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Cytotoxicity of Ultrasmall Gold Nanoparticles on Planktonic and Biofilm Encapsulated Gram‐Positive Staphylococci
Author(s) -
Boda Sunil Kumar,
Broda Janine,
Schiefer Frank,
WeberHeynemann Josefine,
Hoss Mareike,
Simon Ulrich,
Basu Bikramjit,
JahnenDechent Willi
Publication year - 2015
Publication title -
small
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.785
H-Index - 236
eISSN - 1613-6829
pISSN - 1613-6810
DOI - 10.1002/smll.201403014
Subject(s) - biofilm , microbiology and biotechnology , staphylococcus epidermidis , bacteria , antimicrobial , pseudomonas aeruginosa , staphylococcus aureus , lysis , minimum inhibitory concentration , gram negative bacteria , colloidal gold , escherichia coli , chemistry , gram positive bacteria , agar , biology , nanoparticle , materials science , nanotechnology , biochemistry , genetics , gene
The emergence of multidrug resistant bacteria, especially biofilm‐associated Staphylococci , urgently requires novel antimicrobial agents. The antibacterial activity of ultrasmall gold nanoparticles (AuNPs) is tested against two gram positive: S. aureus and S. epidermidis and two gram negative: Escherichia coli and Pseudomonas aeruginosa strains. Ultrasmall AuNPs with core diameters of 0.8 and 1.4 nm and a triphenylphosphine‐monosulfonate shell (Au0.8MS and Au1.4MS) both have minimum inhibitory concentration (MIC) and minimum bactericidal concentration of 25 × 10 −6 m [Au]. Disc agar diffusion test demonstrates greater bactericidal activity of the Au0.8MS nanoparticles over Au1.4MS. In contrast, thiol‐stabilized AuNPs with a diameter of 1.9 nm (AuroVist) cause no significant toxicity in any of the bacterial strains. Ultrasmall AuNPs cause a near 5 log bacterial growth reduction in the first 5 h of exposure, and incomplete recovery after 21 h. Bacteria show marked membrane blebbing and lysis in biofilm‐associated bacteria treated with ultrasmall AuNP. Importantly, a twofold MIC dosage of Au0.8MS and Au1.4MS each cause around 80%–90% reduction in the viability of Staphylococci enveloped in biofilms. Altogether, this study demonstrates potential therapeutic activity of ultrasmall AuNPs as an effective treatment option against staphylococcal infections.