The antibacterial activity of Azadarichta indica (neem) seeds extracts against bacterial pathogens associated with eye and ear infections

The effects of crude extracts of seeds of Azadarichta indica against pathogenic Staphylococcus aureus, Staphylococcus pyogenes, Escherichia coli and Pseudomonas aeruginosa obtained as clinical isolates from patients diagnosed with eye and ear infections were investigated using the agar well diffusion method. The growth of all the isolates were inhibited, though to varying degrees, with gram-positive more susceptible than gram-negative bacteria. The control laboratory strains were more sensitive to the toxic effects of the crude extracts than the corresponding test bacteria. Hexane extracts were more effective, producing larger zones of growth inhibition sizes and smaller MIC and MBC values, than the aqueous extracts. The MIC values ranged from 1.59 - 25 mg/ml while the MBC values ranged from 3.17 - 50 mg/ml. The extracts were more effective under elevated temperature and acidic conditions. The ability of the crude extracts to inhibit the growth of such pathogenic bacteria that frequently cause eye and ear infections as those used in this study is an indication that the neem seed has the potential and can be used as a source for new broad spectrum oral antibiotics. The result obtained in this study validates the use of the neem seeds in traditional medicine to treat infectious conditions especially those involving the eye and ear.