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AquacultureUK2016: Atlantic Salmon Gill Health Research Wins Student Award

Salmonids Health Sustainability +6 more

UK - Ana Herrero, from Moredun Research Institute and the University of Stirling, has been named the winner of the Elanco sponsored 2016 Young Scientist Award, which was presented at the Aquaculture UK conference in Aviemore, Scotland.

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The competition saw students from universities across the UK present their aquaculture research projects.

Ms Herrero won the award for her research 'Comparing different histological methods to detect Desmozoon Lepeophtherii in the gills of Atlantic salmon'.

Explaining the reason behind her research, Ms Herrero said: "Gill diseases have become one of the main issues in the Atlantic salmon industry. In some cases, the disease that results is a complex scenario involving a variety of factors and agents, making it difficult to establish the main cause of the disease. Complex gill diseases such as these require in-depth analyses to understand the disease processes involved so as to improve both fish production and welfare. I find gill health a challenging but fascinating area of research that allows me to learn new things on a daily basis."

Speaking to TheFishSite about her research, Ms Herrero explained: “Desmozoon lepeophtherii is a microsporidian that infects sea lice and Atlantic salmon. Previous studies have indicated that it could be a primary pathogen of “autumn” proliferative gill disease. Nevertheless, the role of D. lepeophtherii is still unknown and one of the main reasons is due to the difficulty in detecting the parasite under light microscopy."

Ana Herrero with Neil Robertson from Elanco

Ms Herrero's study therefore aimed to compare the efficacy of different staining methods to detect the microsporidian. The work is being conducted in collaboration with VetAqua International, Benchmark Animal Health Ltd, Marine Harvest and the Fish Vet Group.

To conduct the study, a number of formalin-fixed, paraffin-wax embedded gill samples, previously diagnosed with the presence of Desmozoon-like spores, were re-sectioned and stained with Haematoxylin and Eosin (H&E), Gram Twort, Calcofluor White (CW) and labelled by immunohistochemistry using a polyclonal antibody raised against a closely related microsporidian species.

Ms Herrero found the differences in the parasite detection were statistically significant between all the techniques. The IHC method consistently detected more spores than the other techniques and H&E was the least sensitive.

"These results indicate that the presence of microsporidian in proliferative gill disease may be severely underestimated using conventional histochemical stains and the use of more sensitive techniques, such as IHC and CW, is recommended to improve the detection of the parasite in tissue sections," said Ms Herrero.

As well as this research, Ms Herrero is also performing a longitudinal study in Scottish salmon farms, screening for the main agents that are thought to be involved in “autumn” proliferative gill disease.

Additionally, she is also trying to culture D. lepeophtherii in vitro in different fish cell lines to determine which cells are susceptible to infection and this will aid studying parasite development.

As the winner of the competition, Ms Herrero will now go on an expenses paid trip to the internationally acclaimed Elanco Animal Health Centre of Excellence for Research and Development in Aquaculture, based in Prince Edward Island, Canada.

Whilst in Canada, Ms Herrero will have the opportunity to meet with leading Elanco scientists, learn about fish vaccines, novel pharmaceutical developments and revolutionary new technologies in fish health.

"Elanco has a rich history of aquaculture innovation and we are proud to extend our research in the field of aquaculture beyond our own internal operations. We believe that encouraging young, talented scientists is pivotal to building the future of our industry," said Carlos Kuada, Global Head of the Aqua Business.