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Updates on the vaccination against bacterial diseases in tilapia, oreochromis spp. and Asian Seabass, Lates Calcarifer
Abstract
The use of vaccines in aquaculture is one of the widely accepted methods of preventing most pathogenic diseases. In warmwater aquaculture, various species of tilapia, Oreochromis spp., and the Asian seabass, Lates calcarifer are widely farmed in freshwater and brackishwater ponds and cages because of their high demand in the market both for local consumption and for export. However, farming of these fish species is hampered by the outbreaks of bacterial diseases that affect production and eventually revenues. This review provides updates on the different bacterial vaccines developed for these farmed fish. In tilapia, experimental trials have been done on the effectiveness of inactivated, attenuated and sub-unit vaccines against Streptococcus iniae, S. agalactiae, Vibrio spp., Aeromonas hydrophila, Edwardsiella tarda and Francisella asiatica. On the other hand, bacterial vaccines have been tested against Vibrio anguillarum in Asian seabass. The immune responses of the fish as a result of vaccination and the protective efficiency of these different vaccines are also discussed.
... However, the mere presence of a pathogen in water does not necessarily lead to the outbreak of diseases . Therefore, applying the measures that are adequate to prevent and control diseases in aquaculture requires studying potential pathogen characteristics and aspects of the biology of the fish hosts as well as a better understanding of environmental factors that may affect aquaculture production (Caipang et al. 2014). Due to the rapid increase in aquaculture production recorded recently, the need for effective disease prevention and control measures is a growing concern. ...
... Vaccines.-The application of vaccines against pathogenic diseases in aquaculture is one of the widely accepted preventive measures (Klesius et al. 2006;Caipang et al. 2014). In recent years, vaccines have received considerable attention for the prevention of streptococcosis in tilapia (Table 2) because they can induce and develop resistance to infection in the fish host; this continues to be a common practice in fish disease prevention (Caipang et al. 2014;Zamri-Saad et al. 2014 Soto et al. 2015). ...
... application of vaccines against pathogenic diseases in aquaculture is one of the widely accepted preventive measures (Klesius et al. 2006;Caipang et al. 2014). In recent years, vaccines have received considerable attention for the prevention of streptococcosis in tilapia (Table 2) because they can induce and develop resistance to infection in the fish host; this continues to be a common practice in fish disease prevention (Caipang et al. 2014;Zamri-Saad et al. 2014 Soto et al. 2015). However, the differences in the distribution of these serotypes as well as their strains in different countries make the development of widely used vaccines difficult. ...
Tilapia culture is a very promising industry within the aquaculture sector. However, disease outbreaks have continued to threaten the industry, causing serious economic losses among the producers. Streptococcosis has become the major bacterial disease affecting tilapia production in most regions of the world. To combat the disease and minimize its economic impact on fish producers, numerous preventive and control measures have been developed and reported over the years. This paper aims to systematically review the measures that could be used to manage the disease outbreaks and maintain fish health based on previously published scientific studies. Although numerous measures currently available have been highlighted, it is far better for the producers to maximize the preventive measures for management to be economically feasible. Among the currently available preventive measures, the use of vaccines has been shown to have the most promise, while the use of herbs has been demonstrated to be a more sustainable and economically affordable control measure. However, there are still a number of important gaps in existing literature that require further investigation. Overall, significant progress has been made in preventing and controlling streptococcosis in tilapia although, no single effective measure has been identified. Therefore, a combination of these measures may provide a more effective result.
... The purpose of vaccination is to induce and build resistance in the host organisms against a wide array of pathogenic diseases; and this remains as the most viable approach in the prevention of fish diseases (Caipang et al., 2014). Generally, there are three type of vaccines in fish, include traditional inactivated vaccine (Sommerset et al., 2005), live attenuated and sub unit vaccines (Caipang et al., 2014). ...
... The purpose of vaccination is to induce and build resistance in the host organisms against a wide array of pathogenic diseases; and this remains as the most viable approach in the prevention of fish diseases (Caipang et al., 2014). Generally, there are three type of vaccines in fish, include traditional inactivated vaccine (Sommerset et al., 2005), live attenuated and sub unit vaccines (Caipang et al., 2014). The administration for these vaccines in fish can be applied through injection (both intraperitoneal and intramuscular injection), oral, direct immersion or spraying (Yang and Chen, 1996). ...
... Injection method remains to be the most popular method of choice in fish vaccination mainly due to the fish received an exact dose of vaccine resulted in the best effect. However, the excessive operation, time-consuming and difficult to administer to fry and other small fishes become the limitation factor of this injection method (Caipang et al., 2014). There are several components that have been tested as vaccines against infection caused by vibriosis. ...
Current growth in aquaculture production is parallel with the increasing number of diseases outbreaks and can affect the production, profitability and sustainability of the industry worldwide. Among the groups of pathogenic microorganisms, vibriosis is the well-known cause of severe economic losses and responsible for (massive) mortality of cultured shrimp, fish and shellfish. Antibiotics and chemicals have been applied in farms for traditional treatment and prevention of Vibriosis. However, the frequent use of chemotherapeutic agents has allowed for the development of drug-resistant strainsand has led to allergy and toxicity in humans. Therefore, the use of prophylactic approaches to stimulate and enhance the immune responses becomes urgent. In this short review, the application of immunostimulant, vaccine, probiotics and quorum quenching molecules to inhibit the communication of Vibrio spp were presented.
Key words: Vibriosis, Aquaculture, Antibiotics, Prophylactic, Virulence, Immune response
... In European sea bass aquaculture, strategies for the prevention of infectious diseases include the application of biosecurity measures, vaccination and the use of probiotics and immunostimulants. In particular, immunization is currently one of the crucial methods for preventing the onset of bacterial diseases in aquaculture species and represents the most effective alternative to the use of antibiotic drugs [25][26][27][28][29]. Moreover, intraperitoneal vaccination of juvenile sea bass is a widespread method for disease prevention in farmed animals, with commercially available products predominantly featuring an oiladjuvanted antigen formulation [7]. ...
... In European sea bass mariculture facilities, immunization represents a key prevention strategy for most bacterial and viral infectious diseases and is considered the most effective alternative treatment to the use of antimicrobial drugs [25][26][27][28][29]. Most commercially available vaccines are prepared with the whole pathogen inactivated using formaldehyde or heat, with or without the addition of adjuvants [55][56]. ...
