The current study evaluated the influence of the treatment with tea tree oil and cefepime on morpho- genetic, histo-immunohistochemical, and biochemical assessments in rats experimentally challenged with Escherichia coli ATCC 4157™. Thirty adult male rats were divided into control, E. coli infected positive group (1×108CFU/I/P/once), E. coli with cefepime-supplemented group (45 mg/kg bw/I/M/day), E. coli with tea tree oil treated group (1.5 ml/per os/day), and the E. coli-challenged group that received a combination of tea tree oil and cefepime. E. coli infection induced morphological changes in color and texture of both liver and kidney. The transcription levels of the PHLPP2 and Nrf2 genes were noticeably lowered in all treated groups related to the E. coli group. Regarding the TLR4 expression, it was clearly up-regulated in the E. coli group in comparison to other groups, while CD14 gene decreased clearly in all treated groups compared to the positive group. The findings revealed that RBC, HGB, and PCV were clearly higher in the positive group compared to all treated groups. AST, ALT, and ALP, total bilirubin and its fractions, urea, and creatinine maximized in the positive group and decreased by the treatment, especially in the E+CF+oil treated group. Regarding the redox balance, MDA levels of MDA were notably reduced in the E+CF+oil treated group compared to the positive and the other treated groups. GSH, SOD, and GPX were significantly induced in the E. coil-treated group and decreased significantly with treatment. Overall, cefepime is highly safe especially when dually supplied with tea tree oil for mitigating E. coli adverse impact.