaviruses, lymphocystiviruses and megalocytiviruses. These three genera are serious impediments to the expansion of global aquaculture because of their tropism for a wide range of farmed-fish species in which they cause high mortality. As economic losses caused by these iridoviruses in aquaculture continue to rise, the urgent need for effective control strategies increases. As a consequence, these viruses have attracted a lot of research interest in recent years. The functional role of some of the genes that form the structure of iridoviruses has not been elucidated. There is a lack of information on the predisposing factors leading to iridovirus infections in fish, an absence of information on the risk factors leading to disease outbreaks, and a lack of data on the chemical and physical properties of iridoviruses needed for the implementation of biosecurity control measures. Thus, the synopsis put forth herein provides an update of knowledge gathered from studies carried out so far aimed at addressing the aforesaid informational gaps. In summary, this review provides an update on the etiology of different iridoviruses infecting finfish and epidemiological factors leading to the occurrence of disease outbreaks. In addition, the review provides an update on the cell lines developed for virus isolation and culture, the diagnostic tools used for virus detection and characterization, the current advances in vaccine development and the use of biosecurity in the control of iridoviruses in aquaculture. Overall, we envision that the information put forth in this review will contribute to developing effective control strategies against iridovirus infections in aquaculture.
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Affiliation(s)
- Pan Qin
- Key Laboratory of Marine Biotechnology of Fujian Province, College of Marine Sciences, Fujian Agriculture and Forestry University, Fuzhou 350002, China
| | | | - Cheng Xu
- Department of Paraclinical Sciences, Faculty of Veterinary Medicine, Norwegian University of Life Sciences, 1433 Ås, Norway
| | - Jianjun Xie
- Key Laboratory of Mariculture and Enhancement of Zhejiang Province, Marine Fisheries Research Institute of Zhejiang, Zhoushan 316100, China
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13
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Jeong YJ, Kim KI. A New Cell Line Derived from the Caudal Fin of the Dwarf Gourami ( Trichogaster lalius) and Its Susceptibility to Fish Viruses. BIOLOGY 2023; 12:829. [PMID: 37372114 DOI: 10.3390/biology12060829] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2023] [Revised: 06/01/2023] [Accepted: 06/06/2023] [Indexed: 06/29/2023]
Abstract
The detection of megalocytiviruses, especially the infectious spleen and kidney necrosis virus (ISKNV), in ornamental fish has increased with the rapid growth of the ornamental fish industry. In this study, dwarf gourami fin (DGF) cells derived from the caudal fin of the dwarf gourami (Trichogaster lalius), which is highly susceptible to red sea bream iridovirus (RSIV) and ISKNV, were established and characterized. The DGF cells were grown at temperatures ranging from 25 °C to 30 °C in Leibovitz's L-15 medium supplemented with 15% fetal bovine serum and were subcultured for more than 100 passages, predominantly with epithelial-like cells. DGF cells had a diploid chromosome number of 2n = 44. Although the initial purpose of this study was to establish a cell line for the causative agents of red sea bream iridoviral disease (RSIV and ISKNV), DGF cells were also susceptible to rhabdoviruses (viral hemorrhagic septicemia virus, hirame rhabdovirus, and spring viraemia of carp virus), exhibiting a significant cytopathic effect characterized by cell rounding and lysis. Additionally, viral replication and virion morphology were confirmed using virus-specific conventional polymerase chain reaction and transmission electron microscopy. Furthermore, both RSIV and ISKNV were replicated at high concentrations in DGF cells compared to other cell lines. Notably, the DGF cells maintained a monolayer during ISKNV infection, indicating the possibility of persistent infection. Thus, DGF can be used for viral diagnosis and may play a critical role in advancing our understanding of ISKNV pathogenesis.
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Affiliation(s)
- Ye-Jin Jeong
- Department of Aquatic Life Medicine, Pukyong National University, Busan 48513, Republic of Korea
| | - Kwang-Il Kim
- Department of Aquatic Life Medicine, Pukyong National University, Busan 48513, Republic of Korea
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14
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Koda SA, Subramaniam K, Groff JM, Yanong RP, Pouder DB, Pedersen M, Pelton C, Garner MM, Phelps NBD, Armien AG, Hyatt MW, Hick PM, Becker JA, Stidworthy MF, Waltzek TB. Genetic characterization of infectious spleen and kidney necrosis virus in Banggai cardinalfish Pterapogon kauderni identified from eight separate cases between 2000 and 2017. JOURNAL OF FISH DISEASES 2023. [PMID: 37057714 DOI: 10.1111/jfd.13788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Revised: 03/23/2023] [Accepted: 03/28/2023] [Indexed: 05/07/2023]
Affiliation(s)
- Samantha A Koda
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
| | - Kuttichantran Subramaniam
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
| | - Joseph M Groff
- Retired, Department of Pathology, Microbiology and Immunology, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Roy P Yanong
- Tropical Aquaculture Laboratory, School of Forest, Fisheries, and Geomatics Sciences, Institute of Food and Agricultural Sciences, University of Florida, Ruskin, Florida, USA
| | - Deborah B Pouder
- Tropical Aquaculture Laboratory, School of Forest, Fisheries, and Geomatics Sciences, Institute of Food and Agricultural Sciences, University of Florida, Ruskin, Florida, USA
| | - Matt Pedersen
- Reef to Rainforest Media, LLC, Shelburne, Vermont, USA
- MiniWaters LLC, Duluth, Minnesota, USA
| | - Craig Pelton
- Sea Life Aquarium, Orlando, Florida, USA
- OdySea Aquarium, Scottsdale, Arizona, USA
| | | | - Nicholas B D Phelps
- Department of Fisheries, Wildlife and Conservation Biology, University of Minnesota, St. Paul, Minnesota, USA
| | - Anibal G Armien
- California Animal Health and Food Safety Laboratory System, School of Veterinary Medicine, University of California Davis, California, USA
| | | | - Paul M Hick
- The University of Sydney, School of Veterinary Science, Camden, New South Wales, Australia
| | - Joy A Becker
- The University of Sydney, School of Life and Environmental Sciences, Camden, New South Wales, Australia
| | | | - Thomas B Waltzek
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, USA
- Sea Life Aquarium, Orlando, Florida, USA
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15
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Kim KH, Kang G, Woo WS, Sohn MY, Son HJ, Kwon MG, Kim JO, Park CI. Red Sea Bream Iridovirus Kinetics, Tissue Tropism, and Interspecies Horizontal Transmission in Flathead Grey Mullets ( Mugil cephalus). Animals (Basel) 2023; 13:ani13081341. [PMID: 37106904 PMCID: PMC10135084 DOI: 10.3390/ani13081341] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Revised: 04/12/2023] [Accepted: 04/12/2023] [Indexed: 04/29/2023] Open
Abstract
Red sea bream iridovirus (RSIV) causes significant economic losses in the aquaculture industry. We analyzed the pathogenicity of RSIV in flathead grey mullets (Mugil cephalus), the correlation of histopathological lesions, and interspecies horizontal transmission, through immersion infection and cohabitation challenges. Flathead grey mullets, which were challenged by immersion infection, exhibited mortality at 14 and 24 days after RSIV exposure. Viral shedding in seawater peaked 2-3 days before or after the observed mortality. Specific lesions of RSIV were observed in the spleen and kidney, and the correlation between histopathological grade and viral load was the highest in the spleen. In a cohabitation challenge, flathead grey mullets were the donors, and healthy rock bream, red sea bream, and flathead grey mullets were the recipients. Viral shedding in seawater was the highest in flathead grey mullet and rock bream at 25 °C, with 106.0 RSIV copies L/g at 14 dpi. No mortality was observed in any group challenged at 15 °C, and no RSIV was detected in seawater after 30 dpi. The virus shed from RSIV-infected flathead grey mullets caused horizontal transmission through seawater. These findings suggest that rapid decision-making is warranted when managing disease in fish farms.
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Affiliation(s)
- Kyung-Ho Kim
- Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 2, Tongyeonghaean-ro, Tongyeong 53064, Republic of Korea
| | - Gyoungsik Kang
- Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 2, Tongyeonghaean-ro, Tongyeong 53064, Republic of Korea
| | - Won-Sik Woo
- Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 2, Tongyeonghaean-ro, Tongyeong 53064, Republic of Korea
| | - Min-Young Sohn
- Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 2, Tongyeonghaean-ro, Tongyeong 53064, Republic of Korea
| | - Ha-Jeong Son
- Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 2, Tongyeonghaean-ro, Tongyeong 53064, Republic of Korea
| | - Mun-Gyeong Kwon
- Aquatic Disease Control Division, National Fishery Products Quality Management Service, 216, Gijanghaean-ro, Gijang, Busan 46083, Republic of Korea
| | - Jae-Ok Kim
- Aquatic Disease Control Division, National Fishery Products Quality Management Service, 17, Jungnim 2-ro, Tongyeong 53019, Republic of Korea
| | - Chan-Il Park
- Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 2, Tongyeonghaean-ro, Tongyeong 53064, Republic of Korea
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Zhao Z, Huang Y, Liu C, Zhu D, Gao S, Liu S, Peng R, Zhang Y, Huang X, Qi J, Wong CCL, Zhang X, Wang P, Qin Q, Gao GF. Near-atomic architecture of Singapore grouper iridovirus and implications for giant virus assembly. Nat Commun 2023; 14:2050. [PMID: 37041173 PMCID: PMC10090177 DOI: 10.1038/s41467-023-37681-9] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2022] [Accepted: 03/28/2023] [Indexed: 04/13/2023] Open
Abstract
Singapore grouper iridovirus (SGIV), one of the nucleocytoviricota viruses (NCVs), is a highly pathogenic iridovirid. SGIV infection results in massive economic losses to the aquaculture industry and significantly threatens global biodiversity. In recent years, high morbidity and mortality in aquatic animals have been caused by iridovirid infections worldwide. Effective control and prevention strategies are urgently needed. Here, we present a near-atomic architecture of the SGIV capsid and identify eight types of capsid proteins. The viral inner membrane-integrated anchor protein colocalizes with the endoplasmic reticulum (ER), supporting the hypothesis that the biogenesis of the inner membrane is associated with the ER. Additionally, immunofluorescence assays indicate minor capsid proteins (mCPs) could form various building blocks with major capsid proteins (MCPs) before the formation of a viral factory (VF). These results expand our understanding of the capsid assembly of NCVs and provide more targets for vaccine and drug design to fight iridovirid infections.
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Affiliation(s)
- Zhennan Zhao
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Youhua Huang
- College of Marine Sciences, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Congcong Liu
- Cryo-EM Center, Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China
- Institute for Hepatology, National Clinical Research Center for Infectious Disease, Shenzhen Third People's Hospital, Shenzhen, 518112, China
| | - Dongjie Zhu
- School of Life Science, University of Science and Technology of China, Hefei, 230026, China
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China
| | - Shuaixin Gao
- Clinical Research Institute, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing, 100730, China
- Department of Human Sciences & James Comprehensive Cancer Center, The Ohio State University, Columbus, 43210, USA
| | - Sheng Liu
- Cryo-EM Center, Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China
| | - Ruchao Peng
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, 19104, USA
| | - Ya Zhang
- College of Marine Sciences, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Xiaohong Huang
- College of Marine Sciences, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China
| | - Jianxun Qi
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
- Beijing Life Science Academy, Beijing, 102209, China.
| | - Catherine C L Wong
- Clinical Research Institute, State Key Laboratory of Complex Severe and Rare Diseases, Peking Union Medical College Hospital, Chinese Academy of Medical Science & Peking Union Medical College, Beijing, 100730, China.
| | - Xinzheng Zhang
- National Laboratory of Biomacromolecules, Institute of Biophysics, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
| | - Peiyi Wang
- Cryo-EM Center, Department of Biology, Southern University of Science and Technology, Shenzhen, 518055, China.
| | - Qiwei Qin
- College of Marine Sciences, South China Agricultural University, Guangdong Laboratory for Lingnan Modern Agriculture, Guangzhou, 510642, China.
| | - George F Gao
- CAS Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing, 100101, China.
- University of Chinese Academy of Sciences, Beijing, 100049, China.
