Facile green synthesis of copper oxide nanoparticles for the eradication of multidrug resistant Klebsiella pneumonia and Helicobacter pylori biofilms

In the present study, copper oxide nanoparticles (CuO NPs) were successfully synthesized from Cassia fistula and Melia azedarach leaf extracts via cupric nitrate approach. The successful biosynthesis of CuO NPs was confirmed by experimental analysis such as color transformation, ultraviolet light spectroscopy (UV-spectroscopy), Fourier transform infrared spectroscopy (FTIR), X-ray diffraction analysis (XRD), dynamic light scattering (DLS) and scanning electron microscopy (SEM). Antibacterial activity of the biosynthesized CuO NPs was confirmed against the two antibiotic resistant clinical strains of Klebsiella pneumonia and Helicobacter pylori. Well diffusion assay and minimum inhibitory concentration (MIC) values were optimum when 1 ?g/ml of the NPs were used. This concentration of the NPs derived from C. fistula inhibited the biofilm formation of K. pneumonia and H. pylori by 99.8% and 100%, respectively. On the other hand, the NPs derived from M. azadarech showed biofilm formation inhibition by 92.5% and 99.5% for K. pneumonia and H. pylori, respectively. Scanning electron microscopy (SEM) further elucidated the antibacterial effect through bacterial cell shape disruption and DNA damage.

Automated summary

This study successfully synthesized copper oxide nanoparticles and confirmed their antibacterial activity against antibiotic-resistant strains, particularly Klebsiella pneumonia and Helicobacter pylori. The nanoparticles derived from Cassia fistula showed stronger inhibition of biofilm formation compared to those from Melia azedarach.