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Tammas I, Bitchava K, Gelasakis AI. Transforming Aquaculture through Vaccination: A Review on Recent Developments and Milestones. Vaccines (Basel) 2024; 12:732. [PMID: 39066370 PMCID: PMC11281524 DOI: 10.3390/vaccines12070732] [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: 05/26/2024] [Revised: 06/21/2024] [Accepted: 06/27/2024] [Indexed: 07/28/2024] Open
Abstract
Aquaculture has rapidly emerged as one of the fastest growing industries, expanding both on global and on national fronts. With the ever-increasing demand for proteins with a high biological value, the aquaculture industry has established itself as one of the most efficient forms of animal production, proving to be a vital component of global food production by supplying nearly half of aquatic food products intended for human consumption. As in classic animal production, the prevention of diseases constitutes an enduring challenge associated with severe economic and environmental repercussions. Nevertheless, remarkable strides in the development of aquaculture vaccines have been recently witnessed, offering sustainable solutions to persistent health-related issues challenging resilient aquaculture production. These advancements are characterized by breakthroughs in increased species-specific precision, improved vaccine-delivery systems, and innovations in vaccine development, following the recent advent of nanotechnology, biotechnology, and artificial intelligence in the -omics era. The objective of this paper was to assess recent developments and milestones revolving around aquaculture vaccinology and provide an updated overview of strengths, weaknesses, opportunities, and threats of the sector, by incorporating and comparatively discussing various diffuse advances that span across a wide range of topics, including emerging vaccine technologies, innovative delivery methods, insights on novel adjuvants, and parasite vaccine development for the aquaculture sector.
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Affiliation(s)
- Iosif Tammas
- Laboratory of Applied Hydrobiology, Department of Animal Science, Agricultural University of Athens, 11855 Athens, Greece;
| | - Konstantina Bitchava
- Laboratory of Applied Hydrobiology, Department of Animal Science, Agricultural University of Athens, 11855 Athens, Greece;
| | - Athanasios I. Gelasakis
- Laboratory of Anatomy & Physiology of Farm Animals, Department of Animal Science, Agricultural University of Athens, 11855 Athens, Greece
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Olsen RH, Finne-Fridell F, Bordevik M, Nygaard A, Rajan B, Karlsen M. The Effect of an Attenuated Live Vaccine against Salmonid Rickettsial Septicemia in Atlantic Salmon ( Salmo salar) Is Highly Dependent on Water Temperature during Immunization. Vaccines (Basel) 2024; 12:416. [PMID: 38675798 PMCID: PMC11053689 DOI: 10.3390/vaccines12040416] [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: 03/18/2024] [Revised: 04/09/2024] [Accepted: 04/11/2024] [Indexed: 04/28/2024] Open
Abstract
Salmonid Rickettsial Septicemia (SRS), caused by the bacterium Piscirickettsia salmonis, is the main reason for antibiotic usage in the Chilean aquaculture industry. In 2016, a live attenuated vaccine (ALPHA JECT LiVac® SRS, PHARMAQ AS) was licensed in Chile and has been widely used in farmed salmonids since then. In experimental injection and cohabitation laboratory challenge models, we found that the vaccine is effective in protecting Atlantic salmon (Salmo salar) for at least 15 months against P. salmonis-induced mortality. However, the protection offered by the vaccine is sensitive to temperature during immunization. Fish vaccinated and immunized at 10 °C and above were well protected, but those immunized at 7 °C and 8 °C (the lower end of the temperature range commonly found in Chile) experienced a significant loss of protection. This temperature-dependent loss of effect correlated with the amount of vaccine-strain RNA detected in the liver the first week after vaccination and with in vitro growth curves, which failed to detect any growth at 8 °C. We found that good vaccine efficacy can be restored by exposing fish to 15 °C for the first five days after vaccination before lowering the temperature to 7 °C for the remaining immunization period. This suggests that maintaining the correct temperature during the first few days after vaccination is crucial for achieving a protective immune response with ALPHA JECT LiVac® SRS. Our results emphasize the importance of temperature control when vaccinating poikilothermic animals with live vaccines.
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Affiliation(s)
| | - Frode Finne-Fridell
- PHARMAQ AS, 0275 Oslo, Norway; (R.H.O.); (F.F.-F.); (M.B.); (A.N.); (B.R.)
- Pure Salmon Technology, 3241 Sandefjord, Norway
| | - Marianne Bordevik
- PHARMAQ AS, 0275 Oslo, Norway; (R.H.O.); (F.F.-F.); (M.B.); (A.N.); (B.R.)
| | - Anja Nygaard
- PHARMAQ AS, 0275 Oslo, Norway; (R.H.O.); (F.F.-F.); (M.B.); (A.N.); (B.R.)
| | - Binoy Rajan
- PHARMAQ AS, 0275 Oslo, Norway; (R.H.O.); (F.F.-F.); (M.B.); (A.N.); (B.R.)
| | - Marius Karlsen
- PHARMAQ AS, 0275 Oslo, Norway; (R.H.O.); (F.F.-F.); (M.B.); (A.N.); (B.R.)
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Okon EM, Okocha RC, Taiwo AB, Michael FB, Bolanle AM. Dynamics of co-infection in fish: A review of pathogen-host interaction and clinical outcome. FISH AND SHELLFISH IMMUNOLOGY REPORTS 2023; 4:100096. [PMID: 37250211 PMCID: PMC10213192 DOI: 10.1016/j.fsirep.2023.100096] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2022] [Revised: 04/09/2023] [Accepted: 05/15/2023] [Indexed: 05/31/2023] Open
Abstract
Co-infections can affect the transmission of a pathogen within a population and the pathogen's virulence, ultimately affecting the disease's dynamics. In addition, co-infections can potentially affect the host's immunological responses, clinical outcomes, survival, and disease control efficacy. Co-infections significantly impact fish production and can change several fish diseases' progression and severity. However, the effect of co-infection has only recently garnered limited attention in aquatic animals such as fish, and there is currently a dearth of studies on this topic. This study, therefore, presents an in-depth summary of the dynamics of co-infection in fish. This study reviewed the co-infection of fish pathogens, the interaction of pathogens and fish, clinical outcomes and impacts on fish immune responses, and fish survival. Most studies described the prevalence of co-infections in fish, with various parameters influencing their outcomes. Bacterial co-infection increased fish mortality, ulcerative dermatitis, and intestinal haemorrhage. Viral co-infection resulted in osmoregulatory effects, increased mortality and cytopathic effect (CPE). More severe histological alterations and clinical symptoms were related to the co-infection of fish than in single-infected fish. In parasitic co-infection, there was increased mortality, high kidney swelling index, and severe necrotic alterations in the kidney, liver, and spleen. In other cases, there were more severe kidney lesions, cartilage destruction and displacement. There was a dearth of information on mitigating co-infections in fish. Therefore, further studies on the mitigation strategies of co-infections in fish will provide valuable insights into this research area. Also, more research on the immunology of co-infection specific to each fish pathogen class (bacteria, viruses, fungi, and parasites) is imperative. The findings from such studies would provide valuable information on the relationship between fish immune systems and targeted responses.