In mariculture facilities, bacterial infections pose significant production challenges, with potentially catastrophic impacts on fish species. Bacterial co-infections are a widespread phenomenon in the natural marine environment, although their impact on aquatic organisms remains poorly investigated. This study aimed to detail the pathological findings associated with a natural bacterial co-infection caused by three different pathogens, namely Photobacterium damselae subsp. piscicida, Tenacibaculum maritimum and Vibrio sp., as the cause of mass mortality in European sea bass. The fish had been reared in open-net cages in Sicily and later transferred for experimental research purposes to a user establishment after immunization with an inactivated vaccine. Macroscopic, cytological and histopathological examinations were performed on 109 animals, and bacterial species were identified by the 16S rRNA gene. Overall, ulcerative skin lesions, necrotizing myositis and tail rot with occasional tail loss were associated with tenacibaculosis and vibriosis, while P. damselae subsp. piscicida mainly caused granulomatous inflammation in the spleen and head kidney. Finally, an injection site reaction due to the oil-adjuvanted vaccine administered intraperitoneally was observed in the abdominal fat. Understanding the impact of bacterial pathogens is essential to manage the health and welfare of farmed fish, and the importance of a good health monitoring program cannot be overstated to avoid outbreaks and the possible emergence of new pathogens due to the intensification of the production systems, antibiotic resistance and climate changes. The study would also highlight the importance of the quarantine period when animals supplied for research come from aquaculture farms and how the main goal in the near future should be to better define the procedures to provide completely pathogen-free animals.
... The annual national per capita consumption of mojarra tilapia is 2 kg (SIAP, 2018). On the other hand, the intensification of aquaculture activities has led to an increase in disease outbreaks, generating a significant limit on the freshwater and saltwater aquaculture industry and significant economic losses worldwide (Caipang et al., 2014). Examples of the different causative agents of fish diseases are Edwardsiella tarda, Aeromonas hydrophila, Streptococcus iniae, Vibrio vulnificus, and Mycobacterium spp. ...
... Using these compounds under proper management and administration is possible; however, preventive actions are recommended, prioritizing the implementation of good aquaculture practices to address the current health challenges related to mitigating the spread of antimicrobial resistance due to the inappropriate use of these compounds in food production activities, which can affect food safety and security (FAO, 2020a;2020b; 247 FAO/WHO, 2020). On the other hand, in addition to the application of good aquaculture practices such as fish disease prevention measures, vaccination may be a promising possibility for ensuring animal health where the experimental development of various vaccines has produced good results in different fish, such as in tilapia related to resisting various bacterial pathogens, including V. vulnificus (Caipang et al., 2014;LaFrentz and Shoemaker, 2015). ...
... Vaksinasi telah terbukti menjadi strategi pencegahan penyakit yang efektif dengan kemampuan untuk mengurangi wabah penyakit (Pridgeon et al., 2012;Sugiani et al., 2013;. Ada beberapa vaksin yang telah dikembangkan untuk melindungi ikan terhadap penyakit yang disebabkan oleh A. hydrophila yaitu vaksin inaktif dari bakteri yang dilemahkan dan vaksin sub-unit (Caipang et al., 2014). Meskipun vaksin suntik dapat mengembangkan kekebalan protektif untuk A. hydrophila (Dash et al., 2011;Sugiani et al., 2014), namun pengembangan aplikasi vaksin pada pembudidaya ikan di Indonesia kurang efektif sehingga memengaruhi tingkat keberhasilan kegiatan vaksinasi ikan. ...
... Meskipun sebagian besar vaksin bakteri terbukti efisien, upaya penelitian masih diperlukan untuk membuat vaksin yang benarbenar efektif untuk ikan. Pemahaman tentang mekanisme kekebalan ikan selama vaksinasi akan menghasilkan desain dan metode vaksinasi yang lebih baik, yang pada akhirnya dapat menghasilkan kemampuan proteksi yang lebih tinggi bila terjadi infeksi bakteri di fasilitas akuakultur (Caipang et al., 2014). ...
Vaksinasi merupakan salah satu cara yang efektif untuk pencegahan penyakit infeksius pada budidaya ikan. Produk vaksin yang tersedia saat ini masih berbasis produk cair (water based vaccines), yang memiliki kekurangan dalam stabilitas produk yang tidak tahan lama jika disimpan dalam suhu ruang dan keterbatasan dalam tranportasi. Penelitian ini bertujuan untuk mengembangkan metode preparasi sediaan produk vaksin sel utuh Aeromonas hydrophila dalam bentuk kering beku (freeze dried) untuk pengendalian penyakit pada ikan lele (Clarias sp.), nila (Oreochromis niloticus), dan gurami (Osphronemus gouramy). Penelitian dilakukan dengan membuat produk vaksin kering beku pada suhu -100°C, uji mutu, uji keamanan, dan uji efikasi. Penelitian ini telah menghasilkan produk vaksin kering beku yang aman diaplikasikan pada ikan lele, nila, dan gurami, serta dapat menginduksi peningkatan level titer antibodi. Sediaan vaksin sel utuh A. hydrophila dengan metode kering beku dapat mereduksi berat produk vaksin cair 100 g menjadi serbuk sebesar 4,2 g. Efikasi vaksin menghasilkan tingkat sintasan relatif (RPS/relative percent survival) pada ikan nila (Oreochromis niloticus) 45,83%; ikan lele (Clarias sp.) 70%; dan ikan gurami (Osphronemus gouramy) 31,67%. Vaksin kering beku sel utuh bakteri Aeromonas hydrophila paling efektif diberikan pada ikan lele untuk mencegah penyakit Motile Aeromonads Septicemia.Vaccination is one of the most effective methods to prevent disease outbreaks and distribution in aquaculture. Commercial fish vaccine products are mainly available in liquid-based products (water-based vaccines), which have several limitations such as stability issues of the products (durability) when stored at room temperature, bulky packaging, and transportation complexity during distribution. This study aimed to develop a method of vaccine preparation using the freeze-dried method as part of the management control of Aeromonads septicemia disease in freshwater aquaculture. The study consisted of several stages: the first stage was the production of freeze-dried Aeromonas hydrophila vaccine product at -100°C. The second stage was vaccine quality test followed by the third stage which was vaccine efficacy test. This research produced frozen dried vaccine products that were considered safe to be applied to catfish, tilapia, and gourami, and could increase the antibody titer. The formation of the whole cell vaccine of A. hydrophila using the freeze-dried method could reduce the weight of the liquid form of the vaccine product from 100 g to a powder weighing only 4.2 g. The results of the vaccine efficacy test showed the relative percent survivals (RPSs) of Clarias sp., Oreochromis niloticus and Osphronemus gouramy were 70%, 45.83%, and 31.67%, respectively. Freeze dried vaccine of whole cells Aeromonas hydrophila are most effective in catfish to prevent Motile Aeromanads Septicemia.
