Zero valent silver nanoparticles capped with capsaicinoids containing Capsicum annuum extract, exert potent anti-biofilm effect on food borne pathogen Staphylococcus aureus and curtail planktonic growth on a zebrafish infection model

Food plants Hungarian wax pepper (HWP) and Green Bell pepper (GBP), belonging to Capsicum annuum were utilized for biogenic fabrication of zero valent, nano-silver (AgNPs) through a photo-mediation procedure. In the bacterial strains evaluated, HWP/GBP AgNPs demonstrated effective bacteriostatic and bactericidal effect against Staphylococcus aureus. Time kill results portrayed that HWP/GBP nano-silver exhibited comparable bactericidal potency on S. aureus. Anti-biofilm potential of HWP/GBP AgNPs displayed significant effects at sub MIC levels, by triggering 50% biofilm reduction of the food spoilage microbe S. aureus, inferring that the anti-biofilm outcome is not dependent on antibacterial result, and this was confirmed by SEM and fluorescence studies. Histopathological analyses of S. aureus infected zebrafish liver did not display any abnormality changes such as extensive cell death and degeneration, upon treatment with HWP/GBP AgNPs and the zero-valent silver nanoparticles were comparatively less toxic and more operative in restraining the bioburden in S. aureus infected zebrafish model by a >1.7 log fold. Ability of light reduced HWP/GBP AgNPs to alleviate the in vitro and in vivo planktonic mode of growth and curb the biofilm formation of S. aureus is also demonstrated. [Display omitted] •Hungarian wax pepper (HWP) and Green Bell pepper (GBP) capped silver nanoparticles were synthesized and characterized.•Studies from time kill revealed AgNPs displayed comparable bactericidal effect against Staphylococcus aureus.•Fluorescent imaging and SEM imaging demonstrated that the AgNPs were effective at sub MIC concentrations in causing 50% biofilm inhibition against Staphylococcus aureus.•HWP/GBP AgNPs were also relatively less toxic as per enzymatic assay and effective in curtailing bioburden of Staphylococcus aureus in infected zebrafish by > 1.7 log fold.•Histopathological analyses of zebrafish liver indicates no extensive cell death and degeneration when treated with HWP/GBP AgNPs.