Biochemical and Histopathological Changes in the Liver of Oreochromis niloticus Experimentaly Infected with Escherichia coli

Abstract

Fish of Oreochromis niloticus were treated with different concentrations of Enterotoxigenic Escherichia coli (ETEC) as (10³-10⁵, 10⁶-10⁷ 10⁹-10¹⁰/ml water). The study was carried out to detect the impact of E. coli toxins on Oreochromis niloticus fish throughout physiological liver function and histopathological changes in the liver. The values of GPT, GOT and alkaline Phosphatase ranged between (905.90 IU/L -75.40 IU/L), (4827.7 IU/L - 385.50 IU/L) and (10⁶- 10⁷ CFU /ml - 10³ - 10⁵ CFU / ml) for the three liver enzymes respectively. When Oreochromis niloticus liver was exposed to Escherichia coli, it showed signs of fatty degeneration, ballooning degeneration, pyknotic hepatocyte nuclei, necrosis of the hepatocytes and pancreatic acini, haemorrhage, inflammatory WBC infiltration, and hemosiderin pigment buildup. The experiment's findings showed that the liver of O. niloticus was extremely vulnerable to E. coli infection, which caused higher liver enzyme levels, reversible and irreversible liver damage, and ultimately the highest concentration of mortality.