Water and methanolic extracts of the leaves, stems, and pulp of Lebanese Cedar (Cedrus libani), were assayed for antibacterial and antifungal properties against human and food spoilage pathogens namely: Klebsiella pneumonia, MRSA, ESBL E. coli, Listeria monocytogenes, and Candida albicans using disk diffusion method. Minimum inhibitory concentration (MIC), minimum bactericidal concentration (MBC), and minimum fungicidal concentration (MFC) were evaluated. The bacterial and fungal strains tested showed a various degree of sensitivity represented by inhibition zone diameter: Klebsiella pneumonia (27mm), MRSA (27mm), ESBL Escherichia coli (20mm), and Candida albicans (21mm). Listeria monocytogenes showed the strongest inhibition zone 70 and 37mm with methanolic and water leaves extracts respectively. The MIC, MBC, and MFC were between 5- 200 µl/ml, and 300 µl/ml respectively. Time-kill curve showed a fast and sharp antimicrobial activity. The efficacy of killing by Lebanese cedar extract was essentially the same in light and dark. Phytochemical analysis of Lebanese cedar extract explored the presence of terpenoids, flavenoids, glycosides, phenols, saponins and traces of tannins. Electron microscopy examination of cells treated with Lebanese cedar extracts showed a great variation in the cell structure.
Keywords: Antimicrobial, Food Spoilage Microorganisms, Human Pathogens, Lebanese Cedar