... However, their protective efficiency is usually not as good as injection under the same conditions. The vaccine might be partially degraded by the digestive fluids when given orally, or the vaccine might not be sufficiently absorbed by the fish body using the immersion and spray methods (Noraini et al. 2013, Caipang et al. 2014. For example, the RPS values of tilapia immunized with a live attenuated Streptococcus agalactiae via IP injection, BI, and oral administration were 96.88, 67.22, and 71.81%, respectively, at 15 dpv, but declined to 93.61, 60.56, and 53.16%, respectively, after 30 dpv (Li et al. 2015). ...
... These results indicate that vaccination by injection provided the strongest protection and that the protection period of oral vaccination was shorter than that of IP injection and BI. Although vaccination by IP injection resulted in a high level and long duration protective effect, the operation could be time-consuming and difficult to administer to small fishes (Caipang et al. 2014). Under the same conditions, tilapia obtained a high protection (RPS = 80%) from vaccination with inactivated S. agalactiae by IP injection at 30 dpv, while the protection was significantly re duced (RPS = 34%) using BI (Evans et al. 2004). ...
Vaccination is a widely accepted and effective method to prevent most pathogenic diseases in aquaculture. Various species of tilapia, especially Nile tilapia Oreochromis niloticus, are farmed worldwide because of their high consumer demand. Recently, the tilapia-breeding industry has been hampered by outbreaks of Streptococcus agalactiae infection, which cause high mortality and huge economic losses. Many researchers have attempted to develop effective S. agalactiae vaccines for tilapia. This review provides a summary of the different kinds of S. agalactiae vaccines for tilapia that have been developed recently. Among the various vaccine types, inactivated S. agalactiae vaccines showed superior protection efficiency when compared with live attenuated, recombinant and DNA vaccines. With respect to vaccination method, injecting the vaccine into tilapia provided the most effective immunoprotection. Freund's incomplete adjuvant appeared to be suitable for tilapia vaccines. Other factors, such as immunization duration and number, fish size and challenge dose, also influenced the vaccine efficacy.
... In recent years, the occurrence of microbial infections in a range of aquaculture species and the use of vaccination strategies as prophylaxis measures have been expanded. For example, researchers examined the defensive efficacy of bacterial vaccinations against V. anguillarum in Asian sea bass in experimental trials [46,47]. Moreover, infections with V. harveyi [48], Streptococcus iniae [49], and infestation with Flavobacterium columnaris [50] in barramundi are also treated with experimental vaccines. ...
The advent of aquaculture has been one of the most significant shifts in world food supply during the last century. Aquaculture has rapidly expanded and become a global food industry, spurred by population expansion, increased seafood consumption, and decreased captured fisheries. Nonetheless, the exponential growth of aquaculture has emerged as a significant contributor to anthropogenic changes. Unexpectedly, the result has focused in the emergence and spread of new diseases. The Asian sea bass (Lates calcarifer) is an economically important species in aquaculture, contributing significantly to the global seafood market. However, bacterial diseases have emerged as a major concern, affecting both wild and cultured populations of this species. The most prevalent bacterial pathogens are streptococcus, vibriosis, nocardiosis, tenacibaculosis, and pot-belly disease. Therefore, this review aims to comprehensively analyze both emerging and non-emerging bacterial diseases affecting L. calcarifer and explore potential management approaches for their control. Through an extensive literature survey and critical evaluation of research findings, this review highlights the current understanding of bacterial diseases in L. calcarifer and proposes strategies for better disease management. In addition, this review looks at the rise and characteristics of aquaculture, the major bacterial pathogens of L. calcarifer and their effects, and the specific attributes of disease emergence in an aquatic rather than terrestrial context. It also considers the potential for future disease emergence in L. calcarifer due to aquaculture expansion and climate changes.
... Fish streptococcosis is one of the major infectious diseases in freshwater and marine aquaculture, affecting the sustainability of aquaculture development worldwide [1,2], and is also a zoonotic disease, with important food safety implications [3][4][5][6]. Even though vaccines have shown positive results, they are not adequately efficacious due to the wide heterogeneity of bacterial species/strains involved in the infections [7]. Consequently, fish streptococcal infections are often treated with various antibiotics, such as florfenicol, erythromycin, doxycycline and oxytetracycline [8][9][10][11]. ...
Citation: Van Doan, H.; Soltani, M.; Leitão, A.; Shafiei, S.; Asadi, S.; Lymbery, A.J.; Ringø, E. Streptococcosis a Re-Emerging
... Fish streptococcosis is one of the major infectious diseases in freshwater and marine aquaculture, affecting the sustainability of aquaculture development worldwide [1,2], and is also a zoonotic disease, with important food safety implications [3][4][5][6]. Even though vaccines have shown positive results, they are not adequately efficacious due to the wide heterogeneity of bacterial species/strains involved in the infections [7]. Consequently, fish streptococcal infections are often treated with various antibiotics, such as florfenicol, erythromycin, doxycycline and oxytetracycline [8][9][10][11]. ...
Simple Summary
Streptococcosis is an economical important bacterial disease that can seriously cause huge losses in the global aquaculture sector. In recent years studies have focused on to use extracts or essences of medicinal herbs and plants to control or treat the disease outbreaks and, in most cases the results were promising. The essential oils of the herbs or plants are more effective than the extracts and, the extracts examined have moderate efficacy in term of increasing fish survival against fish streptococcosis that could be due to the enhancement of fish immunity by the herb bio-compounds. The lack of dosage optimization, toxicity and bioavailability assays of a specific herb/plant or its bioactive compound in fish organs make it difficult to judge the validation of clinical efficacy of a particular herb/plant against fish streptococcosis, and thus, required further investigations.
