Antibacterial Efficacy of Phytosynthesized Multi-Metal Oxide Nanoparticles against Drug-Resistant Foodborne Pathogens

Human health is threatened worldwide by microbial infections. Antibiotic overuse and misuse have resulted in antimicrobial-resistant bacteria. To battle such resistant microbes, we are looking for safe and alternative antimicrobial treatments, and the advent of nanotechnology holds promise in this regard. Metal oxide nanoparticles have emerged as a promising alternative source for combating bacteria resistant to various antibiotics over the last two decades. Due to their diverse physicochemical characteristics, metal oxide nanoparticles can operate as antibacterial agents through various methods. In the present research, six types of metal oxide NPs were synthesized and characterized (XRD, FTIR, SEM with EDAX, and TEM) from different plants such as Hydrangea paniculata (for NiO NP synthesis), Plectranthus amboinicus (for ZnO-NP synthesis), and Andrographis paniculata (V2O5 NPs). On the other hand, drug-resistant pathogens were isolated from clinical samples, those who suffered from foodborne illness. V2O5 NPs produced from Andrographis paniculata plant extract have much higher bactericidal efficacy than other metal oxide NPs against all three bacterial strains. Sensitive bacteria included S. aureus and E. coli, followed by K. pneumoniae. As a result, structural characterization was used to further screen V2O5 NPs. The orthorhombic structure of the crystallites was confirmed by XRD, with an average crystallite size of 20 nm. The absorbance spectrum and functional groups were identified using UV-visible spectral analysis and FTIR. SEM and EDX identified spherical-shaped NPs, and particle size (58 nm) was confirmed by transmission electron microscopy (TEM). As a result, we hypothesized that bioinspired V2O5-NPs could be employed as a possible antibacterial agent against drug-resistant pathogenic bacteria to replace currently existing inefficient antibacterial drugs.