Immunomodulatory effect of sodium alginate enriched diet in kelp grouper Epinephelus brneus against Streptococcus iniae.
The effect of diets containing sodium alginate at 0, 0.5, 1.0, and 2.0 g kg⁻¹ following challenge with Streptococcus iniae in kelp grouper Epinephelus bruneus were assessed with reference to survival rate and innate immune parameters such as alternative complement, lysozyme, natural haemagglutination, respiratory burst, superoxide dismutase, and phagocytic activities on week 1, 2, and 4. Fish fed with sodium alginate containing diet at 1.0 and 2.0 g kg⁻¹ after being challenged with S. iniae had higher survival rates of 75% and 60%, respectively than those fed with control diet (0 g kg⁻¹). With any enriched diet the percentage of macrophages significantly decreased from week 1-4, while the percentage of neutrophils and lymphocytes significantly increased. The alternate complement activity, natural haemagglutination, and phagocytic activities of infected fish fed with sodium alginate containing diet at 1.0 g kg⁻¹ on week 2 and 1.0 and 2.0 g kg⁻¹ diets on week 4 were significantly higher when compared to the control. The lysozyme, respiratory bursts, and superoxide dismutase activities of fish fed with enriched diets at 1.0 and 2.0 g kg⁻¹ were significantly increased on week 2 and 4. We therefore recommend that at 1.0 or 2.0 g kg⁻¹ dietary administration of sodium alginate can enhance innate immunity and disease resistance in kelp grouper against S. iniae.
Department of Aquatic Biomedical Sciences, School of Marine Biomedical Sciences, College of Ocean Sciences & Marine and Environmental Research Institute, Jeju National University, Jeju 690-756, South Korea. rhari123@yahoo.com
Ramasamy
R
Harikrishnan
Man-Chul
MC
Kim
Ju-Sang
JS
Kim
Yong-Jae
YJ
Han
Ik-Soo
IS
Jang
Chellam
C
Balasundaram
Moon-Soo
MS
Heo
D000464:Alginates / Q000494:pharmacology*; D000818:Animals; D003170:Complement Pathway, Alternative / Q000187:drug effects; D004032:Diet; D005393:Fish Diseases / Q000276:immunology / Q000401:mortality / Q000517:prevention & control*; D020723:Glucuronic Acid / Q000494:pharmacology; D006384:Hemagglutination / Q000187:drug effects; D006603:Hexuronic Acids / Q000494:pharmacology; D007107:Immune System / Q000187:drug effects*; D007155:Immunologic Factors / Q000494:pharmacology*; D007962:Leukocytes / Q000187:drug effects; D009113:Muramidase / Q000276:immunology; D010587:Phagocytosis / Q000187:drug effects; D016897:Respiratory Burst / Q000187:drug effects; D013290:Streptococcal Infections / Q000276:immunology / Q000401:mortality / Q000517:prevention & control / Q000662:veterinary*; D013291:Streptococcus; D013482:Superoxide Dismutase / Q000276:immunology
D000464:Alginates; D006603:Hexuronic Acids; D007155:Immunologic Factors; D020723:Glucuronic Acid; D013482:Superoxide Dismutase; D009113:Muramidase