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17
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Kim KH, Kang G, Woo WS, Sohn MY, Son HJ, Kwon MG, Kim JO, Park CI. Impact of Red Sea Bream Iridovirus Infection on Rock Bream (Oplegnathus fasciatus) and Other Fish Species: A Study of Horizontal Transmission. Animals (Basel) 2023; 13:ani13071210. [PMID: 37048466 PMCID: PMC10093424 DOI: 10.3390/ani13071210] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2023] [Revised: 03/29/2023] [Accepted: 03/30/2023] [Indexed: 04/03/2023] Open
Abstract
Red sea bream iridovirus (RSIV) causes significant economic losses in aquaculture. Here, we analyzed the pathogenicity, viral shedding, and transmission dynamics of RSIV in rock bream (Oplegnathus fasciatus) by employing immersion infection and cohabitation challenge models. Rock bream challenged by immersion exposure exhibited 100% mortality within 35 days post RSIV exposure, indicating that the viral shedding in seawater peaked after mortality. At 25 °C, a positive correlation between the viral loads within infected rock bream and virus shedding into the seawater was observed. Specific RSIV lesions were observed in the spleen and kidney of the infected rock bream, and the viral load in the spleen had the highest correlation with the histopathological grade. A cohabitation challenge mimicking the natural transmission conditions was performed to assess the virus transmission and determine the pathogenicity and viral load. The RSIV-infected rock breams (donors) were cohabited with uninfected rock bream, red sea bream (Pagrus major), and flathead grey mullet (Mugil cephalus) (recipients) at both 25 °C and 15 °C. In the cohabitation challenge group maintained at 15 °C, no mortality was observed across all experimental groups. However, RSIV was detected in both seawater and the recipient fish. Our results provide preliminary data for further epidemiological analyses and aid in the development of preventive measures and management of RSIVD in aquaculture.
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Fusianto CK, Becker JA, Subramaniam K, Whittington RJ, Koda SA, Waltzek TB, Murwantoko, Hick PM. Genotypic Characterization of Infectious Spleen and Kidney Necrosis Virus (ISKNV) in Southeast Asian Aquaculture. Transbound Emerg Dis 2023. [DOI: 10.1155/2023/6643006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/03/2023]
Abstract
Infectious spleen and kidney necrosis virus (ISKNV) is a species within the genus Megalocytivirus (family Iridoviridae), which causes high mortality disease in many freshwater and marine fish species. ISKNV was first reported in Asia and is an emerging threat to aquaculture with increasing global distribution, in part due to its presence in ornamental fish with clinical and subclinical infections. The species ISKNV includes three genotypes: red seabream iridovirus (RSIV), turbot reddish body iridovirus (TRBIV), and ISKNV. There is an increasing overlap in the recognized range of susceptible fish hosts and the geographic distribution of these distinct genotypes. To better understand the disease caused by ISKNV, a nucleic acid hybridization capture enrichment was used prior to sequencing to characterize whole genomes from archived clinical specimens of aquaculture and ornamental fish from Southeast Asia (n = 16). The method was suitable for tissue samples containing 2.50 × 104–4.58 × 109 ISKNV genome copies mg−1. Genome sequences determined using the hybridization capture method were identical to those obtained directly from tissues when there was sufficient viral DNA to sequence without enrichment (n = 2). ISKNV genomes from diverse locations, environments, and hosts had very high similarity and matched established genotype classifications (14 ISKNV genotype Clade 1 genomes with >98.81% nucleotide similarity). Conversely, two different genotypes were obtained at the same time and location (RSIV and ISKNV from grouper, Indonesia with 92.44% nucleotide similarity). Gene-by-gene analysis with representative ISKNV genomes identified 59 core genes within the species (>95% amino acid identity). The 14 Clade 1 ISKNV genomes in this study had 100% aa identity for 92–105 of 122 predicted genes. Despite high overall sequence similarity, phylogenetic analyses using single nucleotide polymorphisms differentiated isolates from different host species, country of origin, and time of collection. Whole genome studies of ISKNV and other megalocytiviruses enable genomic epidemiology and will provide information to enhance disease control in aquaculture.
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Volpe E, Errani F, Mandrioli L, Ciulli S. Advances in Viral Aquatic Animal Disease Knowledge: The Molecular Methods' Contribution. BIOLOGY 2023; 12:biology12030466. [PMID: 36979158 PMCID: PMC10045235 DOI: 10.3390/biology12030466] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 03/15/2023] [Accepted: 03/17/2023] [Indexed: 03/30/2023]
Abstract
Aquaculture is the fastest-growing food-producing sector, with a global production of 122.6 million tonnes in 2020. Nonetheless, aquatic animal production can be hampered by the occurrence of viral diseases. Furthermore, intensive farming conditions and an increasing number of reared fish species have boosted the number of aquatic animals' pathogens that researchers have to deal with, requiring the quick development of new detection and study methods for novel unknown pathogens. In this respect, the molecular tools have significantly contributed to investigating thoroughly the structural constituents of fish viruses and providing efficient detection methods. For instance, next-generation sequencing has been crucial in reassignment to the correct taxonomic family, the sturgeon nucleo-cytoplasmic large DNA viruses, a group of viruses historically known, but mistakenly considered as iridoviruses. Further methods such as in situ hybridisation allowed objectifying the role played by the pathogen in the determinism of disease, as the cyprinid herpesvirus 2, ostreid herpesvirus 1 and betanodaviruses. Often, a combination of molecular techniques is crucial to understanding the viral role, especially when the virus is detected in a new aquatic animal species. With this paper, the authors would critically revise the scientific literature, dealing with the molecular techniques employed hitherto to study the most relevant finfish and shellfish viral pathogens.
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Affiliation(s)
- Enrico Volpe
- Department of Veterinary Medical Sciences, Alma Mater Studiorum, University of Bologna, 47042 Cesenatico, FC, Italy
| | - Francesca Errani
- Department of Veterinary Medical Sciences, Alma Mater Studiorum, University of Bologna, 47042 Cesenatico, FC, Italy
| | - Luciana Mandrioli
- Department of Veterinary Medical Sciences, Alma Mater Studiorum, University of Bologna, 47042 Cesenatico, FC, Italy
| | - Sara Ciulli
- Department of Veterinary Medical Sciences, Alma Mater Studiorum, University of Bologna, 47042 Cesenatico, FC, Italy
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Fonseca AA, Laguardia-Nascimento M, Ferreira APS, Pinto CDA, da Silva Gonçalves VL, Barbosa AAS, Rivetti Junior AV, Camargos MF. Genetic differentiation of Megalocytivirus by real time PCR and sequencing. Mol Biol Rep 2023; 50:3439-3450. [PMID: 36757549 DOI: 10.1007/s11033-023-08282-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Accepted: 01/13/2023] [Indexed: 02/10/2023]
Abstract
BACKGROUND Megalocytiviruses (MCV) are double-stranded DNA viruses that infect fish. Two species within the genus are epidemiologically important for fish farming: red sea bream iridovirus (RSIV) and infectious spleen and kidney necrosis virus (ISKNV). The objective of this work was to study regions that allow the differentiation and correct diagnosis of RSIV and ISKNV. METHODS The regions ORF450L, ORF342L, ORF077, and the intergenic region between ORF37 and ORF42R were sequenced and compared with samples from the database. RESULTS The tree constructed using the sequencing of the PCR product Megalocytivirus. ORF077 separated the three major clades of MCV. RISV genotypes were well divided, but not ISKNV. All qPCRs tests showed acceptable repeatability values, that is, less than 5%. CONCLUSION Two qPCRs for ISKNV detection and two for RSIV were considered suitable for use in the diagnosis and typing of MCV. The results of this study demonstrate the importance of an accurate evaluation of methodologies for the differentiation of MCV.
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Affiliation(s)
- Antônio Augusto Fonseca
- Laboratório Federal de Defesa Agropecuária de Minas Gerais, Pedro Leopoldo, Brazil. .,UNIFEMM - Centro Universitário, Sete Lagoas, Brazil.
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Kim KH, Kang G, Woo WS, Sohn MY, Son HJ, Park CI. Development of a Propidium Monoazide-Based Viability Quantitative PCR Assay for Red Sea Bream Iridovirus Detection. Int J Mol Sci 2023; 24:ijms24043426. [PMID: 36834834 PMCID: PMC9958570 DOI: 10.3390/ijms24043426] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 01/30/2023] [Accepted: 02/07/2023] [Indexed: 02/11/2023] Open
Abstract
Red sea bream iridovirus (RSIV) is an important aquatic virus that causes high mortality in marine fish. RSIV infection mainly spreads through horizontal transmission via seawater, and its early detection could help prevent disease outbreaks. Although quantitative PCR (qPCR) is a sensitive and rapid method for detecting RSIV, it cannot differentiate between infectious and inactive viruses. Here, we aimed to develop a viability qPCR assay based on propidium monoazide (PMAxx), which is a photoactive dye that penetrates damaged viral particles and binds to viral DNA to prevent qPCR amplification, to distinguish between infectious and inactive viruses effectively. Our results demonstrated that PMAxx at 75 μM effectively inhibited the amplification of heat-inactivated RSIV in viability qPCR, allowing the discrimination of inactive and infectious RSIV. Furthermore, the PMAxx-based viability qPCR assay selectively detected the infectious RSIV in seawater more efficiently than the conventional qPCR and cell culture methods. The reported viability qPCR method will help prevent the overestimation of red sea bream iridoviral disease caused by RSIV. Furthermore, this non-invasive method will aid in establishing a disease prediction system and in epidemiological analysis using seawater.
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22
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Koda SA, Subramaniam K, Hick PM, Hall E, Waltzek TB, Becker JA. Partial validation of a TaqMan quantitative polymerase chain reaction for the detection of the three genotypes of Infectious spleen and kidney necrosis virus. PLoS One 2023; 18:e0281292. [PMID: 36735738 PMCID: PMC9897559 DOI: 10.1371/journal.pone.0281292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2022] [Accepted: 01/19/2023] [Indexed: 02/04/2023] Open
Abstract
Megalocytiviruses (MCVs) are double-stranded DNA viruses known to infect important freshwater and marine fish species in the aquaculture, food, and ornamental fish industries worldwide. Infectious spleen and kidney necrosis virus (ISKNV) is the type species within the genus Megalocytivirus that causes red seabream iridoviral disease (RSIVD) which is a reportable disease to the World Animal Health Organization (WOAH). To better control the transboundary spread of this virus and support WOAH reporting requirements, we developed and partially validated a TaqMan real-time qPCR assay (ISKNV104R) to detect all three genotypes of ISKNV, including the two genotypes that cause RSIVD. Parameters averaged across 48 experiments used a 10-fold dilution series of linearized plasmid DNA (107-101 copies), carrying a fragment of the three-spot gourami iridovirus (TSGIV) hypothetical protein revealed that the assay was linear over 7 orders of magnitude (107-101), a mean efficiency of 99.97 ± 2.92%, a mean correlation coefficient of 1.000 ± 0.001, and a limit of detection (analytical sensitivity) of ≤10 copies of TSGIV DNA. The diagnostic sensitivity and specificity for the ISKNV104R qPCR assay was evaluated and compared to other published assays using a panel of 397 samples from 21 source populations with different prevalence of ISKNV infection (0-100%). The diagnostic sensitivity and specificity for the ISKNV104R qPCR assay was 91.99% (87.28-95.6; 95% CI) and 89.8% (83.53-94.84). The latent class analysis showed that the ISKNV104R qPCR assay had similar diagnostic sensitivities and specificities with overlapping confidence limits compared to a second TaqMan qPCR assay and a SYBR green assay. This newly developed TaqMan assay represents a partially validated qPCR assay for the detection of the three genotypes of the species ISKNV. The ISKNV104R qPCR assay once fully validated, will serve as an improved diagnostic tool that can be used for ISKNV surveillance efforts and diagnosis in subclinical fish to prevent further spread of MCVs throughout the aquaculture and ornamental fish industries.