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Affiliation(s)
| | - Reuben Chukwuka Okocha
- Department of Animal Science, College of Agricultural Sciences, Landmark University, P.M.B. 1001 Omu-Aran, Kwara State, Nigeria
- Climate Action Research Group, Landmark University SDG 13, Nigeria
| | | | - Falana Babatunde Michael
- Department of Animal Science, College of Agricultural Sciences, Landmark University, P.M.B. 1001 Omu-Aran, Kwara State, Nigeria
- Life Below Water Research Group, Landmark University SDG 14, Nigeria
| | - Adeniran Moji Bolanle
- Department of Animal Science, College of Agricultural Sciences, Landmark University, P.M.B. 1001 Omu-Aran, Kwara State, Nigeria
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Torrealba D, Morales-Lange B, Mulero V, Vasemägi A, Mercado L, Gallardo-Matus J. Heritability of Immunity Traits and Resistance of Atlantic Salmon against the Sea Louse Caligus rogercresseyi. BIOLOGY 2023; 12:1078. [PMID: 37626964 PMCID: PMC10452322 DOI: 10.3390/biology12081078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 07/26/2023] [Accepted: 07/27/2023] [Indexed: 08/27/2023]
Abstract
The immune response of Atlantic salmon to sea lice has been extensively studied, but we still do not know the mechanisms by which some fish become resistant and others do not. In this study, we estimated the heritabilities of three key proteins associated with the innate immunity and resistance of Salmo salar against the sea louse Caligus rogercresseyi. In particular, we quantified the abundance of 2 pro-inflammatory cytokines, Tnfα and Il-8, and an antioxidant enzyme, Nkef, in Atlantic salmon skin and gill tissue from 21 families and 268 individuals by indirect ELISA. This covers a wide parasite load range from low or resistant (mean sea lice ± SE = 8.7 ± 0.9) to high or susceptible (mean sea lice ± SE = 43.3 ± 2.0). Our results showed that susceptible fish had higher levels of Nkef and Tnfα than resistant fish in their gills and skin, although gill Il-8 was higher in resistant fish, while no significant differences were found in the skin. Furthermore, moderate to very high heritable genetic variation was estimated for Nkef (h2 skin: 0.96 ± 0.14 and gills: 0.97 ± 0.11) and Tnfα (h2 skin: 0.53 ± 0.17 and gills: 0.32 ± 0.14), but not for Il-8 (h2 skin: 0.22 ± 0.12 ns and gills: 0.09 ± 0.08 ns). This work provides evidence that Nkef and Tnfα protein expressions are highly heritable and related to resistance against sea lice in Atlantic salmon.
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Affiliation(s)
- Débora Torrealba
- Laboratorio de Genética y Genómica Aplicada, Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Valparaíso 2373223, Chile;
| | - Byron Morales-Lange
- Grupo de Marcadores Inmunológicos en Organismos Acuáticos, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Valparaíso 2373223, Chile; (B.M.-L.); (L.M.)
| | - Victoriano Mulero
- Departamento de Biología Celular e Histología, Facultad de Biología, Universidad de Murcia, C. Campus Universitario, 5, 30100 Murcia, Spain;
| | - Anti Vasemägi
- Department of Aquatic Resources, Swedish University of Agricultural Sciences. Almas Allé 8, SE-750 07 Uppsala, Sweden;
- Institute of Veterinary Medicine and Animal Sciences, Estonian University of Life Sciences, Friedrich Reinhold Kreutzwaldi 1a, 51014 Tartu, Estonia
| | - Luis Mercado
- Grupo de Marcadores Inmunológicos en Organismos Acuáticos, Instituto de Biología, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Valparaíso 2373223, Chile; (B.M.-L.); (L.M.)
| | - José Gallardo-Matus
- Laboratorio de Genética y Genómica Aplicada, Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaíso, Avenida Universidad 330, Valparaíso 2373223, Chile;
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The Infection Dynamics of Experimental Edwardsiella ictaluri and Flavobacterium covae Coinfection in Channel Catfish (Ictalurus punctatus). Pathogens 2023; 12:pathogens12030462. [PMID: 36986384 PMCID: PMC10051119 DOI: 10.3390/pathogens12030462] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2023] [Revised: 03/06/2023] [Accepted: 03/14/2023] [Indexed: 03/17/2023] Open
Abstract
Edwardsiella ictaluri and Flavobacterium covae are pervasive bacterial pathogens associated with significant losses in catfish aquaculture. Bacterial coinfections have the potential to increase outbreak severity and can worsen on-farm mortality. A preliminary assessment of in vivo bacterial coinfection with E. ictaluri (S97-773) and F. covae (ALG-00-530) was conducted using juvenile channel catfish (Ictalurus punctatus). Catfish were divided into five treatment groups: (1) mock control; (2) E. ictaluri full dose (immersion; 5.4 × 105 CFU mL−1); (3) F. covae full dose (immersion; 3.6 × 106 CFU mL−1); (4) E. ictaluri half dose (immersion; 2.7 × 105 CFU mL−1) followed by half dose F. covae (immersion; 1.8 × 106 CFU mL−1); and (5) F. covae half dose followed by half dose E. ictaluri. In the coinfection challenges, the second inoculum was delivered 48 h after the initial exposure. At 21 days post-challenge (DPC), the single dose E. ictaluri infection yielded a cumulative percent mortality (CPM) of 90.0 ± 4.1%, compared with 13.3 ± 5.9% in the F. covae group. Mortality patterns in coinfection challenges mimicked the single dose E. ictaluri challenge, with CPM of 93.3 ± 5.4% for fish initially challenged with E. ictaluri followed by F. covae, and 93.3 ± 2.7% for fish exposed to F. covae and subsequently challenged with E. ictaluri. Despite similarities in the final CPM within the coinfection groups, the onset of peak mortality was delayed in fish exposed to F. covae first but was congruent with mortality trends in the E. ictaluri challenge. Catfish exposed to E. ictaluri in both the single and coinfected treatments displayed increased serum lysozyme activity at 4-DPC (p < 0.001). Three pro-inflammatory cytokines (il8, tnfα, il1β) were evaluated for gene expression, revealing an increase in expression at 7-DPC in all E. ictaluri exposed treatments (p < 0.05). These data enhance our understanding of the dynamics of E. ictaluri and F. covae coinfections in US farm-raised catfish.
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Rozas-Serri M, Peña A, Gardner I, Peñaloza E, Maldonado L, Muñoz A, Mardones FO, Rodríguez C, Ildefonso R, Senn C, Aranis F. Co-Infection by Lf-89-like and Em-90-like Genogroups of Pis-Cirickettsia Salmonis in Farmed Atlantic Salmon in Chile: Implications for Surveillance and Control of Piscirickettsiosis. Pathogens 2023; 12:pathogens12030450. [PMID: 36986371 PMCID: PMC10053882 DOI: 10.3390/pathogens12030450] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2023] [Revised: 03/03/2023] [Accepted: 03/09/2023] [Indexed: 03/14/2023] Open
Abstract
Piscirickettsiosis (SRS), caused by Piscirickettsia salmonis, is the main infectious disease that affects farmed Atlantic salmon in Chile. Currently, the official surveillance and control plan for SRS in Chile is based only on the detection of P. salmonis, but neither of its genogroups (LF-89-like and EM-90-like) are included. Surveillance at the genogroup level is essential not only for defining and evaluating the vaccination strategy against SRS, but it is also of utmost importance for early diagnosis, clinical prognosis in the field, treatment, and control of the disease. The objectives of this study were to characterize the spatio-temporal distribution of P. salmonis genogroups using genogroup-specific real-time probe-based polymerase chain reaction (qPCR) to discriminate between LF-89-like and EM-90-like within and between seawater farms, individual fish, and tissues/organs during early infection in Atlantic salmon under field conditions. The spatio-temporal distribution of LF-89-like and EM-90-like was shown to be highly variable within and between seawater farms. P. salmonis infection was also proven to be caused by both genogroups at farm, fish, and tissue levels. Our study demonstrated for the first time a complex co-infection by P. salmonis LF-89-like and EM-90-like in Atlantic salmon. Liver nodules (moderate and severe) were strongly associated with EM-90-like infection, but this phenotype was not detected by infection with LF-89-like or co-infection of both genogroups. The detection rate of P. salmonis LF-89-like increased significantly between 2017 and 2021 and was the most prevalent genogroup in Chilean salmon aquaculture during this period. Lastly, a novel strategy to identify P. salmonis genogroups based on novel genogroup-specific qPCR for LF-89-like and EM-90-like genogroups is suggested.
