Lactobacillus sakei BK19 enriched diet enhances the immunity status and disease resistance to streptococcosis infection in kelp grouper, Epinephelus bruneus

The effect of Lactobacillus sakei BK19 (108 cells g−1) supplemented diet fed to kelp grouper, Epinephelus bruneus against streptococcosis caused by Streptococcus iniae and Streptococcus parauberis with reference to the innate immune response and disease resistance was evaluated at 1, 2, and 4 weeks. Maximum reduction in mortalities was observed in kelper feeding the probiotic diet for two weeks after challenged with the pathogens when compared to the infected group fed with basal diet; similarly the cellular and humoral immune responses such as head kidney macrophage phagocytic and peroxidase activities, serum lysozyme activity, and total protein levels increased significantly. The results reveal that, in streptococcosis infected kelp grouper feeding L. sakei BK19 enriched diet affords a higher level of disease protection due to stimulation of immune system.