ANTIBACTERIAL ACTIVITY OF CRUDE ETHANOLIC EXTRACT OF Nigella sativa SEED ON MOLECULARLY IDENTIFIED METHICILLIN RESISTANT CLINICAL ISOLATE OF Staphylococcus aureus, IN KADUNA STATE, NIGERIA

The use of herbal plants as alternative medicine over centuries remains a popular choice for primary health care. This study determined the antibacterial activity of crude Aqueous and Ethanolic extracts of Nigella sativa seed against molecularly identified methicillin-resistant Staphylococcus aureus. Finely ground Nigella sativa seed powder was soaked in ethanol in a flask at a ratio of 10:100 and placed on a shaker at room temperature for 72 hrs. The solution was filtered through Whatman filter paper No.24 and dried in a rotary evaporator at 50-60°C. Phytochemical screening was carried out using standard procedures and different concentrations of Aqueous and Ethanolic extracts of Nigella sativa were tested for their antibacterial activity on molecularly identified methicillin-resistant Staphylococcus aureus (MRSA) by using agar well diffusion method. Single cell polymerase chain reaction was carriedout to amplify Mec A gene of Sstaphylococcus aureus strain. Bacterial growth was inhibited at concentrations of 80% and 60% ethanolic extract while it was inhibited at a concentration of 80% aqueous extract. Minimum inhibitory concentration showed the highest concentration (80%) having the less turbidity and the lowest concentration (20%) having the highest turbidity. Phytochemical screening for secondary metabolites shows the presence of steroids, alkaloid, flavonoids, cardiac glycosides, saponins and terpenoids in the plant. There was amplification of mec A gene at 312bp reion of the MRSA. The results obtained from this research shows that Nigella sativa extract could serve as an alternative source of chemotherapy in treating methicillin resistant Staphylococcus aureus caused ailments.