Antibacterial Activity of Allium Cepa (Onion) On Some Pathogenic Bacteria Associated With Ocular Infections

Research was carried out on antibacterial activity of Allium cepa. Two different extracts were made from Allium cepa (onion) using distilled water. The extracts include fresh onion extract and cold water extract. The antibacterial activity of the onion was tested on four bacteria isolates associated with various ocular infections. The bacterial isolates include: Escherichia coli, Staphylococcus aureus, Streptococcus pyogenes, and Streptococcus pneumonia. Among the two extracts, fresh onion extracts exhibited antagonistic effects on the test organisms ranging from observed zone of inhibition (average value) of 15mm for Escherichia coli, 17mm for Staphylococcus aureus, 20mm for Streptococcus pyogenes, and 8mm for Streptococcus pneumonia. The antibiotic used as control was ciprofloxacin with zone of inhibition of 17mm for Streptococcus pneumoniae, 17mm for Escherichia coli, 19mm for Staphylococcus aureus and 20mm for Streptococcus pyogenes respectively. The minimum inhibitory concentration of the potent onion extracts shows positive inhibitory effect when an undiluted extracts was used. Also at the lowest concentration (0.015625 and 0.0068) of fresh onion extracts there was growth of all the organisms. From the research conducted it was concluded that there was no antibacterial activity on the test isolates observed with cold water extracts. Further research is encouraged on the pharmacokinetics of the active components; invitro study of the effectiveness of the purified active component, measuring dosage and some other parameters, on various implicated organisms from ocular infections.