Bacterial synthesis and characterization of ZnO nanoparticles to combat MDR pathogens

Bacterial synthesis of nanomaterials offers an environmentally benign route for producing nanostructures with enhanced surface activity. In the present study, ZnO nanoparticles were synthesized using a potent rhizospheric bacterial isolate by the biogenic extracellular synthesis method. Various characterization techniques, such as UV-Visible spectroscopy, XRD, FTIR, FE-SEM, EDX, DLS, and zeta-potential analysis, confirm the synthesis of pure, crystalline, negatively charged ZnO nanoparticles suitable for biomedical use . The FTIR analysis reports bacterial lipid and proteinaceous compounds as a capping and stabilizing agent. The FE-SEM analysis reveals the Crumpled nanosheet structure of nanoparticles with a high surface-to-volume ratio, which offers good antimicrobial activity against multidrug-resistant clinical pathogens. The antimicrobial activity of ZnO nanoparticles and conventional antibiotics was tested on MDR clinical isolates. The ZnO nanoparticles exhibited broad-spectrum antimicrobial activity at a 500 μg/mL concentration. MIC and MBC of these nanoparticles determine their strong bactericidal potential. The observed protein leakage assay, along with growth curve analysis in K. pneumoniae, highlights membrane disruption as the primary mode of antibacterial action of ZnO nanoparticles. The results of this study mark a significant advancement in microbial nanomaterial technology and help to develop better alternatives to conventional antibiotics in order to combat antibiotic resistance in MDR pathogens.