Antimicrobial Activity of Turmeric (Curcuma longa) and Ginger (Zingiber officinale) Extracts Against Escherichia coli

Rising antibiotic resistance in Escherichia coli has renewed interest in plant-derived antimicrobials as alternatives to synthetic antibiotics. This study evaluated the antimicrobial activity of turmeric (Curcuma longa) and ginger (Zingiber officinale) rhizome extracts, prepared in water and 70% ethanol, against E. coli using the disc diffusion method. Discs impregnated with 50% and 100% concentrations of each extract were tested on Mueller-Hinton agar seeded with a standardized E. coli suspension, and zones of inhibition were measured after 24 h of incubation at 37°C. Both extracts produced measurable zones of inhibition at both concentrations and in both solvents, with inhibition generally increasing with concentration for ginger and for the ethanolic turmeric extract, while the aqueous turmeric extract showed the reverse trend. The minimum inhibitory concentration for both extracts was estimated to lie between 50% and 100%. These findings support the traditional use of turmeric and ginger and suggest their potential as natural antimicrobial agents against E. coli, warranting further work to isolate the active compounds and determine precise inhibitory concentrations.