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Affiliation(s)
- Samantha A. Koda
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
| | - Kuttichantran Subramaniam
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
| | - Paul M. Hick
- Sydney School of Veterinary Science, The University of Sydney, Camden, New South Wales, Australia
| | - Evelyn Hall
- Sydney School of Veterinary Science, The University of Sydney, Camden, New South Wales, Australia
| | - Thomas B. Waltzek
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, Florida, United States of America
- Emerging Pathogens Institute, University of Florida, Gainesville, Florida, United States of America
- * E-mail: (JAB); (TBW)
| | - Joy A. Becker
- School of Life and Environmental Sciences, The University of Sydney, Camden, New South Wales, Australia
- * E-mail: (JAB); (TBW)
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23
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Zhu M, Shen Z, Gu Y, Tong X, Zhang Y, Pan J, Feng Y, Hu X, Wang Y, Cao G, Xue R, Gong C. A recombinant baculovirus vector vaccine (BacMCP) against the infectious spleen and kidney necrosis virus (ISKNV). JOURNAL OF FISH DISEASES 2023; 46:165-176. [PMID: 36423261 DOI: 10.1111/jfd.13731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 11/05/2022] [Accepted: 11/12/2022] [Indexed: 06/16/2023]
Abstract
The infectious spleen and kidney necrosis virus (ISKNV) is a highly lethal virus, which has brought significant losses to aquaculture. Therefore, a new vaccine against ISKNV with high efficiency, safety and convenience must be developed. While baculoviruses are more commonly used as protein expression systems for vaccine antigen production, this paper used baculovirus technology to develop a live-vector vaccine, BacMCP, which contains the coding sequence of the major capsid protein (MCP) (GenBank accession no. AF371960) of ISKNV and is driven by a CMV promoter. Real-time PCR and immunofluorescence showed that the MCP gene was successfully delivered to and expressed in fish cells and tissues inoculated with BacMCP. Immune-related gene (IgM, TGF-β, IL-1, IL-8, TNF-α) expression was induced in BacMCP-treated groups of largemouth bass compared with control groups. Specific antibodies could be detected in the serum of BacMCP injection-vaccinated largemouth bass by ELISA. After injection or immersion vaccination with BacMCP for 21 days, largemouth bass were infected with ISKNV. The immune effect of the injected immunization on fish in different sizes was evaluated. The vaccine efficacy of injection-vaccinated bass was 100% in small bass and 85.7% in large bass. The vaccine efficacy of immersion-vaccinated small bass was 77.3%. This study suggested that BacMCP can be used as a vector-based vaccine candidate to prevent the diseases caused by ISKNV infection.
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Affiliation(s)
- Min Zhu
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
- Agricultural Biotechnology Research Institute, Agricultural biotechnology and Ecological Research Institute, Soochow University, Suzhou, China
| | - Zeen Shen
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
| | - Yuchao Gu
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
| | - Xinyu Tong
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
| | - Yaxin Zhang
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
| | - Jun Pan
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
| | - Yongjie Feng
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
- Agricultural Biotechnology Research Institute, Agricultural biotechnology and Ecological Research Institute, Soochow University, Suzhou, China
| | - Xiaolong Hu
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
- Agricultural Biotechnology Research Institute, Agricultural biotechnology and Ecological Research Institute, Soochow University, Suzhou, China
| | - Yujun Wang
- Guangxi Key Laboratory of Beibu Gulf Marine Biodiversity Conservation, Beibu Gulf University, Qinzhou, China
| | - Guangli Cao
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
- Agricultural Biotechnology Research Institute, Agricultural biotechnology and Ecological Research Institute, Soochow University, Suzhou, China
| | - Renyu Xue
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
- Agricultural Biotechnology Research Institute, Agricultural biotechnology and Ecological Research Institute, Soochow University, Suzhou, China
| | - Chengliang Gong
- School of Biology and Basic Medical Sciences, Soochow University, Suzhou, China
- Agricultural Biotechnology Research Institute, Agricultural biotechnology and Ecological Research Institute, Soochow University, Suzhou, China
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24
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Isolation, Characterization, and Transcriptome Analysis of an ISKNV-Like Virus from Largemouth Bass. Viruses 2023; 15:v15020398. [PMID: 36851612 PMCID: PMC9959643 DOI: 10.3390/v15020398] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2023] [Revised: 01/19/2023] [Accepted: 01/28/2023] [Indexed: 02/03/2023] Open
Abstract
Largemouth bass (Micropterus salmoides) is an important commercial fish farmed in China. Challenges related to diseases caused by pathogens, such as iridovirus, have become increasingly serious. In 2017, we detected iridovirus-infected diseased largemouth bass in Zunyi, Guizhou Province. The isolated virus was identified as an infectious spleen and kidney necrosis virus (ISKNV)-like virus (ISKNV-ZY). ISKNV-ZY induces a cytopathic effect after infecting mandarin fish brain (MFB) cells. Abundant hexagonal virus particles were observed in the cytoplasm of ISKNV-ZY-infected MFB cells, using electron microscopy. The whole genome of ISKNV-ZY contained 112,248 bp and 122 open reading frames. Phylogenetic tree analysis showed that ISKNV-ZY was most closely related to BCIV, indicating that it is an ISKNV-like megalocytivirus. ISKNV-ZY-infected largemouth bass started to die on day six and reached a death peak on days 7-8. Cumulative mortality reached 100% on day 10. Using RNA sequencing-based transcriptome analysis after ISKNV-ZY infection, 6254 differentially expressed unigenes (DEGs) were identified, of which 3518 were upregulated and 2673 downregulated. The DEGs were associated with endocytosis, thermogenesis, oxidative phosphorylation, the JAK-STAT signaling pathway, the MAPK signaling pathway, etc. These results contribute to understanding the molecular regulation mechanism of ISKNV infection and provide a basis for ISKNV prevention.
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25
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Zhang Y, Zhang C, Zhang Z, Sun W, Zhang X, Liu X. Analysis of the transcriptomic profiles of Mandarin fish (Siniperca chuatsi) infected with red sea bream iridovirus (RSIV). Microb Pathog 2023; 174:105921. [PMID: 36470347 DOI: 10.1016/j.micpath.2022.105921] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Revised: 11/27/2022] [Accepted: 11/29/2022] [Indexed: 12/12/2022]
Abstract
Red sea bream iridovirus (RSIV) belongs to the family Iridoviridae, genus Megalocytivirus, which could widely infect marine fish, causing diseases and huge economic losses. Now it has been reported that RSIV was also detected in diseased mandarin fish. Transmission electron microscopy and immunohistochemistry showed that spleen was the main target organ in mandarin fish infected with RSIV. To investigate the immune response mechanism of mandarin fish to RSIV infection, transcriptomics of RSIV-infected mandarin fish was analyzed. A total of 53,040 unigenes were obtained, and there were 21,576 and 17,904 unigenes had significant hit the Nr and SwissProt databases, respectively. In RSIV-infected and non-infected spleen tissues, there were 309 differentially expressed genes (DEGs), including 100 up-regulated genes and 209 down-regulated genes. Gene Ontology database (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways analysis were performed to reveal the function information and give a better understanding of the signal transduction pathways of DEGs. Further analysis of the cytokine-cytokine receptor interactions pathway exhibited that the expression of cytokines was widely activated after viral infection. In addition, ten DEGs were randomly selected and verified by quantitative real-time PCR, which revealed a similar expression tendency as the high-throughput sequencing data. These findings present valuable information that will benefit for better understanding of RSIV infection in mandarin fish.
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Affiliation(s)
- Yanbing Zhang
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Chunjie Zhang
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Zheling Zhang
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Wei Sun
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China
| | - Xiaojun Zhang
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China.
| | - Xiaodan Liu
- College of Animal Science and Technology, Yangzhou University, Yangzhou, 225009, China.
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26
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Chen PH, Hsueh TC, Hong JR. Infectious spleen and kidney necrosis virus induces the reactive oxidative species/Nrf2-mediated oxidative stress response for the regulation of mitochondrion-mediated Bax/Bak cell death signals in GF-1 cells. Front Microbiol 2022; 13:958476. [PMID: 36304944 PMCID: PMC9593061 DOI: 10.3389/fmicb.2022.958476] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Accepted: 09/21/2022] [Indexed: 11/13/2022] Open
Abstract
Infectious spleen and kidney necrosis virus (ISKNV) infections can trigger host cell death and are correlated with viral replication; however, they have rarely been considered in terms of the host organelle involvement. In the present study, we demonstrated that ISKNV triggered an oxidative stress signal in the Nrf2-mediated oxidative stress response and induced stress signals for Bax/Bak-mediated host cell death in fish GF-1 cells. The results showed that after ISKNV infection, the levels of reactive oxidative species (ROS) increased by 60–80% from day 3 to day 5, as assessed by an H2DCFDA assay for tracing hydrogen peroxide (H2O2), which was correlated with up to a one-fold change in the fish GF-1 cells. Furthermore, we found that ISKNV infection induced Nrf2-mediated ROS stress signals from D1 to D5, which were correlated with the upregulation of antioxidant enzymes, such as catalase, SOD1, and SOD2; these effects were blocked by the antioxidants GSH and NAC. By analyzing Nrf2-mediated ROS stress signals for cell death regulation via an apoptotic assay, we found that treatment with antioxidants reduced annexin-V-positive signals by 10% (GSH) to 15% (NAC); moreover, necrotic-positive signals were reduced by 6% (GSH) and 32% (NAC) at day 5 (D5) in GF-1 cells, as indicated by PI staining. Furthermore, we found that Nrf2-mediated ROS stress regulated mitochondrion-mediated Bax/Bak death signals at D3 and D5; this was effectively blocked by antioxidant treatment in the GF-1 cells, as demonstrated by a JC1 assay (ΔΨm) and western blot analysis. In addition, we found that downstream signals for caspase-9 and -3 activation were apparently blocked by antioxidant treatment at D3 and D5. Finally, we found that treatment with GSH and NAC reduced major capsid protein (MCP) expression and virus titer (TCID50%) by up to 15-fold at D5 in GF-1 cells. Thus, our data suggest that ISKNV can induce ROS production, which triggers Nrf2-mediated stress signals. Then, these stress signals can regulate mitochondrion-mediated Bax/Bak apoptotic signaling, which is connected to downstream caspase-9 and -3 activation. If ISKNV-induced Nrf2-mediated stress signaling is blocked, then the antioxidants GSH and NAC can also suppress apoptotic signals or reduce viral replication. These findings may provide insights into the control and treatment of double-stranded DNA viruses.
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Affiliation(s)
- Pin-Han Chen
- Lab of Molecular Virology and Biotechnology, Department of Biotechnology and Bioindustry Sciences, Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
- Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
| | - Tsai-Ching Hsueh
- Lab of Molecular Virology and Biotechnology, Department of Biotechnology and Bioindustry Sciences, Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
- Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
| | - Jiann-Ruey Hong
- Lab of Molecular Virology and Biotechnology, Department of Biotechnology and Bioindustry Sciences, Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
- Institute of Biotechnology, National Cheng Kung University, Tainan City, Taiwan
- *Correspondence: Jiann-Ruey Hong,
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Ishihara H, Harakawa S, Kawakami H, Yoshii K, Murase N, Yamada H, Fukuda Y, Nozaki R, Kawato S, Koiwai K, Hirono I, Kondo H. Whole-genome analysis of red sea bream iridovirus spread in 2021 in Japan provided epidemiological and viral traits insight. JOURNAL OF FISH DISEASES 2022; 45:1593-1597. [PMID: 35862188 DOI: 10.1111/jfd.13690] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2022] [Revised: 07/03/2022] [Accepted: 07/06/2022] [Indexed: 06/15/2023]
Abstract
Red sea bream iridovirus (RSIV) is the pathogen that causes red sea bream iridoviral disease. It causes a huge loss to the Japanese aquaculture industry. In 2021, outbreaks of red sea bream iridovirus occurred in South Japan. This study analysed nine whole-genome sequences of RSIV isolated in Oita and Ehime Prefectures in 2021 using a short-read next-generation sequencer. Nine isolates had highly uniform sequences, and there was no variant depending on locations or host species. Phylogenetic analyses with other reported megalocytivirus isolates showed that RSIV isolated in 2021 was genetically different from RSIV previously isolated in Oita and Ehime Prefectures in 2017-2019. These results suggest that RSIV isolated in Oita and Ehime Prefectures in 2021 might spread from a common ancestor different from the recent one. Additionally, it was found that RSIV isolated in 2021 had sequence mutations on protein-coding sequences that may be involved in viral pathogenicity and infectivity.
