Antibacterial Activity of Azadirachta indica (Neem) Seed Oil against Bacteria Associated with Ear Infection

Plants have been a source of herbal remedies throughout the history of mankind. Various medicinal plants have been used for years in daily life to treat diseases all over the world. In this research, antimicrobial activity of Azadirachta indica seed oil was evaluated against bacteria associated with ear infection using agar well diffusion method. Azadirachta indica (Neem) seed oil was extracted using soxhlet extraction setup with hexane and isopropanol as solvents. Ear specimens were obtained from patients with ear infections attending Specialist Hospital, Yola, and specimens were cultured, sub cultured until pure cultures were obtained and isolates identified, morphologically, following gram staining and biochemical procedures, identified isolates were Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli. Hexane extracts were more effective against the isolates with diameter of zone of inhibition ranging from 18-24mm than the isopropanol extract with 12-20mm. Staphylococcus aureus was most sensitive to the oil followed by E.coli then P. aeruginosa The MIC and MBC of the oil extracts was also determined using double dilution method, the MIC of hexane extracts ranges from 6.25-12.5% and 12.5-25% for isopropanol extracts, while the MBC range from 12.5-25% and 25-50% for hexane and isopropanol extracts respectively. The results obtained in this study indicate the potential of Azadirachta indica seeds oil (crude extracts) to inhibit the growth of such pathogenic organisms that frequently cause ear infections.