ANTIBACTERIAL PROPERTIES OF NEEM SEED OIL AGAINST STAPHYLOCOCCUS AUREUS, STREPTOCOCCUS PYOGENES, AND BACILLUS SUBTILIS

ABSTRACT The study determines the Antibacterial properties of neem (Azadirachta indica) seed oil against selected skin organisms Staphylococcus aureus, Streptococcus pyogenes and Bacillus subtilis. The neem seed oil was obtained by the cold extraction method using distilled water as an organic solvent and the antimicrobial analysis was determined using the agar well diffusion method with zones of inhibition measured to assess the activity. Results revealed that the neem seed oil contains key phytochemical components-tannins, phenol, saponins, flavonoids, alkaloids and terpenoids demonstrating a rich bioactive profile. Bacterial test organisms from skin included S.aureus, S.pyogenes and Bacillus subtilis which were identified culturally and morphologically. Antibacterial activity assays showed dose-dependent inhibition: S.pyogenes had the lowest zone of inhibition (11.00 mm) at (12.5 µg/mL) against neem seed oil and highest (20.00 mm) at (100 µg/mL).MIC evaluation indicated effective concentrations ranging from (12.5 µg/mL) for S.aureus and Bacillus subtilis while (50-100 µg/mL) for S.pyogenes. Compare the antibacterial effect of neem seed oil vs. solvent-based extracts (e.g methanol, ethyl acetate) to determine which yields the most potent bioactivity per unit concentration. These results affirm that neem seed oil, with its diverse phytochemicals, exhibits potent antibacterial activity, particularly at higher concentrations.