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Affiliation(s)
- Hikaru Ishihara
- Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Shogo Harakawa
- Ehime Fisheries Research Center, Ehime Research Institute of Agriculture, Forestry and Fisheries, Ehime, Japan
| | - Hidemasa Kawakami
- Ehime Fisheries Research Center, Ehime Research Institute of Agriculture, Forestry and Fisheries, Ehime, Japan
| | - Keisuke Yoshii
- Fisheries Research Division, Oita Prefectural Agriculture, Forestry and Fisheries Research Center, Oita, Japan
| | - Naoya Murase
- Fisheries Research Division, Oita Prefectural Agriculture, Forestry and Fisheries Research Center, Oita, Japan
| | - Hidetoshi Yamada
- Fisheries Research Division, Oita Prefectural Agriculture, Forestry and Fisheries Research Center, Oita, Japan
| | - Yutaka Fukuda
- Fisheries Research Division, Oita Prefectural Agriculture, Forestry and Fisheries Research Center, Oita, Japan
| | - Reiko Nozaki
- Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Satoshi Kawato
- Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Keiichiro Koiwai
- Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Ikuo Hirono
- Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Hidehiro Kondo
- Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Tokyo, Japan
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Kim KH, Choi KM, Joo MS, Kang G, Woo WS, Sohn MY, Son HJ, Kwon MG, Kim JO, Kim DH, Park CI. Red Sea Bream Iridovirus (RSIV) Kinetics in Rock Bream (Oplegnathus fasciatus) at Various Fish-Rearing Seawater Temperatures. Animals (Basel) 2022; 12:ani12151978. [PMID: 35953967 PMCID: PMC9367270 DOI: 10.3390/ani12151978] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Revised: 07/29/2022] [Accepted: 08/02/2022] [Indexed: 11/20/2022] Open
Abstract
Simple Summary Red sea bream iridoviral disease (RSIVD) generates serious economic losses by causing mass mortality events of rock bream during the season with high water temperature in the Republic of Korea and other Asian countries. However, very few studies have investigated RSIV kinetics in rock bream under various rearing water temperatures. In this paper, we investigated the viral load shedding of RSIV into seawater after artificially infecting rock bream (Oplegnathus fasciatus) with the virus. Overall, our data suggest that the viral load shedding of RSIV into seawater varies depending on water temperature and virus inoculation concentration. Our results reveal the potential of non-invasive virus detection approaches, such as the utilization of environmental DNA in fish farms. In addition, we showed that the quantitative analysis of seawater viruses can indirectly improve our understanding of disease progression in fish, potentially contributing to enhanced disease control. Abstract Red sea bream iridoviral disease (RSIVD) causes serious economic losses in the aquaculture industry. In this paper, we evaluated RSIV kinetics in rock bream under various rearing water temperatures and different RSIV inoculation concentrations. High viral copy numbers (approximately 103.7–106.7 RSIV genome copies/L/g) were observed during the period of active fish mortality after RSIV infection at all concentrations in the tanks (25 °C and 20 °C). In the group injected with 104 RSIV genome copies/fish, RSIV was not detected at 21–30 days post-infection (dpi) in the rearing seawater. In rock bream infected at 15 °C and subjected to increasing water temperature (1 °C/d until 25 °C) 3 days later, the virus replication rate and number of viral copies shed into the rearing seawater increased. With the decrease in temperature (1 °C/d) from 25 to 15 °C after the infection, the virus replicated rapidly and was released at high loads on the initial 3–5 dpi, whereas the number of viral copies in the fish and seawater decreased after 14 dpi. These results indicate that the number of viral copies shed into the rearing seawater varies depending on the RSIV infection level in rock bream.
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Affiliation(s)
- Kyung-Ho Kim
- Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 2, Tongyeonghaean-ro, Tongyeong 53064, Korea
| | - Kwang-Min Choi
- Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 2, Tongyeonghaean-ro, Tongyeong 53064, Korea
| | - Min-Soo Joo
- Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 2, Tongyeonghaean-ro, Tongyeong 53064, Korea
| | - Gyoungsik Kang
- Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 2, Tongyeonghaean-ro, Tongyeong 53064, Korea
| | - Won-Sik Woo
- Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 2, Tongyeonghaean-ro, Tongyeong 53064, Korea
| | - Min-Young Sohn
- Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 2, Tongyeonghaean-ro, Tongyeong 53064, Korea
| | - Ha-Jeong Son
- Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 2, Tongyeonghaean-ro, Tongyeong 53064, Korea
| | - Mun-Gyeong Kwon
- Aquatic Disease Control Division, National Fishery Products Quality Management Service, 216, Gijanghaean-ro, Gijang, Busan 46083, Korea
| | - Jae-Ok Kim
- Aquatic Disease Control Division, National Fishery Products Quality Management Service, 17, Jungnim 2-ro, Tongyeong 53019, Korea
| | - Do-Hyung Kim
- Department of Aquatic Life Medicine, College of Fisheries Science, Pukyong National University, 45, Yongso-ro, Nam-Gu, Busan 48513, Korea
- Correspondence: (D.-H.K.); (C.-I.P.); Tel.: +82-55-772-9153 (C.-I.P.)
| | - Chan-Il Park
- Department of Marine Biology & Aquaculture, Institute of Marine Industry, College of Marine Science, Gyeongsang National University, 2, Tongyeonghaean-ro, Tongyeong 53064, Korea
- Correspondence: (D.-H.K.); (C.-I.P.); Tel.: +82-55-772-9153 (C.-I.P.)
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Jeong MA, Jeong YJ, Kim KI. Virulence difference between red sea bream iridovirus mixed subtype I/II and subtype II and the expression of viral and apoptosis-related genes in infected rock bream (Oplegnathus fasciatus). FISH & SHELLFISH IMMUNOLOGY 2022; 127:195-202. [PMID: 35643355 DOI: 10.1016/j.fsi.2022.05.041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 04/28/2022] [Accepted: 05/19/2022] [Indexed: 06/15/2023]
Abstract
In this study, the virulence of the red sea bream iridovirus (RSIV) subtype II (17RbGs isolate) and a novel RSIV mixed subtype I/II (17SbTy isolate), which was genetically characterized in a previous study, were compared. The infectivity to rock bream (Oplegnathus fasciatus) determined by infectious dose (ID50) revealed that 17RbGs isolate was significantly more infective than 17SbTy isolate using both intraperitoneal injection and bath immersion. In a cohabitation challenge test that mimicked natural conditions, the cumulative mortality of the donor (RSIV-injected rock bream) and the recipient (cohabited naïve rock bream) was significantly higher in the 17RbGs group than in the 17SbTy group, regardless of RSIV injected doses, supporting the correlation between genetic mutation and pathogenicity. In addition, the maximum viral shedding ratio identified from RSIV-infected rock bream suggested that viral transmission through infection with the 17SbTy isolate could have a lower relative risk than that of infection with the 17RbGs isolate. In particular, the odds ratio based on the spleen index after 17RbGs infection was 55.00, which was inconsistent with that of 17SbTy infection (19.38), hence supporting the virulence difference between RSIVs. Furthermore, the expression of viral genes, including DNA membrane and myristoylated protein genes with insertion and deletion mutations, and that of caspase-8, which is related to caspase-dependent apoptosis induced by RSIV infection, were significantly upregulated at 11 days post 17RbGs-infection compared to that following 17SbTy infection. Notably, although viral genes were highly expressed in the early infection stage and caspase-8 was upregulated, the low caspase-3 expression may have inhibited apoptosis, reflecting the difference in virulence between different RSIV isolates. Several virulence factors, including pathogenicity, viral shedding ratio, odds ratio, and gene expression, support that RSIV mixed subtype I/II may be a less pathogenic RSIV isolate compared with general RSIV subtype II in a natural environment.
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Affiliation(s)
- Min A Jeong
- Department of Aquatic Life Medicine, Pukyong National University, Busan, Republic of Korea
| | - Ye Jin Jeong
- Department of Aquatic Life Medicine, Pukyong National University, Busan, Republic of Korea
| | - Kwang Il Kim
- Department of Aquatic Life Medicine, Pukyong National University, Busan, Republic of Korea.
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Wang G, Xu W, Cheng H, Xie J, Bai A, Xu W, Liang Q. Complete genome sequence and phylogenetic analysis of red seabream iridovirus isolated from a cage-cultured small yellow croaker (Larimichthys polyactis) in China. Arch Virol 2022; 167:2085-2088. [PMID: 35752987 DOI: 10.1007/s00705-022-05508-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2021] [Accepted: 05/09/2022] [Indexed: 11/02/2022]
Abstract
Iridoviruses are emerging pathogens that are widespread in diverse environments and hosts. Numerous members of the family Iridoviridae are known to cause severe disease in freshwater and marine organisms. Here, we report the complete genome sequence and phylogenetic analysis of iridovirus strain LPIV-ZS-2021, isolated from a small yellow croaker (Larimichthys polyactis) in China. The genome sequence comprises 110,560 bp with a G+C content of 53.42%, has 104 putative open reading frames (ORFs), and shares the highest sequence similarity with red seabream iridovirus (RSIV) isolated in Japan (98.61%). Phylogenetic analysis revealed that it belongs to RSIV clade 1. This is the first fully sequenced RSIV genome from a small yellow croaker. The host range expansion of members of the genus Megalocytivirus warrants further attention to determine its potential economic and ecological impact.
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Affiliation(s)
- Gengshen Wang
- Zhejiang Marine Fisheries Research Institute, Key Laboratory of Mariculture and Enhancement of Zhejiang Province, Zhoushan, 316021, China.,Marine and Fisheries Research Institute, Zhejiang Ocean University, Zhoushan, 316100, China
| | - Wei Xu
- Marine and Fisheries Research Institute, Zhejiang Ocean University, Zhoushan, 316100, China
| | - Haoxue Cheng
- Marine and Fisheries Research Institute, Zhejiang Ocean University, Zhoushan, 316100, China
| | - Jianjun Xie
- Marine and Fisheries Research Institute, Zhejiang Ocean University, Zhoushan, 316100, China
| | - Aixu Bai
- Huaian Customs District, Huaian, 223001, China
| | - Wenjun Xu
- Zhejiang Marine Fisheries Research Institute, Key Laboratory of Mariculture and Enhancement of Zhejiang Province, Zhoushan, 316021, China.,Marine and Fisheries Research Institute, Zhejiang Ocean University, Zhoushan, 316100, China
| | - Qizhang Liang
- Institute of Preventive Veterinary Medicine and Key Laboratory of Animal Virology of Ministry of Agriculture, College of Animal Sciences, Zhejiang University, Hangzhou, 310058, China.
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Fonseca AA, Laguardia-Nascimento M, Scotá Ferreira AP, Pinto CA, Pereira Freitas TR, Rivetti Júnior AV, Ferreira Homem VS, Camargos MF. Detection of megalocytivirus in Oreochromis niloticus and Pseudoplatystoma corruscans in Brazil. DISEASES OF AQUATIC ORGANISMS 2022; 149:25-32. [PMID: 35510818 DOI: 10.3354/dao03657] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
The infectious spleen and kidney necrosis virus (ISKNV) belongs to the genus Megalocytivirus (MCV), a group of double-stranded DNA genome viruses. The aim of this study was to retrospectively analyze samples from suspected foci of MCV infection in freshwater fish in Brazil. Samples were collected from infected fish between 2017 and 2021. Phylogenetic analysis revealed 2 groups of MCV circulating in the country. A genetically homogeneous group formed a clade with ISKNV samples from different parts of the world. Only 2 of the sequences from the state of Goiás showed a small genetic distance when compared to the larger group in the same clade. This study describes the validation of 3 qPCR methods and the presence of MCV in Brazil since 2017, including a genotype not previously described.
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Affiliation(s)
- Antônio Augusto Fonseca
- Ministério da Agricultura, Pecuária e Abastecimento, LFDA-MG/MAPA, 33600-000 Pedro Leopoldo, MG, Brazil
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32
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Jung MH, Nikapitiya C, Kim SJ, Han HJ, Kim MS, Choi HS, Jung SJ. Protective immunity induced by ankyrin repeat-containing protein-based DNA vaccine against rock bream iridovirus (RBIV) in rock bream (Oplegnathus fasciatus). Virus Res 2022; 318:198827. [DOI: 10.1016/j.virusres.2022.198827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2022] [Revised: 05/19/2022] [Accepted: 05/23/2022] [Indexed: 12/01/2022]
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Infectious Spleen and Kidney Necrosis Virus (ISKNV) Triggers Mitochondria-Mediated Dynamic Interaction Signals via an Imbalance of Bax/Bak over Bcl-2/Bcl-xL in Fish Cells. Viruses 2022; 14:v14050922. [PMID: 35632664 PMCID: PMC9144193 DOI: 10.3390/v14050922] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/26/2022] [Accepted: 04/26/2022] [Indexed: 12/30/2022] Open
Abstract
The molecular pathogenesis of infectious spleen and kidney necrosis virus (ISKNV) infections is important but has rarely been studied in connection to host organelle behavior. In the present study, we demonstrated that ISKNV can induce host cell death via a pro-apoptotic Bcl-2 and anti-apoptotic Bcl-2 family member imbalance in mitochondrial membrane potential (MMP or ΔΨm) regulation in GF-1 cells. The results of our study on ISKNV infection showed that it can induce host cell death by up to 80% at day 5 post-infection. Subsequently, in an apoptotic assay, ISKNV infection was seen to induce an increase in Annexin-V-positive signals by 20% and in propidium iodide (PI) staining-positive signals by up to 30% at day 5 (D5) in GF-1 cells. Then, through our studies on the mechanism of cell death in mitochondria function, we found that ISKNV can induce MMP loss by up to 58% and 78% at days 4 and 5 with a JC1 dye staining assay. Furthermore, we found that pro-apoptotic members Bax and Bak were upregulated from the early replication stage (day one) to the late stage (day 5), but the expression profiles were very dynamically different. On the other hand, by Western blotted analysis, the anti-apoptotic members Bcl-2 and Bcl-xL were upregulated very quickly at the same time from day one (two-fold) and continued to maintain this level at day five. Finally, we found that pro-apoptotic death signals strongly activated the downstream signals of caspase-9 and -3. Taken together, these results suggest that ISKNV infection can induce Bax/Bak-mediated cell death signaling downstream of caspase-9 and -3 activation. During the viral replication cycle with the cell death induction process, the anti-apoptotic members Bcl-2/Bcl-xL interacted with the pro-apoptotic members Bax/Bak to maintain the mitochondrial function in the dynamic interaction so as to maintain the MMP in GF-1 cells. These findings may provide insights into DNA-virus control and treatment.
