Challenging multidrug-resistant urinary tract bacterial isolates via bio-inspired synthesis of silver nanoparticles using the inflorescence extracts of Tridax procumbens

Abstract The increasing drug resistance pattern in bacterial pathogens promotes the need to find out alternative strategies to ensure human health. In the imperative lookout for effective drugs to combat multidrug-resistant bacteria, silver nanoparticles (AgNPs) are given priorities. Hence in the present approach, AgNPs were synthesized using the extract of the inflorescence of a medicinal plant, and its antibacterial activity against multidrug-resistant uropathogens was studied. For the synthesis of AgNPs, the inflorescence of a medicinal plant Tridax procumbens was subjected to a microwave irradiation technique. The characteristics of the synthesized nanoparticles (NPs) were analyzed by using UV- visible spectroscopy (UV-Vis), Dynamic light scattering device (DSL), Scanning electron microscope (SEM), Fourier-transform infrared (FTIR) spectroscopy and Zeta potential analyzer. The synthesized AgNPs were with unique optical morphology and semi-spherical shape having irregular contour with the size range 40.0-52.5 nm. The bacterial isolates Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, and Gram-positive Staphyloccocus saprophyticus from urinary tract infected persons that showed resistance to more than ten antibiotics were chosen for AgNPs impact analysis. The mean diameter of zone of inhibition (in mm) for the different isolates at the dose of 50 µg/mL concentration showed a maximum for S. saprophyticus(21.0±1.7 mm)followed by P. aeruginosa(18.0 ±1.3 mm), K. pneumoniae (18.0±0.09 mm) and E. coli(17.0±1.70). The MIC values for the isolates showed a minimum for S. saprophyticus (2.5 µg/mL) and a maximum for E. coli (55.5 µg/mL). The results show that the T. procumbens phytochemicals inspired silver nanoparticles can be explored further to develop useful antibiotics.