Abstract
Streptococcosis, particularly that caused by S. iniae and S. agalactiae, is a major re-emerging bacterial disease seriously affecting the global sustainability of aquaculture development. Despite a wide spread of the disease in aquaculture, few studies have been directed at assessing the in vitro antagonistic activity and in vivo efficacy of medicinal herbs and other plants against streptococcal agents. Most in vitro studies of plant extractives against S. iniae and S. agalactiae have found antibacterial activity, but essential oils, especially those containing eugenol, carvacrol or thymol, are more effective. Although essential oils have shown better anti-streptococcal activity in in vitro assays, in vivo bioassays require more attention. The extracts examined under in vivo conditions show moderate efficacy, increasing the survival rate of infected fish, probably through the enhancement of immunity before challenge bioassays. The available data, however, lack dosage optimization, toxicity and bioavailability assays of a specific plant or its bioactive compound in fish organs; hence, it is difficult to judge the validation of clinical efficacy for the prevention or treatment of fish streptococcosis. Despite the known bioactive compounds of many tested plants, few data are available on their mode of action towards streptococcal agents. This review addresses the efficacy of medicinal plants to fish streptococcosis and discusses the current gaps.
... However, issues of vaccination also limit their use. Historically, immunizations have been administered through injection, which is time consuming and difficult to deliver to young fish [17]. While oral and immersion vaccinations are simple to administer with minimum stress to the fish, they often generate limited immune responses [12,[18][19][20]. ...
Nanobubble technology has shown appealing technical benefits and potential applications in aquaculture. We recently found that treatment with ozone nanobubbles (NB–O3) activated expression of several immune-related genes leading to effective response to subsequent exposure to fish pathogens. In this study, we investigated whether pre-treatment of Nile tilapia (Oreochromis niloticus) with NB-O3 can enhance specific immune responses and improve efficacy of immersion vaccination against Streptococcus agalactiae. Spleen and head kidney of fish in the vaccinated groups showed a substantial upregulation in expression levels of pro-inflammatory cytokine genes (IL-1β, TNF-α, IL-6) and immunoglobulin classes (IgM, IgD, IgT) compared with the unvaccinated control groups. The mRNA transcript of pro-inflammatory cytokine genes was greatest (approx. 2.8–3.3 folds) on day 7 post-vaccination, whereas the relative expression of immunoglobulin genes was greatest (approx. 3.2–4.1 folds) on day 21 post-immunization. Both systemic and mucosal IgM antibodies were elicited in vaccinated groups. As the result, the cumulative survival rate of the vaccinated groups was found to be higher than that of the unvaccinated groups, with a relative percent survival (RPS) ranging from 52.9-70.5%. However, fish in the vaccinated groups that received pre-treatment with NB-O3, bacterial antigen uptakes, expression levels of IgM, IgD, and IgT, as well as the specific-IgM antibody levels and percent survival, were all slightly or significantly higher than that of the vaccinated group without pre-treatment with NB-O3. Taken together, our findings suggest that utilizing pre-treatment with NB-O3 may improve the immune response and efficacy of immersion vaccination in Nile tilapia.
... The traditional vaccines are commonly immunization by injection, which is time-consuming and difficult to administer to small fishes (Caipang et al., 2014). Oral vaccination is easy to operate without causing any stress to the fish, which is the ideal method of vaccine delivery to fish. ...
Streptococcus agalactiae infection has become a serious bacterial disease of tilapia for its damage. In order to effectively prevent the outbreak of streptococcicosis, a recombinant Lactococcus lactis expressing surface immunogenicity protein (Sip) of S. agalactiae was constructed as probiotic vector oral vaccine in this study. The immunogenicity of the recombinant L. lactis was evaluated through detecting the level of specific serum IgM antibody, expression level of immune-related genes and relative percent survival (RPS). The results showed that the recombinant L. lactis could express a 45.5 kDa protein consistent with the expected size of Sip. The recombinant Sip mainly expressed in the form of inclusion body and the concentration of purified Sip could reach 7.65 mg / mL. Nile tilapia were orally immunized with different concentrations (2.24 × 10⁹, 2.24 × 10¹⁰ and 2.24 × 10¹¹ CFU / mL) of recombinant L. lactis (NZ9000-pNZ8148-sip). The analysis results of specific serum antibody showed that the level of antibody of tilapia which were vaccinated with medium and high concentration of recombinant L. lactis (2.24 × 10¹⁰ CFU / mL and 2.24 × 10¹¹ CFU / mL) were significantly higher than that of control group. The relative percentage of survival (RPS) of tilapia vaccinated with medium concentration of NZ9000-pNZ8148-sip reached 61.6 % at 21 days post-immunization. Quantitative real-time PCR (qRT-PCR) results revealed that the immune-related genes of IgT, IgM, CD8a and C3 were significantly upregulated expression in thymus, liver, spleen and hindgut. In conclusion, the recombinant L. lactis vaccine induced both humoral and cellular responses of tilapia. This study demonstrates the potential of using L. lactis as a delivery system to develop an oral vaccine against S. agalactiae.
... Vaccination is an alternative method of controlling fish diseases apart from the use of antibiotics [7]. The purpose of vaccination is to induce and build resistance in the host against a specific pathogen [8], and injectable vaccines are preferred because the antigen dose is known, thereby making it easy to correlate the antigen dose with vaccine protection [9]. Besides this, the injection method is the most potent route of vaccination, as it produces a stronger immune response compared to other routes of vaccination [10]. ...
Vibrio harveyi causes vibriosis in various commercial marine fish species. The infection leads to significant economic losses for aquaculture farms, and vaccination is an alternative approach for the prevention and control of fish diseases for aquaculture sustainability. This study describes the use of formalin-killed Vibrio harveyi (FKVh) strain Vh1 as a vaccine candidate to stimulate innate and adaptive immunities against vibriosis in a marine red hybrid tilapia model. Tilapia are fast growing; cheap; resistant to diseases; and tolerant to adverse environmental conditions of fresh water, brackish water, and marine water and because of these advantages, marine red hybrid tilapia is a suitable candidate as a model to study fish diseases and vaccinations against vibriosis. A total of 180 healthy red hybrid tilapias were gradually adapted to the marine environment before being divided into two groups, with 90 fish in each group and were kept in triplicate with 30 fish per tank. Group 1 was vaccinated intraperitoneally with 100 µL of FKVh on week 0, and a booster dose was similarly administered on week 2. Group 2 was similarly injected with PBS. Skin mucus, serum, and gut lavage were collected weekly for enzyme-linked immunosorbent assay (ELISA) and a lysozyme activity assay from a total of 30 fish of each group. On week 4, the remaining 60 fish of Groups 1 and 2 were challenged with 10 8 cfu/fish of live Vibrio harveyi. The clinical signs were monitored while the survival rate was recorded for 48 h post-challenge. Vaccination with FKVh resulted in a significantly (p < 0.05) higher rate of survival (87%) compared to the control (20%). The IgM antibody titer and lysozyme activities of Group 1 were significantly (p < 0.05) higher than the unvaccinated Groups 2 in most weeks throughout the experiment. Therefore, the intraperitoneal exposure of marine red hybrid tilapia to killed V. harveyi enhanced the resistance and antibody response of the fish against vibriosis.
