Antibacterial activity of Nigella sativa seed in various germination phases on clinical bacterial strains isolated from human patients

Nigella sativa is an important spice and flavoring agent which is widely used in various European and Asian cuisines. It harbors an array of medicinal properties as shown by various researches. Germination is a phenomenon during which rapid changes in metabolic activities and the interconversions of metabolites take place. The objective of present study was to evaluate the antibacterial activity of N. sativa seed that are on various germination phases against clinical bacterial strains isolated from pus, urine, ascitic fluid and cerebrospinal fluid of various patients. The minimum inhibitory concentration (MIC) values were determined by using a modified macro-broth dilution technique. The agar well diffusion method was used to test the antimicrobial effects of N. sativa extracts. Some broad spectrum antibiotics were used as positive control. The phytochemical constituents of N. sativa seed were also studied in germination phases. The distilled methanolic extracts of N. sativa showed significant antimicrobial activity against tested clinical strains of Gram-positive Staphylococcus aureus and Gram-negative Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa and Proteus mirabilis bacteria. Results showed day-dependent and dose-dependent activity and a significant antimicrobial effect was observed as germination proceeded.