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Affiliation(s)
| | - Andrea Peña
- Pathovet Labs SpA, Puerto Montt 5480000, Chile
| | - Ian Gardner
- Department of Health Management, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada
| | | | | | - Ariel Muñoz
- Pathovet Labs SpA, Puerto Montt 5480000, Chile
| | - Fernando O. Mardones
- Escuela de Medicina Veterinaria, Facultad de Agronomía e Ingeniería Forestal, Facultad de Ciencias Biológicas, Facultad de Medicina, Pontificia Universidad Católica de Chile, Santiago 3542000, Chile
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Valenzuela-Aviles P, Torrealba D, Figueroa C, Mercado L, Dixon B, Conejeros P, Gallardo-Matus J. Why vaccines fail against Piscirickettsiosis in farmed salmon and trout and how to avoid it: A review. Front Immunol 2022; 13:1019404. [PMID: 36466828 PMCID: PMC9714679 DOI: 10.3389/fimmu.2022.1019404] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Accepted: 10/24/2022] [Indexed: 09/28/2023] Open
Abstract
Piscirickettsiosis is the most severe, persistent, and damaging disease that has affected the Chilean salmon industry since its origins in the 1980s. As a preventive strategy for this disease, different vaccines have been developed and used over the last 30 years. However, vaccinated salmon and trout frequently die in the sea cages and the use of antibiotics is still high demonstrating the low efficiency of the available vaccines. The reasons why the vaccines fail so often are still debated, but it could involve different extrinsic and intrinsic factors. Among the extrinsic factors, mainly associated with chronic stress, we can distinguish: 1) biotic including coinfection with sea lice, sealions attacks or harmful algal blooms; 2) abiotic including low oxygen or high temperature; and 3) farm-management factors including overcrowding or chemical delousing treatments. Among the intrinsic factors, we can distinguish: 1) fish-related factors including host's genetic variability (species, population and individual), sex or age; 2) pathogen-related factors including their variability and ability to evade host immune responses; and 3) vaccine-related factors including low immunogenicity and poor matches with the circulating pathogen strain. Based on the available evidence, in order to improve the development and the efficacy of vaccines against P. salmonis we recommend: a) Do not perform efficacy evaluations by intraperitoneal injection of pathogens because they generate an artificial protective immune response, instead cohabitation or immersion challenges must be used; b) Evaluate the diversity of pathogen strains in the field and ensure a good antigenic match with the vaccines; c) Investigate whether host genetic diversity could be improved, e.g. through selection, in favor of better and longer responses to vaccination; d) To reduce the stressful effects at the cage level, controlling the co-infection of pathogens and avoiding fish overcrowding. To date, we do not know the immunological mechanisms by which the vaccines against P. salmonis may or may not generate protection. More studies are required to identify what type of response, cellular or molecular, is required to develop effective vaccines.
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Affiliation(s)
- Paula Valenzuela-Aviles
- Laboratorio de Genética y Genómica Aplicada, Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Débora Torrealba
- Laboratorio de Genética y Genómica Aplicada, Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Carolina Figueroa
- Laboratorio de Genética y Genómica Aplicada, Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
| | - Luis Mercado
- Grupo de Marcadores Inmunológicos en Organismos Acuáticos, Pontificia Universidad Católica de Valparaíso, Instituto de Biología, Valparaíso, Chile
| | - Brian Dixon
- Department of Biology, Faculty of Science, University of Waterloo, Waterloo, Canada
| | - Pablo Conejeros
- Centro de Investigación y Gestión de Recursos Naturales (CIGREN), Facultad de Ciencias, Instituto de Biología, Universidad de Valparaíso, Valparaíso, Chile
| | - José Gallardo-Matus
- Laboratorio de Genética y Genómica Aplicada, Escuela de Ciencias del Mar, Pontificia Universidad Católica de Valparaíso, Valparaíso, Chile
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Glidden CK, Field LC, Bachhuber S, Hennessey SM, Cates R, Cohen L, Crockett E, Degnin M, Feezell MK, Fulton‐Bennett HK, Pires D, Poirson BN, Randell ZH, White E, Gravem SA. Strategies for managing marine disease. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2022; 32:e2643. [PMID: 35470930 PMCID: PMC9786832 DOI: 10.1002/eap.2643] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/25/2021] [Accepted: 02/24/2022] [Indexed: 06/14/2023]
Abstract
The incidence of emerging infectious diseases (EIDs) has increased in wildlife populations in recent years and is expected to continue to increase with global environmental change. Marine diseases are relatively understudied compared with terrestrial diseases but warrant parallel attention as they can disrupt ecosystems, cause economic loss, and threaten human livelihoods. Although there are many existing tools to combat the direct and indirect consequences of EIDs, these management strategies are often insufficient or ineffective in marine habitats compared with their terrestrial counterparts, often due to fundamental differences between marine and terrestrial systems. Here, we first illustrate how the marine environment and marine organism life histories present challenges and opportunities for wildlife disease management. We then assess the application of common disease management strategies to marine versus terrestrial systems to identify those that may be most effective for marine disease outbreak prevention, response, and recovery. Finally, we recommend multiple actions that will enable more successful management of marine wildlife disease emergencies in the future. These include prioritizing marine disease research and understanding its links to climate change, improving marine ecosystem health, forming better monitoring and response networks, developing marine veterinary medicine programs, and enacting policy that addresses marine and other wildlife diseases. Overall, we encourage a more proactive rather than reactive approach to marine wildlife disease management and emphasize that multidisciplinary collaborations are crucial to managing marine wildlife health.
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Affiliation(s)
- Caroline K. Glidden
- Department of Integrative BiologyOregon State UniversityCorvallisOregonUSA
- Present address:
Department of BiologyStanford UniversityStanfordCaliforniaUSA
| | - Laurel C. Field
- Department of Integrative BiologyOregon State UniversityCorvallisOregonUSA
| | - Silke Bachhuber
- Department of Integrative BiologyOregon State UniversityCorvallisOregonUSA
| | | | - Robyn Cates
- College of Veterinary MedicineOregon State UniversityCorvallisOregonUSA
| | - Lesley Cohen
- College of Veterinary MedicineOregon State UniversityCorvallisOregonUSA
| | - Elin Crockett
- College of Veterinary MedicineOregon State UniversityCorvallisOregonUSA
| | - Michelle Degnin
- College of Veterinary MedicineOregon State UniversityCorvallisOregonUSA
| | - Maya K. Feezell
- Department of Integrative BiologyOregon State UniversityCorvallisOregonUSA
| | | | - Devyn Pires
- College of Veterinary MedicineOregon State UniversityCorvallisOregonUSA
| | | | - Zachary H. Randell
- Department of Integrative BiologyOregon State UniversityCorvallisOregonUSA
| | - Erick White
- Department of Integrative BiologyOregon State UniversityCorvallisOregonUSA
| | - Sarah A. Gravem
- Department of Integrative BiologyOregon State UniversityCorvallisOregonUSA
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Commercial Vaccines Do Not Confer Protection against Two Genogroups of Piscirickettsia salmonis, LF-89 and EM-90, in Atlantic Salmon. BIOLOGY 2022; 11:biology11070993. [PMID: 36101374 PMCID: PMC9312220 DOI: 10.3390/biology11070993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/17/2022] [Accepted: 06/21/2022] [Indexed: 11/17/2022]
Abstract
Simple Summary Vaccination represents one of the most relevant strategies to prevent and control infectious diseases in aquaculture. However, vaccines have failed to control and prevent Piscirickettsia salmonis, a bacterium that causes large economic losses to the industry. Therefore, we evaluated the performance of two commercial vaccines in Atlantic salmon through a cohabitation challenge (healthy fish were challenged by cohabitation with infected fish) of the two most prevalent and ubiquitous Piscirickettsia genetic variants in Chile. We found no evidence that vaccines confer protection against the LF-89 or EM-90 genogroups in Atlantic salmon. Abstract In Atlantic salmon, vaccines have failed to control and prevent Piscirickettsiosis, for reasons that remain elusive. In this study, we report the efficacy of two commercial vaccines developed with the Piscirickettsia salmonis isolates AL100005 and AL 20542 against another two genogroups which are considered highly and ubiquitously prevalent in Chile: LF-89 and EM-90. Two cohabitation trials were performed to mimic field conditions and vaccine performance: (1) post-smolt fish were challenged with a single infection of LF-89, (2) adults were coinfected with EM-90, and a low level coinfection of sea lice. In the first trial, the vaccine delayed smolt mortalities by two days; however, unvaccinated and vaccinated fish did not show significant differences in survival (unvaccinated: 60.3%, vaccinated: 56.7%; p = 0.28). In the second trial, mortality started three days later for vaccinated fish than unvaccinated fish. However, unvaccinated and vaccinated fish did not show significant differences in survival (unvaccinated: 64.6%, vaccinated: 60.2%, p = 0.58). Thus, we found no evidence that the evaluated vaccines confer effective protection against the genogroups LF-89 and EM-90 of P. salmonis with estimated relative survival proportions (RPSs) of −9% and −12%, respectively. More studies are necessary to evaluate whether pathogen heterogeneity is a key determinant of the lack of vaccine efficacy against P. salmonis.
