Antibacterial Activity of Cerium Oxide Nanoparticles against ESKAPE Pathogens

We studied the antimicrobial characteristics of cerium oxide (CeO2) nanoparticles synthesized by hydrothermal technique. The versatile characterization techniques were employed to study the CeO2 nanoparticle structural and optical properties. These techniques included field emission scanning electron microscopy, Raman spectroscopy, X-ray diffraction, and transmission electron microscopy. The X-ray diffraction and Raman studies validated the cubic structure of the synthesized CeO2 nanoparticles with average diameters ~3–5 nm. The antibacterial activities and minimal inhibition concentrations (MICs) of CeO2 nanoparticles were tested against ESKAPE pathogens (Enterococcus faecium, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Enterobacter sp.). Our data revealed that CeO2 nanoparticles at a concentration of 50 µg/mL generated a maximum inhibition zone against all tested pathogens. However, S. aureus, P. aeruginosa, and K. pneumoniae exhibited the higher sensitivity, while E. cloacae, E. faecium, and A. baumannii were the least sensitive to CeO2 nanoparticles. In conclusion, our results demonstrate that CeO2 nanoparticles possess an effective antibacterial activity against ESKAPE pathogens and may be used as a potential bionanomaterial for in vivo therapeutic applications.