## 3 Results and Discussion
The extreme inflammatory responses triggered by the bacterial infection are reported as the main causes of the acute death. Collectively, our study demonstrated that \begin{table}
\begin{tabular}{c c c c c} \hline \hline \multicolumn{1}{c}{\multirow{2}{*}{**Normal Control**}} & **Model Control K.** & **9-Methoxyellipticine-Treated** & \multirow{2}{*}{**GEN-Treated Group**} \\  & _pneumoniae_ & **Group** & \\ \hline Lung & _zero_ & Death & \(2\times 10^{1}\) & \(6\times 10^{2}\) \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Quantification of bacterial loads of _K. pneumoniae_ colonization in lungs (CFU/g Tissue). \begin{table}
\begin{tabular}{c c c c c c} \hline \hline  & **Negative Control** & **Positive Control** & **STEC O157 and 9-** & **STEC O157 and** & **Negative** \\  & **Control** & **STEC O157** & **Methoxyellipticine** & **GEN** & **Control** \\ \hline Day zero & \(2\times 10^{4}\) & \(3\times 10^{6}\) & \(4\times 10^{4}\) & \(4\times 10^{6}\) & \(36\times 10^{1}\) \\ Day 4 (before challenge and after treatment with streptomycin) & \(2\times 10^{1}\) & \(1\times 10^{2}\) & \(0\) & \(1\times 10^{1}\) & \(10\times 10^{1}\) \\ Day 7 (after challenge) & \(2\times 10^{1}\) & Death & \(9\times 10^{7}\) & \(1\times 10^{7}\) & \(10\times 10^{6}\) \\ Day10 (after treatment for 3 successive days with GEN i.p., once daily) & \(2\times 10^{1}\) & Death & \(10\times 10^{3}\) & \(2\times 10^{3}\) & \(7\times 10^{8}\) \\ Day 17 (after treatment for 7 days with 9-methoxyelliptic orally, once daily) & \(2\times 10^{1}\) & Death & \(5\times 10^{1}\) & NA & NA \\ Kidney & \multicolumn{2}{c}{zero} & Death & zero & \(1\times 10^{1}\) & zero \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Quantification of bacterial loads of STEC O157 shedding in feces and bacterial colonization in kidney. 9-methoxyelliptic could substantially decrease the bacterial loads and tissue destruction in MDR STEC O157 and _K. pneumoniae_-infected mice. It also considerably eased the inflammation and pathological injury, with the infiltration of inflammatory cells, alveolar interstitial obstruction, and edema in the pulmonary region and renal tissues of the infected animal. The mechanisms of the antibacterial activity of alkaloids were previously reported [47; 48; 49]. Finally, 9-methoxyellipticine is a carbazole (nitrogen-containing heterocyclic) derivative that showed significant antibacterial activity in our study. As reported, carbazole derivatives exhibit several mechanisms, and can act as antibacterial agents. They act by (1) increasing the membrane permeability through inhibiting specific enzymatic processes and increasing the access of the free radicals, which violates the integrity of the bacterial cells, and (2) interacting with bacterial DNA. Accordingly, various carbazoles are being considered as promising solutions for new antibacterial drugs with two potential actions, thus helping to solve the MDR problems worldwide [50]. Searching for natural compounds could become a promising way to fight against multi-drug resistant bacteria and meet the emergency demand for discovering highly effective, low toxicity, and low environmental impact antibiotics. New antibacterial compounds with novel mechanisms of action and properties that are different from the currently used drugs could be obtained from ellipticine derivatives. In addition, the application of 9-methoxyellipticine as the lead compound is among the most promising approaches for bioactive drug discovery in the future. Finally, a significant clinical impact with the roles of 9-methoxyellipticine and its derivatives in challenging areas should be of great interest in the future as to produce more potent and targeted analogues of 9-methoxyellipticine. Nevertheless, novel strategies based on the field of nanotechnologies for safer drug delivery are recommended.