Silver-cored <i>Ziziphus spina-christi</i> extract-loaded antimicrobial nanosuspension: overcoming multidrug resistance supplementary materials

Aims: To synthesize a silver-cored nanosuspension utilizing Ziziphus spina-christi fresh-leaf extract and evaluate their antimicrobial activity against multidrug-resistant pathogenic microbes. Materials and Methods: The prepared nanosuspension was analyzed by spectro-analytical techniques and tested for antimicrobial activity and resistance to biofilm formation. The leaf extract and nanosuspension were tested separately and together as a mixture. Results: Constituent nanoparticles were average-sized (∼34 nm) and were active against both Gram-positive and Gram-negative microbes and yeast. Candida albicans showed a 24.50 ± 1.50 mm inhibition zone, followed by Escherichia coli and Staphylococcus aureus. Increased bioactivity with the highest multifold increments, 150%, for erythromycin against all tested microbes was observed. Carbenicillin and trimethoprim showed 166%- and 300%-fold increments for antimicrobial activity against Pseudomonas aeruginosa, respectively. Conclusion: The nanosuspension exhibited strong potential as an antimicrobial agent and overcame multidrug resistance.Plain language summary: Ziziphus spina-christi leaf extract-coated silver nanoparticles were synthesized using an environment-friendly method, and the preparation was effective against Escherichia coli, Staphylococcus aureus and Candida albicans. The prepared formulation showed increased antimicrobial activity at a 150–300% increase compared with leaf extract-only activity. The prepared suspension was also active against Pseudomonas aeruginosa, the multidrug-resistant microbe, and has the potential to treat drug-resistant microbial infections.