Legume Peptides as Novel Antibacterial Sources for Human Pathogenic Bacteria

Many studies have focused on the use of natural alternatives in the treatment of multidrug-resistant pathogenic bacteria, so the interest focused on Nodule cysteine-rich (NCR) peptides from legumes, exploiting their effect on the differentiation of Rhizobium bacteria within root nodules and inhibiting their growth by affecting the permeability of the bacterial cell membrane. Therefore, concentrations of 50-1.6?g/ml of four NCR peptides extracted from four legumes were used to study their antimicrobial activity on the growth of five genus of multidrug-resistant human pathogenic bacteria. The study was carried out using a disc diffusion method to examine the impact of these peptides on these pathogenic bacteria. It became evident that Gram-positive was more affected by these peptides than Gram-negative bacteria. Using the microplate method, Pseudomonas aeruginosa and Escherichia coli, Staphylococcus aureus showed clear sensitivity to peptides 1 and 2, while Acinetobacter baumannii and Proteus mirabilis were completely resistant to all types of peptides tested. Results in the infected mice revealed that 6.25µg/ml was superior to 50 µg/ml of Medicago sativa peptide in completely healing wounds in laboratory mice 17 days after infection with both Pseudomonas aeruginosa and Staphylococcus aureus. This is the first local study that used NCR peptides from legumes as selected alternatives for antibiotic use.