Katayoon Nofouzi - Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran
Seyyed Sajjad Mousavi Yengejeh - Department of Clinical Sciences, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran
Najmeh Sheikhzadeh - Department of Food Hygiene and Aquatic Animals, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran
Gholamreza Hamidian - Department of Basic Sciences, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran
Amir Ali Shahbazfar - Department of Pathobiology, Faculty of Veterinary Medicine, University of Tabriz, Tabriz, Iran
Amin Marandi - Department of Aquatic Animal Health, Faculty of Veterinary Medicine, University of Tehran, Tehran, Iran

Background and Aim : Arsenic contamination in natural water resources has become a greatdisaster throughout the world which poses serious health problem. The current study wasperformed to evaluate the protective effects of Escherichia coli strain Nissle ۱۹۱۷ (EcN) againstarsenic (As) exposure on the intestine, kidney, liver, gill and skin histomorphology in goldfish.Methods : Fish were fed with different doses (۰, ۱۰۶, ۱۰۷, and ۱۰۸ CFU g-۱) EcN for ۸۰ days andthen challenged with As for ۹۶ h.Results : Results showed that supplemented EcN did not have any side effects on various vitalorgans. It was also observed that the damages to kidney, liver, gill, and skin were pronounced infish exposed to As. However, the histopathological damages in fish tissues induced by As wereless pronounced in the EcN treated groups compared to the fish fed with the basal diet.Conclusion : These findings indicate that EcN had potential for ameliorating the toxicity inducedby As.

Escherichia coli, Goldfish, Arsenic, Probiotics, Histopathology