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Pulpipat T, Heckman TI, Boonyawiwat V, Kerddee P, Phatthanakunanan S, Soto E, Surachetpong W. Concurrent infections of Streptococcus iniae and Aeromonas veronii in farmed Giant snakehead (Channa micropeltes). J Fish Dis 2023; 46:629-641. [PMID: 36866813 DOI: 10.1111/jfd.13774] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2022] [Revised: 02/15/2023] [Accepted: 02/16/2023] [Indexed: 05/07/2023]
Abstract
The giant snakehead, Channa micropeltes, is an increasingly important economic freshwater fish in Thailand and other regions of Asia. Presently, giant snakehead are cultured under intensive aquaculture conditions, leading to high stress and conditions favouring disease. In this study, we reported a disease outbreak in farmed giant snakehead with a cumulative mortality of 52.5%, continuing for 2 months. The affected fish exhibited signs of lethargy, anorexia and haemorrhage of the skin and eyes. Further bacterial isolations revealed two different types of colonies on tryptic soy agar: small white, punctate colonies of gram-positive cocci and cream-coloured, round and convex colonies of rod-shaped gram-negative bacteria. Additional biochemical and species-specific PCR analysis based on 16S rRNA confirmed the isolates as Streptococcus iniae and Aeromonas veronii. Multilocus sequence analysis (MLSA) placed the S. iniae isolate into a large clade of strains from clinically infected fish worldwide. Gross necropsy findings showed liver congestion, pericarditis and white nodules in the kidney and liver. Histologically, the affected fish showed focal to multifocal granulomas with inflammatory cell infiltration in kidney and liver, enlarged blood vessels with mild congestion within the meninges of the brain and severe necrotizing and suppurative pericarditis with myocardial infarction. Antibiotic susceptibility tests revealed that S. iniae was sensitive to amoxicillin, erythromycin, enrofloxacin, oxytetracycline, doxycycline and resistant to sulfamethoxazole-trimethoprim, while the A. veronii was susceptible to erythromycin, enrofloxacin, oxytetracycline, doxycycline, sulfamethoxazole-trimethoprim and resistant to amoxicillin. Conclusively, our findings highlighted the natural concurrent bacterial infections in cultured giant snakehead, which support the implementation of appropriate treatment and control strategies.
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Affiliation(s)
- Theeraporn Pulpipat
- Department of Farm Resources and Production Medicine, Faculty of Veterinary Medicine, Kasetsart University, Nakorn Pathom, Thailand
| | - Taylor I Heckman
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Visanu Boonyawiwat
- Department of Farm Resources and Production Medicine, Faculty of Veterinary Medicine, Kasetsart University, Nakorn Pathom, Thailand
| | - Pattarawit Kerddee
- Department of Veterinary Microbiology and Immunology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand
| | - Sakuna Phatthanakunanan
- Kamphang Saen Veterinary Diagnostic Center, Faculty of Veterinary Medicine, Kasetsart University, Nakorn Pathom, Thailand
| | - Esteban Soto
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California, USA
| | - Win Surachetpong
- Department of Veterinary Microbiology and Immunology, Faculty of Veterinary Medicine, Kasetsart University, Bangkok, Thailand
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Mai TT, Kayansamruaj P, Soontara C, Kerddee P, Nguyen DH, Senapin S, Costa JZ, del-Pozo J, Thompson KD, Rodkhum C, Dong HT. Immunization of Nile Tilapia ( Oreochromis niloticus) Broodstock with Tilapia Lake Virus (TiLV) Inactivated Vaccines Elicits Protective Antibody and Passive Maternal Antibody Transfer. Vaccines (Basel) 2022; 10:167. [PMID: 35214626 PMCID: PMC8879158 DOI: 10.3390/vaccines10020167] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2021] [Revised: 01/17/2022] [Accepted: 01/19/2022] [Indexed: 02/06/2023] Open
Abstract
Tilapia lake virus (TiLV), a major pathogen of farmed tilapia, is known to be vertically transmitted. Here, we hypothesize that Nile tilapia (Oreochromis niloticus) broodstock immunized with a TiLV inactivated vaccine can mount a protective antibody response and passively transfer maternal antibodies to their fertilized eggs and larvae. To test this hypothesis, three groups of tilapia broodstock, each containing four males and eight females, were immunized with either a heat-killed TiLV vaccine (HKV), a formalin-killed TiLV vaccine (FKV) (both administered at 3.6 × 106 TCID50 per fish), or with L15 medium. Booster vaccination with the same vaccines was given 3 weeks later, and mating took place 1 week thereafter. Broodstock blood sera, fertilized eggs and larvae were collected from 6-14 weeks post-primary vaccination for measurement of TiLV-specific antibody (anti-TiLV IgM) levels. In parallel, passive immunization using sera from the immunized female broodstock was administered to naïve tilapia juveniles to assess if antibodies induced in immunized broodstock were protective. The results showed that anti-TiLV IgM was produced in the majority of both male and female broodstock vaccinated with either the HKV or FKV and that these antibodies could be detected in the fertilized eggs and larvae from vaccinated broodstock. Higher levels of maternal antibody were observed in fertilized eggs from broodstock vaccinated with HKV than those vaccinated with FKV. Low levels of TiLV-IgM were detected in some of the 1-3 day old larvae but were undetectable in 7-14 day old larvae from the vaccinated broodstock, indicating a short persistence of TiLV-IgM in larvae. Moreover, passive immunization proved that antibodies elicited by TiLV vaccination were able to confer 85% to 90% protection against TiLV challenge in naïve juvenile tilapia. In conclusion, immunization of tilapia broodstock with TiLV vaccines could be a potential strategy for the prevention of TiLV in tilapia fertilized eggs and larvae, with HKV appearing to be more promising than FKV for maternal vaccination.
