Antibacterial Activity of Fresh Red and White Onion (Allium cepa) Extract against Some Drug Resistant Bacteria

Antibiotics resistance is currently one of the major challenges in the health care system. The antimicrobial properties of some herbs have been used in the treatment of infectious diseases as well as disinfection of surfaces. This in a way helps overcome microbial resistance arising from indiscriminate use of synthetic antimicrobial agents for similar purpose. Some antibiotic resistant bacteria- Pseudomonas aeruginosa, Staphylococus aureus and Escherichia coli isolated from cooking wares in homes were investigated using agar well diffusion and agar dilution method to test for the antibacterial activity of fresh Allium cepa (onion) extract. All were susceptible to the fresh white and red onion extract except Staphylococus aureus which was susceptible to only the white onion extract. The diameter of zones of inhibition ranged from 2 mm-35 mm. The Minimum Inhibitory Concentration (M. I. C.) and the Minimum Bacterial Concentration (M. B. C.) values of the fresh onion juices against the test bacteria were low ranging from 3.125% v/v – 25.0% v/v. This study indicates that the fresh raw extracts of Allium cepa possess significant antibacterial potency against these antibiotic resistant bacteria.