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Swaminathan TR, Johny TK, Nithianantham SR, Sudhagar A, Pradhan PK, S R KS, Nair RR, Sood N. A natural outbreak of infectious spleen and kidney necrosis virus (ISKNV) threatens wild pearlspot, Etroplus suratensis in Peechi Dam in the Western Ghats biodiversity hotspot, India. Transbound Emerg Dis 2022; 69:e1595-e1605. [PMID: 35235241 DOI: 10.1111/tbed.14494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 02/18/2022] [Accepted: 02/20/2022] [Indexed: 11/27/2022]
Abstract
A large-scale mortality of pearlspot, Etroplus suratensis was reported from Peechi Dam, an artificial tropical lake made for irrigation and drinking water supply in Kerala, India during 2018. This dam is located in the premises of Western Ghats, recognized as one of the biodiversity hotspots of the world. The objective of this study was to identify the aetiological agent of this large-scale mortality of E. suratensis by systematic diagnostic investigation and identification of pathogen. Virus isolation was carried out on a species-specific pearlspot fin (PSF) cell line. Infected PSF cells showed cytopathic effects (CPE) like cell shrinkage, rounding, enlargement, clustering, and subsequent detachment of cells with a high viral titre of 106⋅95 TCID50 mL-1 at 8 days post inoculation (dpi). Histopathological examination of the fish showed the presence of numerous abnormal enlarged basophilic cells and intracytoplasmic eosinophilic inclusions in the liver. Moreover, transmission electron microscopy (TEM) analysis revealed the presence of large numbers of 125-132 nm viral particles in the spleen tissues. PCR amplification and phylogenetic analysis of the major capsid protein (MCP) gene sequence confirmed that the causative agent was Infectious spleen and kidney necrosis virus (ISKNV) of the genus Megalocytivirus. The experimental infection recorded 86.7±2.7% mortality in the E. suratensis (body weight - 11.01±2.7 g; body length 8.01±2.23 cm) injected with 1 × 104⋅25 TCID50 mL-1 ISKNV per fish. Our detailed investigation provided definitive diagnosis of ISKNV in the severe mass mortality event in wild E. suratensis in Peechi Dam, India, adding one more species to expanding host range of ISKNV infection. The high mortality rate of ISKNV infection in pearlspot suggests the perilous nature of this disease, particularly among the wild fish population. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Thangaraj Raja Swaminathan
- Peninsular and Marine Fish Genetic Resources Centre, ICAR-NBFGR, CMFRI Campus, Kochi, Kerala, 682 018, India
| | - Tina Kollannoor Johny
- Peninsular and Marine Fish Genetic Resources Centre, ICAR-NBFGR, CMFRI Campus, Kochi, Kerala, 682 018, India
| | - Sundar Raj Nithianantham
- Peninsular and Marine Fish Genetic Resources Centre, ICAR-NBFGR, CMFRI Campus, Kochi, Kerala, 682 018, India
| | - Arun Sudhagar
- Peninsular and Marine Fish Genetic Resources Centre, ICAR-NBFGR, CMFRI Campus, Kochi, Kerala, 682 018, India
| | - Pravata Kumar Pradhan
- ICAR National Bureau of Fish Genetic Resources, Lucknow, Uttar Pradesh, 226002, India
| | - Krupesha Sharma S R
- ICAR Central Marine Fisheries Research Institute, Kochi, Kerala, 682 018, India
| | - Reshma R Nair
- Peninsular and Marine Fish Genetic Resources Centre, ICAR-NBFGR, CMFRI Campus, Kochi, Kerala, 682 018, India
| | - Neeraj Sood
- ICAR National Bureau of Fish Genetic Resources, Lucknow, Uttar Pradesh, 226002, India
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Xu X, Liu L, Feng J, Li X, Zhang J. Comparative transcriptome analysis reveals potential anti-viral immune pathways of turbot (Scophthalmus maximus) subverted by megalocytivirus RBIV-C1 for immune evasion. FISH & SHELLFISH IMMUNOLOGY 2022; 122:153-161. [PMID: 35150827 DOI: 10.1016/j.fsi.2022.02.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/24/2021] [Revised: 01/15/2022] [Accepted: 02/02/2022] [Indexed: 06/14/2023]
Abstract
Successful viral infection and multiplication chiefly rely on virus subversion mechanisms against host anti-viral immune responses. In this study, in order to reveal the anti-viral immune-related pathways suppressed by megalocytivirus infection, transcriptome analysis was performed on the head-kidney of turbot (Scophthalmus maximus) infected with lethal dose of RBIV-C1 at 3, 6 and 9 days post challenge (dpc). The results showed that, compared to unchallenged groups, 190, 1220, and 3963 DEGs were detected in RBIV-C1 infected groups at 3, 6 and 9 dpc, respectively, of which, DEGs of complement components and pattern recognition proteins were up-regulated at 3 dpc and down-regulated at 6 and 9 dpc, DEGs of cytokines were up-regulated at 6 dpc and down-regulated at 9 dpc. Expression trend analysis revealed that DEGs of profiles 9 and 13 featured decreased expression patterns and were significantly enriched into 10 immune-related pathways, i.e., complement and coagulation cascades, cytokine-cytokine receptor interaction, chemokine signaling pathway, B/T cell receptor signaling pathway, antigen processing and presentation, and so on. Further co-expression network analysis (WGCNA) revealed positive correlated innate immune related pathways at 3 and 6 dpc, and negative correlated innate and adaptive immune related pathways at 9 dpc. This study revealed a set of anti-viral immune genes/pathways that would also be potential targets subverted by RBIV-C1 for immune evasion, which can serve as a valuable resource for future studies on the molecular mechanisms of anti-viral immune defense of turbot and immune escape of megalocytivirus.
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Affiliation(s)
- Xiudan Xu
- School of Ocean, Yantai University, 30 Qingquan Road, Yantai, 264005, China
| | - Ling Liu
- School of Ocean, Yantai University, 30 Qingquan Road, Yantai, 264005, China
| | - Jixing Feng
- School of Ocean, Yantai University, 30 Qingquan Road, Yantai, 264005, China
| | - Xuepeng Li
- School of Ocean, Yantai University, 30 Qingquan Road, Yantai, 264005, China
| | - Jian Zhang
- School of Ocean, Yantai University, 30 Qingquan Road, Yantai, 264005, China.
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Isolation and Characterization of Plasma-Derived Exosomes from the Marine Fish Rock Bream (Oplegnathus fasciatus) by Two Isolation Techniques. FISHES 2022. [DOI: 10.3390/fishes7010036] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Exosomes are important mediators of intercellular communication and modulate many physiological and pathological processes. Knowledge of secretion, content, and biological functions of fish exosomes during pathological infection is still scarce due to lack of suitable standardized isolation techniques. In this study, we aimed to isolate exosomes from the plasma of marine fish, rock bream (Oplegnathus fasciatus), by two isolation methods: differential ultracentrifugation (UC) and a commercial membrane affinity spin column technique (kit). Morphological and physicochemical characteristics of the isolated exosomes were determined by these two methods, and the efficiencies of the two methods were compared. Exosomes isolated by both methods were in the expected size range (30–200 nm) and had a characteristic cup-shape in transmission electron microscopy observation. Moreover, more intact exosomes were identified using the kit-based method than UC. Nanoparticle tracking analysis demonstrated a heterogeneous population of exosomes with a mean particle diameter of 114.6 ± 4.6 and 111.2 ± 2.2 nm by UC and a kit-based method, respectively. The particle concentration obtained by the kit method (1.05 × 1011 ± 1.23 × 1010 particles/mL) was 10-fold higher than that obtained by UC (4.90 × 1010 ± 2.91 × 109 particles/mL). The kit method had a comparatively higher total protein yield (1.86 mg) and exosome protein recovery (0.55 mg/mL plasma). Immunoblotting analysis showed the presence of exosome marker proteins (CD81, CD63, and HSP90) in the exosomes isolated by both methods and suggests the existence of exosomes. However, the absence of cytotoxicity or adverse immune responses to fish and mammalian cells by the exosomes isolated by the UC procedure indicates its suitability for functional studies in vitro. Overall, our basic characterization results indicate that the kit-based method is more suitable for isolating high-purity exosomes from fish plasma, whereas UC has higher safety in terms of yielding exosomes with low toxicity. This study provides evidence for the existence of typical exosomes in rock beam plasma and facilitates the selection of an efficient exosome isolation procedure for future applications in disease diagnosis and exosome therapy as fish medicine.
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Jung MH, Kole S, Jung SJ. Efficacy of saponin-based inactivated rock bream iridovirus (RBIV) vaccine in rock bream (Oplegnathus fasciatus). FISH & SHELLFISH IMMUNOLOGY 2022; 121:12-22. [PMID: 34974155 DOI: 10.1016/j.fsi.2021.12.047] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2021] [Revised: 12/06/2021] [Accepted: 12/27/2021] [Indexed: 06/14/2023]
Abstract
Rock bream iridovirus (RBIV) causes severe mortality in rock bream (Oplegnathus fasciatus) for last two decades. In view of this constant threat of RBIV to the rock bream industry, we conducted the present study with the aim to develop a safe and efficient remedial measure against the virus. In this study, we evaluated the safety and potentiality of squalene, aluminium hydroxide and saponin adjuvants, singly or in combinations, which can be used for developing an efficient inactivated (IV) vaccine to protect rock bream from RBIV infection. The evaluation results demonstrated that saponin (Sa) has the required potential in enacting the antiviral immune response in the host and in providing protection against virus mediated lethality, without causing any adverted side-effects. The study further, showed that a single primary dose of Sa-adjuvanted IV vaccine can confer moderate protections in short (60.04% relative percent mortality (RPS) at 4 wpv) and medium (53.38% RPS at 8 wpv) term post RBIV challenge; whereas, the same vaccine when administered in a prime-boost strategy, it resulted enhanced 93.34% RPS post virus challenge at 4 and 8 wpv. The moderate to high survivability demonstrated by the Sa-adjuvanted IV vaccine, was substantiated by the significant (p < 0.05) upregulation of IL-1β, Mx and PKR gene transcript. All surviving fish from the Sa-adjuvanted IV vaccine groups were strongly protected from re-infection with RBIV (1.1 × 107) at 70 days post infection (dpi). In conclusion, it can be inferred that, Sa-adjuvanted IV RBIV vaccine can be an efficient control measure to protect the rock bream aquaculture industry against the lethal RBIV virus.
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Affiliation(s)
- Myung-Hwa Jung
- Department of Marine Bio and Medical Sciences, Hanseo University, Republic of Korea
| | - Sajal Kole
- Department of Aqualife Medicine, Chonnam National University, Republic of Korea
| | - Sung-Ju Jung
- Department of Aqualife Medicine, Chonnam National University, Republic of Korea.
