Antibacterial activity of neem (Azadirachta indica) seed oil extract was investigated using microbial growth inhibition zone. The neem seed oil was obtained by the cold extraction method using ethanol as an organic solvent of which 42ml of oil was obtained from 70g of neem seeds, with 40g (57%) of residue. Oil extracted was screened for its antibacterial properties and phytochemical components. The test organisms used were Salmonella typhi, Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus. Staphylococcus aureus, Pseudomonas aeruginosa and Salmonella typhi had the highest zones of inhibition while Escherichia coli had the least zone of inhibition. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined. The Phytochemical screening of the sample revealed the presence of Tannin, Alkaloid and Hydrogen cyanide.
Keywords: Antibacterial, Inhibition, Phytochemical, extract, neem
