Granulomatous enteritis in rainbow trout (Oncorhynchus mykiss) associated with soya bean meal regardless of water dissolved oxygen level

Abstract

This study investigated morphological changes associated with soya bean meal-induced enteritis (SBMIE) in distal intestine (DI) of rainbow trout (Oncorhynchus mykiss) fed a soya bean meal (SBM)-based diet and exposed to normoxia or hypoxia created by optimal and low water flow rates, respectively. A 28-day adaption period was followed by a 42-day challenge period where 600 fish were subjected to dietary challenge and/or hypoxia. Twelve tanks each containing 50 juvenile trout were assigned randomly in triplicate to each treatment. Histopathological and immunohistochemical evaluation revealed pathological features that have not previously been described in association with SBMIE. Vacuolar degeneration of epithelial cells mainly at the base of mucosal folds, epithelial cysts, epithelial dysplasia, necrosis, shedding of necrotic cells, and granulomatous inflammation including infiltration of enlarged, sometimes finely vacuolated or "foamy" macrophages, multinucleated giant cells and increased proliferation of fibroblasts were observed. Acid-fast bacteria were not detected in enlarged macrophages; however, these cells contained AB-PAS- and sometimes cytokeratin-positive material, which was interpreted to be of epithelial/goblet cell origin. Hypoxia did not affect the morphological changes in DI. These results suggest that SBM was associated with a granulomatous form of enteritis in DI of rainbow trout regardless of water oxygen level.

WITHDRAWN: 1H NMR-based metabolomics investigation of dietary soybean meal substitution in hybrid sturgeon (Acipenser baerii ♀× A. schrenckii ♂)

“…phenylalanine, tyrosine and tryptophan biosynthesis with two differentiated metabolites (phenylalanine and tyrosine) involved deserved the highest impact factor, which indicated severe liver damage by SBM diets. 13] and intestinal inflammation [14][15][16][17], with limited reports regarding the complete metabolomic alterations in fish.…”

WITHDRAWN: 1H NMR-based metabolomics investigation of dietary soybean meal supplementation in hybrid sturgeon (Acipenser. baerii ♀× A. schrenckii ♂)”

“…However, the large inclusion of SBM in aquafeeds will cause negative effect on fish growth and health [ 9, 10] by the presence of anti-nutritional factors (ANFs) such as protease, phytates, lectins and saponins [ 11]. Current studies on the adverse influences of SBM replacement focused mainly on the growth restriction [ 12,13] and intestinal inflammation [14][15][16][17], with limited reports regarding the complete metabolomic alterations in fish.…”

Evaluation of a novel methanotroph bacteria meal grown on natural gas as fish meal substitute in rainbow trout, Oncorhynchus mykiss

“…This may be due to the fatty acid and lipid composition of the BM (Øverland et al, 2010) and warrants further investigation. Reduction in supranuclear vacuolation and decrease in the height of the individual epithelial cells is a well‐known histopathological signature of soybean meal induced enteritis in the distal intestine of salmonids (Romarheim et al, 2011, 2013; Mosberian‐Tanha et al, 2018). Contrarily, in the present study, we noticed an increase in the size of supranuclear vacuolation and height of the epithelium in the posterior intestine of rainbow trout fed BM diets.…”