... In aquaculture, the most commonly used vaccination methods are of three types; 1) Inactivated whole cell vaccine 2) Live-attenuated vaccine and 3) Sub-unit vaccine, of which inactivated whole cell and live attenuated vaccines are gaining wide importance because of their convenience (Caipang et al., 2014). Inactivated whole cell vaccine is the modified heat killed vaccine using formaldehyde, formalin completely kills and inactivate the bacteria, in which it can no longer be able to replicate inside the host (Petrovsky et al., 2004). ...
Immersion vaccination is a widely accepted and sensible technique for
mass vaccination in small fishes (fry and fingerlings). Whole cell
(WC) and Outer membrane protein (OMP) vaccines were prepared
from the Staphylococcus aureus culture. Qualitative analysis by
Lowry’s method and Quantitative analysis by SDS-PAGE of proteins
were performed for the prepared vaccines. Fingerlings were
immunized after pre-treatment with hyper-osmotic solution of 2%
NaCl for 5 minutes by immersion (bath) vaccination of prepared
vaccines for about 30 minutes. Immunization was carried out twice as
booster dose on day 1 and second dose on day 30. After 30 and 60 dpv
fingerlings from each group were bath challenged with virulent Staphylococcus aureus in
lethal dose concentration of 1x108 cells/ml. Fingerlings were observed for pathological signs
and symptoms. Mortality rate and relative percent survival were recorded for up-to 10 days.
After 30 dpv control group showed 100% mortality within 10 days of bacterial challenge,
whereas significant relative percent survival (RPS) was recorded in vaccinated groups with
68% in WC group and 64% in OMP group. After 60 dpv there was a significant increase in
the RPS rate in OMP group with 84% and 76% in WC.
KEYWORDS: Labeo rohita (rohu), Whole cell vaccine (WC), Outer membrane protein
vaccine (OMP), Staphylococcus aureus, Mortality and Relative percent survival
... Over the last ten years, the aquaculture business has grown very fast in the Asia-Pacific region. 6 Notwithstanding, the fact that aquaculture is the fastest growing food-production industry in the world the sector is plagued by diseases. The annual economic loss to the aquaculture industry through diseases is estimated to be billions of US dollars worldwide. 7 Major pathogens that affect the industry include bacteria, 8,9 fungi, 10 viruses 11 and parasites. ...
Tilapia aquaculture is a major source of animal protein, with global production reaching over 6 million tonnes in 2020. The rapid growth of the tilapia sector has led to a number of emerging disease threats and subsequent production losses. Risk analysis can provide a targeted approach for improving biosecurity in the tilapia sector. The aim of this work was to describe the tilapia value chain and review the important infectious agents of tilapia that may affect the different points along the value chain; such points include input and service suppliers, producers (i.e., hatcheries, nurseries and grow-out farms), and processors, traders and marketers. We then describe how risk analysis can be used to identify critical controls points along the value chain and describe potential risk mitigation measures that may be implemented at those points. The control of diseases of tilapia requires a multi-faceted approach, with risk-based control measures chosen based on their feasibility, effectiveness and sustainability. The Progressive Management Pathway for Improving Aquaculture Biosecurity, as a risk-based, collaborative and progressive management approach combined with the systematic preventive principles of Hazard Analysis Critical Control Point, offers a strategic and practical way of improving biosecurity in the tilapia value chain.
Aquaculture is one of the rapidly growing food producing sectors in the world. Incidence of disease occurrence is one of the most important limiting factors in aquaculture. In order to get sustainable production from this sector prevention and control of pathogenic fish disease are crucial measures both economically and environmentally. Although several methods of treatment of fish diseases are introduced but the use of vaccines for some diseases can be very effective in terms of aquatic animal health management. Prophylactic measures based on stimulation of the immune system of the fish have been an effective measure for reducing the pathogens from cultured aquatic organisms. Immuno-prophylaxis plays important role in successful development of aqua farming practices. The objective of the present study is to review fish vaccines its development, importance of fish vaccines in terms of fisheries, route of vaccine administration in fishes and diseases controlled through fish vaccines.
The objective of this study was to evaluate new health strategies by using a biopromoter with different application routes (oral, immersion and intraperitoneal) and a hepatoprotector added to the diet in Nile tilapia Oreochromis niloticus, compared to a control group basal and a vaccinated control, to verify the possibility of improvements in the sanitary framework of the species and increase of resistance to the pathogen Streptococcus agalactiae serotype Ib. 360 juveniles of Nile tilapia with approximately 45 days of life and average weight of 0.72±0.04 g were used, kept in a water recirculation system for 62 days. In this period, different doses of the biopromoter were fractionated in different routes of application. In the oral route, 100 µL and 200 µL of the biopromoter were added to each gram of feed offered; for the immersion bath were used 500 mL and 1000 mL of the biopromoter diluted in 4.5 L and 4 L respectively; for intraperitoneal injection, 200 µL per fish. For this group of animals, a positive control was established, which was vaccinated with a commercial vaccine against streptococcosis. In feed, 0.1% of Di-Heptarine S® hepatoprotector was incorporated into the diet and offered throughout the period. Another control group was established and received only commercial ration. All fish were fed commercial tilapia-specific Nicoluzzi® (40% CP) commercial feed. On day 54 samples were collected for hematological, immunological, histological and enzymatic analyzes; and at day 55 the fish were challenged with S. agalactiae and the efficacy of the biopromoter and hepatoprotector were checked. Samples for hematological, immunological and histological analyzes were also collected during this period of the challenge to verify possible physiological changes in the fish. At the end of the experiment it was observed that the two products provided changes in the hematological, histological, immunological and enzymatic profiles of the animals, developing some resistance against the bacterial pathogen, since at the end of the experimental challenge only the fish of the control group reached a rate of 100% mortality.
