The effectiveness of a plant extract of Nigella sativa (black seed) and Zingiber officinale (ginger) against multidrug-resistant Escherichia coli Strains was carried out. Ten strains were selected from a previous study and diagnosed by biochemical tests and confirmed by the VITEK 2 device. Susceptibility testing against (10) selected antibiotics was performed, which proved that all strains were multidrug-resistant. The Agar Diffusion method was used to test the effectiveness of the extracts through discs saturated with methanol and water extracts at concentrations of 100 mg/ml.
Some strains showed non-significant inhibition zones around the discs which were saturated with methanolic extract. In contrast, the aqueous extracts did not show any noticeable effect. The Minimum Inhibitory Concentration was determined by the dilution method, where the ethanolic extracts reduced the turbidity of some strains at concentrations of (100 mg/ml). Still, the bacterial growth continued as scattered colonies when the samples were re-cultured on an agar medium. These results indicate that the plant extracts that were used did not achieve any effectiveness in inhibiting the growth of multidrug-resistant Escherichia coli, highlighting the need for further studies to explore other methods or concentrations.