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Rozas-Serri M. Why Does Piscirickettsia salmonis Break the Immunological Paradigm in Farmed Salmon? Biological Context to Understand the Relative Control of Piscirickettsiosis. Front Immunol 2022; 13:856896. [PMID: 35386699 PMCID: PMC8979166 DOI: 10.3389/fimmu.2022.856896] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2022] [Accepted: 02/22/2022] [Indexed: 11/28/2022] Open
Abstract
Piscirickettsiosis (SRS) has been the most important infectious disease in Chilean salmon farming since the 1980s. It was one of the first to be described, and to date, it continues to be the main infectious cause of mortality. How can we better understand the epidemiological situation of SRS? The catch-all answer is that the Chilean salmon farming industry must fight year after year against a multifactorial disease, and apparently only the environment in Chile seems to favor the presence and persistence of Piscirickettsia salmonis. This is a fastidious, facultative intracellular bacterium that replicates in the host’s own immune cells and antigen-presenting cells and evades the adaptive cell-mediated immune response, which is why the existing vaccines are not effective in controlling it. Therefore, the Chilean salmon farming industry uses a lot of antibiotics—to control SRS—because otherwise, fish health and welfare would be significantly impaired, and a significantly higher volume of biomass would be lost per year. How can the ever-present risk of negative consequences of antibiotic use in salmon farming be balanced with the productive and economic viability of an animal production industry, as well as with the care of the aquatic environment and public health and with the sustainability of the industry? The answer that is easy, but no less true, is that we must know the enemy and how it interacts with its host. Much knowledge has been generated using this line of inquiry, however it remains insufficient. Considering the state-of-the-art summarized in this review, it can be stated that, from the point of view of fish immunology and vaccinology, we are quite far from reaching an effective and long-term solution for the control of SRS. For this reason, the aim of this critical review is to comprehensively discuss the current knowledge on the interaction between the bacteria and the host to promote the generation of more and better measures for the prevention and control of SRS.
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Adamek M, Matras M, Rebl A, Stachnik M, Falco A, Bauer J, Miebach AC, Teitge F, Jung-Schroers V, Abdullah M, Krebs T, Schröder L, Fuchs W, Reichert M, Steinhagen D. Don't Let It Get Under Your Skin! - Vaccination Protects the Skin Barrier of Common Carp From Disruption Caused by Cyprinid Herpesvirus 3. Front Immunol 2022; 13:787021. [PMID: 35173716 PMCID: PMC8842664 DOI: 10.3389/fimmu.2022.787021] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 01/11/2022] [Indexed: 12/14/2022] Open
Abstract
Vaccination is the best form of protecting fish against viral diseases when the pathogen cannot be contained by biosecurity measures. Vaccines based on live attenuated viruses seem to be most effective for vaccination against challenging pathogens like Cyprinid herpesvirus 3. However, there are still knowledge gaps how these vaccines effectively protect fish from the deadly disease caused by the epitheliotropic CyHV-3, and which aspects of non-direct protection of skin or gill integrity and function are important in the aquatic environment. To elucidate some elements of protection, common carp were vaccinated against CyHV-3 using a double deletion vaccine virus KHV-T ΔDUT/TK in the absence or presence of a mix of common carp beta-defensins 1, 2 and 3 as adjuvants. Vaccination induced marginal clinical signs, low virus load and a minor upregulation of cd4, cd8 and igm gene expression in vaccinated fish, while neutralisation activity of blood serum rose from 14 days post vaccination (dpv). A challenge infection with CyHV-3 induced a severe disease with 80-100% mortality in non-vaccinated carp, while in vaccinated carp, no mortality was recorded and the virus load was >1,000-fold lower in the skin, gill and kidney. Histological analysis showed strongest pathological changes in the skin, with a complete destruction of the epidermis in non-vaccinated carp. In the skin of non-vaccinated fish, T and B cell responses were severely downregulated, inflammation and stress responses were increased upon challenge, whereas vaccinated fish had boosted neutrophil, T and B cell responses. A disruption of skin barrier elements (tight and adherence junction, desmosomes, mucins) led to an uncontrolled increase in skin bacteria load which most likely exacerbated the inflammation and the pathology. Using a live attenuated virus vaccine, we were able to show that increased neutrophil, T and B cell responses provide protection from CyHV-3 infection and lead to preservation of skin integrity, which supports successful protection against additional pathogens in the aquatic environment which foster disease development in non-vaccinated carp.
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Affiliation(s)
- Mikolaj Adamek
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Marek Matras
- Laboratory of Fish Diseases, National Veterinary Research Institute, Pulawy, Poland
| | - Alexander Rebl
- Fish Genetics Unit, Research Institute for Farm Animal Biology (FBN), Institute of Genome Biology, Dummerstorf, Germany
| | - Magdalena Stachnik
- Laboratory of Fish Diseases, National Veterinary Research Institute, Pulawy, Poland
| | - Alberto Falco
- Institute of Research, Development, and Innovation in Healthcare Biotechnology in Elche (IDiBE), Miguel Hernández University (UMH), Elche, Spain
| | - Julia Bauer
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Anne-Carina Miebach
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Felix Teitge
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Verena Jung-Schroers
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Muhammad Abdullah
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Torben Krebs
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Lars Schröder
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Walter Fuchs
- Institute of Molecular Virology and Cell Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany
| | - Michal Reichert
- Laboratory of Fish Diseases, National Veterinary Research Institute, Pulawy, Poland
| | - Dieter Steinhagen
- Fish Disease Research Unit, Institute for Parasitology, University of Veterinary Medicine Hannover, Hannover, Germany
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12
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Caballero-Solares A, Umasuthan N, Xue X, Katan T, Kumar S, Westcott JD, Chen Z, Fast MD, Skugor S, Taylor RG, Rise ML. Interacting Effects of Sea Louse (Lepeophtheirus salmonis) Infection and Formalin-Killed Aeromonas salmonicida on Atlantic Salmon Skin Transcriptome. Front Immunol 2022; 13:804987. [PMID: 35401509 PMCID: PMC8987027 DOI: 10.3389/fimmu.2022.804987] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2021] [Accepted: 02/21/2022] [Indexed: 11/13/2022] Open
Abstract
Lepeophtheirus salmonis (sea lice) and bacterial co-infection threatens wild and farmed Atlantic salmon performance and welfare. In the present study, pre-adult L. salmonis-infected and non-infected salmon were intraperitoneally injected with either formalin-killed Aeromonas salmonicida bacterin (ASAL) or phosphate-buffered saline (PBS). Dorsal skin samples from each injection/infection group (PBS/no lice, PBS/lice, ASAL/no lice, and ASAL/lice) were collected at 24 h post-injection and used for transcriptome profiling using a 44K salmonid microarray platform. Microarray results showed no clear inflammation gene expression signatures and revealed extensive gene repression effects by pre-adult lice (2,189 down and 345 up-regulated probes) in the PBS-injected salmon (PBS/lice vs. PBS/no lice), which involved basic cellular (e.g., RNA and protein metabolism) processes. Lice repressive effects were not observed within the group of ASAL-injected salmon (ASAL/lice vs. ASAL/no lice); on the contrary, the observed skin transcriptome changes –albeit of lesser magnitude (82 up and 1 down-regulated probes)– suggested the activation in key immune and wound healing processes (e.g., neutrophil degranulation, keratinocyte differentiation). The molecular skin response to ASAL was more intense in the lice-infected (ASAL/lice vs. PBS/lice; 272 up and 11 down-regulated probes) than in the non-infected fish (ASAL/no lice vs. PBS/no lice; 27 up-regulated probes). Regardless of lice infection, the skin’s response to ASAL was characterized by the putative activation of both antibacterial and wound healing pathways. The transcriptomic changes prompted by ASAL+lice co-stimulation (ASAL/lice vs. PBS/no lice; 1878 up and 3120 down-regulated probes) confirmed partial mitigation of lice repressive effects on fundamental cellular processes and the activation of pathways involved in innate (e.g., neutrophil degranulation) and adaptive immunity (e.g., antibody formation), as well as endothelial cell migration. The qPCR analyses evidenced immune-relevant genes co-stimulated by ASAL and lice in an additive (e.g., mbl2b, bcl6) and synergistic (e.g., hampa, il4r) manner. These results provided insight on the physiological response of the skin of L. salmonis-infected salmon 24 h after ASAL stimulation, which revealed immunostimulatory properties by the bacterin with potential applications in anti-lice treatments for aquaculture. As a simulated co-infection model, the present study also serves as a source of candidate gene biomarkers for sea lice and bacterial co-infection.
