Antibacterial activity of metallic-core gold and silver nanoparticles against some animal pathogens

The current work aimed to find substitutes for antibiotics because of the side effects of antibacterial agents and the expansion of bacterial resistance to these agents. The scope of this study was to evaluate the antibacterial activity of gold and silver nanoparticles (AuNPs and AgNPs) against selected animal pathogens (Staphylococcus aureus, Klebsiella pneumonia, Streptococcus pneumoniae, Escherichia coli, Bacillus abortus and Mycobacterium bovis). The synthesized nanoparticles were distinguished by scanning electron microscopy (SEM) analysis and tested for antibacterial activity with the broth microdilution method, well diffusion assay, and minimum bactericidal concentration procedure. Results showed that both AuNPs and AgNPs displayed good antibacterial activity against all tested bacteria. The strongest antibacterial action of AgNPS (18 mm) was against E. coli. AuNPs displayed good antibacterial activity against S. aureus and B. bovis with a suppression area of 14 mm. Therefore, it is suggested that AgNPs and AuNPs could be effectively used against animal pathogens and may contribute to reducing antibiotic resistance. However, there is a need for further research on the in vivo toxicity and mechanisms of action of AuNPs and AgNPs.