Abstract
Antimicrobial properties of aqueous extract of date palm and almond against Gram negative pathogens Pseudomonas aeruginosa and Acinetobacter baumannii was investigated in this study. Synergistic antimicrobial activity between b-lactam antibiotic amoxicillin and aqueous extract of date palm and almond was assessed by disk diffusion assay and minimum inhibitory concentration (MIC) determination. Amoxicillin significantly enhanced antimicrobial activity of aqueous extract of date palm and almond against both P. aeruginosa and A. baumannii; overall synergism was more pronounced with almond extract. With aqueous extract of date palm and amoxicillin, the MIC decreased in the range of fold for P aeruginosa and 4-8 fold for A. baumannii strains when compared to date palm extract alone. The decrease in MIC was in the range of 8-16 fold for P aeruginosa and 8-32 fold for A. baumannii strains when almond extract was tested with and without amoxicillin. Date palm extract with amoxicillin showed increase in zone diameter in the range of 40.6% to 89.5 % for P. aeruginosa and 56.8 % to 90.2 % for A. baumannii when compared with extract alone. Similar increase with zone diameter was noted with almond extract containing amoxicillin when compared to almond extract alone which ranged from a minimum of 56.3 % for P aeruginosa to 88.5 % for A. baumannii. Taken together, the findings of this study show that aqueous extract of date palm and almond can act synergistically with amoxicillin against Gram negative pathogens P. aeruginosa and A. baumannii.