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38
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Complete Genome Sequences and Pathogenicity Analysis of Two Red Sea Bream Iridoviruses Isolated from Cultured Fish in Korea. FISHES 2021. [DOI: 10.3390/fishes6040082] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
In Korea, red sea bream iridovirus (RSIV), especially subtype II, has been the main causative agent of red sea bream iridoviral disease since the 1990s. Herein, we report two Korean RSIV isolates with different subtypes based on the major capsid protein and adenosine triphosphatase genes: 17SbTy (RSIV mixed subtype I/II) from Japanese seabass (Lateolabrax japonicus) and 17RbGs (RSIV subtype II) from rock bream (Oplegnathus fasciatus). The complete genome sequences of 17SbTy and 17RbGs were 112,360 and 112,235 bp long, respectively (115 and 114 open reading frames [ORFs], respectively). Based on nucleotide sequence homology with sequences of representative RSIVs, 69 of 115 ORFs of 17SbTy were most closely related to subtype II (98.48–100% identity), and 46 were closely related to subtype I (98.77–100% identity). In comparison with RSIVs, 17SbTy and 17RbGs carried two insertion/deletion mutations (ORFs 014R and 102R on the basis of 17SbTy) in regions encoding functional proteins (a DNA-binding protein and a myristoylated membrane protein). Notably, survival rates differed significantly between 17SbTy-infected and 17RbGs-infected rock breams, indicating that the genomic characteristics and/or adaptations to their respective original hosts might influence pathogenicity. Thus, this study provides complete genome sequences and insights into the pathogenicity of two newly identified RSIV isolates classified as a mixed subtype I/II and subtype II.
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Shahin K, Subramaniam K, Camus AC, Yazdi Z, Yun S, Koda SA, Waltzek TB, Pierezan F, Hu R, Soto E. Isolation, Identification and Characterization of a Novel Megalocytivirus from Cultured Tilapia ( Oreochromis spp.) from Southern California, USA. Animals (Basel) 2021; 11:3524. [PMID: 34944299 PMCID: PMC8697977 DOI: 10.3390/ani11123524] [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] [Received: 11/05/2021] [Revised: 11/27/2021] [Accepted: 11/29/2021] [Indexed: 11/17/2022] Open
Abstract
In spring 2019, diseased four-month-old tilapia (Oreochromis spp.) from an aquaculture farm in Southern California, USA were received for diagnostic evaluation with signs of lethargy, anorexia, abnormal swimming, and low-level mortalities. At necropsy, non-specific external lesions were noted including fin erosion, cutaneous melanosis, gill pallor, and coelomic distension. Internal changes included ascites, hepatomegaly, renomegaly, splenomegaly, and multifocal yellow-white nodules in the spleen and kidney. Cultures of spleen and kidney produced bacterial colonies identified as Francisella orientalis. Homogenized samples of gill, brain, liver, spleen, and kidney inoculated onto Mozambique tilapia brain cells (OmB) developed cytopathic effects, characterized by rounding of cells and detaching from the monolayer 6-10 days post-inoculation at 25 °C. Transmission electron microscopy revealed 115.4 ± 5.8 nm icosahedral virions with dense central cores in the cytoplasm of OmB cells. A consensus PCR, targeting the DNA polymerase gene of large double-stranded DNA viruses, performed on cell culture supernatant yielded a sequence consistent with an iridovirus. Phylogenetic analyses based on the concatenated full length major capsid protein and DNA polymerase gene sequences supported the tilapia virus as a novel species within the genus Megalocytivirus, most closely related to scale drop disease virus and European chub iridovirus. An intracoelomic injection challenge in Nile tilapia (O. niloticus) fingerlings resulted in 39% mortality after 16 days. Histopathology revealed necrosis of head kidney and splenic hematopoietic tissues.
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Affiliation(s)
- Khalid Shahin
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; or (Z.Y.); (S.Y.); (R.H.)
- Aquatic Animal Diseases Laboratory, Aquaculture Department, National Institute of Oceanography and Fisheries, Suez P.O. Box 43511, Egypt
| | - Kuttichantran Subramaniam
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA; (K.S.); (S.A.K.); (T.B.W.)
| | - Alvin C. Camus
- Department of Pathology, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA;
| | - Zeinab Yazdi
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; or (Z.Y.); (S.Y.); (R.H.)
| | - Susan Yun
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; or (Z.Y.); (S.Y.); (R.H.)
| | - Samantha A. Koda
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA; (K.S.); (S.A.K.); (T.B.W.)
| | - Thomas B. Waltzek
- Department of Infectious Diseases and Immunology, College of Veterinary Medicine, University of Florida, Gainesville, FL 32611, USA; (K.S.); (S.A.K.); (T.B.W.)
| | - Felipe Pierezan
- School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte 31270-010, Brazil;
| | - Ruixue Hu
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; or (Z.Y.); (S.Y.); (R.H.)
| | - Esteban Soto
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, CA 95616, USA; or (Z.Y.); (S.Y.); (R.H.)
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Swaminathan TR, Raj NS, Preena PG, Pradhan PK, Sood N, Kumar RG, Sudhagar A, Sood NK. Infectious spleen and kidney necrosis virus-associated large-scale mortality in farmed giant gourami, Osphronemus goramy, in India. JOURNAL OF FISH DISEASES 2021; 44:2043-2053. [PMID: 34449899 DOI: 10.1111/jfd.13519] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 08/09/2021] [Accepted: 08/10/2021] [Indexed: 06/13/2023]
Abstract
Megalocytivirus cause diseases that have serious economic impacts on aquaculture, mainly in East and South-East Asia. Five primary genotypes are known: infectious spleen and kidney necrosis virus (ISKNV), red sea bream iridovirus (RSIV), turbot reddish body iridovirus (TRBIV), threespine stickleback iridovirus (TSIV) and scale drop disease virus (SDDV). ISKNV-mediated infectious spleen and kidney necrosis disease (ISKND) is a major viral disease in both freshwater and marine fish species. In this study, we report the isolation of ISKNV from diseased giant gourami, Osphronemus goramy, in India. Transmission electron microscopy of ultrathin sections of kidney and spleen revealed the presence of numerous polygonal naked viral particles having an outer nucleocapsid layer within the cytoplasm of enlarged cells (115-125 nm). Molecular and phylogenetic analyses confirmed the presence of ISKNV and the major capsid protein (MCP) (1,362 bp) gene in the infected fish had a high similarity to the other ISKNV-I isolates. Moreover, ISKNV was propagated in the Astronotus ocellatus fin (AOF) cell line and further confirmed genotypically. A high mortality rate (60%) was observed in gourami fish injected with ISKNV-positive tissue homogenate through challenge studies. Considering the lethal nature of ISKNV, the present study spotlights the implementation of stringent biosecurity practices for the proper control of the disease in the country.
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Affiliation(s)
- Thangaraj Raja Swaminathan
- Peninsular and Marine Fish Genetic Resources Centre, ICAR-National Bureau of Fish Genetic Resources, CMFRI Campus, Kochi, India
| | - Nithianantham Sundar Raj
- Peninsular and Marine Fish Genetic Resources Centre, ICAR-National Bureau of Fish Genetic Resources, CMFRI Campus, Kochi, India
| | - Prasannan Geetha Preena
- Peninsular and Marine Fish Genetic Resources Centre, ICAR-National Bureau of Fish Genetic Resources, CMFRI Campus, Kochi, India
| | | | - Neeraj Sood
- ICAR- National Bureau of Fish Genetic Resources, Lucknow, India
| | - Rahul Girish Kumar
- Peninsular and Marine Fish Genetic Resources Centre, ICAR-National Bureau of Fish Genetic Resources, CMFRI Campus, Kochi, India
| | - Arun Sudhagar
- Peninsular and Marine Fish Genetic Resources Centre, ICAR-National Bureau of Fish Genetic Resources, CMFRI Campus, Kochi, India
| | - Naresh Kumar Sood
- Guru Angad Dev Veterinary and Animal Sciences University, Ludhiana, India
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Abstract
Red sea bream iridoviral disease (RSIVD) causes high economic damage in mariculture in Asian countries. However, there is little information on the source of infection and viral dynamics in fish farms. In the present study, the dynamics of RSIV in a fish farm that mainly reared juveniles and broodstocks of red sea bream (Pagrus major) were monitored over 3 years (2016 to 2018) by targeting environmental DNA (eDNA) of seawater. Our monitoring demonstrated that red sea bream iridovirus (RSIV) was detected from the eDNA at least 5 days before an RSIVD outbreak in the juveniles. The viral loads of eDNA during the outbreak were highly associated with the numbers for daily mortality, and they reached a peak of 106 copies/liter seawater in late July in 2017, when daily mortality exceeded 20,000 fish. In contrast, neither clinical signs nor mortality was observed in the broodstocks during the monitoring periods, whereas the broodstocks were confirmed to be virus carriers by an inspection in October 2017. Interestingly, the viral load of eDNA in the broodstock net pens (105 copies/liter seawater) was higher than that in the juvenile net pens (104 copies/liter seawater) just before the RSIVD outbreak in late June 2017. After elimination of all RSIV-infected surviving juveniles and 90% of broodstocks, few RSIV copies were detected in the eDNA in the fish farm from April 2018 onward (fewer than 102 copies/liter seawater). These results imply that the virus shed from the asymptomatically RSIV-infected broodstock was transmitted horizontally to the juveniles and caused further RSIVD outbreaks in the fish farm. IMPORTANCE Environmental DNA (eDNA) could be applied in monitoring waterborne viruses of aquatic animals. However, there are few data for practical application of eDNA in fish farms for the control of disease outbreaks. The results of our field research over 3 years targeting eDNA in a red sea bream (Pagrus major) fish farm implied that red sea bream iridoviral disease (RSIVD) outbreaks in juveniles originated from virus shedding from asymptomatically virus-infected broodstocks. Our work identifies an infection source of RSIVD in a fish farm via eDNA monitoring, and it could be applied as a tool for application in aquaculture to control fish diseases.
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He Z, Zhao J, Chen X, Liao M, Xue Y, Zhou J, Chen H, Chen G, Zhang S, Sun C. The Molecular Mechanism of Hemocyte Immune Response in Marsupenaeus japonicus Infected With Decapod Iridescent Virus 1. Front Microbiol 2021; 12:710845. [PMID: 34512588 PMCID: PMC8427283 DOI: 10.3389/fmicb.2021.710845] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 07/28/2021] [Indexed: 11/13/2022] Open
Abstract
As a new type of shrimp lethal virus, decapod iridescent virus 1 (DIV1) has caused huge economic losses to shrimp farmers in China. Up to now, DIV1 has been detected in a variety of shrimps, but there is no report in Marsupenaeus japonicus. In the current study, we calculated the LC50 to evaluate the toxicity of DIV1 to M. japonicus and determined through nested PCR that M. japonicus can be the host of DIV1. Through enzyme activity study, it was found that DIV1 can inhibit the activities of superoxide dismutase, catalase, lysozyme, and phenoloxidase, which could be a way for DIV1 to achieve immune evasion. In a comprehensive study on the transcriptomic changes of M. japonicus in response to DIV1 infection, a total of 52,287 unigenes were de novo assembled, and 20,342 SSR markers associated with these unigenes were obtained. Through a comparative transcriptomic analysis, 6,900 differentially expressed genes were identified, including 3,882 upregulated genes and 3,018 downregulated genes. The Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis showed that some GO terms related to virus invasion, replication, and host antiviral infection were promoted under DIV1 infection, such as carbohydrate binding, chitin binding, chitin metabolic process, and DNA replication initiation, and some KEGG pathways related to immune response were significantly influenced by DIV1 infection, including Toll and IMD signaling pathway, JAK-STAT signaling pathway, IL-17 signaling pathway, C-type lectin receptor signaling pathway, complement and coagulation cascades, antigen processing and presentation, necroptosis, apoptosis, NOD-like receptor signaling pathway, apoptosis-multiple species, and TNF signaling pathway. Further analysis showed that STAT, Dorsal, Relish, heat shock protein 70 (HSP70), C-type lectins, and caspase play an important role in DIV1 infection. This is the first detailed study of DIV1 infection in M. japonicus, which initially reveals the molecular mechanism of DIV1 infection in M. japonicus by using the transcriptome analysis of hemocytes combined with enzyme activity study.