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Affiliation(s)
- Thao Thu Mai
- Center of Excellence in Fish Infectious Diseases (CE FID), Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand; (T.T.M.); (D.-H.N.)
- The International Graduate Program of Veterinary Science and Technology (VST), Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
- Division of Aquacultural Biotechnology, Biotechnology Center of Ho Chi Minh City, Ho Chi Minh 700000, Vietnam
| | - Pattanapon Kayansamruaj
- Center of Excellence in Aquatic Animal Health Management, Faculty of Fisheries, Kasetsart University, Bangkok 10900, Thailand; (P.K.); (C.S.); (P.K.)
| | - Chayanit Soontara
- Center of Excellence in Aquatic Animal Health Management, Faculty of Fisheries, Kasetsart University, Bangkok 10900, Thailand; (P.K.); (C.S.); (P.K.)
| | - Pattarawit Kerddee
- Center of Excellence in Aquatic Animal Health Management, Faculty of Fisheries, Kasetsart University, Bangkok 10900, Thailand; (P.K.); (C.S.); (P.K.)
| | - Dinh-Hung Nguyen
- Center of Excellence in Fish Infectious Diseases (CE FID), Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand; (T.T.M.); (D.-H.N.)
| | - Saengchan Senapin
- 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 12120, Thailand
| | - Janina Z. Costa
- Aquaculture Research Group, Moredun Research Institute, Edinburgh EH26 0PZ, UK; (J.Z.C.); (K.D.T.)
| | - Jorge del-Pozo
- Infection and Immunity Division, Roslin Institute, Edinburgh EH25 9RG, UK;
| | - Kim D. Thompson
- Aquaculture Research Group, Moredun Research Institute, Edinburgh EH26 0PZ, UK; (J.Z.C.); (K.D.T.)
| | - Channarong Rodkhum
- Center of Excellence in Fish Infectious Diseases (CE FID), Department of Veterinary Microbiology, Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand; (T.T.M.); (D.-H.N.)
- The International Graduate Program of Veterinary Science and Technology (VST), Faculty of Veterinary Science, Chulalongkorn University, Bangkok 10330, Thailand
| | - Ha Thanh Dong
- Aquaculture and Aquatic Resources Program, Department of Food, Agriculture and Bioresources, School of Environment, Resources and Development, Asian Institute of Technology, Khlong Nueng 12120, Thailand
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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] [What about the content of this article? (0)] [Affiliation(s)] [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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Kerddee P, Dong HT, Chokmangmeepisarn P, Rodkhum C, Srisapoome P, Areechon N, Del-Pozo J, Kayansamruaj P. Simultaneous detection of scale drop disease virus and Flavobacterium columnare from diseased freshwater-reared barramundi Lates calcarifer. Dis Aquat Organ 2020; 140:119-128. [PMID: 32759470 DOI: 10.3354/dao03500] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Freshwater farming of barramundi Lates calcarifer in Thailand is a growing sector in aquaculture, but mortalities due to infectious diseases are still a major threat to this industry. In 2018, an episode of severe mortality in juvenile barramundi was noted in a freshwater earth pond site. Fish presented with severe gill necrosis, as well as severe cutaneous hemorrhages, scale loss, and discoloration at the base of dorsal fin (saddleback lesions). Histopathology revealed extensive necrosis of skeletal muscle and gill filaments, as well as basophilic inclusion bodies and megalocytosis in muscle, gill, liver, and kidney. Scale drop disease virus (SDDV) infection was subsequently confirmed by virus-specific semi-nested PCR. Further, DNA sequences of the viral major capsid protein (MCP) and ATPase genes had a respective homology of 99.85 and 99.92% with sequences of SDDV infecting barramundi in saltwater culture. Gill necrosis and saddleback lesions are not typical lesions associated with scale drop syndrome. Their presence was explained by Flavobacterium columnare isolation from the gill, followed by positive F. columnare-specific PCR. To our knowledge, this is the first report of SDDV-associated mortality in freshwater-farmed barramundi. Furthermore, this mortality presented as a concurrent infection with SDDV and F. columnare, with typical lesions of both infections.
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Affiliation(s)
- Pattarawit Kerddee
- Center for Agricultural Biotechnology, Kasetsart University, Kamphaeng Saen Campus, Nakhon Pathom 73140, Thailand
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