Vaccines are used in aquaculture to avoid outbreaks of infection from bacteria and viruses. If given at the start of the sea-water phase, oil-based vaccines provide protection against bacterial infection for the entire life in the animal.
However, oil-based vaccines produce local side-effects in the form of pigmentation and adhesions between internal organs, which in some cases are severe enough to reduce the carcase quality at slaughter. The underlying mechanisms of side-effect development are little known.
Stephen Mutoloki discovered that the reaction to the vaccine, and especially to the bacterial component of the vaccine, comes in several “waves”. These waves consist of cells that migrate to the injection site, and in the van of these is the “rapid-response troop”, the neutrophilic granulocytes. These are followed by the “clean-up team”, the macrophages, and later still by the cells that provide the actual protection against disease later in life, the lymphocytes.
This is the same sequence one finds in a natural infection and is the result of a collaboration between the processes of inflammation and of immunity. How aggressive the reaction within the tissue is, depends on how many granulocytes that are involved and how many clean-up cells arrive.
The main findings in Dr. Mutoloki’s work show that the species has a lot to say for how effectively the “clean-up” progresses. The rainbow trout has in general more effective cleaning-up cells, while the Atlantic salmon does a poorer job with a correspondingly greater and longer-lasting tissue reaction. The clean-up phase is also affected by the vaccine’s composition, that is, the more unrefined a vaccine, the more inflammatory cells that will accumulate and the greater the tissue reaction.
The type of antigen in the vaccine is also significant. Moritella viscosa is, for example, more difficult to clean up after than Aeromonas salmonicida. And if the vaccinated fish uses more resources to clean up than to create immunity against future infections, the tissue relation may become too dominating and produce unwanted side-effects.
Magnhild Jenssen | alfa
Robotic fish to replace animal testing
17.06.2019 | Otto-von-Guericke-Universität Magdeburg
Marine oil snow
12.06.2019 | University of Delaware
The well-known representation of chemical elements is just one example of how objects can be arranged and classified
The periodic table of elements that most chemistry books depict is only one special case. This tabular overview of the chemical elements, which goes back to...
Light can be used not only to measure materials’ properties, but also to change them. Especially interesting are those cases in which the function of a material can be modified, such as its ability to conduct electricity or to store information in its magnetic state. A team led by Andrea Cavalleri from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg used terahertz frequency light pulses to transform a non-ferroelectric material into a ferroelectric one.
Ferroelectricity is a state in which the constituent lattice “looks” in one specific direction, forming a macroscopic electrical polarisation. The ability to...
Researchers at TU Graz calculate the most accurate gravity field determination of the Earth using 1.16 billion satellite measurements. This yields valuable knowledge for climate research.
The Earth’s gravity fluctuates from place to place. Geodesists use this phenomenon to observe geodynamic and climatological processes. Using...
Discovery by Brazilian and US researchers could change the classification of two species, which appear more akin to jellyfish than was thought.
The tube anemone Isarachnanthus nocturnus is only 15 cm long but has the largest mitochondrial genome of any animal sequenced to date, with 80,923 base pairs....
Researchers at Chalmers University of Technology, Sweden, have discovered a completely new way of capturing, amplifying and linking light to matter at the nanolevel. Using a tiny box, built from stacked atomically thin material, they have succeeded in creating a type of feedback loop in which light and matter become one. The discovery, which was recently published in Nature Nanotechnology, opens up new possibilities in the world of nanophotonics.
Photonics is concerned with various means of using light. Fibre-optic communication is an example of photonics, as is the technology behind photodetectors and...
29.04.2019 | Event News
17.04.2019 | Event News
15.04.2019 | Event News
17.06.2019 | Information Technology
17.06.2019 | Earth Sciences
17.06.2019 | Ecology, The Environment and Conservation