Teleost fish are the most primitive bony vertebrates that contain immunoglobulins. In contrast to mammals and birds, these species are devoid of immunoglobulin A (IgA) or a functional equivalent. This observation suggests that specialization of immunoglobulin isotypes into mucosal and systemic responses took place during tetrapod evolution. Challenging that paradigm, here we show that IgT, an immunoglobulin isotype of unknown function, acts like a mucosal antibody. We detected responses of rainbow trout IgT to an intestinal parasite only in the gut, whereas IgM responses were confined to the serum. IgT coated most intestinal bacteria. As IgT and IgA are phylogenetically distant immunoglobulins, their specialization into mucosal responses probably occurred independently by a process of convergent evolution.

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IgT, a primitive immunoglobulin class specialized in mucosal immunity

Background: There is growing concern worldwide about the role of polluted soil and water environments in the development and dissemination of antibiotic resistance.Objective: Our aim in this study ...

Management Options for Reducing the Release of Antibiotics and Antibiotic Resistance Genes to the Environment

Vaccination plays an important role in large-scale commercial fish farming and has been a key reason for the success of salmon cultivation. In addition to salmon and trout, commercial vaccines are available for channel catfish, European seabass and seabream, Japanese amberjack and yellowtail, tilapia and Atlantic cod. In general, empirically developed vaccines based on inactivated bacterial pathogens have proven to be very efficacious in fish. Fewer commercially available viral vaccines and no parasite vaccines exist. Substantial efficacy data are available for new fish vaccines and advanced technology has been implemented. However, before such vaccines can be successfully commercialized, several hurdles have to be overcome regarding the production of cheap but effective antigens and adjuvants, while bearing in mind environmental and associated regulatory concerns (e.g., those that limit the use of live vaccines). Pharmaceutical companies have performed a considerable amount of research on fish vaccines, however, limited information is available in scientific publications. In addition, salmonids dominate both the literature and commercial focus, despite their relatively small contribution to the total volume of farmed fish in the world. This review provides an overview of the fish vaccines that are currently commercially available and some viewpoints on how the field is likely to evolve in the near future.

Vaccines for fish in aquaculture

All metazoans possess innate immune defence system whereas parameters of the adaptive immune system make their first appearance in the gnathostomata, the jawed vertebrates. Fish are therefore the first animal phyla to possess both an innate and adaptive immune system making them very interesting as regards developmental studies of the immune system. The massive increase in aquaculture in recent decades has also put greater emphasis on studies of the fish immune system and defence against diseases commonly associated with intensive fish rearing. Some of the main components of the innate and adaptive immune system of fish are described. The innate parameters are at the forefront of immune defence in fish and are a crucial factor in disease resistance. The adaptive response of fish is commonly delayed but is essential for lasting immunity and a key factor in successful vaccination. Some of the inherent and external factors that can manipulate the immune system of fish are discussed, the main fish diseases are listed and the pathogenicity and host defence discussed. The main prophylactic measures are covered, including vaccination, probiotics and immunostimulation. A key element in the immunological control of fish diseases is the great variation in disease susceptibility and immune defence of different fish species, a reflection of the extended time the present day teleosts have been separated in evolution. Future research will probably make use of molecular and proteomic tools both to study important elements in immune defence and prophylactic measures and to assist with breeding programmes for disease resistance.

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Immunological Control of Fish Diseases

In the last decade betanodavirus infections have emerged as major constraints on the culture of marine fish in all parts of the world with the exception of the African continent. The occurrence of these infections appears to be a function of the number of species cultured and the intensity of culture. This has been further complicated by the promiscuous translocation of stock within and between countries. Great strides have been made in defining these agents and producing diagnostic techniques but much more remains to be done. Lack of knowledge of the epidemiology of the diseases caused by nodaviruses, except for vertical transmission of the pathogen in some species, has impeded the development of control measures but, even so, the measures identified to date have not been adequately implemented by producers with the result that catastrophic losses still occur on a regular basis.

Betanodavirus infections of teleost fish: a review

Little evidence to suggest salmonid freshwater reservoirs of piscine orthoreovirus (PRV).

Risk assessment of fish health and welfare in fresh water production systems

The present invention concerns a vaccine for treatment and/or prevention of infectious salmon anaemia in fish. The invention provides for nucleic acid sequence encoding viral proteins of Infectious Salmon Anaemia Virus (ISAV) as well as the isolated (recombinant) protein, which can be used to prepare the vaccine. The invention furthermore pertains to antibodies that are reactive with said viral proteins and their use in diagnostics.

Eirik Biering

Papers

Little evidence to suggest salmonid freshwater reservoirs of piscine orthoreovirus (PRV).

Risk assessment of fish health and welfare in fresh water production systems

Vaccine against isav (infectious salmon anaemia virus)