Powerful antibacterial nanocomposites from Corallina officinalis-mediated nanometals and chitosan nanoparticles against fish-borne pathogens

Abstract The fish-borne zoonotic bacteria may pose a risk to humans; nanobiotechnological techniques could serve as effective solutions for fighting them. The direct phycosynthesis of metals’ nanoparticles (NPs), silver (AgNPs), and selenium (SeNPs) using Corallina officinalis extract (CoE) was achieved. The construction of nanocomposites (NCs) from phycosynthesized NPs and nano-chitosan (NCht) was also accomplished to evaluate these entire compounds/NCs as antibacterial amalgams against fish-borne bacteria, Aeromonas hydrophila, Pseudomonas aeruginosa, Salmonella typhimurium, and Staphylococcus aureus. The entire agents/NCs were characterized and assessed. The structure and interactions of chemicals and NCs were determined using infrared analysis. CoE/AgNPs, CoE/SeNPs, NCht, NCht/CoE/AgNPs, and NCht/CoE/SeNPs had mean particles’ diameter of 5.52, 12.46, 59.81, 64.59, and 77.16 nm, respectively, which were confirmed by size studies and electron microscopy. The challenged bacteria were entirely susceptible to the inspected agents, using both qualitative and quantitative assays; S. aureus was more resistant, while A. hydrophila was the most sensitive strain. The NCs (NCht/CoE/AgNPs and NCht/CoE/SeNPs) have the utmost bactericidal potentialities, respectively; they exceeded the action of ampicillin. The total distortion, disintegration, and lysis of the treated A. hydrophila cells were highlighted by scanning imaging within 10 h of exposure. The conjugation of CoE-mediated NPs with NCht produced effective and harmless NCs, valid for applications to remove fish-borne pathogens with biosafe characteristics.