Antimicrobial activity of the rhizome essential oil of Zingiber officinale Roscoe

Abstract

The antimicrobial activity of the rhizome essential oil of Zingiber officinale (family: Zingiberaceae) was tested against six standard bacteria: Bacillus subtilis, Staphylococcus aureus, Escherichia coli, Klebsiella pneumoniae, Proteus vulgaris, Pseudomonas aeruginosa and against two standard fungi namely Aspergillus niger and Candida albicans using the cup plate agar diffusion method. The rhizome essential oil of Z. officinale dissolved in methanol (1:10), showed high activity against the Gram positive S. aureus (23 mm), B. subtilis (20 mm), Gram negative E. coli (21 mm), P. vulgaris (20 mm) and P. aeruginosa (27 mm). It also showed moderate activity against the Gram negative K. pneumoniae (15 mm), C. albicans (16 mm) and no activity against Aspergillus niger. The rhizome oil was also tested against sixty clinical isolates, collected randomly from Khartoum and Soba Hospitals. The minimum inhibitory concentrations (MICs) of the essential oil against standard bacteria were determined using the agar diffusion method. The antimicrobial activity of the reference drugs were determined against the standard organisms and compared with the antimicrobial activity of the tested oil. The obtained results showed variable sensitivity against the organisms tested and confirmed its folkloric uses.

Keywords: Zingiber officinale (Rhizome), essential oil, antimicrobial activity.