Publications by authors named "Mathiessen Heidi"
Article Synopsis
- - Fish, particularly zebrafish larvae, heavily depend on their innate immune system for protection against pathogens in their aquatic environment, especially during injury and normal life.
- - Zebrafish are excellent research models for studying immunity because their immune system shares similarities with mammals and their transparent bodies allow for easy observation of immune cell functions.
- - Recent discoveries suggest that leukocytes (like neutrophils and macrophages) in zebrafish have more complex roles than expected, being crucial for inflammation control, infection management, and effective wound healing.
Article Synopsis
- The study focuses on a protozoan parasite that poses a significant threat to the aquaculture and ornamental fish industries, infecting various parts of freshwater fish.
- Researchers used transgenic zebrafish larvae to explore the early immune responses to this parasite by analyzing gene expression and the behavior of immune cells like neutrophils and macrophages.
- Findings revealed that while zebrafish larvae exhibit an active local immune response, including the formation of neutrophil extracellular traps, the overall systemic inflammation remains mild, indicating the parasite's ability to evade stronger immune reactions through its dynamic movement.
Vibriosis is a bacterial disease in fish caused by the Gram negative bacterium Vibrio anguillarum with severe impact on rainbow trout (Oncorhynchus mykiss) farming. Sustainable control methods should be developed and we here show that marker assisted selective breeding of fish naturally resistant to the disease is feasible. We have validated the use of a single nucleotide polymorphism (SNP) marker SNP AX-89,945,921 (QTL on chromosome 21).
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- A lipopeptide produced by Pseudomonas H6 shows potential as an alternative treatment for aquatic pathogens in aquaculture due to its antiparasitic and biosurfactant properties.
- Ecotoxicological tests revealed varying toxicity levels: crustaceans were most affected, followed by zebrafish embryos, while juvenile zebrafish and certain algae displayed greater tolerance.
- The findings indicate that the lipopeptide concentration in fish tanks decreases significantly over 24 hours, suggesting possible absorption or degradation, necessitating further research on its effects in diverse environmental conditions relevant to aquaculture.
Plastic nanoparticles cause mild inflammation, disrupt metabolic pathways, change the gut microbiota and affect reproduction in zebrafish: A full generation multi-omics study.
J Hazard Mater
February 2022
Plastic pollution has become a major concern on a global scale. The plastic is broken down into minuscule particles, which have an impact on the biosystems, however long-term impacts through an entire generation is largely unknown. Here, we present the first whole generation study exposing fish to a 500 nm polystyrene plastic particle at environmentally relevant concentrations.
View Article and Find Full Text PDFAeromonas salmonicida subsp. salmonicida, the causative agent of furunculosis, has extensive negative effects on wild and farmed salmonids worldwide. Vaccination induces some protection under certain conditions but disease outbreaks occur even in vaccinated fish.
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- Several biocides commonly used in rainbow trout aquaculture were studied for their effects on inflammation in fish, focusing on gills and fins.
- The study highlighted how different biocides like PAA, H2O2, formalin, and SPH6 influenced immune gene expression, particularly noting that PAA had the strongest impact, followed by H2O2 and formalin.
- The research found that gills were more reactive than fins, with treatments causing varying changes in mucous cell density, including hyperplasia from PAA, while SPH6 led to a decrease in mucous-producing cells.
The protective effects of autogenous and commercial ERM immersion vaccines (bacterins based on Yersinia ruckeri, serotype O1, biotypes 1 and 2) for rainbow trout (Oncorhynchus mykiss) were compared in order to evaluate whether the use of local pathogen strains for immunization can improve protection. In addition, the effect of the bacterin concentration was established for the commercial product. Following sublethal challenge of vaccinated and non-vaccinated control fish with live bacteria, we followed the bacterial count in the fish (gills, liver and spleen).
View Article and Find Full Text PDFGenetic selection of disease resistant fish is a major strategy to improve health, welfare and sustainability in aquaculture. Mapping of single nucleotide polymorphisms (SNP) in the fish genome may be a fruitful tool to define relevant quantitative trait loci (QTL) and we here show its use for characterization of resistant rainbow trout (). Fingerlings were exposed to the pathogen serotype O1 in a solution of 1.
View Article and Find Full Text PDFSurveillance and diagnosis of parasitic Bonamia ostreae infections in flat oysters (Ostrea edulis) are prerequisites for protection and management of wild populations. In addition, reliable and non-lethal detection methods are required for selection of healthy brood oysters in aquaculture productions. Here we present a non-lethal diagnostic technique based on environmental DNA (eDNA) from water samples and demonstrate applications in laboratory trials.
View Article and Find Full Text PDFSelective breeding programmes involving marker assisted selection of innately pathogen resistant strains of rainbow trout rely on reliable controlled infection studies, extensive DNA typing of individual fish and recording of expression of relevant genes. We exposed juvenile rainbow trout (6 h bath to 2.6 × 10 CFU mL) to the fish pathogen Yersinia ruckeri serotype O1, biotype 2, eliciting Enteric Red Mouth Disease ERM, and followed the disease progression over 21 days.
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- Ichthyophthirius multifiliis is a freshwater fish parasite causing white spot disease, with its fitness affected by host availability and environmental factors like temperature, salinity, and pH.
- The study examined the parasite's tolerance to varying pH levels (2-11), finding that it survived and released theronts most effectively at pH 5-10, though lower numbers were released at extreme pH levels.
- Results showed that theronts produced at pH 8 could survive in a range of pH values for an hour, and higher pH levels influenced their size and release rate, indicating that pH significantly affects the lifecycle of the parasite.
Gill parasitic infections challenge farming of rainbow trout (Oncorhynchus mykiss, Walbaum) in freshwater facilities. Apart from flagellates (Ichthyobodo, (Pinto) and ciliates (Ichthyophthirius (Fouquet), Ambiphrya (Raabe), Apiosoma (Blanchard), Trichodinella (Sramek-Husek) and Trichodina (Ehrenberg)), we have shown that amoebae are prevalent in Danish trout farms. Gills were isolated from farmed rainbow trout in six fish farms (conventional and organic earth pond and recirculated systems) and placed on non-nutrient agar (NNA) moistened with modified Neff's amoeba saline (AS) (15°C).
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