Strain specificity in antimicrobial activity of silver and copper nanoparticles.

The antimicrobial properties of silver and copper nanoparticles were investigated using Escherichia coli (four strains), Bacillus subtilis and Staphylococcus aureus (three strains). The average sizes of the silver and copper nanoparticles were 3 nm and 9 nm, respectively, as determined through transmission electron microscopy. Energy-dispersive X-ray spectra of silver and copper nanoparticles revealed that while silver was in its pure form, an oxide layer existed on the copper nanoparticles. The bactericidal effect of silver and copper nanoparticles were compared based on diameter of inhibition zone in disk diffusion tests and minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of nanoparticles dispersed in batch cultures. Bacterial sensitivity to nanoparticles was found to vary depending on the microbial species. Disk diffusion studies with E. coli and S. aureus revealed greater effectiveness of the silver nanoparticles compared to the copper nanoparticles. B. subtilis depicted the highest sensitivity to nanoparticles compared to the other strains and was more adversely affected by the copper nanoparticles. Good correlation was observed between MIC and MBC (r2=0.98) measured in liquid cultures. For copper nanoparticles a good negative correlation was observed between the inhibition zone observed in disk diffusion test and MIC/MBC determined based on liquid cultures with the various strains (r2=-0.75). Although strain-specific variation in MIC/MBC was negligible for S. aureus, some strain-specific variation was observed for E. coli.

[1]  H. White,et al.  Electrochemistry of Sulfur Adlayers on the Low-Index Faces of Silver , 1996 .

[2]  M. Kolář,et al.  Antibiotic selective pressure and development of bacterial resistance. , 2001, International journal of antimicrobial agents.

[3]  V. S. Kumar,et al.  Highly efficient Ag/C catalyst prepared by electro-chemical deposition method in controlling microorganisms in water , 2004 .

[4]  J. Song,et al.  Does the Antibacterial Activity of Silver Nanoparticles Depend on the Shape of the Nanoparticle? A Study of the Gram-Negative Bacterium Escherichia coli , 2007, Applied and Environmental Microbiology.

[5]  Tetsuya Osaka,et al.  THE STUDY OF ANTIMICROBIAL ACTIVITY AND PRESERVATIVE EFFECTS OF NANOSILVER INGREDIENT , 2005 .

[6]  A. Vaseashta,et al.  Nanostructured and nanoscale devices, sensors and detectors , 2005 .

[7]  Jungho Hwang,et al.  Susceptibility constants of Escherichia coli and Bacillus subtilis to silver and copper nanoparticles. , 2007, The Science of the total environment.

[8]  V. Yu,et al.  Individual and combined effects of copper and silver ions on inactivation of Legionella pneumophila , 1996 .

[9]  Genxi Li,et al.  Effect of Silver Nanoparticles on the Electron Transfer Reactivity and the Catalytic Activity of Myoglobin , 2004, Chembiochem : a European journal of chemical biology.

[10]  Navid B. Saleh,et al.  Titanium dioxide (P25) produces reactive oxygen species in immortalized brain microglia (BV2): implications for nanoparticle neurotoxicity. , 2006, Environmental science & technology.

[11]  Won Ho Park,et al.  Antimicrobial cellulose acetate nanofibers containing silver nanoparticles , 2006 .

[12]  Zi-rong Xu,et al.  Preparation and antibacterial activity of chitosan nanoparticles. , 2004, Carbohydrate research.

[13]  M. Rafiee-Tehrani,et al.  Diethylmethyl chitosan as an antimicrobial agent: Synthesis, characterization and antibacterial effects , 2004 .

[14]  E. Comini.  Metal oxide nano-crystals for gas sensing. , 2006, Analytica chimica acta.

[15]  D. Blanca,et al.  Water disinfection with ozone , copper and silver ions , and temperature increase to control Legionella : seven years of experience in a university teaching hospital , 2005 .

[16]  P. Jain,et al.  Potential of silver nanoparticle-coated polyurethane foam as an antibacterial water filter. , 2005, Biotechnology and bioengineering.

[17]  R. Murray,et al.  Sites of metal deposition in the cell wall of Bacillus subtilis , 1980, Journal of bacteriology.

[18]  S. Ryu,et al.  Effects of metal ions on the activity of protein tyrosine phosphatase VHR: highly potent and reversible oxidative inactivation by Cu2+ ion. , 2000, Archives of biochemistry and biophysics.

[19]  Milan Kolar,et al.  Silver colloid nanoparticles: synthesis, characterization, and their antibacterial activity. , 2006, The journal of physical chemistry. B.

[20]  M. Rubner,et al.  Two-level antibacterial coating with both release-killing and contact-killing capabilities. , 2006, Langmuir : the ACS journal of surfaces and colloids.

[21]  Qingsheng Wu,et al.  Synergistic antibacterial effects of β-lactam antibiotic combined with silver nanoparticles , 2005 .

[22]  Julio Santarén,et al.  Antibacterial activity of copper monodispersed nanoparticles into sepiolite , 2006 .

[23]  T. Mukherjee,et al.  Size tunable synthesis of silver nanoparticles in water–ethylene glycol mixtures , 2007 .

[24]  Lina Ghibelli,et al.  Copper Nanoparticle/Polymer Composites with Antifungal and Bacteriostatic Properties , 2005 .

[25]  D. Bagchi,et al.  Oxidative mechanisms in the toxicity of metal ions. , 1995, Free radical biology & medicine.

[26]  Ke Karlovu,et al.  The bactericidal effect of silver nanoparticles , 2010 .

[27]  I. Fried,et al.  Thermal stability of nanostructured superhard coatings: A review , 2007 .

[28]  S. Ghosh,et al.  Green fluorescent protein-expressing Escherichia coli as a model system for investigating the antimicrobial activities of silver nanoparticles. , 2006, Langmuir : the ACS journal of surfaces and colloids.

[29]  Dae Hong Jeong,et al.  Antimicrobial effects of silver nanoparticles. , 2007, Nanomedicine : nanotechnology, biology, and medicine.

[30]  T. Kamiya,et al.  Magnetic and carrier transport properties of Mn-doped p-type semiconductor LaCuOSe: An investigation of the origin of ferromagnetism , 2006 .

[31]  G. Mostafa,et al.  Facile synthesis of silver nano particles with highly efficient anti-microbial property , 2007 .

[32]  I. Sondi,et al.  Silver nanoparticles as antimicrobial agent: a case study on E. coli as a model for Gram-negative bacteria. , 2004, Journal of colloid and interface science.

[33]  P. Zambonin,et al.  Analytical characterization of bioactive fluoropolymer ultra-thin coatings modified by copper nanoparticles , 2005, Analytical and bioanalytical chemistry.

[34]  S. Ehrman,et al.  Evaluation of the microbial growth response to inorganic nanoparticles , 2006, Journal of nanobiotechnology.

[35]  Sishen Xie,et al.  Formation of Silver Nanoparticles and Self-Assembled Two-Dimensional Ordered Superlattice , 2001 .

[36]  Christopher L. Case,et al.  Laboratory Experiments in Microbiology , 1984 .

[37]  P. Midgley,et al.  Uptake of C60 by human monocyte macrophages, its localization and implications for toxicity: studied by high resolution electron microscopy and electron tomography. , 2006, Acta biomaterialia.

[38]  Chi-Ming Che,et al.  Proteomic analysis of the mode of antibacterial action of silver nanoparticles. , 2006, Journal of proteome research.

[39]  V. Yu,et al.  INACTIVATION OF MYCOBACTERIUM AVIUM BY COPPER AND SILVER IONS , 1998 .