The use of Aloe Vera Gel Functionalized Biogenic Zinc-Oxide Nanoparticles against Fish Putative Pathogens

Abstract

Indiscriminate uses of antibiotics have resulted in the development of antibiotic-resistance among pathogens which possess a potential risk to the ecosystem, aquaculture and human health. In this study, biogenic zinc oxide nanoparticles (ZnO-NPs) were synthesized using aqueous extract of Aloe vera gel (AVGE) and tested against putative pathogenic bacterial strains in-vitro. Ultraviolet- Visible (UV-VIS) spectroscopic analysis confirmed the synthesis of AVGE-ZnO-NPs while X-ray diffraction (XRD) and Scanning Electron microscope (SEM) analysis revealed that the average size of synthesized ZnO-NPs is within the nano range. The elemental and chemical compositions of synthesized ZnO-NPs were studied using Energy-dispersive X-ray spectroscopy (EDX) and Fourier- transform infrared (FTIR) spectrometer, respectively. Two widespread bacterial strains, Aeromonas veronii strain ONKP1 (MN602971) and Stenotrophomonas maltophilia strain ONKP2 (MN602972) that are known as emerging opportunistic pathogens in various marine and freshwater fishes as well as humans and other animals, were used as test organisms. AVGE-ZnO-NPs showed strong antibacterial activity, against the tested Gram-negative multi-drug resistant bacteria in the disc diffusion assay. The results of the present investigation could be useful for the development of new disease management strategies in the fisheries industry.