Evaluation of novel prophylactic treatments for penaeid shrimp with emphasis on efficacy and characterization of the immune response

In 2014, shrimp farming reached a production volume of 4 million tons with an export value of USD 22 billion. Shrimp farming has a 17 % market share of internationally traded seafood, and thus surpasses other important commodities such as salmon and tilapia both in volume and value. China is the leading producer, followed by Indonesia, Vietnam, India, Ecuador and Thailand. The majority of the production volume is exported to the US, EU and Japan, and has contributed with substantial income and employment locally. In conjunction with the increased shrimp production, this industry has experienced a substantial negative effect of infectious diseases caused by viruses, bacteria and other parasites. In this regard, severe economic losses has been imposed on the industry, and moreover, the production losses increase the environmental strain on production areas. Historically, white spot syndrome virus (WSSV) is the causative agent for what is considered to be the most important disease in shrimp farming. WSSV has alone been estimated to inflict a USD 8-15 billion loss in production from 1992 to 2012. Unfortunately, there is at present no efficacious medicines available for prevention or treatment of viral diseases in shrimp farming. In this industrial Ph.D. project, the candidate has explored the possibility for development of a preventive treatment that can protect against WSSV infection. Primarily, the focus has been on stimulation of that part of the shrimp?s immune system that is called RNA interference (RNAi). In order to achieve such stimulation, a variant of the information molecule RNA, containing a code similar to what is found in the specific virus, needs to be administered to the shrimp. Such stimulation will significantly increase survival when administered prior to WSSV infection, and the concept can also be modified to induce protection against other shrimp viruses. With RNAi stimulation as a platform, this project has identified preferred gene targets in WSSV, and further evaluated feasibility of novel formulation technologies. A substantial effort has also been allocated to characterize the effect of the treatment on a molecular level. The industrial scheme Ph.D. candidate is affiliated with PHARMAQ, which is recognized as the world's leading pharmaceutical company specializing in aquaculture. PHARMAQ, as a company focused on value creation, considers that this project will serve as an important exploration of a potential new market.

In 2010 the production of shrimp reached 3.8 Mill tons, to a value of Bill USD 16.7, which exceeds both tilapia and salmon. Shrimp is the single largest seafood commodity by value, accounting for 17% of all internationally traded fishery products. Most sh rimp aquaculture is localized to China, followed by Thailand, Indonesia, India, Vietnam, Brazil, Ecuador and Bangladesh.Since 1981 a succession of new pathogens has emerged in Asia and Americas, causing mortality and threatening the economical sustainabil ity of the industry. 40% of potential shrimp production is lost due to infectious diseases, 60% of the losses is from viral pathogens and 20% from bacterial pathogens. 10% of total losses are due to White Spot Syndrome Virus (WSSV). Due to the severe impa ct of WSSV, this virus has dominated the research attention within studies on shrimp pathology and immunology. This project will aim to contribute to the growing knowledge base concerning the immune system of penaeid shrimp and its interaction with vira l pathogens affecting shrimp in aquaculture. Several studies have published results indicating that prophylactic treatment of various sorts can induce protection in shrimp observed after challenge with both bacterial and viral infectious agents. Treatment s that either specifically target a given pathogen or nonspecifically stimulate the immune system have both shown to be potential treatments for consideration in a commercial setting. The research to be conducted will emphasis on the effect of different t reatments on WSSV, which will be evaluated through in vivo challenge trials in approved wet lab facilities. PHARMAQ, with administration, R&D function and production localized in Norway, is recognized as the world's leading pharmaceutical company specia lizing in aquaculture. PHARMAQ, as a company focused on value creation, considers that this project will serve as an important exploration of a potential new market.