Physicochemical Characterization and Evaluation of Antibiofilm Activity against Nosocomial Pathogens
Hend Mohammed Atiyah *
Department of Pathological Analysis, College of Applied Medical Science, Al-Shatrah University of Thi-Qar, Iraq.
Yaqoub Shemall Al- Rumaidh
Department of Animal Production-College of Agriculture- University of Thi-Qar, Iraq.
*Author to whom correspondence should be addressed.
Abstract
Zinc oxide nanoparticles (ZnO NPs) were biosynthesized using Eucalyptus globulus essential oil as a green stabilizing agent and zinc acetate dihydrate as the precursor. The synthesized ZnO NPs were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), UV–Visible spectroscopy, dynamic light scattering (DLS), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and energy dispersive X-ray spectroscopy (EDS). XRD analysis confirmed the formation of crystalline hexagonal wurtzite ZnO with an average crystallite size of ~24 nm.
The antibacterial activity of ZnO NPs was evaluated against clinically isolated nosocomial pathogens using agar well diffusion and broth microdilution methods. The nanoparticles exhibited broad-spectrum antibacterial activity, with minimum inhibitory concentration (MIC) values ranging from 0.5 to 128 µg/mL. Antibiofilm activity was assessed using a 96-well microtiter plate assay against Escherichia coli and Pseudomonas aeruginosa. The ZnO NPs significantly inhibited biofilm formation in a concentration-dependent manner, with maximum inhibition of 95% against E. coli and 97% against P. aeruginosa. Overall, the findings demonstrate that Eucalyptus globulus essential oil-mediated ZnO nanoparticles represent an eco-friendly and effective antibiofilm agent with potential applications in controlling nosocomial infections.
Keywords: Green synthesis, Eucalyptus globulus, Zinc oxide nanoparticles (ZnO NPs), nosocomial pathogens, antibacterial activity, antibiofilm activity