Antibacterial and antibiofilm effects of gold and silver nanoparticles against the uropathogenic Escherichia coli by scanning electron microscopy (SEM) analysis

Uropathogenic Escherichia coli (UPEC) is a nosocomial pathogen associated with urinary tract infections and biofilm formation, which contributes to antibiotic resistance. Discovering potent antibacterial agents is crucial. This study aimed to assess the antibacterial and antibiofilm effects of gold and silver nanoparticles on UPEC using Scanning Electron Microscopy (SEM). UPEC biofilms were cultivated on nitrocellulose membranes for 48 hours at 37°C, then treated with gold nanoparticles (50 ppm and 100 ppm) and silver nanoparticles (50 ppm and 100 ppm) for another 48 hours. Antibacterial and antibiofilm activities were evaluated through cell density and SEM analysis. SEM revealed lower cell density, reduced biofilm formation, and altered cell morphology with rough, wrinkled surfaces after nanoparticle treatment. In conclusion, gold and silver nanoparticles exhibit antibacterial and antibiofilm properties, as observed in SEM analysis. SEM is a valuable tool for studying the antimicrobial effects of nano gold and silver on bacterial cell morphology and biofilm populations.