This study evaluated the use of biopromoter Gamaxine for fish, a product elaborated from the fermentation of purified cultures of inactivated saprophytic bacteria, at the original concentration of 1.0 g L⁻¹, to favor the equilibrium of the intestinal microbiota, providing better protection against the enteric challenges. It is used originally as against enteric challenges and consequently improving the productive performance of poultry. The biopromoter was manufactured by Vetanco company for evaluation under experimental conditions to be tested and validated as an immunomodulator in the Nile tilapia Oreochromis niloticus, against the pathogen Streptococcus agalactiae serotype Ib by different routes of application: oral, immersion and intraperitoneal, as compared to a naïve group and a control group immunized with commercial vaccine. A total of 315 Nile tilapia's juveniles with initial mean weight of 0.72 ± 0.04 g. The treatments were randomly distributed in triplicates in 21 experimental units in a water recirculation system. Different doses of the biopromoter were fractionated for each route of application. In the oral route, 0.1 mg and 0.2 mg of the biopromoter were added to each gram of feed offered; for the immersion bath 500 mg and 1000 mg of the biopromoter diluted in 4.5 L and 4.0 L respectively were used; and for intraperitoneal injection, 0.2 mg per fish. After 54 days of the experiment, the samples were collected for hematological, immunological, histological and enzymatic analyzes. At day 55 the fish were challenged with S. agalactiae, to verify the efficacy of the biopromoter and the possible increase of the bacterial resistance to the pathogens, as well as physiological changes in the fish. Hematoimmunological, histological and enzymatic pre-infection analyzes revealed that the treated fish presented improvements in the immune system, indicating that these animals were better prepared to confront the bacteria. After the experimental infection the fish in the treated groups increased the resistance the pathogen. All the results of this study indicate that the tilapias that received the biopromoter developed improvements in the mechanisms of the immune system and the zootechnical performance.
The effects of feeding ascogen (5 g kg-1 feed) on the humoral and cell-mediate immune response after immunization of tilapia by intramuscular injection (IM) and direct immersion (DI) with formalin killed Aeromonas hydrophila vaccine (FKAHV) were studied. The results showed that ascogen had a marked immunopotentiating effect after IM as well as after DI vaccination. The immunopotentiating effect of ascogen covered both the humoral and cell-mediated immune response. It was manifested by a marked rise in the geometric mean of antibody titres (haemagglutinating units, HAU) at day 70 after vaccination which reached 409·6 ± 62·71 (after IM) and 48.0 ± 10·.12 (after DI) compared to the vaccinated control groups (57·6 ± 6·40 and 11·2 ± 1·96), respectively. In addition, the mitogenic response of lymphocytes obtained from fish fed with ration containing ascogen was significantly stronger than that of lymphocytes isolated from the control group. Supplementation of ascogen before and after vaccination increased the macrophage migration inhibition percent from 14 to 84 days after vaccination. The relative percent survival of challenged fish after IM and DI vaccination was 89·80% and 40·82% in ascogen supplemented groups compared to the vaccinated nontreated control groups where it was 75·51% and 10·20%, respectively.
Partial sequence of the dnaJ gene of Vibrio harveyi, which was isolated from diseased juvenile Asian seabass, Lates calcarifer was identified. The partial sequence of dnaJ gene of V. harveyi was 447 bp and shared at least 77% identity at the nucleotide level with the dnaJ gene of other Vibrios. It was distinct from the dnaJ gene of other Vibrios but was closely related with the dnaJ gene of V. rotiferianus and V. campbellii having at least 90% nucleotide identity. PCR primers targeting this gene were designed to detect the pathogen in Asian seabass. The assay was specific to V. harveyi and the limit of detection was 100 pg of genomic DNA ml-1 or 100 fg of bacterial genomic DNA in a PCR reaction. This corresponded to a sensitivity of approximately 20 genome equivalents (GE) of V. harveyi. These results indicate that the dnaJ gene is a good candidate to develop primers for the PCR assay in detecting V. harveyi in fish.
Immunization by an antigen-encoding DNA was approved for commercial sale in Canada against a Novirhabdovirus infection in fish. DNA vaccines have been particularly successful against the Novirhabdoviruses while there are reports on the efficacy against viral pathogens like infectious pancreatic necrosis virus, infectious salmon anemia virus, and lymphocystis disease virus and these are inferior to what has been attained for the novirhabdoviruses. Most recently, DNA vaccination of Penaeus monodon against white spot syndrome virus was reported. Research efforts are now focused on the development of more effective vectors for DNA vaccines, improvement of vaccine efficacy against various viral diseases of fish for which there is currently no vaccines available and provision of co-expression of viral antigen and immunomodulatory compounds. Scientists are also in the process of developing new delivery methods. While a DNA vaccine has been approved for commercial use in farmed salmon in Canada, it is foreseen that it is still a long way to go before a DNA vaccine is approved for use in farmed fish in Europe.
Streptococcus iniae, a Gram-positive bacterium, and Vibrio vulnificus, a halophilic Gram-negative bacterium, have been associated with severe disease impacting tilapia aquaculture. Recent reports suggest that both bacteria have been associated independently and concomitantly with disease on commercial farms. Monovalent vaccines have been developed for disease control; however, the most effective delivery strategy has been via intraperitoneal (IP) injection. Due to handling stress and the cost associated with injecting each fish, a better strategy is to combine the monovalent vaccines into bivalent formulations. The objective of the present study was to test the ability of a killed bivalent S. iniae and V. vulnificus vaccine delivered by IP injection at protecting sex reversed hybrid tilapia (Oreochromis niloticus × Oreochromis aureus) against challenge with each bacterium, independently. In two independent trials, vaccination of tilapia with the bivalent vaccine conferred protective immunity against V. vulnificus and S. iniae as demonstrated by significant differences (P < 0.05) in survival curves between the sham-vaccinated and vaccinated groups. Relative percent survival values ranged from 79 to 89% for V. vulnificus and 69 to 100% for S. iniae following challenge of bivalent vaccinated fish. Use of this bivalent formulation may be a cost-effective strategy to reduce losses in tilapia co-infected with these two important bacterial pathogens.