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Affiliation(s)
- Zihao He
- College of Fisheries, Guangdong Ocean University, Zhanjiang, China
| | - Jichen Zhao
- College of Fisheries, Guangdong Ocean University, Zhanjiang, China
| | - Xieyan Chen
- College of Fisheries, Guangdong Ocean University, Zhanjiang, China
| | - Minze Liao
- College of Fisheries, Guangdong Ocean University, Zhanjiang, China
| | - Yuan Xue
- College of Fisheries, Guangdong Ocean University, Zhanjiang, China
| | - Jianing Zhou
- College of Fisheries, Guangdong Ocean University, Zhanjiang, China
| | - Haozhen Chen
- College of Fisheries, Guangdong Ocean University, Zhanjiang, China
| | - Guoliang Chen
- Haimao Seed Technology Group Co., Ltd., Zhanjiang, China
| | - Shuang Zhang
- College of Fisheries, Guangdong Ocean University, Zhanjiang, China.,Aquatic Animals Precision Nutrition and High Efficiency Feed Engineering Research Center of Guangdong Province, Zhanjiang, China
| | - Chengbo Sun
- College of Fisheries, Guangdong Ocean University, Zhanjiang, China.,Guangdong Provincial Laboratory of Southern Marine Science and Engineering, Zhanjiang, China.,Guangdong Provincial Key Laboratory of Pathogenic Biology and Epidemiology for Aquatic Economic Animals, Zhanjiang, China
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43
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Sakseepipad C, Nozaki R, Yoshii K, Fukuda Y, Mizuno K, Kawakami H, Hirono I, Kondo H. Development of single nucleotide polymorphism (SNP) application for detection and genotyping of RSIV-type megalocytiviruses. JOURNAL OF FISH DISEASES 2021; 44:1337-1342. [PMID: 33966277 DOI: 10.1111/jfd.13392] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/22/2021] [Accepted: 04/26/2021] [Indexed: 06/12/2023]
Abstract
Red sea bream iridovirus (RSIV) belonging to the genus Megalocytivirus of the family Iridoviridae is the cause of serious mass mortality of cultured marine fishes. RSIV-type megalocytiviruses show extremely high nucleotide sequence identities. Thus, epidemiological studies on this virus are limited. This study developed two primer sets amplifying the regions possessing single nucleotide polymorphism (SNP) to determine the relationships and divergence of RSIV-type megalocytiviruses isolated from cultured marine fishes in Japan. The two regions were designed according to the genome sequences of the representative RSIV genotype II of megalocytivirus members in GenBank. The SNP 1 and 2 regions have sequences homologous to hypothetical protein ORF 24 and ORF 31, respectively, of RSIV (accession no. AP017456.1). By sequencing the regions, 53 polymorphic sites were identified. The phylogenetic analysis of 25 RSIV-type megalocytivirus isolates, classified into RSIV cluster, was clustered into eight haplotypes (seven haplotypes from Oita, two haplotypes from Ehime, and one haplotype shared between Oita and Ehime). These findings suggested that SNP in the RSIV genome is a powerful application for the detection and identification of RSIV-type megalocytiviruses.
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Affiliation(s)
- Channapha Sakseepipad
- Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Tokyo, Japan
- Department of Fisheries, Aquatic Animal Health Research and Development Division, Bangkok, Thailand
| | - Reiko Nozaki
- Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Keisuke Yoshii
- Fisheries Research Division, Oita Prefectural Agriculture, Forestry and Fisheries Research Center, Oita, Japan
| | - Yutaka Fukuda
- Fisheries Research Division, Oita Prefectural Agriculture, Forestry and Fisheries Research Center, Oita, Japan
| | - Kaori Mizuno
- Ehime Fisheries Research Center, Ehime Research Institute of Agriculture, Forestry and Fisheries, Ehime, Japan
| | - Hidemasa Kawakami
- Ehime Fisheries Research Center, Ehime Research Institute of Agriculture, Forestry and Fisheries, Ehime, Japan
| | - Ikuo Hirono
- Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Tokyo, Japan
| | - Hidehiro Kondo
- Laboratory of Genome Science, Tokyo University of Marine Science and Technology, Tokyo, Japan
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Kerddee P, Dinh-Hung N, Dong HT, Hirono I, Soontara C, Areechon N, Srisapoome P, Kayansamruaj P. Molecular evidence for homologous strains of infectious spleen and kidney necrosis virus (ISKNV) genotype I infecting inland freshwater cultured Asian sea bass (Lates calcarifer) in Thailand. Arch Virol 2021; 166:3061-3074. [PMID: 34462803 DOI: 10.1007/s00705-021-05207-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Accepted: 06/21/2021] [Indexed: 11/30/2022]
Abstract
Infectious spleen and kidney necrosis virus (ISKNV) is a fish-pathogenic virus belonging to the genus Megalocytivirus of the family Iridoviridae. In 2018, disease occurrences (40-50% cumulative mortality) associated with ISKNV infection were reported in grown-out Asian sea bass (Lates calcarifer) cultured in an inland freshwater system in Thailand. Clinical samples were collected from seven distinct farms located in the eastern and central regions of Thailand. The moribund fish showed various abnormal signs, including lethargy, pale gills, darkened body, and skin hemorrhage, while hypertrophied basophilic cells were observed microscopically in gill, liver, and kidney tissue. ISKNV infection was confirmed on six out of seven farms using virus-specific semi-nested PCR. The MCP and ATPase genes showed 100% sequence identity among the virus isolates, and the virus was found to belong to the ISKNV genotype I clade. Koch's postulates were later confirmed by challenge assay, and the mortality of the experimentally infected fish at 21 days post-challenge was 50-90%, depending on the challenge dose. The complete genome of two ISKNV isolates, namely KU1 and KU2, was recovered directly from the infected specimens using a shotgun metagenomics approach. The genome length of ISKNV KU1 and KU2 was 111,487 and 111,610 bp, respectively. In comparison to closely related ISKNV strains, KU1 and KU2 contained nine unique genes, including a caspase-recruitment-domain-containing protein that is potentially involved in inhibition of apoptosis. Collectively, this study indicated that inland cultured Asian sea bass are infected by homologous ISKNV strains. This indicates that ISKNV genotype I should be prioritized for future vaccine research.
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Affiliation(s)
- Pattarawit Kerddee
- Center for Agricultural Biotechnology, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom, 73140, Thailand.,Center of Excellence on Agricultural Biotechnology: (AG-BIO/PERDO-CHE), Bangkok, 10900, Thailand
| | - Nguyen Dinh-Hung
- Fish Infectious Diseases Research Unit (FID RU), Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok, 10330, Thailand
| | - Ha Thanh Dong
- Department of Food, Agriculture and Bioresources, School of Environment, Resources and Development, Asian Institute of Technology, Pathum Thani, 12120, Thailand
| | - Ikuo Hirono
- Department of Marine Biosciences, Tokyo University of Marine Science and Technology, Konan, Minato, 4-5-7, Tokyo, 108-8477, Japan
| | - Chayanit Soontara
- Department of Aquaculture, Faculty of Fisheries, Kasetsart University, Bangkok, 10900, Thailand
| | - Nontawith Areechon
- Department of Aquaculture, Faculty of Fisheries, Kasetsart University, Bangkok, 10900, Thailand
| | - Prapansak Srisapoome
- Department of Aquaculture, Faculty of Fisheries, Kasetsart University, Bangkok, 10900, Thailand.,Center of Excellence in Aquatic Animal Health Management, Faculty of Fisheries, Kasetsart University, Bangkok, 10900, Thailand
| | - Pattanapon Kayansamruaj
- Department of Aquaculture, Faculty of Fisheries, Kasetsart University, Bangkok, 10900, Thailand. .,Center of Excellence in Aquatic Animal Health Management, Faculty of Fisheries, Kasetsart University, Bangkok, 10900, Thailand.
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45
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Ko EJ, Kim H, Lee AR, Jeon KY, Kim A, Kim DH, Park CI, Choi YH, Kim S, Kim HS, Ock MS, Cha HJ. Proteome profile of spleen in rock bream (Oplegnathus fasciatus) naturally infected with rock bream iridovirus (RBIV). Genes Genomics 2021; 43:1259-1268. [PMID: 34427872 DOI: 10.1007/s13258-021-01149-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2021] [Accepted: 08/04/2021] [Indexed: 11/29/2022]
Abstract
BACKGROUND Rock bream iridovirus (RBIV) is one of the most dangerous pathogens that causes the highest mortality in the aquaculture of rock bream (Oplegnathus fasciatus). Even though RBIV infection leads to huge economic loss, proteome studies on RBIV-infected rock bream have not been conducted to provide information about the differential protein expression pattern by the host protection system. OBJECTIVE The purpose of this study was to investigate the protein expression patterns in spleens of rock bream olive after infection by RBIV or mixed infection by RBIV and bacteria. METHODS Depending on the infection intensity and sampling time point, fish were divided into five groups: uninfected healthy fish at week 0 as the control (0C), heavily infected fish at week 0 (0H), heavily mixed RBIV and bacterial infected fish at week 0 (0MH), uninfected healthy fish at week 3 (3C), and lightly infected fish at week 3 (3L). Proteins were extracted from the spleens of infected rock bream. We used 2-DE analysis with LC-MS/MS to investigate proteome changes in infected rock bream. RESULTS The results of the LC-MS/MS analyses showed different protein expression profiles after infection. Proteins related to oxygen transport and energy generation, such as hemoglobin, beta-globin, and ATP synthase, were mostly expressed in the infected spleen. Whereas proteins involved in structure and cell movement, such as tubulin, myosin, actin binding proteins, and intermediate filament proteins, were down-regulated in the infected spleens. The protein expression profiles between infection by RBIV and mixed infection by RBIV and bacteria showed similar patterns. CONCLUSIONS Our results indicated that infection by RBIV or mixed infection by RBIV and bacteria triggered energy generation and oxygen-transport, but cell migration and constructional changes in the spleen were extremely decreased.
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Affiliation(s)
- Eun-Ji Ko
- Department of Parasitology and Genetics, Kosin University College of Medicine, Busan, Republic of Korea
| | - Hyunsu Kim
- Department of Parasitology and Genetics, Kosin University College of Medicine, Busan, Republic of Korea
| | - A-Reum Lee
- Department of Parasitology and Genetics, Kosin University College of Medicine, Busan, Republic of Korea
| | - Kyung-Yoon Jeon
- Department of Parasitology and Genetics, Kosin University College of Medicine, Busan, Republic of Korea
| | - Ahran Kim
- Pathology Research Division, National Institute of Fisheries Science, Busan, Republic of Korea
| | - Do-Hyung Kim
- Department of Aquatic Life Medicine, College of Fisheries Science, Pukyong National University, Busan, Republic of Korea
| | - Chan-Il Park
- Department of Marine Biology and Aquaculture, College of Marine Science, Gyeongsang National University, Tongyeong, Republic of Korea
| | - Yung Hyun Choi
- Department of Biochemistry, College of Oriental Medicine, Dongeui University, Busan, Republic of Korea
| | - Suhkmann Kim
- Department of Chemistry, College of Natural Sciences, Pusan National University, Busan, Republic of Korea
| | - Heui-Soo Kim
- Department of Biological Sciences, College of Natural Sciences, Pusan National University, Busan, Republic of Korea
| | - Mee Sun Ock
- Department of Parasitology and Genetics, Kosin University College of Medicine, Busan, Republic of Korea
| | - Hee-Jae Cha
- Department of Parasitology and Genetics, Kosin University College of Medicine, Busan, Republic of Korea.
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46
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Fu Y, Li Y, Fu W, Su H, Zhang L, Huang C, Weng S, Yu F, He J, Dong C. Scale Drop Disease Virus Associated Yellowfin Seabream ( Acanthopagrus latus) Ascites Diseases, Zhuhai, Guangdong, Southern China: The First Description. Viruses 2021; 13:v13081617. [PMID: 34452481 PMCID: PMC8402775 DOI: 10.3390/v13081617] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Revised: 08/09/2021] [Accepted: 08/12/2021] [Indexed: 01/28/2023] Open
Abstract
Scale drop disease virus (SDDV), an emerging piscine iridovirus prevalent in farmed Asian seabass Lates calcarifer in Southeast Asia, was firstly scientifically descripted in Singapore in 2015. Here, an SDDV isolate ZH-06/20 was isolated by inoculating filtered ascites from diseased juvenile yellowfin seabream into MFF-1 cell. Advanced cytopathic effects were observed 6 days post-inoculation. A transmission electron microscopy examination confirmed that numerous virion particles, about 140 nm in diameter, were observed in infected MFF-1 cell. ZH-06/20 was further purified and both whole genome and virion proteome were determined. The results showed that ZH-06/20 was composed of 131,122 bp with 135 putative viral proteins and 113 of them were further detected by virion proteome. Western blot analysis showed that no (or weak) cross-reaction was observed among several major viral proteins between ZH-06/20 and ISKNV-like megalocytivirus. An artificial challenge showed that ZH-06/20 could cause 100% death to juvenile yellowfin seabream. A typical sign was characterized by severe ascites, but not scale drop, which was considerably different from SDD syndrome in Asian seabass. Collectively, SDDV was confirmed, for the first time, as the causative agent of ascites diseases in farmed yellowfin seabream. Our study offers useful information to better understanding SDDV-associated diseases in farmed fish.
