Tridax procumbens mediated silver nanoparticles synthesis against biofilm forming pyogenic bacteria associated with...

Green synthesis of silver nanoparticles (AgNPs) was achieved using leaf extract of Tridax procumbens, which served as a reducing, capping, and stabilising agent. The synthesized TP-AgNPs showed a reddish-brown color, with a surface plasmon resonance confirmed by UV-Vis spectroscopy at 420.32 nm. Morphological analysis by SEM revealed spherical nanoparticles, XRD patterns confirmed their crystalline nature. FT-IR spectroscopy identified the presence of various functional groups involved in stabilization, including phenolic, flavonoids, and proteins. DLS analysis showed a hydrodynamic diameter of 150.4 nm, with a zeta potential of -15.3 mV, indicating moderate colloidal stability. The antibacterial and antibiofilm activities of TP-AgNPs were evaluated against wound associated pathogens: Acinetobacter radioresistens, Pseudomonas aeruginosa, and Klebsiella aerogenes. Biofilm-forming capacity, assessed via tube method and Congo red assay, varied among isolates A. radioresistens exhibited strong biofilm formation, K. aerogenes showed moderate activity, P. aeruginosa showed weak activity, and E. coli non-biofilm forming. Quantitative biofilm inhibition assays using crystal violet demonstrated dose-dependent effect, with the highest inhibition (up to 10% inhibition at 43.2 µg/mL) observed against K. aerogenes (), while A. radioresistens and P. aeruginosa showed limited susceptibility among the tested strains. These findings highlight the selective antibiofilm potential of TP-AgNPs and support their further development as topical agents for managing biofilm associated infections.