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Affiliation(s)
- Albert Caballero-Solares
- Department of Ocean Sciences, Memorial University, St. John’s, NL, Canada
- *Correspondence: Albert Caballero-Solares,
| | | | - Xi Xue
- Department of Ocean Sciences, Memorial University, St. John’s, NL, Canada
| | - Tomer Katan
- Department of Ocean Sciences, Memorial University, St. John’s, NL, Canada
| | - Surendra Kumar
- Department of Ocean Sciences, Memorial University, St. John’s, NL, Canada
| | | | - Zhiyu Chen
- Department of Ocean Sciences, Memorial University, St. John’s, NL, Canada
- Fisheries and Marine Institute, Memorial University, St. John’s, NL, Canada
| | - Mark D. Fast
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Stanko Skugor
- Cargill Aqua Nutrition, Cargill, Sea Lice Research Center (SLRC), Sandnes, Norway
| | | | - Matthew L. Rise
- Department of Ocean Sciences, Memorial University, St. John’s, NL, Canada
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13
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Comparative Reverse Vaccinology of Piscirickettsia salmonis, Aeromonas salmonicida, Yersinia ruckeri, Vibrio anguillarum and Moritella viscosa, Frequent Pathogens of Atlantic Salmon and Lumpfish Aquaculture. Vaccines (Basel) 2022; 10:vaccines10030473. [PMID: 35335104 PMCID: PMC8954842 DOI: 10.3390/vaccines10030473] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2022] [Revised: 03/14/2022] [Accepted: 03/15/2022] [Indexed: 02/06/2023] Open
Abstract
Marine finfish aquaculture is affected by diverse infectious diseases, and they commonly occur as co-infection. Some of the most frequent and prevalent Gram-negative bacterial pathogens of the finfish aquaculture include Piscirickettsia salmonis, Aeromonas salmonicida, Yersinia ruckeri, Vibrio anguillarum and Moritella viscosa. To prevent co-infections in aquaculture, polyvalent or universal vaccines would be ideal. Commercial polyvalent vaccines against some of these pathogens are based on whole inactivated microbes and their efficacy is controversial. Identification of common antigens can contribute to the development of effective universal or polyvalent vaccines. In this study, we identified common and unique antigens of P. salmonis, A. salmonicida, Y. ruckeri, V. anguillarum and M. viscosa based on a reverse vaccinology pipeline. We screened the proteome of several strains using complete available genomes and identified a total of 154 potential antigens, 74 of these identified antigens corresponded to secreted proteins, and 80 corresponded to exposed outer membrane proteins (OMPs). Further analysis revealed the outer membrane antigens TonB-dependent siderophore receptor, OMP assembly factor BamA, the LPS assembly protein LptD and secreted antigens flagellar hook assembly protein FlgD and flagellar basal body rod protein FlgG are present in all pathogens used in this study. Sequence and structural alignment of these antigens showed relatively low percentage sequence identity but good structural homology. Common domains harboring several B-cells and T-cell epitopes binding to major histocompatibility (MHC) class I and II were identified. Selected peptides were evaluated for docking with Atlantic salmon (Salmo salar) and Lumpfish MHC class II. Interaction of common peptide-MHC class II showed good in-silico binding affinities and dissociation constants between −10.3 to −6.5 kcal mol−1 and 5.10 × 10−9 to 9.4 × 10−6 M. This study provided the first list of antigens that can be used for the development of polyvalent or universal vaccines against these Gram-negative bacterial pathogens affecting finfish aquaculture.
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14
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Cai W, Kumar S, Navaneethaiyer U, Caballero-Solares A, Carvalho LA, Whyte SK, Purcell SL, Gagne N, Hori TS, Allen M, Taylor RG, Balder R, Parrish CC, Rise ML, Fast MD. Transcriptome Analysis of Atlantic Salmon ( Salmo salar) Skin in Response to Sea Lice and Infectious Salmon Anemia Virus Co-Infection Under Different Experimental Functional Diets. Front Immunol 2022; 12:787033. [PMID: 35046944 PMCID: PMC8763012 DOI: 10.3389/fimmu.2021.787033] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2021] [Accepted: 12/06/2021] [Indexed: 11/13/2022] Open
Abstract
Sea lice (Lepeophtheirus salmonis) are ectoparasitic copepods that cause significant economic loss in marine salmoniculture. In commercial salmon farms, infestation with sea lice can enhance susceptibility to other significant pathogens, such as the highly contagious infectious salmon anemia virus (ISAv). In this study, transcriptomic analysis was used to evaluate the impact of four experimental functional feeds (i.e. 0.3% EPA/DHA+high-ω6, 0.3% EPA/DHA+high-ω6+immunostimulant (IS), 1% EPA/DHA+high-ω6, and 1% EPA/DHA+high-ω3) on Atlantic salmon (Salmo salar) during a single infection with sea lice (L. salmonis) and a co-infection with sea lice and ISAv. The overall objectives were to compare the transcriptomic profiles of skin between lice infection alone with co-infection groups and assess differences in gene expression response among animals with different experimental diets. Atlantic salmon smolts were challenged with L. salmonis following a 28-day feeding trial. Fish were then challenged with ISAv at 18 days post-sea lice infection (dpi), and maintained on individual diets, to establish a co-infection model. Skin tissues sampled at 33 dpi were subjected to RNA-seq analysis. The co-infection’s overall survival rates were between 37%-50%, while no mortality was observed in the single infection with lice. With regard to the infection status, 756 and 1303 consensus differentially expressed genes (DEGs) among the four diets were identified in “lice infection vs. pre-infection” and “co-infection vs. pre-infection” groups, respectively, that were shared between the four experimental diets. The co-infection groups (co-infection vs. pre-infection) included up-regulated genes associated with glycolysis, the interferon pathway, complement cascade activity, and heat shock protein family, while the down-regulated genes were related to antigen presentation and processing, T-cell activation, collagen formation, and extracellular matrix. Pathway enrichment analysis conducted between infected groups (lice infection vs. co-infection) resulted in several immune-related significant GO terms and pathways unique to this group, such as “autophagosome”, “cytosolic DNA-sensing pathway” and “response to type I interferons”. Understanding how experimental functional feeds can impact the host response and the trajectory of co-infections will be an essential step in identifying efficacious intervention strategies that account for the complexities of disease in open cage culture.
