RESUMO
OBJECTIVES: Among infectious diseases, bloodstream infection (BSI) caused by gram-negative bacteria (E. coli) is the leading cause of death worldwide. However, the bacteria have produced resistance to many of these antibiotics. Thus, the present study aimed to develop silver nanoparticles (AgNPs) loaded with Emilia sonchifolia (ES) extract (ES-AgNPs) to treat BSI efficiently. METHODS: AgNPs were synthesized by reduction of silver nitrate (AgNO3) solution by ES extract. Furthermore, these ES-AgNPs were characterized for particle size and zeta potential, crystallinity by powder X-ray diffraction (P-XRD) technique, in vitro antibacterial activity, time-kill assay, film bio adhesion, and fluorescence assay. RESULTS: Surface plasmon resonance (SPR) has been used to confirm the formation of AgNPs by seeing a shift in colour to dark-brown. The ES-AgNPs displayed a mean particle size of 137±3nm (PDI of 0.168±0.02) and zeta potential of 18.2±0.8mV. Furthermore, according to P-XRD results, the developed AgNPs are highly crystalline. The ES-AgNPs showed effective antibacterial action against E. coli with minimum inhibitory concentrations (MIC) and minimum bactericidal concentrations (MBC) of 0.4±0.02µg/mL and 0.8±0.03µg/mL, respectively. In addition, ES-AgNPs inhibited biofilm formation and bacterial adhesion in a dose-dependent manner with 100% inhibition obtained in 48h at MBC. CONCLUSIONS: Present research work revealed that the ES-AgNPs obtained by green synthesis holds a prominent antibacterial activity in the treatment of BSIs caused by E. coli and they may be used as a competent substitute for current treatments. However, further, in vivo antibacterial studies are required to establish its efficacy in the treatment of BSIs.