Investigation of Nanoparticle Metallic Core Antibacterial Activity: Gold and Silver Nanoparticles against Escherichia coli and Staphylococcus aureus

• Published in: International journal of molecular sciences Vol. 22; no. 4; p. 1905
• Main Authors: Gouyau, Jimmy, Duval, Raphaël E, Boudier, Ariane, Lamouroux, Emmanuel
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI 14-02-2021; MDPI AG
• Subjects: Anti-Bacterial Agents - chemistry; Anti-Bacterial Agents - toxicity; characterization; Chemical Sciences; Drug Resistance, Multiple, Bacterial - drug effects; Dynamic Light Scattering; Escherichia coli - drug effects; Escherichia coli - growth & development; gold; Gold - chemistry; Life Sciences; Metal Nanoparticles - chemistry; Metal Nanoparticles - toxicity; Metal Nanoparticles - ultrastructure; metallic nanoparticles; Microbial Sensitivity Tests - methods; Microscopy, Electron, Transmission; Physics; silver; Silver - chemistry; Spectrophotometry; Staphylococcus aureus - drug effects; Staphylococcus aureus - growth & development; surface reactivity; synthesis; antibacterial activity; gold; synthesis; multidrug resistant bacteria; Escherichia coli; surface reactivity; silver; metallic nanoparticles; characterization; Staphylococcus aureus; stability
• ISSN: 1422-0067; 1661-6596; 1422-0067
• DOI: 10.3390/ijms22041905

Multidrug-resistant (MDR) bacteria constitute a global health issue. Over the past ten years, interest in nanoparticles, particularly metallic ones, has grown as potential antibacterial candidates. However, as there is no consensus about the procedure to characterize the metallic nanoparticles (MNPs; i.e., metallic aggregates) and evaluate their antibacterial activity, it is impossible to conclude about their real effectiveness as a new antibacterial agent. To give part of the answer to this question, 12 nm gold and silver nanoparticles have been prepared by a chemical approach. After their characterization by transmission electronic microscopy (TEM), Dynamic Light Scattering (DLS), and UltraViolet-visible (UV-vis) spectroscopy, their surface accessibility was tested through the catalytic reduction of the 4-nitrophenol, and their stability in bacterial culture medium was studied. Finally, the antibacterial activities of 12 nm gold and silver nanoparticles facing
and
have been evaluated using the broth microdilution method. The results show that gold nanoparticles have a weak antibacterial activity (i.e., slight inhibition of bacterial growth) against the two bacteria tested. In contrast, silver nanoparticles have no activity on
but demonstrate a high antibacterial activity against
, with a minimum inhibitory concentration of 128 µmol/L. This high antibacterial activity is also maintained against two MDR-
strains.