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Affiliation(s)
- Wenlong Cai
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada.,Department of Infectious Diseases and Public Health, Jockey Club College of Veterinary Medicine and Life Sciences, City University of Hong Kong, Hong Kong, Hong Kong SAR, China
| | - Surendra Kumar
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | | | | | - Laura A Carvalho
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Shona K Whyte
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Sara L Purcell
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Nellie Gagne
- Fisheries and Oceans Canada, Moncton, NB, Canada
| | - Tiago S Hori
- Centre for Aquaculture Technologies Canada, Souris, PE, Canada
| | - Melissa Allen
- Centre for Aquaculture Technologies Canada, Souris, PE, Canada
| | | | - Rachel Balder
- Cargill Animal Nutrition, Elk River, MN, United States
| | - Christopher C Parrish
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Matthew L Rise
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John's, NL, Canada
| | - Mark D Fast
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
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15
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Korkea‐aho TL, Viljamaa‐Dirks S, Heinikainen S, Kuronen H, Tiirola M. Genetic diversity and phenotypic characterization of Iodobacter limnosediminis associated with skin lesions in freshwater fish. JOURNAL OF FISH DISEASES 2021; 44:1711-1724. [PMID: 34218448 PMCID: PMC8596759 DOI: 10.1111/jfd.13490] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Revised: 06/21/2021] [Accepted: 06/22/2021] [Indexed: 06/13/2023]
Abstract
The relatively unknown genus Iodobacter sp. has been repeatedly isolated from skin ulcers and saprolegniosis on freshwater fish in Finland, especially farmed salmonids. Genetic characterization verified that all 23 bacterial isolates studied here belonged to the species Iodobacter limnosediminis, previously undescribed from the fish microbiota. Whole-genome pulsed-field gel electrophoresis revealed variability between the I. limnosediminis strains, suggesting that they were most likely of environmental origin. Two I. limnosediminis strains caused lesions in 27%-53% of brown trout (Salmo trutta) injected intramuscularly (p ≤ .05). The lesions represented moderate to severe tissue damage, but for most fish, the tissues had been repaired by the end of the experiment through the accumulation of fibrocytes and macrophages at the site of the lesion. I. limnosediminis was reisolated from some lesions and/or internal organs. Phenotypically and biochemically, I. limnosediminis resembles several common bacterial species found in the aquatic environment, as it grows well on several media as whitish medium-sized colonies, is Gram negative and rod-shaped. Here, we characterized I. limnosediminis strains with several methods, including MALDI-TOF. This characterization will help in further investigations into the occurrence and possible involvement of I. limnosediminis in skin lesions of freshwater fish.
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Affiliation(s)
- Tiina Liisa Korkea‐aho
- Veterinary Bacteriology and Pathology UnitLaboratory and Research DivisionFinnish Food AuthorityKuopioFinland
| | - Satu Viljamaa‐Dirks
- Veterinary Bacteriology and Pathology UnitLaboratory and Research DivisionFinnish Food AuthorityKuopioFinland
| | - Sirpa Heinikainen
- Veterinary Bacteriology and Pathology UnitLaboratory and Research DivisionFinnish Food AuthorityKuopioFinland
| | - Henry Kuronen
- Veterinary Bacteriology and Pathology UnitLaboratory and Research DivisionFinnish Food AuthorityKuopioFinland
| | - Marja Tiirola
- Department of Biological and Environmental ScienceNanoscience CenterUniversity of JyväskyläJyväskyläFinland
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16
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Gamil AAA, Gadan K, Gislefoss E, Evensen Ø. Sea Lice ( Lepeophtheirus salmonis) Infestation Reduces the Ability of Peripheral Blood Monocytic Cells (PBMCs) to Respond to and Control Replication of Salmonid Alphavirus in Atlantic Salmon ( Salmo salar L.). Viruses 2020; 12:v12121450. [PMID: 33339349 PMCID: PMC7766357 DOI: 10.3390/v12121450] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2020] [Revised: 12/09/2020] [Accepted: 12/14/2020] [Indexed: 12/21/2022] Open
Abstract
Here we have studied the impact of lice (Lepeophtheirus salmonis) infestation of donor fish on the ability of isolated peripheral blood monocytes (PBMCs) to control the replication of salmonid alphavirus (SAV) ex vivo. PBMCs were collected by Percoll gradients at eight and nine weeks post copepodid infestation of Atlantic salmon post smolt. Uninfested fish were controls. PBMCs were then infected ex vivo with SAV (subtype 3), and samples were collected for analysis at two, four, and six days post virus infection. Virus titer in the supernatant was assayed in CHH-1 cells, and in addition, the relative expression of the virus structural protein E2 and selected host antiviral genes, IRF9, ISG15, Mx, and IFIT5, were assayed using real-time PCR. Significantly higher virus replication was detected in cells collected from lice-infested fish compared to controls. Higher virus titer coincided with an inability to upregulate the expression of different immune genes, IFIT5, IRF9, and Mx. These findings point towards compromised ability of PBMCs from lice-infested fish to control virus replication, and, to our knowledge, is the first report showing the direct effect of lice infestation on the interplay between viruses and immune cells. There is a possible impact on the dynamic spread of viral diseases in the aquatic environment.
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17
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Host genetic variation explains reduced protection of commercial vaccines against Piscirickettsia salmonis in Atlantic salmon. Sci Rep 2020; 10:18252. [PMID: 33106499 PMCID: PMC7588420 DOI: 10.1038/s41598-020-70847-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2020] [Accepted: 08/04/2020] [Indexed: 12/11/2022] Open
Abstract
Vaccination is a widely used control strategy to prevent Piscirickettsia salmonis causing disease in salmon farming. However, it is not known why all the currently available commercial vaccines generally fail to protect against this pathogenic bacteria. Here, we report, from two different populations, that between-family variation is a strong intrinsic factor that determines vaccine protection for this disease. While in some full-sib families, the protection added by vaccination increased the survival time in 13 days in comparison with their unvaccinated siblings; in other families, there was no added protection by vaccination or even it was slightly negative. Resistance to P. salmonis, measured as days to death, was higher in vaccinated than unvaccinated fish, but only a moderate positive genetic correlation was obtained between these traits. This disputes a previous hypothesis, that stated that both traits were fully controlled by the same genes, and challenges the use of unvaccinated fish as gold standard for evaluating and selecting fish resistant to P. salmonis, particularly if the offspring will be vaccinated. More studies are necessary to evaluate if variation in the host immune response to vaccination could explain the between-family differences in resistance observed in vaccinated fish.
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18
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Braden LM, Monaghan SJ, Fast MD. Salmon immunological defence and interplay with the modulatory capabilities of its ectoparasite Lepeophtheirus salmonis. Parasite Immunol 2020; 42:e12731. [PMID: 32403169 DOI: 10.1111/pim.12731] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 03/13/2020] [Accepted: 05/06/2020] [Indexed: 12/16/2022]
Abstract
The salmon louse Lepeophtheirus salmonis (Lsal) is an ectoparasitic copepod that exerts immunomodulatory and physiological effects on its host Atlantic salmon. Over 30 years of research on louse biology, control, host responses and the host-parasite relationship has provided a plethora of information on the intricacies of host resistance and parasite adaptation. Atlantic salmon exhibit temporal and spatial impairment of the immune system and wound healing ability during infection. This immunosuppression may render Atlantic salmon less tolerant to stress and other confounders associated with current management strategies. Contrasting susceptibility of salmonid hosts exists, and early pro-inflammatory Th1 type responses are associated with resistance. Rapid cellular responses to larvae appear to tip the balance of the host-parasite relationship in favour of the host, preventing severe immune-physiological impacts of the more invasive adults. Immunological, transcriptomic, genomic and proteomic evidence suggests pathological impacts occur in susceptible hosts through modulation of host immunity and physiology via pharmacologically active molecules. Co-evolutionary and farming selection pressures may have incurred preference of Atlantic salmon as a host for Lsal reflected in their interactome. Here, we review host-parasite interactions at the primary attachment/feeding site, and the complex life stage-dependent molecular mechanisms employed to subvert host physiology and immune responses.