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Affiliation(s)
- Yuting Fu
- School of Marine Sciences, Sun Yat-Sen University, Guangzhou 510006, China; (Y.F.); (L.Z.)
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China; (W.F.); (S.W.)
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Yong Li
- Zhuhai Modern Agriculture Development Center, Zhuhai 519000, China; (Y.L.); (H.S.); (C.H.); (F.Y.)
| | - Weixuan Fu
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China; (W.F.); (S.W.)
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Huibing Su
- Zhuhai Modern Agriculture Development Center, Zhuhai 519000, China; (Y.L.); (H.S.); (C.H.); (F.Y.)
| | - Long Zhang
- School of Marine Sciences, Sun Yat-Sen University, Guangzhou 510006, China; (Y.F.); (L.Z.)
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China; (W.F.); (S.W.)
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Congling Huang
- Zhuhai Modern Agriculture Development Center, Zhuhai 519000, China; (Y.L.); (H.S.); (C.H.); (F.Y.)
| | - Shaoping Weng
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China; (W.F.); (S.W.)
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
| | - Fangzhao Yu
- Zhuhai Modern Agriculture Development Center, Zhuhai 519000, China; (Y.L.); (H.S.); (C.H.); (F.Y.)
| | - Jianguo He
- School of Marine Sciences, Sun Yat-Sen University, Guangzhou 510006, China; (Y.F.); (L.Z.)
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China; (W.F.); (S.W.)
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
- Correspondence: (J.H.); (C.D.)
| | - Chuanfu Dong
- Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Zhuhai 519000, China; (W.F.); (S.W.)
- State Key Laboratory of Biocontrol, School of Life Sciences, Sun Yat-Sen University, Guangzhou 510275, China
- Correspondence: (J.H.); (C.D.)
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Figueiredo HCP, Tavares GC, Dorella FA, Rosa JCC, Marcelino SAC, Pierezan F, Pereira FL. First report of infectious spleen and kidney necrosis virus in Nile tilapia in Brazil. Transbound Emerg Dis 2021; 69:3008-3015. [PMID: 34223695 DOI: 10.1111/tbed.14217] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 06/29/2021] [Indexed: 12/16/2022]
Abstract
In June 2020, an atypical fatal outbreak in a Brazilian Nile tilapia farm was investigated. Twenty-three animals were collected and different tissues were used for bacterial isolation, histopathological and electron microscopic examination and viral detection using molecular methods. A large number of megalocytes were observed in the histopathological analysis of several tissues. Icosahedral virions, with a diameter of approximately 160 nm, were visualized inside the megalocytes through transmission electron microscopy of the spleen tissue. The virions were confirmed to be infectious spleen and kidney necrosis virus (ISKNV) through PCR and sequencing analyses of the fish samples. Phylogenetic analysis indicated that the virus belongs to the Clade 1 of ISKNV. This viral pathogen is associated with high mortality in the early stages of cultured Nile tilapia in the United States, Thailand and Ghana; however, until now, there have been no reports from ISKNV affecting cultured fish in Brazil. Additionally, in 14 out of 23 sampled fish, Streptococcus agalactiae, Edwardsiella tarda or Aeromonas hydrophila infections were also detected. This is the first report of fatal ISKNV infections in the Brazilian Nile tilapia fish farms and represents a new challenge to the aquaculture sector in the country.
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Affiliation(s)
- Henrique César Pereira Figueiredo
- Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Guilherme Campos Tavares
- Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Fernanda Alves Dorella
- Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Júlio César Câmara Rosa
- Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Sóstenes Apolo Correia Marcelino
- Department of Veterinary Clinics and Surgery, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Felipe Pierezan
- Department of Veterinary Clinics and Surgery, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Felipe Luiz Pereira
- Department of Preventive Veterinary Medicine, School of Veterinary Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil
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Zeng R, Pan W, Lin Y, He J, Luo Z, Li Z, Weng S, He J, Guo C. Development of a gene-deleted live attenuated candidate vaccine against fish virus (ISKNV) with low pathogenicity and high protection. iScience 2021; 24:102750. [PMID: 34278259 PMCID: PMC8261673 DOI: 10.1016/j.isci.2021.102750] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Revised: 11/29/2020] [Accepted: 06/16/2021] [Indexed: 01/17/2023] Open
Abstract
Aquaculture provides important food, nutrition, and income sources for humans. However, aquaculture industry is seriously threatened by viral diseases. Infectious spleen and kidney necrosis virus (ISKNV) disease causes high mortality and economic losses to the fish culture industry in Asia and has been listed as a certifiable disease by the International Epizootic Office. Vaccine development is urgent to control this disease. Here, a gene-deleted live attenuated candidate vaccine (ΔORF022L) against ISKNV with low pathogenicity and high protection was developed. ΔORF022L replicated well in mandarin fish fry-1 cells and showed similar structure with wild-type ISKNV. However, the pathogenicity was significantly lower as 98% of the mandarin fish infected with ΔORF022L survived, whereas all those infected with wild-type ISKNV died. Of importance, 100% of the ΔORF022L-infected fish survived the ISKNV challenge. ΔORF022L induced anti-ISKNV specific antibody response and upregulation of immune-related genes. This work could be beneficial to the control of fish diseases.
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Affiliation(s)
- Ruoyun Zeng
- State Key Laboratory for Biocontrol, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, No.132 Waihuan Dong Road, Higher Education Mega Center, Guangzhou, Guangdong 510006, PR China.,Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Weiqiang Pan
- State Key Laboratory for Biocontrol, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, No.132 Waihuan Dong Road, Higher Education Mega Center, Guangzhou, Guangdong 510006, PR China
| | - Yifan Lin
- Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Jian He
- State Key Laboratory for Biocontrol, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, No.132 Waihuan Dong Road, Higher Education Mega Center, Guangzhou, Guangdong 510006, PR China
| | - Zhiyong Luo
- State Key Laboratory for Biocontrol, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, No.132 Waihuan Dong Road, Higher Education Mega Center, Guangzhou, Guangdong 510006, PR China
| | - Zhimin Li
- State Key Laboratory for Biocontrol, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, No.132 Waihuan Dong Road, Higher Education Mega Center, Guangzhou, Guangdong 510006, PR China
| | - Shaoping Weng
- Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Jianguo He
- State Key Laboratory for Biocontrol, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, No.132 Waihuan Dong Road, Higher Education Mega Center, Guangzhou, Guangdong 510006, PR China.,Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
| | - Changjun Guo
- State Key Laboratory for Biocontrol, Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai), Guangdong Provincial Key Laboratory of Marine Resources and Coastal Engineering, School of Marine Sciences, Sun Yat-sen University, No.132 Waihuan Dong Road, Higher Education Mega Center, Guangzhou, Guangdong 510006, PR China.,Guangdong Province Key Laboratory for Aquatic Economic Animals, School of Life Sciences, Sun Yat-sen University, 135 Xingang Road West, Guangzhou 510275, PR China
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49
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Johan CAC, Zainathan SC. Megalocytiviruses in ornamental fish: A review. Vet World 2020; 13:2565-2577. [PMID: 33363355 PMCID: PMC7750215 DOI: 10.14202/vetworld.2020.2565-2577] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/19/2020] [Indexed: 12/13/2022] Open
Abstract
Iridoviruses, especially megalocytiviruses, are related to severe disease resulting in high economic losses in the aquaculture industry worldwide. The ornamental fish industry has been affected severely due to Megalocytivirus infections. Megalocytivirus is a DNA virus that has three genera; including red sea bream iridovirus, infectious spleen and kidney necrosis virus, and turbot reddish body iridovirus. Megalocytivirus causes non-specific clinical signs in ornamental fish. Cell culture, histology, immunofluorescence test, polymerase chain reaction (PCR) assay, and loop-mediated isothermal amplification assay have been used to diagnose megalocytiviruses. Risk factors such as temperature, transportation (export and import), and life stages of ornamental fish have been reported for the previous cases due to Megalocytivirus infections. In addition, other prevention and control methods also have been practiced in farms to prevent Megalocytivirus outbreaks. This is the first review of megalocytiviruses in ornamental fish since its first detection in 1989. This review discusses the occurrences of Megalocytivirus in ornamental fish, including the history, clinical signs, detection method, risk factors, and prevention measures.
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Affiliation(s)
- Che Azarulzaman Che Johan
- Department of Fisheries and Aquaculture, Faculty of Fisheries and Food Science, University Malaysia Terengganu, Terengganu, Malaysia
| | - Sandra Catherine Zainathan
- Department of Fisheries and Aquaculture, Faculty of Fisheries and Food Science, University Malaysia Terengganu, Terengganu, Malaysia
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Kwon WJ, Choi JC, Hong S, Kim YC, Jeong MG, Min JG, Jeong JB, Kim KI, Jeong HD. Development of a high-dose vaccine formulation for prevention of megalocytivirus infection in rock bream (Oplegnathus fasciatus). Vaccine 2020; 38:8107-8115. [PMID: 33189430 DOI: 10.1016/j.vaccine.2020.11.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Revised: 10/30/2020] [Accepted: 11/01/2020] [Indexed: 01/09/2023]
Abstract
A formalin-inactivated red sea bream iridovirus (RSIV) vaccine was prepared using the culture supernatant of a persistently infected Pagrus major fin cell line (PI-PMF) with IVS-1 strain (RSIV subtype II Meglaocytivirus). Rock bream (Oplegnathus fasciatus) were injected with a high-dose, ultracentrifuged megalocytivirus vaccine (Ultra HSCMV, 7.0 × 1010 copies/mL), a high-dose supernatant of cultured megalocytivirus vaccine (HSCMV, 1.0 × 1010 copies/mL), a supernatant of cultured megalocytivirus vaccine (SCMV, 1.0 × 109 copies/mL), and a low-dose of cultured megalocytivirus vaccine (LSCMV, 1.0 × 108 copies/mL). The vaccine efficacies for the various vaccine formulations were determined done following injection challenge with IVS-1 (1.0 × 104 copies/0.1 mL/fish), and the four different vaccines exhibited cumulative mortalities of 10.0 ± 0.0%, 48.3 ± 7.6%, 75.0 ± 5.0%, and 100.0 ± 0.0%, respectively. Additionally, the dose-dependent vaccine efficacy was also confirmed using two different cohabitation methods that included challenges G (general) and I (individual). When squalene + aluminum hydroxide (SqAl) was used as an adjuvant for the HSCMV or SCMV vaccine, cumulative mortalities of 30.0 ± 5.0% and 48.3 ± 7.6%, respectively, were obtained; moreover, these two adjuvants exhibited the highest efficacy in this study. The observed difference in survival post-challenge for the different vaccine concentrations was not reflected in the differences in neutralizing antibody titers. It was found that the water temperature during immune induction plays a less important a role than the water temperature during the challenge test, in which lowering the water temperature from 25 °C to 21 °C during a challenge improved the level of protection from cumulative mortalities from 35% to 10%. This study demonstrated that protection against mortality using inactivated vaccines against RSIVD in rock bream, which are known to be the most susceptible species to RSIV infection, is dependent upon antigen dose and temperature during the challenge.
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Affiliation(s)
- Woo Ju Kwon
- Department of Aquatic Life Medicine, Pukyong National University, Busan 48513, Republic of Korea
| | - Jae Chan Choi
- Gyeongsangbuk-do Fisheries Technology Center, Pohang, 37556, Republic of Korea
| | - Suhee Hong
- Department of Marine Biotechnology, Gangneung-Wonju National University, Gangneung 25457, Republic of Korea
| | - Young Chul Kim
- National Fishery Products Quality Management Service, Busan 49111, Republic of Korea
| | - Min Gyeong Jeong
- Department of Aquatic Life Medicine, Pukyong National University, Busan 48513, Republic of Korea
| | - Joon Gyu Min
- Department of Aquatic Life Medicine, Pukyong National University, Busan 48513, Republic of Korea
| | - Joon Bum Jeong
- Department of Aquatic Biomedical Science, Jeju National University, Jeju 63243, Republic of Korea
| | - Kwang Il Kim
- Department of Aquatic Life Medicine, Pukyong National University, Busan 48513, Republic of Korea.
| | - Hyun Do Jeong
- Department of Aquatic Life Medicine, Pukyong National University, Busan 48513, Republic of Korea
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