This study explores the potential of the probiotics and immunostimulants combination (Vimolert®) to enhance the blood biochemistry profile, histopathology, and immune response of Nile Tilapia against Aeromonas hydrophila infection. A total of ۱۵۰
Nile tilapia were used and divided into five groups, including a negative control group, a positive control group, and three groups fed with Vimolert®-supplemented diets at different doses for four weeks. After this period, groups ۲ to ۵ were infected with A. hydrophila. The biochemistry parameters including alanine aminotransferase, Aspartate aminotransferase, alkaline phosphatase, urea, and creatinine significantly increased in the positive control group compared to the treated groups. The total protein and albumin levels were significantly lower in the positive control group than in the treated groups, while the globulin level was higher in the treated groups than in the positive control group. Regarding the immune response, which includes nitroblue tetrazolium and lysozyme activity, it was observed that the groups receiving Vimolert® experienced significant increases in the fourth and sixth weeks compared to the positive control group. The histopathological examination unveiled that the positive control group exhibited pronounced pathological alterations, including degeneration and necrosis in the liver tissue, necrosis, and a reduction in hematopoietic cells in the kidney tissue, as well as edema, degeneration, and necrosis in the muscle tissue. Furthermore, there were infiltrations of mononuclear cells and melanomacrophages between the necrotic muscle fibers. In contrast, the treated group displayed milder to moderately altered tissue conditions. Group ۴ had the maximum protection after infection compared to the other treated groups. In conclusion, this study underscores the potential of Vimolert® (a mixture of probiotics and immunostimulants) in improving the immune response and resistance of
Nile tilapia against A. hydrophila infection. This finding holds significant promise for enhancing the health status and survival of Nile Tilapia in the aquaculture industry, thereby contributing to the sustainability and productivity of this industry.