IF Okonkwo and KM Achilike

Department of Applied Microbiology and Brewing, Nnamdi Azikiwe University, PMB 5025, Awka, Anambra State, Nigeria

To Cite this Article :

Okonkwo IF and Achilike KM, 2022. Comparative assessment of antimicrobial activities of Allium cepa (onions) extracts. Agrobiological Records 9: 73-79.


The evolution of resistivity by microorganisms is a worldwide public health contest that renders antimicrobial agents impotent, leading to an upsurge in diseases and mortality in man and livestock. The current study was designed to ascertain the antimicrobial activities of Allium cepa (onions) extracts. The antimicrobial activities of the onion extracts on the trial organisms, including both gram-positive and -negative bacteria, were carried out using the Agar Well Diffusion method. The tube macro-dilution method determined the extracts' MIC (mg/mL). We investigated the MBC and MFC of the extracts. The antimicrobial assay proved that; the microorganisms tested were sensitive at 50mg/mL but resistant at 3.125mg/mL. From the MIC results, the increasing order of activity of the extracts was Staphylococcus epidermidis (MIC 3.125mg/mL), Pseudomonas aeruginosa, Escherichia coli, and Salmonella typhimurium (MIC 6.25mg/mL), Candida albicans and Staphylococcus aureus (MIC 12.5mg/mL) and Klebsiella pneumoniae (25mg/mL). The MBC results proved that the onion extracts (50mg/mL) were bactericidal except for Staphylococcus aureus and fungistatic. Comparatively, at a 5% alpha level, pronounced differences were observed between the zones of inhibition and the solvent extracts by cold and hot water extract on the experimental organisms. However, no significant disparity was observed between the effect of aqueous and solvent extracts. Hence, the study recommends using onions, natural herbal medicine, and antimicrobial agents.

Article Overview

  • Volume : 9 (Jul-Sep 2022)
  • Pages : 73-79