DOI: 10.36347/sjams.2016.v04i11.053

Pages: 4128-4133

Onion (Allium cepa) is among the oldest cultivated plants, and is used for multiple purposes. In addition to its nutritional effects, the antioxidant and antimicrobial activities of onion has also been postulated, and continue to be extensively investigated. Therefore, this study was designed to investigate the possible antibacterial effects of three types of onions; red, green and white onion. Different concentration of each onion was prepared in water extraction form. Six types of bacteria were tested, and their selection was based upon their common involvement in causing infectious bacterial diseases among people who live in Saudi Arabia. These tested bacteria included methicillin-resistant Staphylococcus aureus (MRSA), methicillin-sensitive Staphylococcus aureus (MSSA), Escherichia coli (E. coli), Pseudomonas aeruginosa (P. aeruginosa), Klebsiella species (Klebsiella Spp.), and Salmonella species (Salmonella Spp.). The antibacterial effects of each onion water extraction against these 6 bacteria species were carried out in vitro by using filter paper method, different agar in media containing different concentration of onion extrat method, suspension method and pieces of onion method. The results showed that the three types of onions had inhibitory effects on the growth of all investigated bacteria; however, their antibacterial effects were varies according to onion type and its water extraction concentration as well as on the type of tested bacteria.