Use of functional feeding strategies to protect Atlantic salmon from virally-induced inflammatory diseases- mechanistic insights revealed by transcriptomic analysis

• Published in: PLoS ONE
• Main Author: Martinez-Rubio, Laura
• Other Authors: Tocher, Douglas, Bell, Gordon, EWOS Innovation AS, School of Natural Sciences, Aquaculture
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: University of Stirling 2012
• Subjects: Microarray; Functional feeds; Atlantic salmon; Transcriptomic; HSMI; CMS; Viral disease; Atlantic salmon Diseases Scotland; Norway; Salmo salar
• Online Access: http://hdl.handle.net/1893/10451; https://doi.org/10.1371/journal.pone.0040266; http://dspace.stir.ac.uk/bitstream/1893/10451/1/Final%20format%20thesis%20Laura.pdf

Over the past few years one of the major concerns in the Atlantic salmon (Salmo salar) farming industry has been the increasing incidence and severity of inflammatory viral diseases. Heart and skeletal muscle inflammation (HSMI) and cardiomyopathy syndrome (CMS) are currently two of the most prevalent viral diseases in commercial Atlantic salmon farms in Norway. Mortality levels in both diseases are generally low but morbidity can be very high with the associated chronic inflammatory response lasting for several months. The consequent reduced growth performance is causing considerable financial impact as HSMI has become increasingly widespread in recent years. The impact of CMS is further exacerbated as it generally affects large fish close to harvest. HSMI lesions occur in the atrium and ventricle in the heart including inflammation and necrosis in epi- endo- and myocardium along with myositis of red skeletal muscle. CMS lesions are commonly observed in the spongy myocardium in the atrium and ventricle of the heart with severe mononuclear inflammation and necrosis. Furthermore, circulatory disturbances associated with reduced cardiac function cause multifocal liver steatosis and necrosis in both diseases. Currently there are no vaccines or any other effective treatments for these diseases and so alternative therapies that could potentially modulate the intensity of the inflammatory response could be crucial to improve the clinical manifestation of the diseases. Therefore, the overall aim of the present study was to evaluate the concept of “clinical nutrition” to improve the clinical symptoms of both viral diseases, HSMI and CMS, through the use of functional feeds formulated with reduced lipid content and increased proportions of anti-inflammatory fatty acids to moderate the apparently uncontrolled inflammatory response in the heart tissue associated with both diseases and also alleviate the secondary hepatic lesions. The experimental work consisted of three major dietary trials in Atlantic salmon in seawater. ...