Green Synthesis of Silver Nanoparticles: Antimicrobial Efficacy against MDR Clinical Isolates and In Vitro Cytotoxicity Assessment
الكلمات المفتاحية:
NDM-1, Cytotoxicity, Biofilm Inhibition, Antimicrobial Activity, Multidrug Resistance, Lactobacillus plantarum, Green Synthesis, and Silver Nanoparticlesالملخص
The environmental crises and rising multidrug -resistant (MDR) infections demand sustainable antimicrobial solutions. This study biosynthesized silver nanoparticles using Lactobacillus plantarum cell -free supernatant, characterized their physicochemical properties, and evaluated antimicrobial, antibiofilm, synergistic, and cytotoxic activityes against MDR clinical isolates from Iraq . AgNPs were synthesized via AgNO3 reduction and characterized using UV-Vis, FTIR,XRD, TEM, SEM, and zeta potential. Fifty isolates— including Escherichia coli , Klebsiella pneumoniae , Staphylococcus aureus, Pseudomonas aeruginosa, shigella spp., and NDM-1- positive strains— were obtained from Thi Qar, Iraq. UV-Vis confirmed bio reduction at 420 nm; XRD revealed 18 nm crystallite size; TEM/SEM showed uniform spherical morphology and zeta potential indicated colloidal stability. AgNPs exhibited potent bactericidal / bacteriostatic activity and 62-89% biofilm inhibition at sub- MIC concentrations. Synergistic effects with ampicillin and ciprofloxacin were confirmed via checkerboard assay. MTT assay demonstrated selective toxicity against human dermal fibroblasts. Biogenic AgNPs represent promising biocompatible alternatives for combating MDR infection, combining potent antimicrobial efficacy, antibiofilm activity, antibiotic synergy, and favorable safety profiles for clinical translation.
