Abstract

Zingiber officinale, commonly known as ginger, has been used as a medicinal plant for decades for medical and culinary purposes. This study aimed to determine the antimicrobial potential of ginger root extracts using the Kirby-Bayer agar diffusion method to compare the zones of inhibition of the extracts to those of synthetic antibiotics against five clinical bacterial pathogens (Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Enterobacter aerogenes and Klebsiella pneumoniae). Ginger extracts showed more antimicrobial activity against the five test organisms compared to the synthetic antibiotics. The least resistant bacterium was S. aureus while the remaining four bacterial strains were strongly resistant to most of the antibiotics. Antimicrobial activity of ginger root extracts at various concentrations revealed that E. coli had the lowest concentration (1.2 mg/ml) in 20 mg/ml while the highest concentration (9.1 mg/ml) was observed for S. aureus in 75 mg/ml. Phytochemical screening of the ginger root extracts revealed the presence of all the tested secondary metabolites (saponins, tannin, flavonoids, glycoside, terpenoids and alkaloids). A number of phytochemicals present in ginger were identified to be possibly responsible for the antibacterial activity of ginger roots. These could be used independently or in combination with synthetic antibiotics to create more efficient antibiotics. Findings of this study can contribute to on-going research towards identifying alternative treatment of nosocomial infections that eliminate the use of antibiotics. With these findings, scientists could be employed in the health sector to create antibiotics that are not resisted by pathogens that cause infections in health care facilities.

Key words: Antibacterial, ginger, phytochemical, zone of inhibition.