The author expresses gratitude to the Aquaculture Department of the Southeast Asian Fisheries Development Center under budget code 5110-20, and to J. Toledo and A. Gamuza for providing the samples, and H. Marcial for assistance in bacterial isolation.
Streptococcus iniae causes invasive infections in fresh and saltwater fish and occasional zoonoses. Vaccination against S. iniae is complicated by serotypic variation determined by capsular polysaccharide. A potential target for serologically cross-protective vaccines is the M-like protein SiMA, an essential virulence factor in S. iniae that is highly conserved amongst virulent strains. The present study determined how SiMA is regulated and investigated potential as a cross-protective vaccine for fish. Electrophoretic mobility shift suggested that SiMA is regulated by the multigene regulator Mgx via a binding site in the -35 region of the simA promoter. Moreover, expression of simA and mgx was highly correlated, with the highest level of simA and mgx expression during exponential growth under iron limitation (20-fold increase in relative expression compared to growth in Todd-Hewitt broth). Based on these results, a vaccination and challenge experiment was conducted in barramundi (Lates calcarifer) to determine whether SiMA is protective against S. iniae infection and cross-protective against a different capsular serotype. The challenge resulted in 60% mortality in control fish. Formalin-killed bacterins prepared from the challenge strain resulted in 100% protection, whereas bacterins prepared from a serotypically heterologous strain resulted in significantly reduced protection, even when culture conditions were manipulated to optimise SiMA expression. Moreover, recombinant SiMA protein was not protective against the challenge strain in spite of eliciting specific antibody response in vaccinated fish. Specific antibody did not increase oxidative activity or phagocytosis by barramundi macrophages. Indeed incubating S. iniae with antisera significantly reduced phagocytosis. Lack of specific-antibody mediated opsonisation in spite of 100% protection against challenge with the homologous vaccine suggests that other immune parameters result in protection of challenged fish.
Protection and serum antibody production againstAeromonas hydrophila was examined in nile tilapia,Tilapia nilotica (L.). Intraperitoneally injected formalin-killed and Freunds complete adjuvant vaccines were compared using different doses (2.9 × 107 and 2.9 × 109cfu/ml). Upon challenge, the protective ability and antibody titers resulting were significantly different between vaccinated and unvaccinated groups. A relative level of protection of 100% was obtained within two-weeks, and a maximum level of 53 – 61% protection was found one-week post-vaccination.
The present study documents the susceptibility of Nile tilapia to the experimental vibriosis caused by Vibrio vulnificus biotype 2 (serovar E) using a reference strain (Spanish Collection of Type Cultures, CECT 4604) selected for its high degree of virulence for eels. The biotype 1 of this species is one of the usual organisms involved in epizootics occurred in tilapia. After intraperitoneal injection, the selected strain developed a haemorrhagic septicaemia similar to eel vibriosis with a LD50 four log units lower than that exhibited by the type strain of the species, which belongs to the biotype 1. The results obtained in waterborne and intubation challenges indicated that water and feed could act as a vehicle for vibriosis transmission to healthy tilapia. Moreover, live cells and the extracellular products derived from the strain CECT 4604 showed remarkable activity against tilapia erythrocytes, which correlated with the in vivo production of extensive haemorrhagic areas. Our results suggest that this bacterium could constitute a serious health hazard for tilapia, especially if it is cocultured with eels. Thus, vaccination of tilapia with a vaccine against V. vulnificus biotype 2 could be the best strategy to prevent any cross transmission of the disease from eels to tilapia under intensive rearing conditions.
Vibrio vulnificus causes disease in economically important aquaculture raised fish and is an opportunistic human pathogen. This study reports on the isolation of V. vulnificus from diseased hybrid tilapia (Oreochromis niloticus × O. aureus) cultured in a North American water reuse facility. Our objectives were to characterize the isolate using biochemical and molecular methods, develop a disease challenge model, and determine the ability of a formalin inactivated whole-cell vaccine to protect against V. vulnificus. The V. vulnificus isolate recovered was biotype 1, 16S rRNA type B, vcg type C, and vvhA type 2 and caused disease in tilapia held in static salt water (1.5 g/l sea salt). Fish vaccinated with the formalin inactivated whole-cell vaccine responded to vaccination with titers from vaccinated fish ranging from 32 to 64 and titers from non-vaccinated fish ranging from 4 to 8. In two trials, vaccinated tilapia exhibited relative percent survival (RPS) of 73 and 60% following homologous isolate challenge. In two additional trials, vaccinated tilapia exhibited RPS values of up to 88% following challenge with a heterologous isolate; the use of a mineral oil adjuvant enhanced protection. This vaccine may provide an effective means of preventing infections caused by biochemically and genetically diverse V. vulnificus.
Twenty-eight expressed sequence tags (ESTs) were isolated from a Nile tilapia (Oreochromis niloticus) vaccinated vs non-vaccinated subtractive library at 12-h post injection of a formalin killed Streptococcus iniae ARS-98-60 vaccine. The 28 ESTs were classified in terms of their putative functions. Half of the ESTs identified were unknown proteins. Of the remaining half ESTs, 17% have putative functions in protein biosynthesis and 11% have putative functions in immunity, energy production, and signal transduction, respectively. Immunity-related ESTs identified included high density lipoprotein-binding protein vigilin, immunoglobulin heavy chain, and QM-like protein. Quantitative PCR revealed that one EST (cytochrome c oxidase subunit II) was highly upregulated (1825 ± 336 fold) in vaccinated fish compared to that in non-vaccinated fish. Of the remaining 27 ESTs, nine were significantly (P<0.05) upregulated (<20 fold) in vaccinated fish. The nine significantly upregulated genes included five unknown or hypothetical proteins and four known proteins (high density lipoprotein-binding protein vigilin, QM-like protein, ribosomal protein S13, and ribosomal protein L5). The upregulation of these genes induced by killed S. iniae vaccines suggest that they might play important role in Nile tilapia defense against S. iniae infection.
