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. 2014 Jun 2:8:11.
doi: 10.1186/1754-1611-8-11. eCollection 2014.

Investigation of antimicrobial activity of photothermal therapeutic gold/copper sulfide core/shell nanoparticles to bacterial spores and cells

Ebenezer Addae  1 , Xiuli Dong  1 , Eric McCoy  1 , Chang Yang  2 , Wei Chen  3 , Liju Yang  1
Affiliations

Investigation of antimicrobial activity of photothermal therapeutic gold/copper sulfide core/shell nanoparticles to bacterial spores and cells

Ebenezer Addae et al. J Biol Eng. .

Abstract

Background: Au/CuS core/shell nanoparticles (NPs) were designed as a new type of transducer agent for photothermal therapy (PTT), with attractive features of easy preparation, low cost and small size for targeting. This paper studied for the first time the intrinsic antimicrobial activity of Au/CuS NPs to B. anthracis spores and cells in addition to its PTT effect.

Results: It was found that Au/CuS NPs were highly efficient in inactivating B. anthracis cells, but not effective to the spores. Treatment with NPs at ~0.83 μM for 30 min achieved a 7 log reduction in viable cells. The antimicrobial effect was both NPs concentration and treatment time dependent. SEM imaging and the efflux of DNA test demonstrated the damage of cell membrane after NPs treatment, yet further research is necessary to fully understand the precise inactivation mechanism.

Conclusions: The Au/CuS NPs had strong antimicrobial activity to B. anthracis cells, which showed a great potential to be an effective antimicrobial agent to bacterial cells.

Keywords: Antimicrobial; Bacillus anthracis; Bioterrorism; Nanoparticles.

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Figures

Figure 1
Figure 1
The effects of Au/CuS NPs’ pre-treatment and continuous presence in medium on the growth of B. anthracis spores. (A) The representative growth curves of B. anthracis spores after being pre-treated with 0.0083 μM, 0.083 μM and 0.83 μM Au/CuS for 30 min and subsequent growth in nutrient broth without removing the NPs. (B) The comparison of the growth curves of B. anthracis spores pre-treated with 0.083 μM, 0.83 μM AuCuS NPs, when the NPs were removed before growth and when the NPs were in the presence in the growth medium. Initial spore concentration: ~107 spores/mL, pre-treated with NPs in DI water for 30 min.
Figure 2
Figure 2
The percentages of surviving B. anthracis spores upon pre-treatment with Au/CuS NPs at 0.83 μM and 4.15 μM and treatment durations varying from 1 h to 24 h. Initial spore concentration: 105 spores/mL in DI water.
Figure 3
Figure 3
SEM images of untreated B. anthrcis spores (A) and spores treated with 4.15 μM Au/CuS NPs for 1 h (B).
Figure 4
Figure 4
The effect of Au/CuS NPs pre-treatment on B. anthracis cells. (A) The percentages of surviving B. anthracis cells upon the treatment with Au/CuS NPs at 0.083 μM, 0.83 μM, and 4.15 μM and treatment duration varying from 0.5 h to 3 h. Initial cell concentration: 1.6 ×107 cells/mL in DI water. (B) The fluorescence images of the control B. anthracis cells and cells interacted with Au/CuS NPs in DI water for ~25 min, ~35 min and ~45 min. Cells were stained with the Live/dead BacLight bacteria staining kit, live cell in green, and dead cells in red.
Figure 5
Figure 5
The comparison of the percentages of surviving cells after B. anthracis cells were treated with 0.083 μM, 0.83 μM, and 4.15 μM Au/CuS NPs for 1 h in PBS, DI-H2O and nutrient broth. Initial cell concentration: (0.79-3.8) ×107 cells/mL.
Figure 6
Figure 6
The SEM images of (A) the control B. anthracis cells, and (B) cells treated with 4.15 μM Au/CuS NPs for 30 min.
Figure 7
Figure 7
The amount of DNA effluxed from B. anthracis cells treated by 0.83 μM and 4.15 μM Au/CuS NPs for 30 min. Cell concentration: 1.2×107 cells/mL.
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References

    1. Elsaka SE, Hamouda IM, Swain MV. Titanium dioxide nanoparticles addition to a conventional glass-ionomer restorative: influence on physical and antibacterial properties. J Dent. 2011;8:589–598. - PubMed
    1. Sondi I, Salopek-Sondi B. Silver nanoparticles as antimicrobial agent: a case study on E. coli as a model for Gram-negative bacteria. J Colloid Interface Sci. 2004;8:177–182. - PubMed
    1. Stoimenov PK, Klinger RL, Marchin GL, Klabunde KJ. Metal Oxide Nanoparticles as Bactericidal Agents. Langmuir. 2002;8:6679–6686.
    1. Zawrah M, El-Moez SA, Center D. Antimicrobial activities of gold nanoparticles against major foodborne pathogens. Life Sci J. 2011;8:37–44.
    1. Lin J, Zhang H, Chen Z, Zheng Y. Penetration of lipid membranes by gold nanoparticles: insights into cellular uptake, cytotoxicity, and their relationship. ACS Nano. 1021;8:5421–5429. - PubMed