Antimicrobial and Biofilm Formation Inhibition Properties of Biogenic Silver Nanoparticles Synthesised Using Tuber Extract of Cyperus esculentus

The use of silver nanoparticles obtained by the green synthesis approach in the field of nanomedicine is on the rise. Therefore, it is imperative to search for and develop simple, safe, and quick methods for mass production. Our previous study demonstrated a green synthesis approach that offers the possibility to reuse biomaterial to synthesise silver nanoparticles. Cyperus esculentus tubers were used as bio-reductant to synthesise silver nanoparticles (CpE-AgNPs) with sizes ranging from 50 to 80 nm. In the present study, the antimicrobial properties of the CpE-AgNPs were studied. The efficacy of the CpE-AgNPs was demonstrated against selected microorganisms, namely, Escherichia coli, Klebsiella pneumoniae, Salmonella typhi, Bacillus subtilis, Pseudomonas aeruginosa, methicillin-resistant Staphylococcus aureus (MRSA), Streptococcus mutans, and Candida albicans. The minimum inhibitory concentration of the CpE-AgNPs against the selected microorganisms ranged from 7.81 to 250 mu g/mL, with B. subtilis being the most susceptible. The CpE-AgNPs were bacteri-/fungi-cidal against all the studied microorganisms. The efficacy of prepared CpE-AgNPs to enhance the potency of standard antibiotics was also demonstrated in combination with tetracycline and ciprofloxacin. The combinatory effect ranged from synergistic to antagonistic. The CpE-AgNPs were also efficacious in inhibiting microbial biofilm formation. Biofilm inhibition up to 100% was demonstrated against MRSA, S. mutans, P. aeruginosa, and C. albicans at a concentration of 250 mu g/mL. The results from the study show that the CpE-AgNPs can serve as an effective drug candidate in the fight against the growing antimicrobial-resistant menace.