Immunology of a sea bream parasite
Sparus aurata, or the gilthead bream, is one of the most important fish cultivated in the saline aquaculture industry. As an important endoparaiste of the gilthead bream, the organism responsible for enteromyxosis, E. leei, has gained importance in recent years due to large economic losses. Despite this, there are vast gaps in the knowledge regarding the life cycle, methods of transmission and immunology of the parasite. Innate and adaptative immune factors were monitored in three groups of fish - disease donor, recipient and control groups. Central to the innate defense mechanism against pathogenic microorganisms, cellular factors including cytotoxic activity and respiratory burst, were monitored. The development of humoral or serum immune response factors provided a second prong to the study of innate response features and several indicators were assayed including peroxidase activity levels. With regard to adaptative immune factors, the project partners used immunohistochemistry (IHQ) to analyse the sera of infected fish and levels of antibodies specific for E. leei were measured. It was discovered that enteromyxosis induced several of the immune response indicators under study. The implications of this are that the bream's immunological system and consequent immunity could constitute part of a holistic approach to management of the disease. This could lead to more effective control of this devastating parasite.
