C. aromaticus leaf extract mediated synthesis of Zinc oxide nanoparticles and their antimicrobial activity towards clinically multidrug-resistant bacteria isolated from pneumonia patients in nursing care

Current study examined the potential of Zinc Oxide Nanoparticles (ZnO-NPs) fabricated using the Caryophyllus aromaticus (C. aromaticus) leaf extract to inhibit multidrug-resistant (MDR) Acinetobacter baumannii infection. Analytical results confirmed the stable ZnO-NPs fabrication with mean particle size of about 18 nm. Zeta potential and Fourier transform infrared (FTIR) findings proved the ZnO-NPs capping with polyphenols of phyto-extract. Selected area electron diffraction (SAED) and x-ray diffraction (XRD) studies displayed the synthesized ZnO-NPs crystalline nature. The findings revealed that ZnO-NPs fabricated by leaf extract of C. aromaticus induced-bacterial cell-death, triggered DNA condensation of MDR A. baumannii and showed an obvious effect on the production of biofilm, cells grown in biofilm, microbial cell attachment as well as invading human lung cells depending on the concentration. The ZnO-NPs fabricated using C. aromaticus plant leaf extract did not show any obvious effect on the human lung cell viability. Furthermore, approximately 90% MDR A. baumannii infection was inhibited by the fabricated ZnO-NPs without cytotoxic effect at 0.028 μg ml⁻¹ EC₅₀. Thus, fabricated ZnO-NPs were considered as potent anti-MDR A. baumannii agent for efficient therapy and further lead to advancement of various efficient biomedical applications in nursing care. (paper)