Effect of AgWPA nanoparticles on the inhibition of Staphylococcus aureus growth in biofilms

Staphylococcus aureus (S. aureus) is known as a food-borne pathogenic bacteria that is difficult to deal with, especially in a biofilm. An appropriate and effective agent against S. aureus is urgently needed, especially due to the high pathogenicity of S. aureus within biofilms. This paper aims to synthesize Ag3PW12O40 nanoparticles (AgWPA-NPs) and investigate their antimicrobial activity and mechanism against S. aureus. N-phenyl-l-naphthylamine (NPN) uptake and membrane potential assays showed that AgWPA-NPs damaged the structure of the cell membrane. Furthermore, the results of crystal violet staining and fluorescence microscopy indicated that AgWPA-NPs were remarkably efficient at suppressing the formation of S. aureus biofilms. Furthermore, real-time PCR analysis showed that the expression of the biofilm-related genes, icaA, sarA and cidA, was downregulated. Taken together, these results suggest that AgWPA-NPs have the potential to be an anti-S. aureus biofilm agent.