Streptococcus iniae is one of the most economically important Gram-positive pathogens in cultured fish species worldwide. The USDA-ARS Aquatic Animal Health Research Unit developed a modified (contains concentrated culture supernatant) S. iniae bacterin that has been demonstrated to be efficacious, and protection is mediated by specific anti-S. iniae antibodies. Although effective, the specific vaccine components important for efficacy are not known. In the present study, an immunoproteomic approach was utilized to identify whole-cell lysate proteins of S. iniae that stimulated specific antibody production in Nile tilapia (Oreochromis niloticus) following vaccination. Groups of tilapia were vaccinated by intraperitoneal injection with the modified S. iniae bacterin or were mock-vaccinated, and at 30 d post-vaccination sera samples were obtained from individual fish. Vaccination of tilapia with the S. iniae vaccine stimulated significantly elevated specific antibody responses against proteins of the bacterium and passive immunization of tilapia with this serum demonstrated the antibodies were highly protective. Whole-cell lysate proteins of S. iniae were separated by 2D-PAGE and were probed with a pooled serum sample from vaccinated tilapia. A total of eleven unique immunogenic proteins were positively identified by mass spectrometry. Based on research conducted on homologous proteins in other Streptococcus spp., antibodies specific for three of the identified proteins, enolase, glyceraldehyde-3-phosphate dehydrogenase, and fructose-bisphosphate aldolase, are likely involved in protection from streptococcosis caused by S. iniae.
Formalin-killed Streptococcus difficile strains used as vaccines delivered intraperitoneally were able to protect tilapia against a challenge of 100 LD50. The protection obtained was not strain specific. A vaccine based on an S. difficile extract containing 50% protein conjugated to alum also protected tilapia challenged with a virulent S. difficile strain. Protection in tilapia was correlated with the development of specific agglutinins. Western blot analysis supported the hypothesis that only a few proteins act as protective antigens in both the whole-cell vaccine and the streptococcal extract. The high efficacy of these vaccines make them good candidates for the control of streptococcal fish meningoencephalitis.
We evaluated the effectiveness of a Streptococcus agalactiae vaccine in tilapia (Oreochromis niloticus) for prevention of streptococcal disease. The vaccine was prepared from formalin-killed cells and concentrated extracellular products (greater than 3 kDa) of a single isolate of S. agalactiae (ARS-KU-MU-11B). Intraperitoneal (IP) and bath immersion (BI) vaccine trials were conducted at two temperatures, 32 and 26 degrees C, and mean fish weights, 5 and 30 g. Control tilapia were injected with tryptic soy broth. Thirty gram tilapia vaccinated and challenged by IP injection with 1.5 x 10(4) colony-forming units (CFU)/fish of Streptococcus agalactiae at 30 days post-immunization had a relative percent survival (RPS) of 80. Smaller tilapia vaccinated and challenged under similar conditions had an RPS of 25. An RPS of zero was noted in 30 g fish IP vaccinated with Streptococcus iniae and IP challenged with S. agalactiae. The 5 and 30 g tilapia bath immunized with S. agalactiae and IP challenged with 3.6 x 10(5) and 1.7 x 10(6) CFU/fish of S. agalactiae had RPS values of 34. Intraperitoneal administration of the vaccine provided efficacious protection only in the 30 g tilapia regardless of whether the fish were immunized and challenged at 26 or 32 degrees C. Bath immunization of both 5 and 30 g tilapia resulted in RPS values that were two times lower than those achieved with IP vaccination. The results of this study suggest that there is a lack of cross-protection of S. iniae bacterins against S. agalactiae challenge. Protection against S. agalactiae infection is, however, provided through vaccination with a S. agalactiae modified bacterin vaccine.
Vibriosis is one of the most prevalent fish diseases caused by bacteria belonging to the genus Vibrio. Vibriosis caused by Vibrio anguillarum produces a 38-kDa major outer membrane porin protein (OMP) for biofilm formation and bile resistant activity. The gene encoding the porin was used to construct DNA vaccine. The protective efficiency of such vaccine against V. anguillarum causing acute vibrio haemorrhagic septicaemia was evaluated in Asian seabass (Lates calcarifer Bloch), a common species of the Indian coast and a potential resource for the aquaculture industry. In vitro protein expression of porin gene was determined by fluorescent microscopy after transfection of seabass kidney cell line (SISK). Fish immunized with a single intramuscular injection of 20 microg of the OMP38 DNA vaccine showed significant serum antibody levels in 5th and 7th weeks after vaccination, compared to fish vaccinated with the control eukaryotic expression vector pcDNA3.1. Asian seabass vaccinated with the OMP38 DNA vaccine was challenged with pathogenic V. anguillarum by intramuscular injection. A relative percent survival (RPS) rate of 55.6% was recorded. Bacterial agglutination and serum complement activity was analysed by using DNA vaccinated seabass serum above 80% of analysed strain was killed at the highest agglutination titre. Histopathological signs of V. anguillarum challenged fish were observed in around 45% of pVAOMP38, 90% of PBS and 87% of pcDNA3.1-vaccinated control fish. The results indicate that L. calcarifer vaccinated with a single dose of DNA plasmid encoding the major outer membrane protein shows moderate protection against acute haemorrhagic septicaemia and mortality by V. anguillarum experimental infection.
In recent years, attention has been focused on the possibility of utilizing DNA vaccines in fish aquaculture. A successful regime for intramuscular injection of naked DNA into fish has been developed and novel methods to deliver this DNA to fish are under investigation. The potential of chitosan as a polycationic gene carrier for oral administration has been explored since 1990s. The present study examines the potential efficacy of DNA vaccine against Vibrio anguillarum through oral route using chitosan nanoparticles encapsulation. The porin gene of V. anguillarum was used to construct DNA vaccine using pcDNA 3.1, a eukaryotic expression vector and the construct was named as pVAOMP38. The chitosan nanoparticles were used to deliver the constructed plasmid. In vitro and in vivo expression of porin gene was observed in sea bass kidney cell line (SISK) and in fish, respectively by fluorescent microscopy. The cytotoxicity of chitosan encapsulated DNA vaccine construct was analyzed by MTT assay and it was found that the cytotoxicity of pVAOMP38/chitosan was quite low. Distribution of gene in different tissues was studied in fish fed with the DNA (pVAOMP38) encapsulated in chitosan by using immunohistochemistry. The results indicate that DNA vaccine can be easily delivered into fish by feeding with chitosan nanoparticles. After oral vaccination Asian sea bass were challenged with Vibrio anguillarum by intramuscular injection. A relative percent survival (RPS) rate of 46% was recorded. The results indicate that Sea bass (Lates calcarifer) orally vaccinated with chitosan-DNA (pVAOMP38) complex showed moderate protection against experimental V. anguillarum infection.