Effect of Dietary Beta-1, 3 Glucan on Immunomodulation on Diseased Oreochromis Niloticus Experimentally Infected with Aflatoxin B1

A hundred and fifty samples of fish rations were collected and subjected to mycological examination. The total prevalence of Aspergillus flavus was 66.67%. Fifteen isolates among them were aflatoxinB1 producers. AFB1 was extracted and tested for pathogencity. AFB1 intoxicated fish showed off feed, sluggish swimming, dark skin, loss of reflexes, increased mucus secretion, loss of scales and ascities .Internally, liver displayed pale coloration with patches of congestion and pin point hemorrhages. The spleen and the Kidneys appeared enlarged, congested and dark in color. The effects of aflatoxin B1 (AFB1), beta-1, 3 glucans and their interactions on non-specific immunity and disease resistance of Nile tilapia (Oreochromis niloticus) were studied. The immunostimulant beta-1,3 glucan was fed at 0.1% and/or AFB1 at 200μg crude /Kg feed for 21 days in Nile tilapia were investigated. Dietary supplementation of AFB1 group showed normocytic normochromic anemia, lymphopenia as well as alteration in some biochemical parameters related to organs damage induced by AFB1. The AFB1 treated group showed significant reduction in non-specific immunity as reduced superoxide anion production of blood phagocytes, serum lysozyme, serum bactericidal activity, and neutrophils glass adhesion and macrophage phagocytic indices. Also the specific immunity as measured through reduced protection against S reptococcus iniae challenge in comparison to control fish. Feeding of beta-1, 3 glucans to healthy fish raised the nonspecific immunity and protection against bacterial infection compared with the control. Moreover feeding of beta-1, 3 glucans to AFB t