الملخص

ABSTRACT This study indicates the biological activity of Allium. The activity extracts including alcoholic and ethanolic volatile oil was studied against eight bacterial species: Salmonella typhi, Shigella flexneri, Escherichia coli, Proteus mirabilis, Klebsiella pneumoniae, Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis. The results showed that alcoholic extract of onion has a comparable inhibitory effects against Sal. typhi, Sh. flexneri, E. coli and Pr. mirabilis compared to the antibiotics Cephalexin and Amoxicillin. The diameter of inhibition zone at concentration 200 microgram/cm3 was 24 mm toward Sal. typhi, while in case of Cephaloxin the diameter of inhibition zone is 21 mm using the same concentration. The study also showed moderate activity compared to the antibiotic Gentamycin. The results also revealed that the acetonic extract and the volatile oil showed moderate activity against compared to the antibiotic cephalexin and lower effect compared to the antibiotic Gentamycin and has higher effect compared to Amoxicillin. The alcoholic, acetonic and volatile oil showed meditate effects against the Ps. aeruginosa while they showed negligible effect toward the studied antibiotic. Three types of antibiotics have been used for this study (Amoxicillin, Cephalexin and Gentamycin). The results of this study revealed that Sh. flexneri, Pr. mirabilis and Staph. aureus, became more sensitive against the antibiotic Gentamycin in the presence of alcoholic extract while Sal. typhi and Staph. aureus showed higher sensitivity toward cephalexin in the presence of the active ingradient, while showed no significant sensitivity of Amoxicillin against the microorganism in presence of the active compound. The study also include the identification of diallyl disulfide and diallyl trisulfide compound in hexane extract using TLC technique.