Biosynthesis, characterization, antibacterial, antibiofilm, and antioxidant activities of sodium nanoparticles from Escherichia coli metabolites

Abstract

This study emphasizes the need for strategies to tackle multi-drug resistant pathogens by investigating the antibacterial, antibiofilm, and antioxidant properties of sodium nanoparticles (NaNPs) derived from metabolites of Escherichia coli. The configuration of the NaNPs was examined through X-ray diffraction (XRD), Transmission electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), Photoluminescence (PL), and Ultraviolet–visible spectroscopy (UV–Vis). XRD and TEM analyses revealed that NaNPs possess a grain size around 125 nm, exhibiting a crystallinity of 63.45 % and a rod-shaped morphology. The UV–Vis revealed considerable absorbance at 280 nm, leading to an optical bandgap of 4.125 eV. To evaluate antibacterial and antibiofilm characteristics, clinical bacteria including Streptococcus pneumonia, Enterococcus faecium, Klebsiella pneumonia, and Salmonella Typhimurium were identified and examined for multidrug resistance using antibiogram testing. The antibacterial activity was assessed through agar well diffusion, minimum inhibitory and bactericidal concentrations (MIC and MBC) tests, and a time-kill assay. The antibiofilm effect was assessed by preventing biofilm formation and removing established biofilm assays. The antioxidant potential was assessed through the 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical scavenging assay. Antibacterial results demonstrated a bactericidal effect on Enterococcus faecium and Salmonella Typhimurium (MBCs 0.0625 and 0.125 mg/mL, respectively). Inhibition zones ranged from 7.3 to 10.5 mm. NaNPs inhibited bacterial growth following 5 h of incubation. Antibiofilm results revealed an inhibitory effect on biofilm development (with an inhibition percentage of 62 %) and a minimal impact on biofilm elimination (showing a destruction percentage of 21 %). Antioxidant results showed a significant scavenging effect, with the percentage of radical scavenging reaching 23 %. The results suggest positive effects of the NaNPs in biomedical applications.