Antagonistic activity of a novel chitosan-selenium nanoflower against common aquaculture pathogen Aeromonas caviae

Aquatic pathogens contribute the most severe economic loss in fishes. Nanoparticles are being developed as potent antimicrobial agents against various pathogens. This study involved the synthesis and characterization of a novel chitosan‐selenium nanoflower employing multiple spectroscopic and microscopic approach. The UV‐vis spectra obtained at 265 nm indicated the formation of the Chitosan‐selenium nanoflower. The Particle size analysis revealed the size of the nanoflowers to be 186.3 nm. The Transmission Electron Micrographs revealed a unique nanoflower like morphology. XRD spectrum revealed amorphous nature and the Raman spectrum showed characteristic resonance peak at 254 cm −1 was a characteristic absorption band for monoclinic Se and α‐Se. Cytotoxicity analysis of the synthesized nanoflowers against isolated fish pathogen A. caviae showed increasing toxicity in a dose dependent manner. The DCFDA assay was conducted for estimating increase in ROS production and the highest percentage increase in ROS was observed at 1000 µg/mL. The lipid peroxidation assay was performed by quantification of lipid oxidation product Malondialdehyde (MDA). The highest percentage lipid peroxidation was found to occur at a dose of 500 µg/mL. As a result, the synthesised chitosan‐selenium nanoflowers can be exploited as a promising antibacterial treatment against the fish pathogen A. caviae .