Oral immunostimulation of the oyster Ostrea edulis: Impacts on the parasite Bonamia ostreae

• Published in: Fish & shellfish immunology 2015-07, Vol.45 (1), p.43-51
• Main Authors: Prado-Alvarez, M., Lynch, S.A., Kane, A., Darmody, G., Pardo, B.G., Martínez, P., Cotterill, J., Wontner-Smith, T., Culloty, S.C.
• Format: Article
• Language: English
• Subjects: Adjuvants, Immunologic - administration & dosage; Adjuvants, Immunologic - pharmacology; Administration, Oral; Alginate microcapsules; Alginates - administration & dosage; Alginates - pharmacology; Animals; beta-Glucans - administration & dosage; beta-Glucans - pharmacology; Bonamia ostreae; Haplosporida - physiology; Host-Parasite Interactions; Immune response; Immunity, Innate - drug effects; Immunostimulation; Ostrea - immunology; Ostrea - parasitology; Ostrea edulis; Zymosan - administration & dosage; Zymosan - pharmacology
• ISSN: 1050-4648; 1095-9947
• DOI: 10.1016/j.fsi.2015.01.019

Bioactive compounds were orally administered to the native European oyster Ostrea edulis to evaluate the immune response and the progression of infection of the protozoan parasite Bonamia ostreae. The immunostimulants lipopolysaccharide and zymosan directly administrated to the water column induced an increase in lysozyme activity and the percentage of granulocytes in naïve oysters over a period of 7 days. In another set of experiments, zymosan and curdlan were microencapsulated in alginate and also administered to the water column to naïve and B. ostreae infected O. edulis. Oyster mortality, prevalence and intensity of infection and several immune parameters were evaluated up to 28 days post-administration. Lysozyme activity, nitric oxide production and the expression of galectin, lysozyme and superoxide dismutase increased after 24 h in both infected and uninfected oysters. Zymosan immunostimulated oysters displayed a decrease in the prevalence of B. ostreae infection not attributed to mortalities but which could be associated to the enhanced ability of immunostimulants to evoke an enhanced immune response in the oysters and reduce infection. •We studied the oral administration of immunostimulants in the oyster Ostrea edulis.•Immune response enhanced after oral administration of encapsulated stimulants.•Encapsulated immunostimulants boosted the response of Bonamia ostreae infected oysters.•Prevalence of B. ostreae decreased after stimulation with encapsulated zymosan.