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Affiliation(s)
- Laura M Braden
- AquaBounty Canada, Bay Fortune, PEI, Canada.,Department of Pathology and Microbiology, Atlantic Veterinary College-UPEI, Charlottetown, PEI, Canada
| | - Sean J Monaghan
- Institute of Aquaculture, University of Stirling, Stirling, UK
| | - Mark D Fast
- Department of Pathology and Microbiology, Atlantic Veterinary College-UPEI, Charlottetown, PEI, Canada
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19
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Abdel-Latif HMR, Dawood MAO, Menanteau-Ledouble S, El-Matbouli M. The nature and consequences of co-infections in tilapia: A review. JOURNAL OF FISH DISEASES 2020; 43:651-664. [PMID: 32315088 DOI: 10.1111/jfd.13164] [Citation(s) in RCA: 61] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 03/02/2020] [Accepted: 03/02/2020] [Indexed: 06/11/2023]
Abstract
Co-infections commonly arise when two or multiple different pathogens infect the same host, either as simultaneous or as secondary concurrent infection. This potentiates their pathogenic effects and leads to serious negative consequences on the exposed host. Numerous studies on the occurrence of the bacterial, parasitic, fungal and viral co-infections were conducted in various tilapia species. Co-infections have been associated with serious negative impacts on susceptible fish because they increase the fish susceptibility to diseases and the likelihood of outbreaks in the affected fish. Co-infections can alter the disease course and increase the severity of disease through synergistic and, more rarely, antagonistic interactions. In this review, reports on the synergistic co-infections and their impacts on the affected tilapia species are highlighted. Additionally, their pathogenic mechanisms are briefly discussed. Tilapia producers should be aware of the possible occurrence of co-infections and their effects on the affected tilapia species and in particular of the clinical signs and course of the disease. To date, there is still limited information regarding the pathogenicity mechanisms and pathogen interactions during these co-infections. This is generally due to low awareness regarding co-infections, and in many cases, a dominant pathogen is perceived to be of vital importance and hence becomes the target of treatment while the treatment of the co-infectious agents is neglected. This review article aimed at raising awareness regarding co-infections and helping researchers and fish health specialists pay greater attention to these natural cases, leading to increased research and more consistent diagnosis of co-infectious outbreaks in order to improve control strategies to protect tilapia when infected with multiple pathogens.
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Affiliation(s)
- Hany M R Abdel-Latif
- Department of Poultry and Fish diseases, Faculty of Veterinary Medicine, Alexandria University, Alexandria, Egypt
| | - Mahmoud A O Dawood
- Department of Animal Production, Faculty of Agriculture, Kafrelsheikh University, Kafrelsheikh, Egypt
| | | | - Mansour El-Matbouli
- Clinical Division of Fish Medicine, University of Veterinary Medicine Vienna, Vienna, Austria
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20
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Carvalho LA, Whyte SK, Braden LM, Purcell SL, Manning AJ, Muckle A, Fast MD. Impact of co-infection with Lepeophtheirus salmonis and Moritella viscosa on inflammatory and immune responses of Atlantic salmon (Salmo salar). JOURNAL OF FISH DISEASES 2020; 43:459-473. [PMID: 32100325 DOI: 10.1111/jfd.13144] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2019] [Revised: 01/16/2020] [Accepted: 01/17/2020] [Indexed: 06/10/2023]
Abstract
This study was conducted to determine the effects of a co-infection with Moritella viscosa at different exposure levels of sea lice Lepeophtheirus salmonis in Atlantic salmon (Salmo salar). M. viscosa (1.14 × 106 cfu/ml) was introduced to all experimental tanks at 10 days post-lice infection (dpLs). Mean lice counts decreased over time in both the medium lice co-infection (31.5 ± 19.0 at 7 dpLs; 16.9 ± 9.3 at 46 dpLs) and high lice co-infection (62.0 ± 10.8 at 7 dpLs; 37.6 ± 11.3 at 46 dpLs). There were significantly higher mortalities and more severe skin lesions in the high lice co-infected group compared to medium lice co-infected group or M. viscosa-only infection. Quantitative gene expression analysis detected a significant upregulation of genes in skin from the high lice co-infection group consistent with severe inflammation (il-8, mmp-9, hep, saa). Skin lesions retrieved throughout the study were positive for M. viscosa growth, but these were rarely located in regions associated with lice. These results suggest that while M. viscosa infection itself may induce skin lesion development in salmon, co-infection with high numbers of lice can enhance this impact and significantly reduce the ability of these lesions to resolve, resulting in increased mortality.
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Affiliation(s)
- Laura A Carvalho
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Shona K Whyte
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | | | - Sara L Purcell
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Anthony J Manning
- Food Fisheries and Aquaculture Department, The New Brunswick Research and Productivity Council (RPC), Fredericton, NB, Canada
| | - Anne Muckle
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
| | - Mark D Fast
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE, Canada
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Umasuthan N, Xue X, Caballero-Solares A, Kumar S, Westcott JD, Chen Z, Fast MD, Skugor S, Nowak BF, Taylor RG, Rise ML. Transcriptomic Profiling in Fins of Atlantic Salmon Parasitized with Sea Lice: Evidence for an Early Imbalance Between Chalimus-Induced Immunomodulation and the Host's Defense Response. Int J Mol Sci 2020; 21:E2417. [PMID: 32244468 PMCID: PMC7177938 DOI: 10.3390/ijms21072417] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2020] [Accepted: 03/27/2020] [Indexed: 01/08/2023] Open
Abstract
Parasitic sea lice (e.g., Lepeophtheirus salmonis) cause costly outbreaks in salmon farming. Molecular insights into parasite-induced host responses will provide the basis for improved management strategies. We investigated the early transcriptomic responses in pelvic fins of Atlantic salmon parasitized with chalimus I stage sea lice. Fin samples collected from non-infected (i.e. pre-infected) control (PRE) and at chalimus-attachment sites (ATT) and adjacent to chalimus-attachment sites (ADJ) from infected fish were used in profiling global gene expression using 44 K microarrays. We identified 6568 differentially expressed probes (DEPs, FDR < 5%) that included 1928 shared DEPs between ATT and ADJ compared to PRE. The ATT versus ADJ comparison revealed 90 DEPs, all of which were upregulated in ATT samples. Gene ontology/pathway term network analyses revealed profound changes in physiological processes, including extracellular matrix (ECM) degradation, tissue repair/remodeling and wound healing, immunity and defense, chemotaxis and signaling, antiviral response, and redox homeostasis in infected fins. The QPCR analysis of 37 microarray-identified transcripts representing these functional themes served to confirm the microarray results with a significant positive correlation (p < 0.0001). Most immune/defense-relevant transcripts were downregulated in both ATT and ADJ sites compared to PRE, suggesting that chalimus exerts immunosuppressive effects in the salmon's fins. The comparison between ATT and ADJ sites demonstrated the upregulation of a suite of immune-relevant transcripts, evidencing the salmon's attempt to mount an anti-lice response. We hypothesize that an imbalance between immunomodulation caused by chalimus during the early phase of infection and weak defense response manifested by Atlantic salmon makes it a susceptible host for L. salmonis.
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Affiliation(s)
- Navaneethaiyer Umasuthan
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada; (X.X.); (A.C.-S.); (S.K.)
| | - Xi Xue
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada; (X.X.); (A.C.-S.); (S.K.)
| | - Albert Caballero-Solares
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada; (X.X.); (A.C.-S.); (S.K.)
| | - Surendra Kumar
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada; (X.X.); (A.C.-S.); (S.K.)
| | - Jillian D. Westcott
- Fisheries and Marine Institute, Memorial University of Newfoundland, P.O. Box 4920, St. John’s, NL A1C 5R3, Canada; (J.D.W.); (Z.C.)
| | - Zhiyu Chen
- Fisheries and Marine Institute, Memorial University of Newfoundland, P.O. Box 4920, St. John’s, NL A1C 5R3, Canada; (J.D.W.); (Z.C.)
| | - Mark D. Fast
- Department of Pathology and Microbiology, Atlantic Veterinary College, University of Prince Edward Island, Charlottetown, PE C1A 4P3, Canada;
| | - Stanko Skugor
- Cargill Aqua Nutrition, Cargill, Sea Lice Research Center (SLRC), Hanaveien 17, 4327 Sandnes, Norway;
| | - Barbara F. Nowak
- Institute of Marine and Antarctic Studies, University of Tasmania, Locked Bag 1370, Launceston 7250, TAS, Australia;
| | - Richard G. Taylor
- Cargill Animal Nutrition, 10383 165th Avenue NW, Elk River, MN 55330, USA;
| | - Matthew L. Rise
- Department of Ocean Sciences, Memorial University of Newfoundland, St. John’s, NL A1C 5S7, Canada; (X.X.); (A.C.-S.); (S.K.)
