Characterization of green Synthesis of cucumber extract -Derived Zinc-Copper Oxide Nanocomposite Antibacterial Activity and Effects on MexA Gene Expression on Efflux Pumps in Pseudomonas aeruginosa.

Background : The investigation of heavy metal-containing materials synthesized with plant extracts' antibacterial properties remains ongoing. In this study, zinc oxide and copper nanoparticles (ZnONPs and CuONPs) were produced with cucumber aerial part extract. The antibacterial effect of cucumber nanoparticles, in particular, demonstrated promising potential in combating microbial infections. Material and methods : Green production of selenium nanoparticles. Atomic force microscopy (AFM), field emission scanning electron microscope (FESEM), X-ray diffraction (XDR), UV visible spectroscopy, and physical characteristics were used to characterize the samples. XRD confirmed the spherical structure, while AFM examination revealed the roughness and distribution of nanoparticles. Results: the oxide nanoparticles were characterized using X-ray diffraction (XRD), UV-Vis spectrometer, Fourier-transformed infrared spectrometer, and transmission electron microscopy (TEM). The particle size was less than 33 nm, approximately. The diameter inhibitory zone showed that all of the strains had more sensitivity against nanocomposite. The novel composite showed antimicrobial activity against several human pathogens, such as Staphylococcus aureus , Staphylococcus haemolyticus, Staphylococcus epidermidis, Staphylococcus lentus , and Staphylococcus warneri . The effective antibacterial activity and size-dependent characteristics of nano-scale antibacterial substances have attracted considerable attention. This effect is evidenced by the utilization of cucumber extract in the synthesis of nanoparticles, namely ZnONPs, and CuONPs, which exhibited significant antibacterial properties. For molecular procedure, detection of the MexA gene in 10 isolates of MDR Pseudomonas aeruginosa using real-time polymerase chain reaction (RT-PCR). The effect of nanocomposite on MexA gene expression revealed fold changes in expression (downregulation) in two isolates of MDR P. aeruginosa and upregulation in only one isolate. The biologically synthesized NPs exhibit great antimicrobial activity and can down-regulate the expression of the efflux pump MexA gene. In addition, treating bacteria with the nanocomposite caused a significant reduction of MexA genes, which can improve the efficacy against P. aeruginosa by reducing the expression of MexA efflux pump genes. Conclusions : This work used cucumber extract as an environmentally friendly and green biosynthesis of selenium nanoparticles (ZnO-CuO NPs) and their antibacterial applications. In conclusion, Nanocomposite were successfully biosynthesized using Cucumber extract, derived from fresh cucumber fruits (Cucumis sativus) through the green method and had promising activity against antibacterial multidrug-resistant bacteria. The expression of the MexA gene was significantly downregulated in the isolates treated with Nanocomposite.