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Ma J, Bruce TJ, Oliver LP, Cain KD. Co-infection of rainbow trout (Oncorhynchus mykiss) with infectious hematopoietic necrosis virus and Flavobacterium psychrophilum. JOURNAL OF FISH DISEASES 2019; 42:1065-1076. [PMID: 31074078 DOI: 10.1111/jfd.13012] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/01/2019] [Revised: 04/09/2019] [Accepted: 04/10/2019] [Indexed: 06/09/2023]
Abstract
Co-infection of rainbow trout with infections haematopoietic necrosis virus (IHNV) and Flavobacterium psychrophilum is known to occur, and it has been speculated that a combined infection can result in dramatic losses. Both pathogens can persist in fish in an asymptomatic carrier state, but the impact of co-infection has not been well characterized or documented. In this study, it was hypothesized that fish co-infected with F. psychrophilum and IHNV would exhibit greater mortality than fish infected with either pathogen alone. To test this, juvenile rainbow trout were co-infected with low doses of either IHNV or F. psychrophilum, and at 2 days post-initial challenge, they were given a low dose of the reciprocal pathogen. This combined infection caused high mortality (76.2%-100%), while mortality from a single pathogen infection with the same respective dose was low (5%-20%). The onset of mortality was earlier in the co-infected group (3-4 days) when compared with fish infected with F. psychrophilum alone (6 days) or IHNV (5 days), confirming the synergistic interaction between both pathogens. Co-infection led to a significant increase in the number of F. psychrophilum colony-forming units and IHNV plaque-forming units within tissues. This finding confirms that when present together in co-infected fish, both pathogens are more efficiently recovered from tissues. Furthermore, pathogen genes were significantly increased in co-infected groups, which parallel the findings of increased systemic pathogen load. Extensive tissue necrosis and abundant pathogen present intracellularly and extracellularly in haematopoietic tissue. This was pronounced in co-infected fish and likely contributed to the exacerbated clinical signs and higher mortality. This study provides novel insight into host-pathogen interactions related to co-infection by aquatic bacterial and viral pathogens and supports our hypothesis. Such findings confirm that mortality in fish exposed to both pathogens is greatly elevated compared to a single pathogen infection.
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Affiliation(s)
- Jie Ma
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, Idaho
| | - Timothy J Bruce
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, Idaho
| | - Luke P Oliver
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, Idaho
| | - Kenneth D Cain
- Department of Fish and Wildlife Sciences, College of Natural Resources, University of Idaho, Moscow, Idaho
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Gorgoglione B, Taylor NGH, Holland JW, Feist SW, Secombes CJ. Immune response modulation upon sequential heterogeneous co-infection with Tetracapsuloides bryosalmonae and VHSV in brown trout (Salmo trutta). FISH & SHELLFISH IMMUNOLOGY 2019; 88:375-390. [PMID: 30797951 DOI: 10.1016/j.fsi.2019.02.032] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Revised: 02/12/2019] [Accepted: 02/15/2019] [Indexed: 06/09/2023]
Abstract
Simultaneous and sequential infections often occur in wild and farming environments. Despite growing awareness, co-infection studies are still very limited, mainly to a few well-established human models. European salmonids are susceptible to both Proliferative Kidney Disease (PKD), an endemic emergent disease caused by the myxozoan parasite Tetracapsuloides bryosalmonae, and Viral Haemorrhagic Septicaemia (VHS), an OIE notifiable listed disease caused by the Piscine Novirhabdovirus. No information is available as to how their immune system reacts when interacting with heterogeneous infections. A chronic (PKD) + acute (VHS) sequential co-infection model was established to assess if the responses elicited in co-infected fish are modulated, when compared to fish with single infections. Macro- and microscopic lesions were assessed after the challenge, and infection status confirmed by RT-qPCR analysis, enabling the identification of singly-infected and co-infected fish. A typical histophlogosis associated with histozoic extrasporogonic T. bryosalmonae was detected together with acute inflammation, haemorrhaging and necrosis due to the viral infection. The host immune response was measured in terms of key marker genes expression in kidney tissues. During T. bryosalmonae/VHSV-Ia co-infection, modulation of pro-inflammatory and antimicrobial peptide genes was strongly influenced by the viral infection, with a protracted inflammatory status, perhaps representing a negative side effect in these fish. Earlier activation of the cellular and humoral responses was detected in co-infected fish, with a more pronounced upregulation of Th1 and antiviral marker genes. These results reveal that some brown trout immune responses are enhanced or prolonged during PKD/VHS co-infection, relative to single infection.
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Affiliation(s)
- Bartolomeo Gorgoglione
- Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Scotland, UK; CEFAS Weymouth Laboratory, The Nothe, Weymouth, Dorset, England, UK.
| | - Nick G H Taylor
- CEFAS Weymouth Laboratory, The Nothe, Weymouth, Dorset, England, UK
| | - Jason W Holland
- Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Scotland, UK
| | - Stephen W Feist
- CEFAS Weymouth Laboratory, The Nothe, Weymouth, Dorset, England, UK
| | - Christopher J Secombes
- Scottish Fish Immunology Research Centre, School of Biological Sciences, University of Aberdeen, Scotland, UK.
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Delphino MK, Barone RS, Leal CA, Figueiredo HC, Gardner IA, Gonçalves VS. Economic appraisal of vaccination against Streptoccocus agalactiae in Nile tilapia farms in Brazil. Prev Vet Med 2019; 162:131-135. [DOI: 10.1016/j.prevetmed.2018.12.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2018] [Revised: 11/20/2018] [Accepted: 12/06/2018] [Indexed: 01/23/2023]
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Merikanto I, Laakso JT, Kaitala V. Outside-host phage therapy as a biological control against environmental infectious diseases. Theor Biol Med Model 2018; 15:7. [PMID: 29879998 PMCID: PMC5992827 DOI: 10.1186/s12976-018-0079-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Accepted: 05/09/2018] [Indexed: 12/03/2022] Open
Abstract
BACKGROUND Environmentally growing pathogens present an increasing threat for human health, wildlife and food production. Treating the hosts with antibiotics or parasitic bacteriophages fail to eliminate diseases that grow also in the outside-host environment. However, bacteriophages could be utilized to suppress the pathogen population sizes in the outside-host environment in order to prevent disease outbreaks. Here, we introduce a novel epidemiological model to assess how the phage infections of the bacterial pathogens affect epidemiological dynamics of the environmentally growing pathogens. We assess whether the phage therapy in the outside-host environment could be utilized as a biological control method against these diseases. We also consider how phage-resistant competitors affect the outcome, a common problem in phage therapy. The models give predictions for the scenarios where the outside-host phage therapy will work and where it will fail to control the disease. Parameterization of the model is based on the fish columnaris disease that causes significant economic losses to aquaculture worldwide. However, the model is also suitable for other environmentally growing bacterial diseases. RESULTS Transmission rates of the phage determine the success of infectious disease control, with high-transmission phage enabling the recovery of the host population that would in the absence of the phage go asymptotically extinct due to the disease. In the presence of outside-host bacterial competition between the pathogen and phage-resistant strain, the trade-off between the pathogen infectivity and the phage resistance determines phage therapy outcome from stable coexistence to local host extinction. CONCLUSIONS We propose that the success of phage therapy strongly depends on the underlying biology, such as the strength of trade-off between the pathogen infectivity and the phage-resistance, as well as on the rate that the phages infect the bacteria. Our results indicate that phage therapy can fail if there are phage-resistant bacteria and the trade-off between pathogen infectivity and phage resistance does not completely inhibit the pathogen infectivity. Also, the rate that the phages infect the bacteria should be sufficiently high for phage-therapy to succeed.
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Affiliation(s)
- Ilona Merikanto
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland.
- Department of Psychology and logopedics, Faculty of Medicine, University of Helsinki, Helsinki, Finland.
- National Institute for Health and Welfare, Helsinki, Finland.
| | - Jouni T Laakso
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
- Centre of Excellence in Biological Interactions, University of Jyväskylä, Jyväskylä, Finland
| | - Veijo Kaitala
- Faculty of Biological and Environmental Sciences, University of Helsinki, Helsinki, Finland
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